THE UH-60A/L BLACKHAWK PERFORMANCE PLANNING CARD DA … PPC Guide.pdf · UH-60A/L BLACKHAWK...

THE UH-60A/L BLACKHAWK

PERFORMANCE PLANNING CARD

DA Form 5703-R

VERSION 1.0

November 2003

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TABLE OF CONTENTS TABLE OF CONTENTS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2/3 INTRODUCTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 DA Form 5703-R DATA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5 DA Form 5703-R COMPUTATIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . 5 SIGNIFICANT CHANGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7 DA FORM DA Form 5703-R (Front) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 DEPARTURE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Pressure Altitude (ITEM 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Free Air Temperature (ITEM 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Aircraft Gross Weight (ITEM 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Fuel Weight (ITEM 4) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Stores Weight (ITEM5) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Sling Weight (ITEM 6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Engine Torque Factor (ITEM 7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10 Aircraft Torque Factor (ITEM 7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 Torque Ratio (ITEM 8) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11-13 Maximum Torque Available (ITEM 9) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-23 Maximum Allowable Gross Weight OGE/IGE (ITEM 10) . . . . . . . . . . . . . . . . 24-25 GO/NO GO Torque (ITEM 11) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25-29 Maximum Hover Height IGE (ITEM 12) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30-31 Predicted Hover Torque (ITEM 13) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32-33 Min SE-IAS – W/O Stores / W/Stores (ITEM 14) . . . . . . . . . . . . . . . . . . . . . . . 34-35 Zero Fuel Weight (ITEM 15) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35-36 Remarks (ITEM 16) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 GO/NO GO External Loads. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . … 38 CRUISE DATA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Pressure Altitude (ITEM 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Free Air Temperature (ITEM 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Torque Ratio (ITEM 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Maximum Torque Available (ITEM 4) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 39 Critical Torque (ITEM 5) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Duel Engine Min/Max Vh-IAS (ITEM 6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Cruise Speed IAS/TAS (ITEM 7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Cruise/Continuous Torque (ITEMS 8) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Cruise Fuel Flow (ITEM 9) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Maximum Endurance IAS/Torque (ITEM 10) . . . . . . . . . . . . . . . . . . . . . . . . . . 49 Maximum Range IAS/Torque (ITEM 10) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 Maximum Rate of Climb IAS/Torque (ITEM 11) . . . . . . . . . . . . . . . . . . . . . . . . 50 Dual Engine Maximum Allowable Gross Weight (ITEM 12) . . . . . . . . . . . . . . . . . 52 Dual Engine Optimum IAS at Maximum Allowable Gross Weight (ITEM 12) . . . 52 Single-Engine Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 Single Engine Min/Max Vh-IAS (ITEM 13) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

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Single-Engine Cruise Speed IAS/TAS (ITEM 14) . . . . . . . . . . . . . . . . . . . . . . . . . .57 Single-Engine Cruise/Continuous Torque (ITEM 15) . . . . . . . . . . . . . . . . . . . . . 57 Single-Engine Cruise Fuel Flow (ITEM 16) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 MAX ALLOWABLE GWT and OPTIMUM IAS AT MAX ALLOWABLE GWT (single-engine) (ITEM 17) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 Single-Engine Maximum Altitude – MSL (Item 18). . . . . . . . . . . . . . . . . . . . . . . . . 62 Emergency Single-Engine IAS (ITEM 19). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 Maximum Angle of Bank (ITEM 20) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 Velocity Never to Exceed (ITEM 21) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 ARRIVAL DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 UPDATES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 DA FORM DA Form 5703-R (Back) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 HIGH DRAG/EXTERNAL LOAD COMPUTATIONS . . . . . . . . . . . . . . . . . . . . . 74

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INTRODUCTION

The authors would like to extend their gratitude to CW4 Bill Young who gave the original explanations for the UH-60 DA Form 5703-R “What The numbers Mean”. ��

��All explanations referenced in this booklet are for the UH-60A and the UH-60L

Item numbers in parenthesis correlate with respective block numbers on the DA Form 5703-R identified in figure 6-5 and 6-6 in TC 1-212 dated 8 March 1996 (Change 1, dated 15 January 2003). Items listed in this document from TC 1-212 (Change 1) are verbatim and incorporate both UH-60A/L information and are identified with a (♦). Items listed in this document from TM 1-1520-237-10 are verbatim and are identified with a Unless this publication states otherwise, masculine nouns and pronouns do not refer exclusively to men. This booklet contains information in an exercise format and is intended as an aid to understanding the DA Form 5703-R Performance Planning Card, and how to derive the values, what the numbers mean and how to apply that information towards safe and efficient utilization of the aircraft for given mission conditions. Instructions for completing the DA Form 5703-R can be found in TC 1-212 (Chg-1), the UH-60 Aircrew Training Manual (ATM) Task 1004, the aircraft operator's manual (-10, dated 1 May 2003), and this booklet. AR 95-1, paragraph 5-2, requires crews to familiarize themselves with aircraft performance. Accurate DA Form 5703-R completion and interpretation is critical to safe and successful mission accomplishment. Regular use of this information will enable the aircrew to achieve maximum safe utilization of the helicopter and provide a basis for a sound foundation in performance planning. Failure to complete a DA Form 5703-R would be found as a contributing or non-contributing factor in any incident or accident investigation where a power management was in question.

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DA Form 5703-R DATA

The purpose of the new DA Form 5703-R and is to give the pilots a dynamic tool to enhance the mission accomplishment in determining the maximum aircraft performance for any given mission scenario. The data presented in the performance charts are primarily derived for a clean UH-60A/L helicopter and are based on US Army test data. The clean configuration assumes all doors and windows are closed and include the following external configurations:

� Fixed provisions for the External Stores Support System (ESSS). � Main and tail rotor deice system. � Mounting brackets for infrared (IR) jammer and chaff dispenser. � Hover Infrared Suppressor System (HIRSS) with baffles installed. � Includes wire strike protection system (WSPS).

The data presented in high drag charts are primarily derived for a UH-60A/L with ESSS system installed and the two 230-gallon tanks mounted on the outboard pylons, and are based on US Army test data. The high drag configuration assumes all doors and windows are closed and include the following external configurations:

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� ESSS installed. � Two 230-gallon tanks mounted on the outboard pylons. � Inboard vertical pylons empty. � IR jammer and chaff dispenser installed. � HIRSS with baffles installed. � Main and tail rotor deice and wire strike protection systems installed.

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Drag considerations will be discussed briefly in this booklet where appropriate. Drag corrections can be made for either a clean configuration aircraft, or for a High Drag configuration aircraft. ��

DA Form 5703-R COMPUTATIONS

Of first concern to the aviator is the question of when a DA Form 5703-R must be completed. According to the ATM, the aviator will determine and have available aircraft performance data necessary to complete the mission. The DA Form 5703-R is used as an aid in organizing this information, or to handle emergency procedures that may arise during the mission. In accordance with the ATM (♦), the DA Form 5703-R must be used during RL progression, annual Aircrew Training Program (ATP) evaluations, and when required during other training and evaluations. Additionally, when the planned or actual gross weight for departure and/or arrival is within 3,000 pounds maximum allowable gross weight OGE or when the planned or actual gross weight is within 3,000 pounds of the maximum

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allowable gross weight for cruise (See Figure 28 for computation, Cruise Section). To determine if the DA Form 5703-R must be completed, perform the following procedures:

Step 1: DEPARTURE - Compare the maximum allowable gross weight for departure from either the -CL tabular data or appropriate -10 HOVER chart with the planned or actual aircraft gross weight.

Step 2: CRUISE – Compare the maximum allowable gross weight for cruise from the appropriate -10 CRUISE chart with the planned or actual aircraft gross weight.

NOTE

If you were planning to takeoff and depart from low-pressure altitudes, yet cruise at very high altitudes, maximum allowable gross weight for cruise could be the determining factor. For instance, looking at the Tabular data for a Clean Configuration, a .90 ATF UH-60A departing at Sea Level and 20°C will have a Maximum allowable gross weight OGE of 21,000 pounds. This means that if the aircraft weighs more than 18,000 pounds, a DA Form 5703-R will be required. But, since this pilot is planning on cruising at Maximum Range airspeed at his planned cruise of 10,000 feet with a forecast temperature of 0° C, the cruise chart reveals that the Maximum allowable gross weight at the cruise conditions is 20,100 pounds. In this example, a DA Form 5703-R is required anytime the planned gross weight is more than 17,100 pounds.

NOTE 1: If the dual-engine maximum torque available exceeds a torque limit, use the tabular data equal to the torque limit, or enter the CRUISE chart at the torque limit line.

NOTE 2: If the maximum torque available line used on a CRUISE chart is to the right of the -10, Chapter 5 maximum gross weight limitation line, use the maximum gross weight limit line.

SIGNIFICANT CHANGE COMPUTATIONS

Step 3: ARRIVAL - Compare the maximum allowable gross weight for arrival from either the -CL tabular data or appropriate -10 HOVER chart with the planned or actual aircraft gross weight.

b. When a significant change in the mission's conditions occurs, recompute all affected values. A significant change is defined as any one of the following:

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(1) An increase of over 10 degrees C, 2,000 feet PA, and/or 1,000 pounds gross weight.

(2) An increase or decrease of an ETF by 0.03 or more.

NOTE: An increase or decrease of .03 ETF, normally caused by inaccurate information or a change in aircraft, can significantly enhance or degrade single engine performance under certain conditions. Therefore, when the ETF is different from the planned value, an update of all affected values is required.

c. The data presented in the performance charts in the -10 are primarily derived for either a "clean" or "high drag" aircraft. When the external equipment or configuration differs significantly from the "clean" or "high drag" configuration, drag compensation will be made.

This configuration is referred to as the "alternative or external load" configuration and the appropriate drag compensation is described.

d. The procedures for determining performance-planning data are the same for the UH-60A/L, UH-60Q/HH-60L and EH-60A aircraft unless specifically noted in the appropriate items.

The figures below show the numerical sequence of each task item for completing DA Form DA Form 5703-R (front and back) IAW Task 1004 and the USAAVNC UH-60 Performance Planning Student Handout (dated Jan 2003).

NOTE: Maximum pressure altitude and temperature will be used when computing all items in the departure section except item 13. Item 13 (See below DA Form 5703-R example) will be computed using forecast temperature and PA at time of departure.

Use of the AMCOM approved Performance Planning Software is authorized. It is important to remember that the knowledge of how to complete the DA Form 5703-R using the – 10/Tabular Data is a perishable and necessary skill.

e. DEPARTURE. (Figure 1, below) shows the numerical sequence of each task item for completing DA Form 5703-R (front).

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DA FORM DA Form 5703-R (Front)

Figure 1

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DEPARTURE

PRESSURE ALTITUDE (PA)- Is the height measured above the 29.92 inches of mercury pressure level (standard datum plane). It is used to correlate aerodynamic and engine performance in the non-standard atmosphere. The higher the pressure altitude is above standard, the lower the aircraft performance becomes due to thinner air density. Enter the maximum and current pressure altitude. Technique: To derive the Pressure Altitude in the aircraft, dial in 29.92 on the Barometric Altimeter Kollsman Window and read the dial indicator. This will tell you the PA.

(♦) (1) PA- Record forecast maximum pressure altitude for the mission and pressure altitude for time of departure.

(♦) (1) Record forecast +2,500 maximum pressure altitude for the mission. (Figure 2)

(♦) (1) +1,500 current pressure altitude for departure. (Figure 2)

FREE AIR TEMPERATURE (FAT)- Enter the maximum and current FAT.

(♦) (2) FAT- Record forecast maximum free air temperature for the mission and free air temperature for time of departure.

(♦) (2) Record forecast +25°C maximum temperature for the mission. (Figure 2)

(♦) (2) +20°C current temperature for departure. (Figure 2)

AIRCRAFT GROSS WEIGHT-Is defined as the weight of the aircraft at takeoff and is the sum of operating weight, usable fuel weight, payload items required to perform the particular defined mission, and other items to be expended during flight. This includes the aircraft basic weight, internal load, total fuel, and when applicable, ESSS stores (exclude sling load). Obtain this value from the DD Form 365-4 (Weight and Balance Clearance Form F) or by the Pilot-In-Command estimating this weight. For example: a 365-4, Chart F for 4 Crewmembers and 11 passengers is one of the completed weight and balance forms in the aircraft logbook. The first serial you have 8 passengers, 9 passengers on the second serial. The completed Chart F with 4 Crewmembers and 11 passengers remained within CG limits. Therefore, your planned passenger load for the first and second serials will remain within CG limits too.

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(♦) (3) AIRCRAFT GROSS WEIGHT. Record 14, 000 pounds planned aircraft gross weight at takeoff. This includes the aircraft basic weight, internal load, total fuel. (Figure 2)

FUEL WEIGHT- The estimated weight of the fuel the crew will have onboard at takeoff.

(♦) (4) FUEL WEIGHT. Record total planned fuel weight (internal and/or external) 2,200 pounds of fuel at takeoff. (Figure 2)

Items (5) and (6) are completed when applicable

(♦) (5) STORES WEIGHT. Record the planned jettisonable weight of the ESSS stores (if installed).

(♦) (6) SLING WEIGHT. Record the planned weight of the sling load (if required for the mission).

The maximum pressure altitude and maximum temperature forecasted during the mission are used to determine torque ratios, maximum torque available, maximum gross weight, and go/no-go torque values. Predicted hover torque is computed using current takeoff conditions.

(♦) (7) ATF/ETF. Record the ATF and ETFs in the appropriate blocks.

ENGINE TORQUE FACTOR (ETF)- Defined as the ratio of individual engine torque available as compared to a specification engine at a reference temperature of 35°C. The ETF range is from .85 to 1.0. A 1.0 value means that the engine(s) will perform to, or exceed, a specified (specification) performance level (power) as defined in the Army's UH-60 development contract with General Electric (developer of T-700 engines). As with any engine, as operating times increase; performance

2,500 +25 14,000 +20 1,500

Figure 2

2,200

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levels will decrease due to wear and tear. The ETF indicates how far that below specification the engine performance will be, For example, an ETF of .85 would perform 85 percent as well as a specification engine. The ATF and ETF values for an individual aircraft can be found on each engine Health Indicator Test (HIT) log in the logbook. AIRCRAFT TORQUE FACTOR (ATF)- Defined as the ratio of aircraft power available as compared to specification engines at a reference temperature of 35°C. The ATF is the average of the ETF’s of both engines and this value is allowed to range from .90 to 1.0. A .85 ETF engine would require a minimum of a .95 ETF on the second engine to provide a minimum required .90 aircraft torque factor (ATF). An aircraft with a 1.0 ATF is ideal, as it provides more power than a lower ATF aircraft. Although the ATF is an average of the ETF’s, the proper name is Aircraft Torque Factor, not Average Torque Factor.

