Stabilized Landing Concept - NBAA · Stabilized Landings - Charbonneau CASS 2010 4 4 Major...

Stabilized Landings - Charbonneau CASS 2010

1

Stabilized Landing

Concept

A Runway Excursion Prevention Tool

NBAA 2010


2

2

Steve CharbonneauAltria Client Services IncSr. Manager Aviation Safety and Security

[email protected]

804-218-9165

Located in Richmond, Virginia

Operate:1 G5502 G450


3

3

Introduction

Stabilized Approach Criteria has successfully elevated the in-cockpit awareness of risky approachesPrograms such as FOQA monitor stabilized approach rates – and go around ratesGo-around rates following un-stabilized approaches are low

This presentation investigates and proposes the concept of Stabilized Landing criteria.

This presentation investigates and proposes the concept of Stabilized Landing criteria. Conceptually, stabilized landing criteria establish the performance requirements for landings from the threshold to the end of the landing roll out. The stabilized landing concept serves to reinforce the requirement for pilots to perform landings in accordance with aircraft performance certification, FAA guidelines and industry standard best practices, similarly as with the stabilized approach criteria. The purpose of this presentation is to define and present the elements of a stabilized landing. Additionally, to propose that pilots seek to achieve successful landings by combiningthe elements of stabilized approach and stabilized landing criteria.


4

4

Major References

Flight Safety Foundation. (2010) Approach and Landing Accident Reduction Toolkit Update

Flight Safety Foundation. (2009). Reducing the Risk of Runway Excursions. Runway Safety Initiative Report

US DOT. Federal Aviation Administration. (11/06/07).Advisory Circular 91-79. Runway Overrun Prevention

US DOT. Federal Aviation Administration. (6/3/99).Advisory Circular 25-7A Change 1. Flight Test Guide for the Certification of Transport Category Airplanes


5

5

Outline

Consider the Flight Safety Foundation data for Runway ExcursionsUnderstand landing certification concepts

Look into threats to safe landings

Define Stabilized Landing Concept and identify Criteria

Demonstrate how C-FOQA can reveal opportunities to improve

Stabilized landing criteria are derived from guidelines established by the FAA, manufacturer’s performance certification data, safety research, and empirical data gathered from review of Corporate Flight Operations Quality Assurance (hereafter C-FOQA) reports. It considers the effects of excessive height, airspeed, groundspeed, landing beyond the touchdown zone, and insufficient or ineffective braking. Each of the criteria will need to be met, within reasonable tolerances, in order for a landing to be considered as stabilized. Once the concept of stabilized landings is defined, this presentation serves to reinforce the benefits of monitoring both stabilized approaches and landings using a flight operations quality assurance program, such as C-FOQA.


66

6

Approach and Landing Accidents, by Year

The trend line, calculated using least squares linear regression, indicates that the absolute number of approach and landing accidents gradually decreased during the study period.


7

7

FSF Data: All Approach and Landing Accidents 1995-2007

Figure 1: FSF ALAR Update - Killers in Aviation Update Pg. 5

Approach Final approach Landing Other Unknown

Flight phase


88

8

Most Common Types ofApproach and Landing Accidents

1995–2007

These comprise 77 percent of the total approach and landing accidents.

• Landing veer‐off• Landing overrun• Unstabilized approach• Controlled flight into terrain (CFIT)• Collision with terrain, non‐CFIT• Runway undershoot

These were the most common types of approach and landing accidents (ALAs) found in the 2009 study. Runway excursions, comprising veer-offs and overruns, account for approximately 45 percent of all ALAs. Some accidents can be categorized as more than one type.


9

9

Runway Excursion

According to the Flight Safety Foundation, a runway excursion occurs when an aircraft on a runway surface departs the end or the side of that runway surface.

Runway excursions can occur on takeoff or landing – Veer Off – Depart the side of the runway– Overrun – Depart the end of the runway

(FSF.ALAR Briefing Note 8.1, p.159).


10

10

Runway Excursion Accidents

Figure 2: Proportion of Fatal and Non Fatal Accidents (FSF, 2009, RSI Report, p. 5)

The FSF Report of the Runway Safety Initiative (RSI) published May, 2009 documented alarming evidence that from 1995-2008, runway related accidents accounted for a full 30% of all commercial transport category aircraft; furthermore, runway excursion accidents represented 97% of those accidents.