(♦) (8) TR. Use the aircraft TORQUE FACTOR chart to compute torque ratios as described below.

TORQUE RATIO (TR)- This figure provides an accurate indication of available power by incorporating ambient temperature effects on engine performance. Simply stated, the TR allows the pilot to correct a non-specification engine (less than 1.0 ETF) for less than reference temperature (35°C). For temperatures below 35°C, a non-specification engine will be corrected. The colder the temperature goes below 35°C, the denser the air becomes and the more efficient the engines becomes to a point. Use the same TR value for temperatures less than -5°C. At this temperature, Ng limiting has a significant effect on power available due to a significant increase in air density, and corresponding engine efficiency. Figure 7-2 provides a chart to determine TR. The TR will not change for a specification engine since a 1.0 engine already meets required design performance. Intuitively, however, the performance would actually increase on days less than 35°C, even for a 1.0 engine, but performance planning charts do not allow us to determine this value. Additionally, the TR will not change for temperatures of 35°C or above, since the ATF/ETFs are based on this temperature anyway. In these cases, the TR will equal the ETF/ATF. For temperatures less than –5 degrees C use the -10, Para 7.10.2 below.

Para 7.10.2 and Para 7A.10.2 Torque Factor Procedure. The use of the ATF or ETF to obtain the TR from Figure 7-2(7A-2) for ambient temperatures between -5°C (21°F) and 35°C (95°F) is shown by the example. The ATF and ETF values for an individual aircraft are in the engine HIT Log. Use the -5°C (21°F) TR value for temperatures less than -5°C (21°F). The TR equals the ATF or ETF for temperatures of 35°C (95°F) and above. For these cases, and for an ATF or ETF value of 1.0, Figure 7-2 does not to be used.

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Step 1: Enter the appropriate aircraft TORQUE FACTOR chart on the left at the appropriate temperature. Move right to the ATF or ETF.

The ATF Torque Ratio is not the average of the two ETF Torque Ratios. It must be computed separately IAW TC 1-212 (Task 1004). Step 2: Move straight down to the bottom of the chart, note the TR~

The chart below is used to determine Torque Ratios and gives examples on how to derive the values.

The chart below is used to determine Torque Ratios for the 701C and gives examples on how to derive the values.

Enter at Maximum FAT

Move across to Torque Factor

ATF: .95 ETF: .90 ETF: 1.0 TR: .956 TR: .910 TR: 1.0

(1.0 + .910) ÷2 = ��

Averaging is not the ATM way to do this. Use the chart. Move down to

read Torque Ratio

Figure 3

.910 .956

.84 .85 .86 .87 .88 .89 .90 .91 .92 .93 .94 .95 .96 .97 .98 .99 1.00

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Figure 7A-2

TO OBTAIN TORQUE RATIO: 1. ENTER TORQUE FACTOR CHART AT KNOWN FAT 2. MOVE RIGHT TO THE ATF VALUE 3. MOVE DOWN, READ TORQUE RATIO = .954.

The continuation of how to complete the T701C 5703-R is detailed below (See Figure 14-17)

Figure 4

.954

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The following is an example of a completed DA Form 5703-R ETF/ATF and Torque Ratios section (T700).

MAX TORQUE AVAIL(UH-60A) - This torque value represents the maximum torque available at zero airspeed and 100% RPM R for the operational range of PA and temperature. This torque value may or may not be continuous due to Chapter 5 limitations. The actual maximum torque available figure will be annotated on the DA Form 5703-R, regardless of whether it is above continuous transmission (XMSN) torque limits. If applicable, the aviator is responsible for ensuring that Chapter 5 transient limits are applied when using MTA.

Based on flight test data, the MAX TORQUE AVAILABLE chart in the operator's manual reflects the maximum torque the engines can produce without exceeding the maximum of any of three 30-minute engine operating limitations (1) TGT 850°C, (T700), TGT 851°C, (T701C), (2) Ng 102%, or (3) Eng Oil Temp 150°C. MAX TORQUE AVAILABLE is limited by the HMU through TGT limiting, or Ng limiting. A TGT limiter circuit within the ECU causes the HMU to limit fuel to the engine when TGT reaches the 30 min TGT limit. Refer to your respective MAX TORQUE AVAILABLE charts, TGT limiting would probably occur in the regions where the max torque lines slant up and left as temperature increases. TGT limiting is usually what will limit MAX TORQUE AVAILABLE for the PA and temperature combinations where most Army aviators operate. Ng limiting limits fuel flow (via Ng governing or max fuel flow) to control the rotational speed of the compressor/gas generator turbine rotors (actual limiting speeds depends on T-2 (Turbine Inlet Temperature)), keep in mind TGT limiting may precede Ng limiting depending on TGT. As a rule, more Ng is allowed in warmer weather, less Ng is allowed in cold weather. When Ng speeds reach approximately 102%, the HMU also limits fuel to the Ng section through Ng governing/max fuel flow. Do not confuse this function with Ng shutdown, which shuts down the engine reaches Ng speeds of 110 ± 2 %. Because the speed at which Ng limiting occurs changes based upon the temperature, it would be difficult for the aircrew to determine if Ng limiting has been reached. If MAX TORQUE AVAILABLE is reached and/or rotor droop (decreasing RPM R) without reaching the TGT limiter range the aircraft is probably in Ng limiting. Refer to your respective MAX TORQUE AVAILABLE charts, Ng limiting

2,500 +25 14,000 +20 1,500

.95 .90 1.0

2,200

1.0 .910 .956

Figure 5

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would likely occur in the regions where the max torque lines slant down and left as temperature decreases. As shown on the MAX TORQUE AVAILABLE chart, even though colder and denser air improves engine performance, the MAX TORQUE AVAILABLE eventually begins to decrease, rather than increase because critical mach speed decreases with colder air. Ng speed is limited to prevent airflow through the engine from reaching mach. Although the axial compressor blades themselves are operating above mach speeds, the airflow through the engine must remain sub-sonic. Mach airflow through the engine would cause engine roughness, engine surge and/or compressor stall. For the UH-60A with T700 engines, if MAX TORQUE AVAILABLE is more than 100% torque dual-engine, or 110% single-engine(T700) the aircraft is said to be structurally limited. The engines are capable of producing the power, but components in the XMSN are incapable of sustaining these torque loads continuously without damage. Figure 6 shows the MAX TORQUE AVAILABLE each XMSN component can receive continuously without damage. Concerning dual-engine operation, the input modules could individually accept more than 100% torque continuously (up to 110% actually), but this would generate more than 200% combined torque to the main module if operating dual-engine. The main module cannot accept these torque loads continuously. Therefore, main module capability limits dual-engine MAX TORQUE AVALILABLE. Concerning single-engine operation, the main module can take up to 200% torque continuously, but the smaller gears in each individual input module cannot. Therefore, the input module is limited because of structural integrity and will limit single-engine MAX TORQUE AVAILABLE. In a structurally limited aircraft (MAX TORQUE AVAILABLE greater than 100% torque dual-engine/110% torque single-engine, attempting to operate continuously above the allowable torque value in chapter 5 will result in structural damage to the transmission. Refer to chapter 5 of the -10 for current transient limitations. If MAX TORQUE AVAILABLE is below dual-engine or single-engine torque the aircraft is said to be environmentally limited. Due to environmental conditions, the engines are incapable of producing specification power and XMSN torque limits will not be reached. In an environmentally limited aircraft, attempting to demand more torque than Max

Figure 6

Figure 7

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Torque Available, will result in rotor droop. For the UH-60A the pilot will need to limit operation of an environmentally limited aircraft to 30 minutes to prevent the engines from operating longer than the three 30 minute engine limits. It is important to understand what the aircrew will observe in the cockpit when MAX TORQUE AVAILABLE is needed. One scenario would be an aircraft with identical ETF’s, resulting in identical MAX TORQUE AVAILABLE values for both dual and single engine. See Figure 8. When MAX TORQUE AVAIL- ABLE is demanded the aircrew would observe 98% torque on both the #1 and #2 engine torque gauges, with the respective TGT for each engine at the TGT. Torque from both engines would rise evenly (torque matching). TGT limiting would prevent the pilot from receiving more torque. Attempting to do so would result in rotor droop. See PDU indications in Figure 7. A second and more common scenario is an aircraft with different ETFs, resulting in different MAX TORQUE AVAILABLE values for each engine. See Figure 9 below. When MAX TORQUE AVAILABLE is demanded in this situation, the aircrew would not see 98% on the torque gauges, as this is only an averaged number between both engines. As the aviator demands power, torque on both engines would rise evenly to 92%. At this time, the #1 engine would reach its TGT limiter and would remain at 92% torque. If the aviator continues to demand more power, the stronger 1.0 engine would produce up to 104% before reaching its TGT limiter. Thus, the aircrew would observe 92% and 104% torque respectively, with TGT on both engines at TGT limiting. See PDU indications in Figure 10 below. Attempting to demand more power in this case would result in rotor droop.

.95

98

.90 1.0 1.0

92 104

Figure 9

A/C GW, PA, FAT omitted for discussion purposes

.961 .902

.95 .95 .95

.952 .952 .952

Figure 8


98 98 98

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A demand for maximum power from engines with different engine torque factors (ETF) will

cause a torque split when the low ETF engine reaches TGT limiting. This torque split is normal. Under these circumstances, the high power engine may exceed the dual engine limit. (Example: #1 TRQ = 96% at TGT limiting, #2 TRQ is allowed to go up to 104%. Total helicopter torque = 96% + 104%)/2 = 100%). The aviator will notice that with unequal ETFs, a torque split may result when power demanded exceeds that of the weakest engine.

Although this is a dual-engine situation and the #2 engine is above 100% continuous, as long as the average torque between both engines is at or below 100% (98% in Figure 9) there would be no transient limitation for this dual-engine power setting. In figure 11, TGT is in the 30-minute range (-10 chapter 5). This scenario does not exceed the continuous combined torque limit, dual-engine, for the main module. MAX TORQUE AVAIL(UH-60L) The

explanation of what Max Torque Available means is fundamentally the same between the two airframes. However, the difference is that the Maximum Torque available is based on the 10-minute TGT range of 851-878°C and the values are derived in Chapter 7A on page 7A-11. The TGT Limiting values for the UH-60L are 860-872°C 10 min, or 886-896°C 2.5 min OEI (One Engine Inoperative). TGT limiting would prevent the pilot from receiving more torque on this airframe as well as the UH-60A given the right ambient conditions. Note that the torque limits are significantly different than on the T700 engine. On the T701C, Dual Engine Torque Limits (12-second) above 80 knots are 100-144%, 120-144% below 80 knots, while the continuous Torque Limits are above 80 knots, 0-100% and below 80 knots, 0-120%. For Single Engine Operation on the T701C the 12-second torque limits are 135-144%, while the continuous torque limits are 0-135%. Note that engine bleed air is used to pressurize the external range fuel system (ERFS), however, the bleed air loss is not significant enough to require MAX TORQUE AVAILABLE adjustments. Note also that cruise and hover power torque remain unaffected when bleed air is utilized. The reduction in torque is lost from MAX TORQUE AVAILABLE. For both the UH-60A and the UH-60L, understand also that the 16% or 18% torque reduction is a maximum value, which would result from the operation of

Figure 10

Figure 11

18

both engine anti-ice and engine inlet anti-ice. Engine anti-ice uses 5th stage bleed air to heat engine swirl vanes, nose splitters, and inlet guide vanes. However, depending on the ambient air temperature, the engine inlet anti-ice valve may or may not open. With the temperature of +4°C or below, the engine inlet anti-ice modulating valve should open and additional bleed air will travel to the engine inlet section to warm the inlet to a minimum of 93°C. At temperatures of +4°C to +13°C, the engine inlet anti-ice modulating valve may or may not open. At a temperatures above +13°C, the engine inlet anti-ice modulating valve should not open.

�� T700

With engine bleed air turned on, MAX TORQUE AVAILABLE is adjusted as follows:

a. Engine Anti-Ice On.............................................. -16% b. Cockpit Heater On............................................... - 4% c. No IR suppressors, or suppressors w/o baffles...+1%

��

�� T701C

With engine bleed air turned on,

MAX TORQUE AVAILABLE is adjusted as follows:

a. Engine Anti-Ice On.............................................. -18% b. Cockpit Heater On............................................... - 4% c. No IR suppressors, or suppressors w/o baffles...+1%

If conditions are such that the engine inlet anti-ice valve remains closed, engine bleed air demand will be less due to engine anti-icing only, and the aircrew will probably not lose a full 16%/18% from MAX TORQUE AVAILABLE. This can be observed during the engine HIT check by watching the difference in TGT rise when engine inlet anti-ice is on, as compared to when it is off. TGT will be higher when the engine inlets are heated, which results in reaching TGT limiting at a lower MTA. Regardless of whether engine inlet anti-icing is in operation or not, a 16%/18% torque reduction will be used for flight planning purposes.

(♦) (9) MAX TORQUE AVAILABLE. Use the appropriate MAXIMUM TORQUE AVAILABLE chart to compute engine specification torque available as described below.

(♦) NOTE 1: The maximum torque available is also referred to as intermediate rated power (IRP) Max 10 or 30-minute limit (Dual Engine) in the 5703-R computer program.

(♦) NOTE 2: Certain temperature and pressure altitude combinations will exceed -10, Chapter 5 torque limitations. This item represents actual maximum torque

19

available values. During aircraft operations, -10, Chapter 5 torque limitations shall not be exceeded.

(a) T700-GE-700 engines.

(♦) Step 1: Enter the MAXIMUM TORQUE AVAILABLE chart at the appropriate temperature then move right to the appropriate PRESSURE ALTITUDE ~ 1000 FT.

(♦) Step 2: Move down and read the SPECIFICATION TORQUE AVAILABLE PER ENGINE ~ %.

(♦) Step 3: If the ATF or ETF is less than 1.0, multiply the specification torque by the torque ratio to obtain maximum torque available. An alternate method is to continue down to the TORQUE RATIO, item 8. Move left to read the maximum TORQUE AVAILABLE ~ % per engine. Record MAX TORQUE AVAILABLE.

(♦) NOTE: Adjust maximum torque available as required for planned use of engine anti-ice and/or cockpit heater according to the -10. (Figure 12)

(b) T700-GE-701C engines.

NOTE 1: The maximum torque available – 2.5 minute limit is also referred to as SINGLE-ENGINE CONTINGENCY POWER – 2.5-MINUTE LIMIT.