11

11


Runway Excursions 1995-2008

051015202530354045

1995

1997

1999

2001

2003

2005

2007

Number ofAccidents

Trend

Figure 3: Runway Excursions 1995-2008 (FSF, 2009, RSI Report, p. 6)

Considering the last 14 years, it appears that the trend has bottomed overall;


12

12


Runway Excursions 2004-2008

0

10

20

30

40

50

2004 2005 2006 2007 2008

Number ofAccidents

Trend

Figure 4: Runway Excursions 2004-2008 (FSF, 2009, RSI Report, p. 6)

However, a closer look at the last 5 years, 2004-2008, reveals that the trend is climbing (FSF, 2009, RSI Report, p. 6). In 2009, the year over year results show an 18% reduction in the number of accidents; although, the overall percentage of runway excursion accidents still accounted for some 26% of all accidents, repeating the 2008 results. (IATA.ORG, Feb. 2010, Press Release No. 5).


13

13


Runway Excursions - 1995-2008

0

100

200

300

400

500

Takeoff Landing

21% 79%

Figure 5: Runway Excursion by Type (FSF, 2009, RSI Brief)

According to the FSF the majority (79%) of runway excursion accidents occur in the landing phase with a near balance of overruns and veer offs.


14

14

Runway Excursion Factors

The FSF cites the major risk factors in landing excursions were: – go-around not conducted, – long landings, – ineffective braking (contaminated runways), – gear malfunctions, and – fast approaches and landings.

The FSF cites the major risk factors in landing excursions were: go-around not conducted, long landings, ineffective braking (contaminated runways), gear malfunctions and fast approaches and landings. IATA has determined that un-stabilized approaches, failure to conduct a go-around, abnormal touchdowns, and contaminated runways were the major contributors to landing excursions (IATA.ORG – Fact Sheet). Clearly, the risk factors have been well documented and published by the ALAR and RERR Toolkits.


15

15

Outline

Consider the Flight Safety Foundation data for Runway Excursions

Understand landing certification concepts






16

16

Landing Certification

FAR Section 25.125 specifies the requirement to provide landing distances, defined as the horizontal distance necessary to land from a point 50 feet above a dry hard surface and come to a complete stop.

The aircraft must be in the landing configuration, having flown a stabilized approach at a speed of not less than VREF down to the 50 foot height, amongst other requirements.

The Flight Test Guide for the Certification of Transport Category Airplanes, Advisory Circular 25-7A, provides manufacturers with guidance to ensure compliance with the regulations.

It states that the landing must be made without excessive vertical acceleration and the pressures on the wheel braking systems may not exceed those specified by the brake manufacturer. The landing distance data must also include correction factors for not more than 50 percent of head wind components and not less than 150 percent of the tail wind component.


17

17


Distances are treated in two parts: – the airborne distance from 50 feet to touchdown, and – the ground distance from touchdown to stop

AirborneGround

The guide details the test and demonstration requirements for manufacturers during certification. It is interesting to note that for landing performance, distances are treated in two parts: the airborne distance from 50 feet to touchdown, and the ground distance from touchdown to stop (AC 25-7A, Chap. 2, p. 98).


18

18

Landing CertificationAirborne Distance– 3 or 3½ degree approach path– Sink rates as much as 8 feet per second at touchdown

(480 fpm)

The test guide allows for airborne distances to be calculated at 3 or 3½ degrees, given appropriate requirements are met, with sink rates at touchdown as much as 8 feet per second. For example, the Gulfstream G-550 aircraft has been certified with a 3½º and 8 feet per second descent giving the shortest possible airborne distance (G-550, AFM Rev 29, Chap. 5, p. 05-120).


19

19


Ground Distance

Transition within 2 secs

Based on FULL Braking

Figure 6 Landing Time Delays (AC 25-7a, p. 103)

In the ground distance calculation, the test guide allows for the use of transition distances, which is the distance from the point of touchdown to the full braking configuration, and stopping distances; or, a combination of the two, whichever is preferred by the applicant (AC 25-7a, p. 101). In either case, it is critical to note that the ground distance is based upon the aircraft decelerating with maximum allowable brake pressure and other aerodynamic devices deployed within two seconds or less after touchdown, as the test guide permits for manufacturers to reduce the two second delay by expanding the AFM data when seeking credit for automatic deceleration devices.Figure 4 Landing Time Delays (AC 25-7a, p. 103)


20

“Landing distances determined

during certification are aimed at

demonstrating the shortest landing

distances… Therefore, the landing

distances determined under FAR

23.75 and 25.125 are much shorter

than the landing distances achieved

in normal operations”.

(AC 91-79, App. 1, p. 8)

They further amplify that “The importance of adhering to the landing procedures outlined in the AFM cannot be overemphasized… The AFM assumes that the deceleration devices will be fully deployed by 2 seconds after touchdown… The maximum braking condition is assumed to be maintained until the airplane reaches a full stop (AC 91-79, 11/06/07, App. 3, p. 3)”.