(♦) Step 1: Enter the MAXIMUM TORQUE AVAILABLE – 10-MINUTE LIMIT chart for dual-engine and 2.5-MINUTE LIMIT chart for single-engine at the appropriate FREE AIR TEMPERATURE (FAT) ~ ° C.

(♦) Step 2: Move right to the appropriate PRESSURE ALTITUDE ~ 1000 FT. line then move down and read the TORQUE AVAILABLE PER ENGINE ~ %.

(♦) Step 3: If the ATF or ETF is less than 1.0, multiply the SPECIFICATION TORQUE by the TORQUE RATIO to obtain maximum torque available.

(♦) Step 4: An alternate method is to enter the bottom of the TORQUE CONVERSION chart at the TORQUE AVAILABLE PER ENGINE (SPECIFICATION TORQUE) ~ %. Move up to the torque ratio, item 8, then left to read ACTUAL TORQUE AVAILABLE %. Record MAX TORQUE AVAILABLE. (Figure 12)

(♦) NOTE 2: Adjust the maximum torque available as required for planned use of engine anti-ice and/or cockpit heater according to the -10.

20

Figure 12

Read Torque here for 1.0

Read Torque here for other than 1.0

98 %

88 %

50 60 70 80 90 100 110 120

The chart below is used to determine Maximum Torque Available and gives examples on how to derive the values (T700).

2,500 +25 14,000 +20 1,500

.95 .90 1.0

98 88

Figure 13 93

2,200

1.0 .910 .956

21

The chart below is used to determine Maximum Torque Available and gives examples on how to derive the values (T701C).

TO DETERMINE SPECIFICATION TORQUE AVAILABLE - 10-MINUTE LIMITS: 4. ENTER MAXIMUM TORQUE AVAILABLE CHART AT KNOWN FAT (FIGURE 7A-4). 5. MOVE RIGHT TO KNOWN PRESSURE ALTITUDE 6. MOVE DOWN, READ SPECIFICATION TORQUE = 98%.

Figure 14

98%

22

The chart below is used to determine Maximum Torque Available for the 701C and gives examples on how to derive the values.

TO OBTAIN ACTUAL TORQUE VALUE AVAILABLE FROM THE TORQUE CONVERSION CHART: 7. ENTER TORQUE CONVERSION CHART FIGURE 7A-3 AT % TORQUE OBTAINED FROM FIGURE 7A-4. 8. MOVE UP TO TORQUE RATIO OBTAINED FROM FIGURE 7A-2 9. MOVE LEFT, READ MAXIMUM TORQUE AVAILABLE – 10 MINUTE LIMIT = 93%.

Figure 15

NOTE: EITHER OF THE TWO TORQUES AVAILABLE CHARTS MAY BE USED. MAXIMUM ALLOWABLE DUAL ENGINE TORQUE LIMITS SHALL NOT BE EXCEEDED.

93%

23

10. ENTER DUAL-ENGINE TORQUE LIMIT CHART FIGURE 7A-5

AT 30°C. MOVE RIGHT TO INTERSECTION AT 6,000 FT. PA.

MOVE DOWN TO READ 90.4% TORQUE.

The following is an example of a completed DA Form 5703-R ETF/ATF /TR and Max Torque Available Section (T701C).

2,500 +25 16,000

.95 .90

116 107 112

1.0

Figure 17

+20 1,500

.920 .96 1.0

2,200

Figure 16

90.4%

24

MAX ALLOWABLE GWT (OGE/IGE)- This is the maximum weight the aircraft is capable of, or allowed to operate at a 10 foot hover height for IGE operations, or to a 70 foot hover height for OGE operations. This weight will be limited by either engine capabilities or aircraft structural design. There is no reference in the -10 definitively stating that 70 feet defines an OGE hover, however, OGE hover height is defined in FM 1-203 (Fundamentals of Flight) as 1¼ rotor diameters. 70 feet for an OGE hover in a Blackhawk is obtained by multiplying rotor diameter (53 feet 8 inches) by 1.25 (53.8 x 1.25 = 67.25 feet) rounded to 70.

The MAX ALLOWABLE GWT IGE or OGE is 22,000 lbs. If this value is predicted to be 22, 000 lbs (as applicable for both the UH-60A and L models), then the aircraft is structurally limited. Although the engines may be capable of lifting more weight, the airframe is not. When the MAX ALLOWABLE GWT value is 22,000 lbs (as applicable), attempting to operate at a weight above that value will result in exceeding a structural design limitation and damage is likely. If your MAX ALLOWABLE GWT IGE or OGE is less than 22,000 lbs then the aircraft is environmentally limited. Although the airframe is capable of lifting up to the chapter 5 maximum, the engines cannot lift that much weight for the given environmental conditions. When the MAX ALLOWABLE GWT value is less then 22,000 lbs, attempting to operate at a weight above that value will result in rotor droop, but no structural damage should occur.

(♦) (10) MAX ALLOWABLE GWT OGE / IGE. Use the appropriate HOVER chart to compute maximum allowable gross weight for OGE/IGE as described below. Annotate the computed maximum allowable gross weight OGE/IGE or the maximum gross weight per -10, Chapter 5, whichever is less.

NOTE: If OGE capability does not exist, the MAX HOVER HEIGHT IGE, item 12, must be computed.

(a) MAX ALLOWABLE GWT OGE / …

Step 1: Enter the HOVER chart at the TORQUE PER ENGINE ~ % (OGE) at the dual-engine MAX TORQUE AVAILABLE, item 9, then move right to the GROSS WEIGHT ~ 1000 LB chart. If the dual-engine maximum torque available exceeds transmission torque limits, use the DUAL ENGINE TRANS LIMIT line to compute the maximum allowable gross weight OGE.

Step 2: Reenter the HOVER chart at the appropriate FREE AIR TEMP ~ °C and move right to the appropriate PRESSURE ALTITUDE ~ 1000 FT, then move down to the GROSS WEIGHT ~ 1000 LB chart. Read the maximum allowable

25

gross weight OGE at the intersection of this step and step 1 above. Record the MAX ALLOWABLE GWT OGE / ….

(b) MAX ALLOWABLE GWT … / IGE.

Step 1: Enter the HOVER chart at the TORQUE PER ENGINE ~ % (IGE) at the dual-engine MAX TORQUE AVAILABLE, item 9, then move up to the desired IGE WHEEL HEIGHT ~ FT (normally the 10-ft line), then move right to the GROSS WEIGHT ~ 1000 LB chart. If the dual-engine maximum torque available exceeds transmission torque limits, use the DUAL ENGINE TRANS LIMIT line to compute the maximum allowable gross weight IGE.

Step 2: Reenter the HOVER chart at the appropriate FREE AIR TEMP. ~ °C and move right to the appropriate PRESSURE ALTITUDE ~ 1000 FT then move down to the GROSS WEIGHT ~ 1000 LB chart. Read the maximum allowable gross weight IGE at the intersection of this step and step 1 above. Record the MAX ALLOWABLE GWT … / IGE.

GO/NO-GO TORQUE (OGE/IGE)- This value provides a way for the aircrew to verify that the aircraft weight is at or below maximum limits. At a 10-foot hover height, this torque will determine if the aircraft is at or below the maximum weight that the aircraft is capable of lifting to an IGE or OGE altitude. Hover power checks are normally done at an altitude of 10 feet. If performing slingload operations, plan a GO/NO-GO value that will place the load at 10 feet AGL. Following are typical examples that aviators may be faced with during typical missions. If the torque required to maintain a stationary hover is above the GO/NO-GO IGE (greater than 91% torque GO/NO-GO IGE Figure 18) then the aviator cannot operate in compliance with the -10 because he is exceeding the maximum structural gross weight of 22,000 lbs. The -10 requires an entry on the 2408-13-1 any time an operational limit is exceeded. The aircrew should verify conditions and computations for accuracy. If the GO/NO-GO value is correct, the helicopter shall not be flown until corrective maintenance action has been taken. Some aviators may elect to land, burn down fuel or remove cargo to reduce weight, and then recheck their hover torque. If it is at or below the GO/NO-GO on the DA Form 5703-R, the aircraft would be below the maximum weight, but the fact is, the aircraft maximum structural weight was still previously exceeded and damage may have been done. In contrast, if the MAX ALLOWABLE GWT OGE is an environmental limitation (less than 22,000 lbs), then damage will not result to the aircraft by exceeding the OGE GO/NO-GO and the aircrew would be able to reduce weight and try again.

26

Refer to Fig. 18, Notice that the MAX ALLOWABLE GWT OGE is an environmental limitation (20,500 lbs), meaning that the MAX ALLOWABLE WT is less than what chapter 5 allows (22,000 lbs). The airframe could handle more than 20,500 lbs OGE, but the PA and temperature will not allow the engines to produce the necessary power to achieve OGE altitudes with weights greater than 20,500 lbs. This will require a GO/NO-GO value for both IGE and OGE. In this scenario, if the torque at a 10 foot hover is at 83% (GO/NO-GO OGE), then the aircraft weighs 20,500 lbs and the crew is at the maximum weight to perform OGE operations. If the torque required to maintain a stationary hover exceeds 83% (GO/NO-GO OGE), but does not exceed 91% (GO/NO-GO IGE), then only IGE maneuvers may be attempted. If the aircraft was hovering above GO/NO-GO OGE at 10 feet and the aircrew attempted a climb to OGE altitudes, MAX TORQUE AVAILABLE values of 93% and 104% would be reached before obtaining out-of-ground effect and rotor droop would result if the climb attempt was continued. Refer to Figure 19, notice that for an aircraft that is environmentally limited for both OGE and IGE, (meaning that the MAX ALLOWABLE GWT is less than the max chapter 5 allows), the aircrew should not be able to exceed the GO/NO-GO IGE. The GO/NO-GO IGE will equal the MAX TORQUE AVAILABLE (90% in the example). As such, if the aircrew tries to hover IGE at a heavier weight, rotor droop will develop when the engines reach their TGT or Ng limiters. No structural damage should result. In summary, inaccurate calculations and/or a poor understanding can result in not having the necessary power available to successfully complete a maneuver and/or could result in aircraft damage. Use extra vigilance when attempting to operate an aircraft that is structurally or environmentally limited OGE or IGE.

STRUCTURALLY LIMITED AIRCRAFT

.95 .90 1.0

20,500


Figure 18

.951 .902 1.0

22,000 83

104 93

91

98

Figure 19 ENVIRONMENTALLY LIMITED AIRCRAFT

.95 .90 1.0

21,000

.951 90

.902 1.0

77 90

93 87 18,900


27

Exceeding GO/NO-GO OGE/IGE Torque, the aircrew has very likely hovered a helicopter that is over MAX ALLOWABLE GWT, which requires maintenance action. It is important to be as accurate as possible on the weight and balance and cargo load weights, so as to ensure the aircraft is not above MAX ALLOWABLE GWT "on paper" before you attempt to weigh the helicopter at a hover. If the maximum structural weight can be lifted to OGE altitudes, then it can obviously be lifted to IGE altitudes, which requires less power due to ground effect. In this scenario, if the torque required to maintain a stationary hover is at or below the GO/NO-GO IGE/OGE value (82% torque in the example), the aviator has confirmed aircraft weight to be at or below MAX ALLOWABLE GWT and any maneuver requiring OGE power or less may be attempted.

��FOR LOW WIND CONDITIONS AIRCRAFT SHOULD BE HEADED INTO

WIND. 3-5 KT CROSSWIND OR TAILWIND MAY INCREASE TORQUE REQUIRED BY UP TO 4% OVER ZERO WIND VALUES

(♦) (11) GO/NO-GO TORQUE OGE / IGE. Use the appropriate HOVER chart as described below. (Figure 20)

(a) OGE. Use maximum allowable gross weight OGE, item 10.

(b) IGE. Use maximum allowable gross weight IGE, item 10.

NOTE : GO/NO-GO is computed using the maximum forecast pressure altitude and temperature for the mission. When the actual temperature is less than maximum, the torque required to hover at a given gross weight is less.

To ensure that structural limits are not exceeded, or that OGE capabilities exist at maximum forecast temperature, reduce GO/NO-GO by 1% for each 10° C that actual temperature is less than maximum forecast temperature.

(♦) Step 1: Enter the chart at the appropriate FREE AIR TEMP ~ °C.

(♦) Step 2: Move right to the appropriate PRESSURE ALTITUDE ~ 1000 FT.

(♦) Step 3: Move down to the weight(s) computed for item 10.

(♦) Step 4: Move left to the 10-foot hover line (or WHEEL HEIGHT ~ FT that will be used to check the GO/NO-GO).

(♦) Step 5: Move down to read the GO/NO-GO torque value(s). Record the GO/NO-GO TORQUE OGE / IGE. (See Figure 20)

28

��

(♦) On page 6-4 of the ATM, dated 08 March 1996, all maneuvers requiring OGE power are as follows: Fast Rope Operations, Rappelling Operations, External Load Operations, STABO Operations and Hoist Operations. Other maneuvers in the ATM will indicate by means of a NOTE, that OGE power may be required.

This will depend on such factors as barrier height, aircraft speed, winds, pilot technique, etc. The need for OGE power in these situations is left to the determination of the aircrew.

�� When the FAT is cooler, the engines are more capable of lifting the same amount of weight using a lower torque value. Although a decrease in temperature would make all other values on the DA Form 5703-R more conservative, the GO/NO-GO will get the aviator in trouble. The colder temperatures would allow the same aircraft to hover with less torque. Therefore, operating at the higher (original) GO/NO-GO torque value would mean the aviator is actually hovering an aircraft weighing more than the chapter 5 maximum.

29

The chart below is used to determine Max Allowable GWT OGE/IGE and GO/NO-GO Torque values and gives examples on how to derive the values.

= Max Allowable GWT OGE (20,700 lb) = Go/No-GO Torque OGE (86%) = Max Allowable GWT IGE (22,000 lb) = Go/No-Go Torque IGE (91%)

IGE weight on the chart is above structural limits. However, 22,000 lb is the limit on our aircraft.

20, 700 lbs MAX GW OGE MGW OGE

22, 000 lbs MAX GW IGE MGW OGE

Figure 20

30

MAXIMUM HOVER HEIGHT IGE (DUAL ENGINE)- For use in determining maximum hover height when aircraft gross weight exceeds max allowable gross weight OGE; you do not have the power to make it to an OGE hover.

(♦) (12) MAX HOVER HEIGHT IGE. If OGE capability does not exist, use the appropriate HOVER chart to compute the MAX HOVER HEIGHT IGE, as described below.

(♦) Step1: Enter the HOVER chart at the appropriate FREE AIR TEMP ~ °C and move right to the appropriate PRESSURE ALTITUDE ~ 1000 FT, then move down to take-off GW ~ 1000 LB, item 3 (plus sling load weight, item 6, if applicable), then move left to the WHEEL HEIGHT FT ~ lines.

(♦) Step 2: Reenter the bottom of the HOVER chart at the TORQUE PER ENGINE ~ % (IGE) at the dual-engine MAX TORQUE AVAILABLE, item 9, then move up to the intersection from step 1 above. Interpolate hover height as required. Record the MAX HOVER HEIGHT IGE.

FIGURES 21 AND 22 ARE TO SHOW HOW TO DISPLAY THE MAX HOVER

HEIGHT VALUES AND DERIVE THEM FROM THE CHARTS

The DA Form 5703-R is used to show Max Hover Height OGE values and the following page gives examples on how to derive the values.

Figure 21

2500 1500 25 20

.95 .956

.90 1.0

.910 95

19400 22000

16

21000

79 95

98 89

2000

1.0

31

(12) MAX HOVER HEIGHT IGE

40 50 60 70 80 90 100

100

95

90

85

80

75

70

65

60

55

50

Figure 22

16 FEET

80 100 120 140

32

PREDICTED HOVER TORQUE (Dual Engine PREDICTED HOVER TORQUE)- This is the estimated torque required for a stationary 10 foot hover, dual engine, using takeoff gross weight, PA and FAT. The aircrew compares the actual hover torque against this value derived on the DA Form 5703-R in an effort to validate actual takeoff weight. For external load operations, record the predicted torque required to hover at a height that will place the load at 10 feet AGL.

��

If the actual hover torque is not equal to the predicted value, it could be attributed to some of the following conditions:

a. The aircraft weight is not as predicted. Was the 365-4 reviewed? If the correct weight was used from the 365-4, and the actual hover torque is still different than predicted, the aircrew can work the hover chart backwards to determine the current weight.

b. Environmental conditions have changed since the computation of the DA Form 5703-R. Hover values are based on zero wind conditions and strong winds can affect hover performance. Hovering over other than level, smooth surfaces can also affect hover Torque.

c. Making an error deriving this value from the chart.

(♦) (13) PREDICTED HOVER TORQUE. Use the appropriate HOVER chart as described below for torque required to hover. Use AIRCRAFT GWT, item 3, and current PA, item 1, and FAT, item 2.

(a) Predicted hover torque (dual-engine). Compute the torque the same as for item 11 above using the AIRCRAFT GWT, item 3, instead of the MAX ALLOWABLE GWT. Record dual-engine PREDICTED HOVER TORQUE.

(b) Predicted hover torque (single-engine). Double the PREDICTED HOVER TORQUE value that was computed in step (a) above. If the value exceeds the appropriate MAX TORQUE AVAILABLE, item 9, single-engine, record NA in the appropriate block(s). Record single-engine PREDICTED HOVER TORQUE.

Max Torque values are derived using Max PA/FAT. Hover Torque values are derived using Departure PA/FAT.

33

.95 1.0 .90

2500 +25 14,000 +20 1500

.956 92

19,100

.910 1.0

2,000 NA NA

21,600 78 92

OGE 52 N/A N/A

Forecast Takeoff Conditions

52%

Figure 23

97 88

34

MIN SE - IAS - W/O STORES / W/STORES- This is the airspeed value for OGE conditions where consideration should be given to an IGE takeoff if conditions merit.

(♦) (14) MIN SE - IAS - W/O STORES / W/STORES. Use the appropriate CRUISE chart for the minimum single-engine airspeed with external stores and without external stores as described below.

NOTE 1: If the aircraft will be operating without external stores, record NA in the w/stores block.

NOTE 2: External stores are defined as a sling load, ESSS wing stores, or both.

Step 1: Enter the bottom of the CRUISE chart at one-half the single-engine MAX TORQUE AVALABLE, item 9, for the low ETF engine, but no more than one-half of the TRANSMISSION TORQUE LIMIT. Step 2: Move up to the first intersection of aircraft gross weight (without external stores). Read left or right for the IAS ~ KTS. Record MIN SE – IAS – W/O STORES /…. NOTE 3: If aircraft will be operating with external stores, proceed with steps 3 and 4 below. Step 3: Enter the bottom of the appropriate CRUISE chart at one-half the single-engine MAX TORQUE AVAILABLE, item 9, for the low ETF engine, but no more than one-half of the TRANSMISSION TORQUE LIMIT. Step 4: Move up to the first intersection of aircraft gross weight (with external stores). Read left or right for the IAS ~ KTS. Record MIN SE – IAS – … / W/STORES.

35

The chart below is used to determine MIN SE - IAS - W/O STORES / W/STORES and gives an example on how to derive the values.

ZERO FUEL WEIGHT- The zero fuel weight is necessary for Dynamic Updates of the 5703-R when required. It is computed using standard, average or estimated weight for personnel, equipment, and fuel. Actual weights may vary greatly from those on the DD Form 365-4. The method to determine adjusted ZERO FUEL WEIGHT or to validate the DD Form 365-4 is described below. It is equivalent to takeoff gross weight at a 10’ hover less usable fuel indicated in the main tanks.

.95 1.0 .90

2500 +25 14,000 +20 1500

.956 92

19,100

.910 1.0

2,000 NA NA

21,600 78 92

1/2 MAX TORQUE AVAILABLE of the Weakest Engine 88 x 1/2 = 44%

Figure 24

22

88

NA 22 NA

97

52 NA NA

36

DES CLARIFICATION:

ZERO FUEL WEIGHT The new DA Form 5703-R was developed to aid in increasing power management/power available awareness. One of the critical components of this philosophy is Zero Fuel Weight. When computed properly, this will give you the weight of the aircraft at any given time. Using the Zero Fuel Weight from the DD Form 365-4 may not be accurate due to the use of standardized weights used in the DD Form 365-4 calculations. In order to determine the true Zero Fuel Weight the items needed to compute this should be gathered during the hover check and calculated on the ground, or if not practical, shortly after takeoff or level off. TC 1-212 states that when DA Form 5703-R is required it will be completed in its entirety. This computation must be completed each time a DA Form 5703-R is required IAW TC 1-212.

(♦) (15) ZERO FUEL WEIGHT: Use the appropriate HOVER chart from the -CL to compute the adjusted ZERO FUEL WEIGHT as described below.

Step 1: Note free air temperature, pressure altitude, and total indicated fuel weight.

Step 2: While at a hover, note wheel height and hover torque.

Step 3: Enter the HOVER chart at the noted FREE AIR TEMP ~ ° C. Move right to the noted PRESSURE ALTITUDE ~ 1000 FT then down to the GROSS WEIGHT ~ 1000 LB chart.

Step 4: Reenter the HOVER chart at the TORQUE PER ENGINE ~ % (IGE) at the noted hover torque. Move up to the WHEEL HEIGHT ~ FT to the noted hover height then move right to the intersection of step 3 above. Note aircraft gross weight.

Step 5: Subtract the noted total indicating fuel weight from the gross weight computed in step 4 above. Record the adjusted ZERO FUEL WEIGHT.

NOTE 2: Although data needed to compute ZERO FUEL WEIGHT is noted at a hover, the calculation may be made on the ground or, if not practical, shortly after takeoff or level off.

37

The chart below is used to determine Zero Fuel Weight and gives examples on how to derive the values.

(♦) (16) REMARKS- Use this area to note useful data for the particular mission, such as mission fuel, drag factors and drag computations such as GO/NO-GO Torque for External Loads.

The following is the technique to derive the Go/No-Go Torques for External Loads

Step 1: Enter the chart at the appropriate FREE AIR TEMP ~ °C.

Step 2: Move right to the appropriate PRESSURE ALTITUDE ~ 1000 FT.

Step 3: Move down to the Max Allowable Gross Weight (OGE).

Step 4: Move left to the 40-foot hover line (or WHEEL HEIGHT ~ FT that will be used to check the GO/NO-GO)*.

FAT: 21oC PA: 2,000 Fuel: 1,750 Height: 10 Torque: 54

14,300 - 1,750 = 12,550

Figure 25

14, 300

38

*Note: This is conducted at the external load height of 10’ it is not the aircraft at 10’ but the external load at 10’ which is usually conducted at an aircraft altitude of 40’.

Step 5: Move down to read the GO/NO-GO torque value(s). Record the GO/NO-GO TORQUE OGE / IGE. Enter this value in the Remarks section and have the 5703-R on your kneeboard during external loads for quick reference.

Figure 26

96%

20,500 97

16,500 +1500 +25

GO/NO-GO 40’: 96%

62

83

39

CRUISE

CRUISE.

(♦) (1) PA. Record planned cruise pressure altitude. This is the altitude which the cruise portion of the mission is conducted.

(♦) (2) FAT. Record forecast temperature at the planned cruise pressure altitude.

(♦) (3) TR. Use the TORQUE FACTOR chart to compute torque ratios, if required. The torque ratio is computed the same as item 8, DEPARTURE data, using cruise temperature instead of departure temperature.

NOTE: The maximum torque available values found in the cruise charts of the -10 and the tabular performance data of the -CL are adjusted for torque ratio.

Cruise data is computed at the planned cruise PA and forecast FAT at that altitude. It is not regulatory, but it is prudent to consider rounding up (worst case) to the nearest 10° degrees and 2,000' PA rather than interpolate between higher and lower charts. If forecast temperatures at cruise altitude are not available, use the surface temperature and apply the standard lapse rate of 2°C for every 1,000' increase in altitude. MAX TORQUE AVAILABLE - This torque can be computed with MAX TORQUE AVAILABLE or cruise charts. One method is to use the same MAX TORQUE AVAILABLE charts used previously on the DA Form 5703-R, but with cruise conditions. Interpolate if the ATF is between .90 and 1.0. Understand, however, that identical MAX TORQUE AVAILABLE values will not be obtained between the two methods unless the temperature is in an increment of 10°C and the PA is an increment of even thousands (e.g. S.L., 2,000, 4,000). The cruise charts have fixed temperature and PA combinations, unlike the MAX TORQUE AVAILABLE chart, which has unlimited temperature and PA combinations. However, in many cases, the new cruise charts are more accurate due to the computation of adding ram air effects. Unless the aviator can match the temperature and PA on the cruise chart, it is probably best to use the hover chart. This will allow the aviator to match the exact temperature and PA conditions, with no rounding error.

(♦) (4) MAX TORQUE AVAILABLE. Compute maximum torque available for dual- and single-engine the same as item 9, DEPARTURE data, using cruise temperature and pressure altitude.

40

NOTE 1: Adjust as required for planned use of engine anti-ice and/or cockpit heater according to the -10.

NOTE 2: Maximum torque available can be derived from the CRUISE chart by referencing the TORQUE AVAILABLE ~ 30-MINUTE ATF 1.0 and/or 0.9 line, if shown. If the ATF or ETF is between these values, interpolation is required. The maximum torque available – 30-minute limit for the T-700 engine and the 10-minute limit for the T-701C can also be derived from the tabular data in the -CL. If the ATF is between 1.0 and 0.9, interpolation is required (See Figure 35/36).

CRITICAL TORQUE-If an engine fails during takeoff, the aircrew should note their airspeed. If the aircraft has accelerated to or above the MIN SE IAS, the aircraft should be able to continue flight to a suitable landing area. If the torque demanded is above the CT-Critical Torque value, then the resultant rotor drag will cause rotor droop and aircraft descent, even though the aircraft is above MIN SE IAS! Note also that the aircrew does not have to attempt continued flight, but may elect to land immediately if sufficient runway remains ahead. If an engine fails below this value, the aircrew must make a quick decision, based on altitude attained, runway remaining, and aircrew reaction time. If there is sufficient altitude available, the pilot on the controls can attempt to lower the nose and adjust collective to below the Critical Torque value to minimize rotor bleed-off while attempting to trade altitude for airspeed that will allow the aircraft to attain single-engine “fly away” airspeed (MIN SE IAS). The aircraft can accelerate and climb to a safe cruise airspeed and altitude then complete a roll-on landing as soon as practicable.

Para 9.9, Single Engine Failure-General: At low altitude and low airspeed, it may be necessary to lower the collective only enough to maintain % RPM R (normal range). At higher altitude, however, the collective may be lowered significantly to increase % RPM R to 100%. When hovering in ground effect, the collective should be used only as required to cushion the landing, and the primary consideration is in maintaining a level attitude. In forward flight at low altitude (as in takeoff), when a single-engine capability to maintain altitude does not exist, a decelerating attitude will initially be required to prepare for landing. Conversely, if airspeed is low and altitude sufficient, the helicopter should be placed in an accelerating attitude to gain sufficient airspeed for single-engine fly away to a selected landing site. If there is insufficient altitude available to trade for airspeed, then the aircrew must maintain controlled flight to the ground, as a forced landing will be unpreventable. Aircraft damage may be unavoidable. Concerning single-engine roll-on landings, the ATM requires that the aircraft touch down below 60 knots ground speed, but above ETL. However, if the aircrew thinks that keeping the aircraft above ETL (16-24 knots) will ensure the aircraft keeps flying, there could be an unpleasant surprise coming. As the ATM

41

states, the aircraft should not be decelerated below MIN SE IAS until obstacles in the flight path have been cleared. It would be even more conservative not to decelerate below MIN SE IAS until the landing area is assured (within reach). The MIN SE IAS for an aircraft can be well above ETL. If the aviator needed to arrest a sink rate during a roll-on approach, he would likely droop RPM R if below MIN SE IAS, even though he is still above ETL.

(♦) (5) CT (critical torque). Record the value of one half the maximum torque available of the engine with the lowest ETF.

NOTE: CT is the dual-engine torque value, which when exceeded, may not allow the aircraft to maintain % RPM R within normal limits under single-engine operations in the same flight conditions. CT was incorporated to give the pilot an aid to situational awareness.

During dual-engine flight, conditions that require torque settings greater than the critical torque indicates the pilot is operating outside the aircraft low ETF single-engine capability. If operating dual-engine above the CT and an engine fails, malfunctions or must be shut down; the pilot must immediately adjust torque, airspeed and or gross weight to establish single-engine level flight.

MIN / MAX Vh – IAS (dual-engine)- This value is defined as the highest speed attainable in steady-state, level flight for a specific altitude, weight, configuration, and power setting. It is the maximum level flight airspeed (Vh) obtained at the intersection of gross weight arc and max torque available or the transmission torque limit whichever is lower. Conversely, the Min airspeed is usually zero for dual engine.

(♦) (6) MIN / MAX Vh – IAS (dual-engine). Use the appropriate CRUISE chart to compute the minimum/maximum Vh indicated airspeeds as described below in Figure 27.