21

21

Outline



Look into threats to safe landingsDefine Stabilized Landing Concept and identify Criteria




22

22

Threats to Safe Landings

According to AC 91-79:Un-stabilized ApproachExcess AirspeedExcess Threshold Crossing HeightLanding Long (Beyond the touchdown zone)Adverse wind conditionsFailure to assess required landing distance

RERR provides an excellent Threat Analysis presentation

FAA AC 91-79 identified the major risks to runway excursions. Specifically it highlighted: a non-stabilized approach, excess airspeed, landing beyond the intended touchdown point, and failure to assess the required landing distance to account for contamination or the landing environment (AC 91-79, p. 3). The advisory circular went further to provide specific risk mitigation recommendations as well as comprehensive additional information including guidance on regulatory interpretation and technique.

The Runway Excursion Risk Reduction Toolkit offers an excellent presentation on Managing the Risks During Approach and Landing: How to Avoid a Runway Overrun


23

23

Un-stabilized Approach

Un-stabilized approaches typically co-exist with other risk factors– According to the RSI unstable approaches were a factor in:

88% of long/fast overrun accidents, and51% of hard landing veer off accidents

There are strong associations with unstable approaches and long/hard/fast landings

Failure to Go-Around contributed to one-third of all landing excursion accidents.

Could be avoided by a go-around as required with stabilized approach criteria

The FSF RSI report indicated that the failure to go-around following an un-stabilized approach contributed to one-third of all landing excursion accidents. Furthermore, the resulting landing attempt contributed to long landings, fast approaches, and fast and hard touchdowns. Complicating the issue with un-stabilized approaches is the fact that they typically co-exist with other risk factors; for example, unstabilized approach was cited in 77 of 87 long/fast overrun landing events (88%), and 20 of 39 hard landing veer off events (51%).


24

24

Un-stabilized Approach

Why do pilots continue to attempt to salvage unstabilized approaches?

Four possible behaviors: – excessive confidence in a quick recovery; – excessive confidence because of runway or environmental

conditions; – inadequate preparation or lack of commitment to conduct a go-

around; or, – absence of decision because of fatigue or workload

The question remains, why do pilots continue to attempt to salvage unstabilized approaches? The ALAR Toolkit indicated four possible behaviors: excessive confidence in a quick recovery; excessive confidence because of runway or environmental conditions; inadequate preparation or lack of commitment to conduct a go-around; or, absence of decision because of fatigue or workload (ALAR, Briefing Note 7.1, p. 136).


25

25

Excess Airspeed

Excess airspeed has been a cause factor in nearly 15% of landing excursion accidents

The performance data is normally based upon Vref not Vapp at a height of 50 feet above the threshold – Corrections to Vref are meant to be bled off to arrive at

threshold on speed

Excess Speed affects either airborne or ground landing distances – or both

Typically, the Vref speed is used to determine an approach speed which is maintained while on final approach in the landing configuration. Normally five or ten knots is added to the Vref speed, and perhaps also corrected for strong or gusty winds, or other conditions. The approach speed; however, must be reduced to Vref to cross the threshold at the 50 foot crossing height, as the performance data is based upon that speed.


26

26

Excess Airspeed

Airborne Landing Distance Effects:– 230 feet per knot of increased landing flare distance

Ground Landing Distance Effects (Dry):– 20-30 feet per knot of increased landing distance

Ground Landing Distance Effects (Wet):– 40-50 feet per knot of increased landing distance

AC 91-79 provides a breakdown of the increased landing distances as follows:Airborne Distance – 230 feet per knot of increased landing flare distance; orGround distance – Dry – 20-30 feet per knot of increased landing distance; orGround distance – Wet – 40-50 feet per knot of increased landing distance;

Note: Ground distance – Contaminated – not indicated in the circular.For example, an approach with 10 knots of excess airspeed at the 50 threshold crossing height may result in a 2300 foot extended flare or a 200-300 foot increased landing roll.


27

27

Excess Airspeed

A 10 knot excess airspeed has the potential of extending the landing distance by – 2300 feet with an extended float/flare; or– 200-300 feet (dry) with a fly on landing in the touchdown zone

Floating the landing has a 10X effect on landing distances

For example, an approach with 10 knots of excess airspeed at the 50 threshold crossing height may result in a 2300 foot extended flare or a 200-300 foot increased landing roll. It is important to note that the effects of excess airspeed at the threshold are ten times greater if the pilot elects to bleed the energy off in the flare, rater than flying the airplane onto the runway and promptly transitioning to the braking configuration. If the operator had a hypothetical 3000 foot dry landing distance; then the 10 knot excess airspeed would have resulted in an actual landing distance of up to 5300 feet. Even if the operator is in the habit of factoring landing distances, or adding safety margins, this seemingly innocuous airspeed error would have greatly reduced those expected margins.