(a) Clean and high drag configuration.

Step 1: Enter the bottom of the CRUISE chart at the MAX TORQUE AVAILABLE, item 4, CRUISE data.

Step 2: Move up to the first intersection of AIRCRAFT GWT, item 3, DEPARTURE data. Read left or right for minimum IAS ~ KTS. Record the dual-engine MIN / … Vh – IAS. If the maximum torque available line is right of the gross weight line, record 0 for the MIN / … Vh - IAS.

42

Step 3: Continue up to the second intersection of AIRCRAFT GWT, item 3, DEPARTURE data. Read left or right for maximum Vh IAS ~ KTS. Record the dual-engine ... / MAX Vh – IAS.

NOTE: If the maximum torque available line is to the left of (does not intersect) the AIRCRAFT GWT, item 3, DEPARTURE data, the aircraft cannot maintain dual-engine level flight for the conditions. Item 18 must be computed and a new cruise altitude selected.

(b) Alternative or external load configuration.

NOTE 1: For alternative or external load configurations, refer to the -10, Chapter 7, Section VI, DRAG. Determine and add together the appropriate Drag Multiplying Factors.

NOTE 2: The torque change to compensate for drag (alternative or external load configuration) at minimum Vh IAS is often negligible and not computed. The dual-engine maximum Vh indicated airspeed is adjusted for alternate or external load configuration as follows:

Step 1: Enter the CRUISE chart at maximum Vh IAS ~ KTS, (a) step 3 above, then left or right to the curved dashed line then move up to read � TRQ ~ % FOR DRAG AREA OF 10 SQ FT of � F.

Step 2: Multiply the � TRQ times the drag multiplying factor. Subtract the result from the maximum torque available used initially in (a) step 1 above.

Step 3: Reenter the bottom of the CRUISE chart at the adjusted torque value and move up to the second intersection of AIRCRAFT GWT, item 3, DEPARTURE data. Read left or right for maximum Vh IAS. Record the adjusted dual-engine .../MAX Vh – IAS.

NOTE 3: If the adjusted maximum torque available line is to the left of (does not intersect) the AIRCRAFT GWT, item 3, DEPARTURE data, the aircraft cannot maintain dual-engine level flight for the conditions. Item 18 must be computed and a new cruise altitude selected, if the aircraft is too heavy to cruise at the planned altitude.

43

The chart below is used to determine DUAL ENG MIN/MAX Vh-IAS and gives an example on how to derive the values.

Figure 27

If MAX TORQUE AVAILABLE is Right of GWT then MIN IAS = 0 knots

4,000 10

1.0 .94 .971 100 94 97

22,000

47

0

154

0 154

44

CRUISE SPEED (IAS/TAS)- Cruise speed is dictated by the mission or chosen by the pilot within aircraft limits. Indicated airspeed is the airspeed as shown on the airspeed indicator that has been calibrated for standard atmosphere at sea level and is uncorrected for airspeed system errors.

��

Calibrated airspeed (CAS) is the indicated airspeed corrected for position and instrument error. Calibrated airspeed would be equal to true airspeed at standard atmosphere at sea level. If desired, CAS can be found by referring to the CAS placard located in the aircraft on the left hand side of the lower console. The difference between IAS and CAS is not enough to be considered significant. As such, a note in chapter 7 of the -10 states that conversion data from KIAS to KTAS is provided directly in the cruise charts without regard for other chart information (CAS).

TAS is calibrated airspeed (equivalent airspeed is not applicable in the absence of compressibility effects) corrected for error due to density altitude. Since the airspeed indicator is calibrated for the dynamic pressures corresponding to airspeeds at sea level conditions, variations must account for air density other than standard. When determining what airspeed (dual engine) to use for the DA Form 5703-R, the cruise IAS planned for the majority of the flight should be used. This will provides the best estimate of fuel flow (burn rate) per hour. For dual-engine operation, 120 KIAS is commonly used, however this varies depending on fuel endurance requirements and aircraft configuration (i.e. ERFS).

(♦) (7) CRUISE - IAS / TAS (dual-engine). Record planned CRUISE – IAS / … (inner IAS ~ KTS scale). Enter the CRUISE chart at cruise IAS and move laterally to the outer TRUE AIRSPEED ~ KTS scale. Record dual-engine CRUISE - … / TAS.

MAX CONTINUOUS POWER Dual Engine and Single Engine- This is the most torque the engines can produce continuously and remain out of the 30 minute engine operating limitations. The aircraft will be at the top of one or more of the continuous range(s) (1) TGT 775°C (T700), TGT 851°C (T701C), (2) Ng 99%, or (3) Eng Oil Temp 135°C. As the name implies, there is no time limit on maintaining this torque. The proper way to compute this value is to enter the chart horizontally at the cruise airspeed until you intercept the continuous torque line and then read straight down for the torque. Note however, that if the continuous torque line is to the right of your aircraft GWT line, then you will be in a climb if using MAX CONT POWER while maintaining a constant airspeed. So how would you apply this torque value?

45

This continuous torque, as it is currently used, may have value to the aircrew if fuel economy was not a concern and the crew wanted to make an extended climb of several thousand feet, while maintaining a given airspeed and remaining out of any 30-minute limits. Remember that you may be in your 30-minute time limits based on engine anti-ice and heater usage. For another application, perhaps the aircrew is on an IFR flight enroute to a destination and ATC advises the crew to climb to a higher altitude. If there is more than 1,000' to climb, the pilot should climb at an optimum rate consistent with the aircraft capabilities until within 1,000' of the assigned altitude. By utilizing MAX CONT POWER, the aviator could climb at an optimum rate (not within 30-minute limits) while still maintaining the airspeed filed on the flight plan.

As previously mentioned, using MAX CONT POWER on the DA Form 5703-R for a given airspeed will make the aircraft climb, if the max continuous power line (MCP) on the chart is to the right of your aircraft GWT line. A constant climb enroute to a destination is not desirable. Although the ATM/-10 does not say to use MAX CONT POWER in this manner, perhaps a more useful application would be to obtain a continuous level airspeed, (rather than a continuous torque) which could be used in the flight planning stage, and would allow the aircrew to determine times enroute and flight plan speeds.

7.17 USE OF CHARTS.

The continuous torque available values shown represent the minimum torque available for ATFs of 1.0 with an ATF = 0.9 scale at the bottom of the torque scale. For ATFs less than 0.95 maximum continuous torque available may be slightly reduced. Higher torque than that represented by these lines may be used if it is available without exceeding the limitations presented in Chapter 5. An increase or decrease in torque required because of a drag area change is calculated by adding or subtracting the change in torque from the torque on the curve, and then reading the new fuel flow total. Both the continuous and ATF lines are slanted to the right as they move upward. With increased airspeed, the inlet of each engine will receive a larger volume of air, which results in greater efficiency and a cooler TGT, hence TGT limiting will occur at a higher torque setting.

��Use the same values used in MAX TORQUE AVAILABLE adjustments (-16% engine anti-ice (T700), -18% engine anti-ice (T701C), -4% heater). Example: You are planning a 2 hr IFR mission. You plan to use the heater and engine anti-ice but you notice that when subtracting 20/22% this will put your cruise torque in the 30-minute time limit ranges. Careful consideration by the crew must be given to the use of each of these systems on the aircraft.

As mentioned earlier, bleed air reduces torque available from the top end of MAX TORQUE AVAILABLE. Cruise and hover torque required remain

46

unaffected. Why then do we adjust MAX CONT POWER for bleed air operation? When bleed air is taken from the engines, they operate less efficiently and result in higher TGTs to produce the same amount of torque as without bleed air usage.

(♦) (8) CRUISE/CONTINUOUS TORQUE (dual-engine). Use the appropriate CRUISE chart to compute the torque required for cruise and continuous torque available as described below.

NOTE: The continuous torque available is also referred to as MAXIMUM CONTINUOUS POWER (MCP).


Step 1: Enter the CRUISE chart at the selected cruise IAS in item 7 above. Move left or right as appropriate to the aircraft GW ~ 1000 LB, item 3 (plus sling load weight, item 6, if applicable), DEPARTURE data.

Step 2: Move down to the TORQUE PER ENGINE ~ % line to read the CRUISE torque. Record the dual-engine CRUISE / … TORQUE.

Step 3: Renter the CRUISE chart at the selected cruise IAS in item 7 above. Move left or right as appropriate to the TORQUE AVAILABLE - CONTINOUS line.

Step 4: Move straight down (do not follow the slant of the line) to the TORQUE PER ENGINE ~ % to read the CONTINUOUS torque. Record the dual-engine … / CONTINUOUS TORQUE.

NOTE 1: If the selected CRUISE ~ IAS line is below the depicted TORQUE AVAILABLE – CONTINOUS line, use the torque value indicated by the lowest extreme of the TORQUE AVAILABLE ~ CONTINUOUS line.

NOTE 2: Adjust CRUISE / CONTINUOUS TORQUE for planned use of engine anti-ice and/or heater.


Step 1: Enter the appropriate CRUISE chart at the IAS in item 7 above, then move left or right as appropriate to the curved dashed line. Move up to read the ∆ TRQ ~ % FOR DRAG AREA OF 10 SQ FT OF∆ F.

Step 2: Multiply the ∆ TRQ ~ % by the drag multiplying factor.

Step 3: Add or subtract the value in step 2 to/from the uncorrected clean or high drag cruise/continuous torque values in (a) steps 2 and 4 above (do not exceed

47

the dual-engine transmission torque limit). Record the adjusted CRUISE / CONTINUOUS TORQUE.

NOTE: If the adjusted torque value exceeds the dual-engine transmission torque limit, use the dual-engine transmission torque limit and adjust cruise airspeed.

(♦) (9) CRUISE FUEL FLOW (dual-engine).

(a) Cruise chart method. Use the appropriate CRUISE chart.

Step 1: Enter the bottom of the chart at the cruise torque value computed in item 8 above.

Step 2: Move up to TOTAL FUEL FLOW ~ 100 LB/HR and read cruise fuel flow. Record the dual-engine CRUISE FUEL FLOW.

NOTE: Adjust as required for planned use of engine anti-ice and cockpit heater according to the -10.

(b) Engine fuel flow chart method. Use the SINGLE/DUAL-ENGINE FUEL FLOW chart.

Step 1: Enter the chart at the INDICATED TORQUE PER ENGINE ~ % for the cruise torque value computed in item 8 above.

Step 2: Move right to the cruise PRESSURE ALTITUDE ~ 1000 FT.

Step 3: Move up to the DUAL-ENGINE FUEL FLOW ~ LB/HR line and read cruise fuel flow. Record the dual engine CRUISE FUEL FLOW.

NOTE: Adjust as required for FAT and/or planned use of engine anti-ice and cockpit heater according to the -10.

48

The chart below is used to determine CRUISE VALUES, MAX END, MAX RANGE, MAX ALLOWABLE GW Cruise-Dual Engine and gives an example on how to derive the values. Max R/C values will be shown later.

= Cruise Values

= Max End- IAS/Torque Values

= Max Range IAS/Torque Values

= Max Allowable Gross Weight Cruise-Dual Engine/Optimum IAS at Max Allowable Gross Weight

Figure 28

para 7.17b b. Torque. Since pressure altitude and temperature are fixed for each chart, torque required varies according to gross weight and airspeed. The torque and torque limits shown on these charts are for dual-engine operation. The maximum torque available is presented on each chart as either the transmission torque limit or torque available - 30-minute for an ATF of 1.0 with an ATF = 0.9 scale at the bottom of the torque scale. The maximum torque available for helicopter with an ATF value between these shall be interpolated as depicted in Figure 7-6. The continuous torque available values shown represent the minimum torque available for ATF’s of 1.0 with an ATF = 0.9 scale at the bottom of the torque scale. For ATF’s less than 0.95 maximum continuous torque available may be slightly reduced. Higher torque than that represented by these lines may be used if it is available without exceeding the limitations presented in Chapter 5.

= Continuous Torque (MCP)

74

4,000 10

1.0 .942 .971

22,000

57 193

53

34

125

86

97

0 100 94 97 47

120

62

74

126

850

55

154

49

MAX ENDURANCE IAS/TORQUE-This is defined as the speed which yields the minimum fuel flow attainable for a specific configuration, weight, and altitude. The maximum endurance figures are the values necessary for minimum powered flight and indicate the combinations of gross weight and airspeed that will produce the maximum endurance and the maximum rate of climb. The torque required for level flight at this condition is a minimum, providing a minimum fuel flow (maximum endurance) and a maximum torque change available for climb (maximum rate of climb). The MAX ENDURANCE IAS is the airspeed where total drag is the lowest for a given combination of GWT and environmental conditions. MAX ENDURANCE IAS will allow the aircraft to fly straight and level for the longest period of time (time aloft or loiter time) due to the lowest fuel burn rate. This airspeed will produce MAX ENDURANCE only when operating at a torque value that provides level flight. This associated torque value can be derived from the cruise charts. Perhaps there is mountainous terrain to clear along the route. By entering the chart at a given airspeed, the groundspeed and estimated times enroute could be computed for flight planning purposes. The rate of climb could be computed by determining the excess power between CRUISE TORQUE and MAX TORQUE AVAILABLE for the airspeed selected (MAX TORQUE AVAILABLE minus CRUISE TORQUE). This excess torque value would allow the aviator to refer to the Climb/Descent charts in the -10 (Fig 7-33/7-34) and compute a rate-of-climb and an approximate time to reach the desired altitude. Keep in mind that as temperature and PA change during the climb, so does MAX CONT POWER as well, and/or airspeed, depending on what the aircrew is trying to maintain. MAX RANGE IAS/TORQUE-This is defined as the speed which yields the maximum nautical miles per pound of fuel for a specific configuration, weight, and altitude. The maximum range lines (MAX RANGE) indicate the combinations of gross weight and airspeed that will produce the greatest flight range per pound of fuel under zero wind conditions. When the maximum range airspeed line is above the max torque available, the resulting maximum airspeed should be used for maximum range. This is a good value to use for planning when the mission will not allow large fuel reserves between refueling stops. A method of estimating maximum range speed in winds is to increase IAS by 2.5 knots per each 10 knots of effective headwind (which reduces flight time and minimizes loss in range) and decrease IAS by 2.5 knots per 10 knots of effective tailwind for economy. This airspeed can also be used as the maximum turbulence penetration airspeed, provided it is less than Vne minus 15 knots (-10 chapter 8).

(♦) (10) MAX END - IAS / TORQUE and MAX RANGE - IAS / TORQUE. Use the appropriate CRUISE chart to compute maximum endurance indicated airspeed/torque and maximum range indicated airspeed/torque as described below.

50


Step 1: Enter the bottom of the appropriate cruise chart at AIRCRAFT GWT, item 3, DEPARTURE data. Move up along the gross weight line to the intersection of the gross weight line and the MAX END AND R/C line. Move left or right as required to the IAS ~ KTS value then read maximum endurance indicated airspeed. Record MAX END – IAS/…. Move down to the TORQUE PER ENGINE ~ % line, then read torque for the maximum endurance indicated airspeed. Record MAX END - … / TORQUE.

Step 2: Continue up along the gross weight line to the intersection of the gross weight line and the MAX RANGE line. Move left or right as required to the IAS ~ KTS value, then read maximum range indicated airspeed. Record MAX RANGE – IAS / …. Move down to the TORQUE PER ENGINE ~ % line, then read torque for the maximum range indicated airspeed. Record MAX RANGE - … / TORQUE.


NOTE 1: The torque change to compensate for drag (alternative or external load configuration) at MAX END – IAS is often negligible and not computed.

NOTE 2: Maximum range airspeed is adjusted for alternative or external load configurations as follows:

Step 1: Insert the indicated change in flat plate drag (∆F ft2) into the formula found in the -10, Chapter 7, Section IV, (6 Kts/10 ft2X∆ F ft2 = N Kts) to derive the change in maximum range IAS. See example in the -10, Chapter 7, Section IV.

Step 2: Subtract the IAS change in (b) step 1 above from (a) step 2 above. Record the adjusted MAX RANGE – IAS / ….

MAX R/C IAS/TORQUE- This is the airspeed that allows the aircraft to climb from one altitude to a higher altitude in the least amount of time when using Max Torque Available.

NOTE�Although the aircraft may be at the MAX R/C airspeed, it will only produce a maximum rate of climb if MAX TORQUE AVAILABLE is utilized. Any torque setting less than the maximum, will produce the BEST R/C performance for the power applied. Notice then that the MAX R/C airspeed will always be the lowest total drag airspeed.

As mentioned earlier, the MAX ENDURANCE IAS normally works satisfactorily for MAX R/C performance. It is now necessary for the aircrew to determine the airspeed correction. The following is a brief explanation of why MAX R/C airspeed may need to be corrected for different rates of climb.

51

There are two different pitot static systems on the UH-60A. The first type is the original, and increasingly uncommon, flush mounted pitot tubes. These can only be found on UH-60A model Blackhawks. The second type is the wedge mounted pitot tubes which rotates the tubes 20°outboard and 3° nose down. All indicated airspeeds shown on the cruise charts are based on level flight of an aircraft with the modified pitot tubes.

To minimize sensing errors, the pitot tubes are in a location and position that allows minimum disturbance of air caused by aircraft motion. An error results from climbs less than 1400 fpm and will result in a lower indicated airspeed (-10 Figures 7-36 thru 7-37). Climbs greater than 1400 fpm will result in a higher indicated airspeed. These pitot tube sensing errors occur as a result of disturbed airflow in and around the pitot tubes. Note on Figures 7-36 thru 7-37 (airspeed system correction) that autorotative airspeeds should also be corrected due to the large sink rates involved.

(♦) (11) MAX R/C - IAS / TORQUE. Use the MAX END – IAS, item 10 above, and desired torque setting as described below.

Step 1: Use the MAX TORQUE AVAILABLE dual-engine, item 4, CRUISE data. Record this value for MAX R/C - … / TORQUE. Subtract the torque value found in MAX END - … / TORQUE, item 10 above from the MAX R/C - … / TORQUE to find the TORQUE INCREASE – PER ENGINE - % TRQ.

Step 2: Use the CLIMB/DESCENT charts in the -10, Chapter 7, Section VII. Enter the bottom of the Climb/Descent chart for clean or high drag, as appropriate, at the TORQUE INCREASE – PER ENGINE - % TRQ using the value from Step 1 above.

Step 3: Move up to the GROSS WEIGHT ~ 1000 LB line from item 3 DEPARTURE data, then move left to read the RATE OF CLIMB ~ FT/MIN.

Step 4: Use the AIRSPEED SYSTEM CORRECTIONS charts in the -10, Chapter 7, Section IX. Enter the appropriate AIRSPEED SYSTEM CORRECTION chart for clean or high drag at the MAX END – IAS / … from item 10 above. Move up to the appropriate segmented line for the rate of climb value derived from Step 3 above (R/C greater or less than 1400 ft/min).

Step 5: Move left to read the CORRECTION TO ADD ~ KNOTS. Add or subtract this value to/from the MAX END – IAS / … item 10. Record the resultant MAX R/C – IAS / ….

52

The chart on the following page is used to determine Max R/C-IAS/Torque Values gives an example on how to derive the values.

OPTIMUM IAS AT MAX ALLOWABLE GWT (dual-engine).- This will provide the aircrew with an air speed value to fly level as quickly as possible to the destination, while remaining out of any 30-minute limits. This is a more practical pre-mission planning value that may prove more useful to the aviator.

(♦) (12) MAX ALLOWABLE GWT and OPTIMUM IAS AT MAX ALLOWABLE GWT (dual-engine). Use the appropriate CRUISE chart to compute the maximum allowable gross weight and optimum indicated airspeed at maximum allowable gross weight as described below.


Step 1: Enter the bottom of the CRUISE chart at the MAX TORQUE AVAILABLE, item 4, CRUISE data.

Step 2: Move up to the intersection of MAXIMUM END AND R/C line then read the indicating maximum gross weight. Record dual-engine MAX ALLOWABLE GWT. Read left or right for optimum indicated airspeed (IAS ~ KTS) at maximum allowable gross weight. Record dual-engine OPTIMUM IAS AT MAX ALLOWABLE GWT. If the maximum torque available line is right of the gross weight lines, enter maximum gross weight according to the -10, Chapter 5 limits then read left or right from the respective value for optimum indicated airspeed at that maximum allowable gross weight.

3200

Figure 29

Add 12 knots

53


NOTE: The dual-engine maximum allowable gross weight and optimum indicated airspeed at maximum allowable gross weight are adjusted for alternate or external load configuration as follows.

Step 1: Enter the CRUISE chart at the optimum indicated airspeed at maximum allowable gross weight, (a) step 2 above, then read left or right to the curved dashed line. Move up to read ∆ TRQ ~ % FOR DRAG AREA OF 10 SQ FT of ∆ F.

Step 2: Multiply the ∆ TRQ times the drag multiplying factor. Subtract the result from the maximum torque available value used initially in (a) step 1 above.

Step 3: Reenter the bottom of the CRUISE chart at the adjusted torque value then move up to the intersection of MAX END AND R/C line. Read maximum gross weight and optimum IAS at maximum allowable gross weight. Record the adjusted dual-engine MAX ALLOWABLE GWT and OPTIMUM IAS AT MAX ALLOWABLE GWT. If the adjusted torque value is right of the gross weight lines, enter maximum gross weight according to the -10, Chapter 5 limits then read left or right from the respective value for optimum indicated airspeed at that maximum allowable gross weight.

SINGLE-ENGINE DATA SINGLE-ENG MIN / MAX Vh – IAS (single-engine) This is a very important block, but unfortunately, it often receives very little attention by aircrews. For example, a rapid application of collective from flight lead in a multi-ship is great example of this. Engine failures are uncommon in the Blackhawk, but the consequences can be undesirable and even unavoidable during certain flight modes. Quick application of these values will often make the difference between flying away to a safe landing, or merely extending your glide path to the crash sight. Keeping your airspeed between these two values in a single-engine situation is critical! MIN SE IAS is the minimum airspeed possible without losing altitude during single-engine operation. At the MIN SE IAS, the aircraft would be operating at maximum torque available 30-minutes and TGT (2.5 min for L model) would be at the limiter. Remember that if the derived airspeed is less than 40 KIAS, indicated airspeed would be unreliable (-10 chapter 7) and perhaps unreadable. There are some modifying variables that will affect operation at or below this value. They will be discussed after a basic explanation of minimum and maximum values. The MIN SE IAS can be applied not just for cruise flight, but also for takeoffs and landings. MAX SE IAS is the maximum airspeed possible without losing altitude with a single engine operating. If the derived maximum airspeed exceeds 130 KIAS, use 130 KIAS (max chapter 5 airspeed for one engine operative). If at the MAX

54

SE IAS, the aircraft would be operating at maximum power available 30-minute and TGT would be at the limiter. If the aircraft is operating above the MAX SE IAS value when an engine fails, rotor-droop will occur quickly. Delayed pilot reaction slowing the aircraft down will result in rotor bleed-off and altitude loss. It is a good technique not to operate low-level above the MAX SE IAS, due to minimal altitude available to recover in the event of slow engine failure recognition and/or reaction time by the aircrew! Remember, rotor RPM has already begun to decay by the time the low-rotor audio activates (RPM < 96%), and even the sharpest aircrew may not be able to respond in time. It’s important to note two significant areas with respect to this block. First, remember that the accuracy of these values depends on which engine becomes inoperative. These figures are based on the lowest ETF engine operating and at takeoff GWT. If the lowest ETF engine is the one that fails, then the figures will be conservative. The stronger engine will power the aircraft through a larger speed range. This speed range will also widen as fuel is consumed during the mission and the aircraft becomes lighter. Secondly, both the minimum and maximum airspeeds are based on cruise PA and temperature. As such, the airspeeds are for OGE altitudes. Don't assume that flight is not possible below the minimum single-engine airspeed. If operating IGE, airspeeds below the minimum single-engine airspeed, and/or hovering flight may be possible. After completing a few drag corrections for MIN/MAX SE IAS, an interesting problem may occur. Referring to Figure 30, notice that after correcting for drag, the CRUISE TORQUE section indicates that the sling load can be flown single-engine at 80 KIAS. The sling load requires an additional 8% torque to overcome the drag (82 + 8= 90%). This is less than the 98% MAX TORQUE AVAILABLE that is available for the weakest engine (No. 1).

2,000 15

.932 1.0 .965

98 105 101

22,000

49

0 154

54 86

830 64 34

125 57

75 97

105 80 89

505

20,300

NA NA

57 193

120 127

69

19,200

70

34

Figure 30

72

90

T/O GW- 17, 000 3,000 lb sling ∆F= 16 DMF 16

82 85

70

55

Notice also that the actual T/O GWT (17,000 lbs) is less than the MAX ALLOWABLE GWT- SE after a correction for drag (19,200 lbs). This also indicates that the aviator should be able to fly single-engine with the sling load. The inconsistency is found in the MAX SE IAS value. Notice in the example that after the drag correction is made, a value of 69 KIAS was obtained for MAX SE IAS. This "maximum" value is less than the 80 KIAS cruise that we earlier determined to be achievable with the sling load. This does not always occur, but can depending on conditions. In some situations, a MAX SE IAS is not even obtainable for drag, even though a CRUISE IAS was. The problem arises due to the different methods by which drag is determined between the CRUISE TORQUE and MAX SE IAS values. Remember the important principle that total drag increases as airspeed increases above MAX ENDURANCE IAS. There is a direct correlation between the two. Therefore, if the cruise chart is entered at a higher airspeed value, the resulting total drag will be larger. This is key to understanding the problem. The drag correction for the CRUISE SE airspeed of 80 KIAS was accurate because the 80 KIAS that the drag was derived from is an airspeed that could be obtained with the sling load. There was enough torque available to overcome the drag and obtain 80 KIAS. Therefore, the drag used correlated to the correct airspeed. Contrast the above method with MAX SE IAS. The bottom of the chart is entered at half of the lowest MAX TORQUE AVAILABLE single-engine (49% in the example). Trace 49% torque vertically on the chart to the second Intersection of the GWT line (17,000 lbs) and trace horizontally to read MAX IAS clean and the torque adjustment for drag. The way to correct for this problem with MAX SE IAS is by trial and error. Begin by choosing an airspeed that might be obtainable, then start "bracketing down" if the airspeed is too high (requires more power than MAX TORQUE AVAILABLE to achieve), or "bracketing up" if the airspeed is too low (requires less power than MAX TORQUE AVAILABLE to achieve). Eventually, a maximum airspeed can be found that works. If the torque required is equal to or less than the MTA, the airspeed value can be obtained with drag. Also consider Min/Max Vh-IAS when you are conducting external loads. In summary, single-engine cruise speed of 80 KIAS was obtainable with a sling load. The 90% torque required to fly 80 KIAS was less than the MAX TORQUE AVAILABLE single-engine (No. 1) of 98%. Since there was 8% more torque available than was necessary, the "bracketing down" method was used, by beginning with a higher IAS of 100 KIAS. After computation, 100 KIAS required too much torque (106%). 95 KIAS required too much torque (104%), but was closer to the 98% MAX TORQUE AVAILABLE that would power the aircraft in level flight. Finally, 90 KIAS required 96% torque, just below the lowest MAX TORQUE AVAILABLE single-engine and would therefore be the actual MAX IAS SE. A speed of 90 KIAS should be entered on the DA Form 5703-R in place of

56

the 69 KIAS previously recorded. Refer once again to Figure 31 below for an example of the bracketing method.

(♦) (13) MIN / MAX Vh – IAS (single-engine). Use the appropriate CRUISE chart to compute the minimum/maximum Vh indicated airspeeds single-engine, as described below.


Step 1: Enter the bottom of the CRUISE chart at one-half the maximum torque available for the low ETF engine, item 4 above, but no more than one-half of transmission torque limit single-engine.

Step 2: Move up to the first intersection of the AIRCRAFT GWT, item 3, DEPARTURE data then read left or right for minimum Vh IAS ~ KTS. Record the single-engine MIN / … Vh – IAS.

Step 3: Continue up to the second intersection of the AIRCRAFT GWT, item 3, DEPARTURE data then read left or right for maximum Vh IAS. Record the single-engine … / MAX Vh – IAS.

NOTE: If the maximum torque available line is to the left of (does not intersect) the AIRCRAFT GWT, item 3, DEPARTURE data, the aircraft cannot maintain single-engine level flight for the conditions. Item 18 must be computed. As fuel is burned, single-engine capability during the flight may be possible.

- 1st Try - 100 KIAS �Cruise TRQ- 46 x 2= 92% SE Clean �4% σ TRQ x 1.6 DMF = 6.4% to overcome drag. Rounded to 7.0 �46 + 7= 53% Double to 106% SE Only have 98% available. TOO FAST.

- 2nd Try - 95 KIAS �Cruise TRQ- 45 x 2= 90% SE clean �4% σ TRQ x 1.6 DMF = 6.4% to overcome drag. Rounded to 7.0 �45 + 7= 52% Double to 104% SE Only have 98% available. TOO FAST.