28

28

Excess Threshold Crossing Height

Represents a high energy situation which logically will result in an extended airborne landing distance or ground roll out

AC 91-79 estimates that this distance is equivalent to 200 feet for each 10 feet of excess TCH

50’ TCH = 1000’

100’ TCH = 2000’

150’ TCH = 3000’

A TCH of 100 feet would extend the landing distance by 1000 feet (AC 91-79, p. 10). Excess TCH normally leads to long landings, beyond the desired touchdown point, as the pilot seeks to maintain a continuous stabile approach angle to a revised aim point, increasing the airborne distance; or, noses over the aircraft to achieve the desired touchdown point thus increasing the airspeed and the ground roll distance.


29

29

Landing Long Shallow approaches will also increase the airborne distance, as will a negative slope on the runway; approximately adding a 10% penalty to landing distances

Pilots should seek to accomplish firm landings in the landing zone; which is defined as the first third, or 3000 feet of the runway whichever is less.

While excess airspeed and high TCH may contribute to landing beyond the touchdown point, other potential contributors are negative runway slope, shallow approach, tailwind conditions and landing technique. While most airplanes are certified to touchdown following a 3 or 3½ degrees approach slope with as much as an 8 foot per second sink rate, it is rare that pilots will operationally use this same technique. As AFM landing distance calculations are based upon this technique, pilots must make efforts to achieve touchdowns close to the intended touchdown point; otherwise, landing distances will not be accurate.


30

30

Landing Long The Touchdown Zone

Most airplanes are certified to touchdown following a 3 or 3½ degrees approach slope with as much as an 8 foot per second sink rate (480 FPM), giving

Touchdown points approximately 1000 feet from the threshold

Painted Runway Marking aim points are depicted at approximately 1000 feet from the threshold, which corresponds to most type certifications

Touchdown Zones – 1000-1500 from threshold –allows for cushioned landings

While excess airspeed and high TCH may contribute to landing beyond the touchdown point, other potential contributors are negative runway slope, shallow approach, tailwind conditions and landing technique.


31

31

The RSI determined that long landings were strongly associated with each of the other risk factors during overrun excursions, including:– Unstabilized approaches – 77 of 87 events (88%)– Hard Landing/Bounce – 15 of 17 events (88%)– Go-Around not conducted – 91 of 107 events (85%)– Tailwind conditions – 20 of 30 events (67%)– Gusty or wind-shear conditions – 14 of 22 events (64%)– Contaminated Runways conditions – 53 of 101 events (52%)– Crosswind events – 9 of 18 events (50%)

Landing Long - The Common Culprit

The RSI determined that long landings were strongly associated with each of the other risk factors during overrun excursions, including:Unstabilized approaches – 77 of 87 events (88%)Hard Landing/Bounce – 15 of 17 events (88%)Go-Around not conducted – 91 of 107 events (85%)Tailwind conditions – 20 of 30 events (67%)Gusty or wind-shear conditions – 14 of 22 events (64%)Contaminated Runways conditions – 53 of 101 events (52%)Crosswind events – 9 of 18 events (50%)


32

32

Adverse wind conditionsTailwinds on Landing

Most aircraft are certified with 10 or 15 knots maximum tailwind

Tailwind conditions serve to increase the groundspeed which extends the airborne distance during the flare

Any tailwind on contaminated runways is not encouraged due to the inherent hazards

Tailwind conditions can also complicate landings when they co-exist with other risk factors, such as contaminated runway conditions. Indeed, manufacturers will often have specific limitations prohibiting tailwind conditions when contaminated runway conditions are present. Gulfstream specifically cautions operators, “Operations with any tailwind on contaminated runways is not encouraged due to the inherent hazards of operating on such runways”


33

33

According to the RSI report, crosswinds, wind gusts and turbulence are also associated with runway excursion accidents. They contributed to:– 16 of 18 (89%) of overrun excursions, and – 22 of 47 (47%) of veer off landing excursions

Adverse wind conditions were involved in 33% of accidents between 1984-1997, and

When wet runways co-existed, adverse winds were involved in the majority of the runway excursions

Adverse wind conditionsCrosswinds and Gusts on Landing

Pilots must consider that when adverse wind conditions are combined with adverse runway surface conditions they should seek alternative runways with preferable conditions.