- 3rd Try - 90 KIAS �Cruise TRQ- 43 x 2= 86% SE clean �3.1% σ TRQ x 1.6 DMF = 4.96% to overcome drag. Rounded to 5.0 �43 + 5= 48% Double to 96% SE 98% is available. 90 KIAS is the MAX IAS SE with the Sling Load.

2,000 15

.932 1.0 .965 98 105 101

22,000

49 0

120 127

Figure 31

154

54 86

63 34

75 97

74

105

82/ 90

505

20,300/ 19,200

72

60

N/A NA

85

830

125 57

34

80/ 90 89

57 193

57


NOTE 1: The torque change to compensate for drag (alternative or external load configuration) at minimum Vh IAS is often negligible and not computed.

NOTE 2: The maximum Vh indicated airspeed, single-engine, is adjusted for alternate or external load configuration as follows:

Step 1: Enter the CRUISE chart at maximum Vh IAS ~ KTS, (a) step 3, above, then move left or right to the curved dashed line. Move up to read ∆ TRQ ~ % FOR DRAG AREA OF 10 SQ FT of ∆ F.


Step 3: Reenter the bottom of the CRUISE chart at one-half the adjusted torque value and move up to the second intersection of the AIRCRAFT GWT, item 3, DEPARTURE data. Read left or right for maximum Vh IAS. Record the adjusted single-engine .../MAX Vh – IAS.

SINGLE-ENGINE CRUISE SPEED-In determining single-engine cruise speed, the aviator has the option of choosing any speed that falls within the MIN/MAX SE speed range. The aviator may wish to consider using at least 80 KIAS or higher. The -10 manual recommends 80 KIAS for autorotation. Speeds below 80 KIAS would not ensure that sufficient airspeed was available to arrest the aircraft rate of descent, should the other engine become inoperative (-10 para 9.12). Autorotative decelerations initiated at speeds below 80 KIAS will most likely result in aircraft damage. If the airspeed is below 80 KIAS then maybe think about accelerating to 80 KIAS during an autorotation. Although it is not always possible, single-engine cruise airspeed should be chosen that would maintain cruise flight at or below continuous torque available single-engine. Torque above the continuous value will be limited to 30, 10 or 2.5 minute limits. CRUISE TORQUE- This is the torque required to maintain the Cruise Speed (IAS/TAS) that the aircrew selects for the mission. When correcting for drag, the additional torque required to overcome the drag will be added to the clean torque value to ensure that the cruise speed can be maintained. For single-engine drag correction, be sure to first add the torque correction to the dual-engine torque before doubling the value, not after.

58

CRUISE FUEL FLOW- This is the predicted fuel flow (burn rate) that the aircraft should have at CRUISE TORQUE. Note that the cruise fuel flow requires a relatively constant torque setting to be accurate. Aircraft flying in the rear of formations typically consume 50 to 100 pph more than predicted. This will vary depending on formation size and aircrew proficiency in maintaining slot positions. Don’t get caught short on multi-ship missions!

��

�

a. Eng Anti-Ice On.…About 60 lbs/hr a. Engine anti-ice on…. About 100 lbs/hr.

b. Heater On.............About 20 lbs/hr b Heater on ……………About 12 lbs/hr

c. Both On................About 80 lbs/hr c Both on……………….About 112 lbs/hr

For single-engine fuel flow, reduce dual-engine values by one-half (-10 chapter 7). In addition, when an IR suppressor system is installed and the baffles removed, the dual-engine fuel flow will decrease about 16 lbs/hr, 8 lbs/hr single-engine (T700). The dual engine fuel flow will decrease about 14 lbs/hr(T701C) The decrease in exhaust back pressure improves engine efficiency.

(♦) (14) CRUISE SPEED – IAS / TAS (single-engine). Select an IAS that falls within the range of MIN / MAX Vh – IAS, item 13 above. Convert to TAS as described in item 7 above.

(♦) (15) CRUISE/CONTINUOUS TORQUE (single-engine). Use the appropriate CRUISE chart to compute torque required for cruise and continuous torque (single-engine), as described below.

(a) Clean and High Drag configuration.

Step 1: Enter the CRUISE chart at the selected single-engine cruise IAS, item 14 above. Move left or right as appropriate to the aircraft GW ~ 1000 LB, item 3, DEPARTURE data.

Step 2: Move down to the TORQUE PER ENGINE ~ % line to read the CRUISE torque, then double the torque value. Record the single-engine CRUISE/… TORQUE.

Step 3: Reenter the CRUISE chart at the selected CRUISE – IAS in item 14 above. Move left or right as appropriate to the TORQUE AVAILABLE - CONTINOUS line.

59

Step 4: Move straight down (do not follow the slant of the line because the new cruise charts are corrected for ram-air) to the TORQUE PER ENGINE ~ % to read the CONTINUOUS torque. Record the single-engine …/CONTINUOUS TORQUE. .

NOTE 1: If the selected CRUISE ~ IAS line is below the depicted MAX CONTINUOUS POWER line, use the torque value indicated by the lowest extreme of the~ MAX CONTINUOUS POWER line.

NOTE 2: Adjust CRUISE / CONTINUOUS TORQUE for planned use of engine anti-ice and/or heater.


Step 1: Enter the appropriate CRUISE chart at the selected single-engine cruise IAS in item 14 above the move left or right to the curved dashed line. Move up to read the ∆ TRQ ∆ % FOR DRAG AREA OF 10 SQ FT OF ∆ F.

Step 2: Multiply the ∆ TRQ ∆ % by the drag multiplying factor.

Step 3: Add or subtract the value in step 2 to/from the uncorrected clean or high drag cruise/continuous torque values in (a) steps 2 and 4 above, then double the torque value (do not exceed the single-engine transmission torque limit). Record the adjusted single-engine CRUISE / CONTINUOUS TORQUE.

NOTE: If the adjusted torque value exceeds the single-engine transmission torque limit, use the single-engine transmission torque limit and adjust cruise airspeed.

(♦) (16) CRUISE FUEL FLOW (single-engine).

(a) Cruise chart method. Use the appropriate CRUISE chart.

Step 1: Enter the bottom of the chart at the torque value computed in item 15 above.

Step 2: Move up to TOTAL FUEL FLOW ~ 100 LB/HR and read the cruise fuel flow.

Divide the cruise fuel flow value in half. Record the single-engine CRUISE FUEL FLOW.

NOTE: Adjust as required for planned use of engine anti-ice and cockpit heater according to the -10.

60

(b) Engine fuel flow chart method. Use the SINGLE/DUAL-ENGINE FUEL FLOW chart.

Step 1: Enter the chart at the INDICATED TORQUE PER ENGINE ~ % for the cruise torque value computed in item 15 above.

Step 2: Move right to the cruise PRESSURE ALTITUDE ~ 1000 FT.

Step 3: Move down to the SINGLE-ENGINE FUEL FLOW ~ LB/HR line and read fuel flow value. Record the single-engine CRUISE FUEL FLOW.

NOTE: Adjust as required for FAT and/or planned use of engine anti-ice and cockpit heater according to the -10.

MAX ALLOWABLE GWT-SINGLE ENG- This is the maximum weight that one engine is capable of powering in level flight. As mentioned before, this weight is based on the weaker of the two engines available. Pay particular attention to whether you will be operating dual engine at weights above this value. If flying at a weight above MAX ALLOWABLE GWT- SE, an engine failure will force a controlled decent and landing with power or executing a descent to a lower altitude, if RPM R is to be maintained in the normal range. Flying above MAX ALLOWABLE GWT- SE should be identified in the risk management process. If the flight is over water or heavily wooded and/or mountainous terrain, such conditions increase the risk involved with a forced landing. If it isn't an operational necessity, avoid this situation. Consider adding another aircraft to the mission to distribute the load. ERFS operations will commonly cause the aircraft to operate above the MAX ALLOWABLE GWT-SINGLE ENG value for high drag configuration (external tanks attached). This cannot be avoided and increases the risk during single-engine situations. Aircrews may have little choice but to jettison the external tanks (or any external loads for that matter) in order to maintain single-engine flight. As a technique, if the aircraft has to operate above the MAX ALLOWABLE GWT-SINGLE ENG value for high drag configuration, the crew can determine the necessary amount of fuel, which needs to be consumed in order to lower the aircraft GWT below the MAX ALLOWABLE GWT-SINGLE ENG value. As a technique, use your zero fuel weight value and the approximate time it will be reached during the flight profile (hours and minutes after takeoff) can be noted and recorded in the remarks section of the DA Form 5703-R. This will heighten aircrew awareness of aircraft capabilities and hopefully reduce reaction time based on the flight profile.

(♦) (17) MAX ALLOWABLE GWT and OPTIMUM IAS AT MAX ALLOWABLE GWT (single-engine). Use the appropriate CRUISE chart to compute the maximum allowable gross weight, and optimum indicated airspeed at maximum allowable gross weight, single-engine, as described below.

61


Step 1: Enter the bottom of the CRUISE chart at one-half the single-engine MAX TORQUE AVAILABLE, item 4, CRUISE data, for the low ETF engine, but no more than one-half of transmission torque limit single-engine.

Step 2: Move up to the intersection of MAX END AND R/C line then read the indicating maximum allowable gross weight. Record the single-engine MAX ALLOWABLE GWT. Read left or right for optimum IAS ~ KTS at maximum allowable gross weight. Record the single-engine OPTIMUM IAS AT MAX ALLOWABLE GWT.

NOTE: If the torque used does not intersect aircraft gross weight, the aircraft cannot maintain single-engine level flight for the conditions. Item 18 must be computed. As fuel is burned, single-engine capability during the flight may be possible.


NOTE 1: The single-engine maximum allowable gross weight and optimum indicated airspeed at maximum allowable gross weight are adjusted for alternate or external load configuration as follows:

Step 1: Enter the CRUISE chart at the optimum indicated airspeed at maximum allowable GWT, step 2 above. Read left or right to the curved dashed line then move up to read ∆ TRQ ~ % FOR DRAG AREA OF 10 SQ FT of ∆ F.


Step 3: Reenter the bottom of the CRUISE chart at one-half the adjusted torque value then move up to the intersection of MAX END AND R/C line. Read maximum allowable gross weight and optimum IAS at maximum allowable gross weight. Record the adjusted single-engine MAX ALLOWABLE GWT and OPTIMUM IAS AT MAX ALLOWABLE GWT.

NOTE 2: If the adjusted torque value does not intersect the AIRCRAFT GWT, item 3, DEPARTURE data, the aircraft cannot maintain single-engine level flight for the conditions. Item 18 must be computed. As fuel is burned, single-engine capability during the flight may be possible.

62

The chart below is used to determine Single Engine Values and gives an example on how to derive the values.

(♦) (18) MAX ALTITUDE – MSL. When cruise flight, dual and/or single-engine, is not possible at the planned cruise pressure altitude, item 1, CRUISE data, use the appropriate CRUISE chart to compute the maximum altitude MSL as described below.

NOTE: Several different cruise charts may be referenced when selecting an optimum maximum cruise altitude, using a variety of temperature, altitude, aircraft gross weight and cruise IAS combinations.

4,000 10

1.0 .942 .971

100 94 97

22,000

47

120 127 154

54 86

830

63 34 125 57

75 97

74

19 111

80 89 72 85 505

19,500

72

60

57 193

NA N/A

0

= Single Engine Cruise Values

= Single Engine Optimum IAS at MAX Allowable GWT-SE

Values

= Single Engine Continuous TRQ Values

Figure 32

63

(a) Dual-engine.

Step 1: Enter the appropriate cruise chart at the maximum torque available for that chart. Move up to the second intersection of the aircraft gross weight, item 3, DEPARTURE data.

Step 2: Move left or right to read the IAS ~ KTS. If the indicated IAS ~ KTS is less than the planned cruise IAS, adjust planned temperature, altitude, IAS and/or gross weight combinations to find a suitable cruise altitude. Record the dual-engine MAX ALTITUDE – MSL.

(b) Single-engine.

NOTE 1: When the capability to maintain level flight after an engine failure or malfunction is not possible, continued flight may be possible by descending to a lower pressure altitude. Adjust to the appropriate maximum endurance indicated airspeed and adjust collective to the maximum torque available to attain minimum rate of descent as required.

Step 1: Enter the appropriate CRUISE chart at one half of the single-engine MAX TORQUE AVAILABLE, item 4, CRUISE data, of the lowest ETF engine.

Step 2: Move up until intersecting the MAX END AND R/C line and interpolate the maximum gross weight. If the interpolated maximum gross weight is less than the aircraft gross weight, item 3, DEPARTURE data, progressively use lower altitude/temperature combination CRUISE charts until interpolated gross weight is at or greater than the aircraft gross weight. Record the single-engine MAX ALTITUDE – MSL.

WARNING

If allowable altitude/temperature combination cruise charts do not yield a gross weight greater than/or equal to the AIRCRAFT GWT, item 3, DEPARTURE data, level flight is not possible. Record NA in item 18.

NOTE 2: Changes in maximum torque available due to changes in pressure altitude and temperature may be derived from the -CL tabular performance data.

EMERGENCY SE-IAS- Do not confuse single-engine cruise speed with emergency single-engine airspeed. The emergency single-engine airspeed is the speed used immediately following an emergency that requires adjustment to a single-engine airspeed. Single-engine cruise speed and associated data is used in the pre-mission planning process. In the event an engine fails, malfunctions or must be shut down, and single-engine operations are possible but landing is not practical (such as over water, jungle, densely forested areas, mountainous terrain or other impractical landing areas), the single-engine cruise speed may

64

be used after establishing emergency single-engine speed when required to reach the intended landing area. The single-engine cruise speed may, in some instances, equal the emergency single-engine speed.

(♦) (19) EMERGENCY SE – IAS. This value is the emergency single-engine airspeed based on the mission and briefed to the crew for the purpose of crew coordination. This airspeed is selected from the MIN / MAX Vh - IAS range computed in item 13, CRUISE data and is used immediately following an emergency that requires adjustment to a single-engine airspeed. When an aircraft does not have single-engine capability, the MAX END - IAS, item 10, or the OPTIMUM IAS AT MAX ALLOWABLE GWT, item 17, as appropriate, should be briefed as the emergency single-engine airspeed.

NOTE 1: Normally only one EMERGENCY SE – IAS is selected. However, when the MIN / MAX Vh – IAS range, item 13, is wide, the crew may select two emergency single engine airspeeds, one slow and one fast based on mission profile, modes of flight, environmental conditions or other factors.

NOTE 2: There is no power margin available when operating single-engine at the MIN / MAX Vh - IAS, item 13. These airspeeds are computed using the maximum torque available single-engine for the lowest ETF engine. It is not recommended that the aircraft be flown at airspeeds that require maximum power for continued single-engine flight.

VELOCITY NEVER TO EXCEED (Vne)- The maximum permitted airspeed as a function of temperature, PA, and aircraft weight. This airspeed cannot be obtained in level flight. The aircraft will have to be in a dive/descent to achieve this speed. Exceeding this airspeed may cause the aircraft to encounter the effects of retreating blade stall, compressibility, and/or aircraft structural damage. Chapter 5 of the -10 states that retreating blade stall has not been encountered in one G flight up to the airspeeds shown on the Vne chart. Note that retreating blade stall may be encountered at airspeeds much less than Vne when maneuvering. MAX ANGLE- Item b of the same paragraph discusses the application of Figure 5-8, which is used to determine airspeed/angle of bank combinations that will likely produce blade stall. While the airspeed/angle of bank chart is not an aircraft limitation, the -10, expressly prohibits any maneuvering which results in severe blade stall and a significant increase in 4 per revolution vibration. Compressibility is given consideration by referring to Figure 5-9 in the -10. Note that any airspeed below the dashed lines labeled "mach limits" could result in compressible flow over the advancing blades. Note that this should not be a problem for temperatures above -10°C. Lastly, aircraft structural damage and/or component failure is a possible outcome if the aircraft exceeds Vne during flight.

65

If Vne minus 15 knots is less than MAX RANGE airspeed, it will be the recommended maximum turbulence penetration airspeed for moderate turbulence (-10 chapter 8). The 15-knot speed subtraction from Vne reduces the likelihood of the pilot exceeding Vne due to airspeed fluctuations associated with turbulence.

(♦) (20) MAX ANGLE. Use the AIRSPEED FOR ONSET OF BLADE STALL chart in the -10, Chapter 5, to compute the maximum bank angle for the planned cruise IAS as described below.

Step 1: Enter the chart at the cruise PRESSURE ALTITUDE ~ 1000 FT. Move right to the cruise temperature FAT ° C.

Step 2: Move down to the aircraft GROSS WEIGHT ~ 1000 LBS, item 3 (plus sling load weight, item 6, if applicable), DEPARTURE data then move left to the ANGLE OF BANK ° DEG chart.

Step 3: Reenter the chart at the INDICATED AIRSPEED ~ KTS at the planned cruise airspeed, item 7 above, then move up to the ANGLE OF BANK ° DEG chart. Record derived MAX ANGLE or 60° whichever is less.

(♦) (21) Vne - IAS. Use the appropriate AIRSPEED OPERATING LIMITATIONS chart of the -10, Chapter 5, to compute the velocity not to exceed as described below.

Step 1: Enter the chart at the cruise FREE AIR TEMPERATURE ~ ° C. Move right to the cruise PRESSURE ALTITUDE ~ FT.

Step 2: Move down to the aircraft GROSS WEIGHT ~ LBS, item 3 (plus sling load weight, item 6, if applicable), DEPARTURE data. If the COMPRESSIBILITY LIMITS ~ FAT or the MACH LIMIT dashed temperature line (-10 to -50° C) is reached prior to the aircraft GROSS WEIGHT ~ LBS, stop there.

Step 3: Move left to the MAXIMUM INDICATED AIRSPEED (VNE) ~ KNOTS line for the Vne value. Record Vne-IAS.

66

The chart on the following page is used to determine MAX ANGLE and Vne-IAS and gives an example on how to derive the values.

Figure 33

193

4,000 10

1.0 .942 .971

100 94 97

22,000

47 0

120 127 154

54 86 830

63 34

125 57

75 97

74

19 111

80 89 72 85

505

19,500 72

57 193

57

NA NA

60

67

ARRIVAL

(♦) ARRIVAL. Complete this section if arrival conditions at destination differ significantly from departure conditions as defined in paragraph 2b above.

(♦) (1) PA. Record forecast pressure altitude for time of arrival. If unavailable, use maximum forecast pressure altitude for the mission.

(♦) (2) FAT. Record forecast temperature for time of arrival. If unavailable, use maximum forecast temperature for the mission.

(♦) (3) LANDING GWT. Record the estimated gross weight for arrival.

(♦) (4) TR. Compute the torque ratios for dual- and single-engine the same as item e(8), DEPARTURE data, using arrival temperature and pressure altitude.

(♦) (5) MAX TORQUE AVAILABLE. Compute maximum torque available for dual- and single-engine the same as item e(9), DEPARTURE data, using arrival forecast pressure altitude and temperature.

NOTE 1: Adjust as required for planned use of engine anti-ice and/or cockpit heater according to the -10.

NOTE 2: This information can also be derived from the tabular performance data in the -CL.

(6) PREDICTED HOVER TORQUE. Compute the predicted hover torque the same as item e(13), DEPARTURE data, using arrival forcast pressure altitude and temperature.

(7) MAX ALLOWABLE GWT OGE/IGE. Compute the maximum allowable gross weight the same as item e(10), DEPARTURE data, using arrival forecast pressure altitude and temperature.

(8) MAX HOVER HEIGHT IGE. If OGE capability does not exist, compute the maximum hover height IGE the same as item e(12), DEPARTURE data, using arrival forecast pressure altitude and temperature.

(9) MIN SE – IAS - W/O STORES / W/STORES. Compute the minimum single-engine airspeed with external stores and without

68

external stores the same as item e(14), DEPARTURE data, using arrival forecast pressure altitude and temperature.

See Figure 37 Sample UH-60 Performance Planning Card (back).

DES CLARIFICATION: DYNAMIC INFLIGHT UPDATES The new DA Form 5703-R task and DA Form DA Form 5703-R was developed to aid in increasing power management/power available awareness. One of the critical components of this philosophy is the “Dynamic In-flight Update”. To complete the update, tabular data must be used IAW standard 7 from Task 1004, Prepare a Performance Planning Card. IAW TC 1-212 this update is required to be completed when operating within 3000 lbs of Maximum Allowable Gross Weight (OGE) and there is an increase of 500 feet pressure altitude and/or 5 degrees C from the planned DA Form 5703-R. In order to ensure that all pilots are proficient in this task, the “Dynamic In-flight Update” must be accomplished during RL progression training, annual ATP evaluations, and when required during other training and evaluations. A technique for completion would require the IP to give a simulated mission change that meets the requirements of TC 1-212, Task 1004, Prepare a Performance Planning Card, section h, Updates.

(♦) UPDATES- The DA Form 5703-R may be updated in flight or on the ground as the mission progresses. Updates are required when there is an intent to land and/or takeoff and when operating within 3,000 pounds of the MAX ALLOWABLE GWT (OGE), there is an increase of 500-feet pressure altitude, and/or 5 ° C from the planned DA Form 5703-R.

(1) AIRCRAFT WEIGHT. Update the aircraft weight as described below.

(a) When internal and/or external load weights have not changed. Add the total remaining indicated fuel weight (internal/external) to the zero fuel weight computed, item 15, DEPARTURE data.

(b) When internal and/or external load weights have changed. Perform a hover check to determine a readjusted zero fuel weight as described in item e. (15), DEPARTURE data.

NOTE: The tabular performance data in the back of the -CL will be used for the following computations.

(2) MAX TORQUE AVAILABLE. Use the appropriate tabular performance data Maximum Torque Available table as described in Figure 35.

69

Step 1: Enter the table at the appropriate HP∼ FT (pressure altitude) and move right to the ATF 1.0 or 0.9 value as required.

Step 2: Continue right to the appropriate FREE AIR TEMPERATURE ° C column. Read MAX TORQUE AVAILABLE.

NOTE 1: See tabular performance data examples in Figure 35.

NOTE 2: The ATF’s shown on the chart are 1.0 and 0.9. If the aircraft has an ATF between these values, interpolation is required.

(3) MAX ALLOWABLE GWT OGE. Use the appropriate Maximum OGE Hover Weight and Torque Required table as described below.

Step 1: Enter the table at the appropriate HP ∼ FT (pressure altitude) and move right to the GW ∼ 100 LB line.

Step 2: Continue right to the appropriate FREE AIR TEMPERATURE ∼ ° C column. Multiply the indicated value by 100 to determine the MAX ALLOWABLE GWT OGE.

Step 3: Move down to Q ~ OGE ~ % line. Read torque required to hover OGE, at the MAX ALLOWABLE GWT OGE.

NOTE : See tabular performance data examples below.

(4) GO/NO-GO OGE. Use the appropriate Maximum OGE Hover Weight And Torque Required table as described below.

Step 1: Enter the table at the appropriate HP∼ FT (pressure altitude) and move right to the Q ∼ IGE ~ % line.

Step 2: Continue right to the appropriate FREE AIR TEMPERATURE ∼ ° C column. Read the GO/NO-GO OGE torque value. This is also the torque required to hover IGE, at the MAX ALLOWABLE GWT OGE.

NOTE: See tabular performance data examples in Figure 36.

i. Tabular Performance Data. The following examples are provided to explain the tabular performance data presented in the -CL.

It is important to remember that when flying to a higher altitude or higher temperature destination, the aircrew will have to check the GO/NO-GO torque at the departure point before leaving. This will ensure that the aircraft is not above the MAX ALLOWABLE GWT for the arrival destination. Do not use the GO/NO-GO value in the departure section of the DA Form 5703-R to determine if hover capability exists at your destination.

70

Failure to use the correct values in this situation could result in the pilot running out of power, ideas, and altitude all at the same time because the aircraft is above MGWT! Refer to Figure 34 below for an example of this situation. If the aircrew was going to fly to a pinnacle (which is 6,000 feet MSL), and the departure point elevation is 2,000' MSL, the MAX ALLOWABLE GWT that the aircraft can lift will be significantly less at the higher altitude (750 lbs less). The GO/NO-GO block on the DA Form 5703-R reflects departure data, which will not be correct for the destination. If the aircrew used departure data to determine the GO/NO-GO (normal method), then the wrong MAX ALLOWABLE GWT (19,500 lbs) would be verified, rather than the MAX ALLOWABLE GWT for the destination (18,750 lbs). Accurate DA Form 5703-R completion and interpretation is critical to safe and successful mission accomplishment. Regular use of this information will enable the aircrew to receive maximum safe utilization of the helicopter and provide a basis for a sound foundation in performance planning. Compute a GO/NO-GO for the departure airfield using this GWT (19,000 lbs) at departure conditions (2000' PA and 32°C FAT). The aircrew must ensure that they are at or below this GO/NO-GO (78%) before leaving for the destination.

Figure 34

71

The charts in figure 35 and 36 are used to determine Tabular Performance Data and give an example on how to derive the values.

Figure 35 Maximum torque available chart.

72

Figure 36- Maximum OGE hover weight and torque required chart.

73

DA FORM DA Form 5703-R (Back)

Figure 37-. Sample UH-60 Performance Planning Card (back).

74

HIGH DRAG COMPUTATIONS

+2000 +20 193

.956 1.0 .912

101 105 97 48

100 105 80 87

42 83 72 83

760 520

63 129

75

20,000

73

80

* *

* *

*

*

* * *

*

* 16 N/A

22,000

75

60º

34

60

100

N/A 10,000 N/A 10,000

((112255))

(151)

157 ((110066))

(45)

(790)

112

(75)

(535)

(19,750) (72)

(N/C)

(N/C)

*

* *

Figure 38

The information below is used to determine the External Load Drag for use With Clean Cruise Chars and gives an example on how to derive the values.

FFoorr eevveerryy 1100 ssqq fftt ooff ffllaatt ppllaattee ddrraagg,, 66 kkttss mmuusstt bbee ssuubbttrraacctteedd ffrroomm tthhee MMaaxxiimmuumm RRaannggee AAiirrssppeeeedd..

OORR ""BBNN"" BBiigg NNuummbbeerr ffrroomm cchhaarrtt oonn ppaaggee 77--114477 xx 66kkttss//1100fftt22 ((sseeee nneexxtt lliinnee)) BBNN xx 66kkttss//1100fftt22 == RReedduuccttiioonn iinn MMaaxx RRaannggee AAiirrssppeeeedd

66((BBNN)) xx 00..66 == 33..66 129 129 -- 3.6 = 125.43.6 = 125.4

New Max Range A/S = 125New Max Range A/S = 125DO THEN ROUNDDO THEN ROUND129 129 -- 3.6 = 125.43.6 = 125.4

New Max Range A/S = 125New Max Range A/S = 125DO THEN ROUNDDO THEN ROUND

TTMM 11--11552200--223377--1100 pp77--1144 77..1177ff

*=indicates values required to be recomputed for high drag

75

The chart below is used to determine the External Load Drag for use With Clean Cruise Chats and gives an example on how to derive the values.

UUssee tthhiiss CChhaarrtt TToo AAttttaaiinn tthhee DDMMFF ffoorr aann EExxtteerrnnaall LLooaadd

BBiigg NNuummbbeerr--BBNN

FFiigguurree 77--3311.. EExxtteerrnnaall LLooaadd DDrraagg

22

2200

LLiittttllee NNuummbbeerr--LLNN

PPaaggee 77--114488

Figure 39

76

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��

�� ! �" � �� #��$ %��%��

��a. Both cargo doors open b. Cargo doors removed c. Cargo mirror installed d. IR Countermeasure Transmitter (ALQ-144) installed e. Chaff Dispenser installed f. HIRSS not installed g. Flare Dispenser

Big Number-BN Little Number-LN

PPaaggee 77--114477 Figure 40

��6.0 4.0 0.3 0.8 0.3 -2.2 0.3��

0.60 0.40 0.30 0.08 0.03 -0.22 0.03

77

�� TTRRQQ -- %% FFOORR DDRRAAGG AARREEAA OOFF 1100 SSQQ FFTT �� F

DLVDLV157 = 19157 = 19112 = 6112 = 6100 = 4100 = 480 = 280 = 275 = 2 75 = 2 73 = 273 = 2

LNLN0.60.60.60.60.60.60.60.60.60.60.60.6

xxxxxxxxxxxxxx

== ��TQ TQ = 11.4= 11.4= 3.6= 3.6= 2.4= 2.4= 1.2= 1.2= 1.2= 1.2= 1.2 = 1.2

DDootttteedd LLiinnee VVaalluuee ((DDLLVV)) oorr ��FF

110000 == 44

8800 == 22

111122 == 66

7733 == 22

7755 == 22

115577 == 1199 30ºC

CRUISE 2000FT T700

CRUISE CLEAN CONFIGURATION PRESS ALT : 2000 FT

Page 7-44

Once you have these torque values re-enter the cruise charts at the adjusted values IAW TC 1-212.

Figure 41

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