34

34

Adverse wind conditionsCrosswinds and Wet/Contaminated Runway

Assess the runway condition

Apply correction factors using chart

ALAR Toolkit provided detailed guidance concerning landings in crosswind conditions (ALAR, 8.7)

Figure 7 GIV - QRH - PA-3

If landings must be conducted, pilots are strongly encouraged to consult tools such as the Gulfstream Crosswind Limits Based on the Canadian Runway Friction Index or Braking Coefficient Chart and have a plan to go around should the landing prove to be hazardous.


35

35

Failure to assess required landing distance

50 percent of the operators surveyed did not have adequate policies in place for assessing whether sufficient landing distance exists at the time of arrival at the destination airport (AC 91-79)

Two fundamental elements; – Correctly assessing the environmental conditions of the

runway, and – Properly assessing the correct aircraft performance given the

actual runway conditions

“A survey of numerous operators’ Flight Operations or General Operating Manuals by the FAA’s Landing Performance Team indicated that approximately 50 percent of the operators surveyed did not have adequate policies in place for assessing whether sufficient landing distance exists at the time of arrival at the destination airport” (AC 91-79, App. 1, p. 7).


36

36

Operators need to develop policies to compel flight crew to verify the runway condition prior to landing and apply sufficient safety margins to certified landing distances

The use of factored landing distances can assist with the ease of in-cockpit calculations (ALAR 8.3)

It is critical that pilots understand that AFM landing distances are based upon landings which are not normally operationally achievable and represent the starting point for determining accurate landing distances

Failure to assess required landing distance

As most certified landing performance does not include wet or contaminated data, un-approved data offered by the manufacturer should be used to determine landing distance requirements. Often, those data are not easily accessible in the cockpit as the data cannot be programmed into flight management system computers. Operators need to ensure that methodology is developed to allow crews to quickly refer to data and apply it to landing distance calculations. The ALAR Toolkit Briefing Note 8.3 provides a quick reference for pilots when considering landing distance factors. Pilots should be cautioned that simply factoring dry landing distances will only account for the known and planned performance deviations; unplanned deviations may quickly squander any/all safety margins and pilots should always strive to achieve planned performance distances. AC 91-79 Appendix 1 is an excellent reference to understand the complexities of landing distance calculations.


3737

37

Top Five Causal Factors of Approach and Landing Accidents

Slow/delayedreaction

Aircrafthandling

Failure in CRM

Poorprofessionaljudgment/airmanship

Omissionof action/

inappropriateaction

Causal factor

CRM = crew resource management

This slide shows the top five causal factors of approach and landing accidents from 1995 through 2007.


3838

38

Top Five Circumstantial Factors in Approach and Landing Accidents

Traininginadequate

Runwaycontamination

Poorvisibility

Otherweatherfactors

CRM failure

Circumstantial factor

CRM = crew resource management

This slide shows the five most frequent circumstantial factors in approach and landing accidents.


3939

39

Consequences of Approach and Landing Accidents

Loss ofcontrolin flight

Groundcollision

with object

Post‐impactfire

Undershoot Collision(non‐CFIT)

Accident consequence

CFIT Overrun Veer‐off

CFIT = controlled flight into terrain

Not shown on this slide is the most frequent — and obvious — consequence of ALAs: significant damage to the airplane, which was the result of 466, or 46 percent, of the 1,007 approach and landing accidents in 1995–2007.


40

40

Outline








41

41

Stabilized Landing

A landing conducted where the aircraft is positively controlled from a point 50 feet above the threshold to a full stop on the landing surface, without any unintended or adverse aircraft deviations from the planned and briefed maneuver.

Arriving at the threshold, following a stabilized approach, represents the transition point from the approach to the landing phase of flight. It is also the last opportunity for the pilot to assess the performance conditions and determine if it is safe to continue the landing; or, should the flight parameters be not as briefed or desired, conduct an immediate go-around.


42

42

Stabilized Landing Criteria

A landing is stabilized when all of the following criteria are met:– The runway conditions are properly assessed and a realistic

landing distance calculation, with appropriate safety margin, is planned and briefed (landing strategy);

– The aircraft achieves a threshold crossing height of 50 feet;– The aircraft speed at the threshold is not more than Vref + 5

knots;– Tailwind conditions not more than 10 knots for a dry runway,

and nil for a wet or contaminated runway;– The aircraft touches down firmly in the landing zone and is

promptly transitioned to the desired braking condition; and– The aircraft is slowed to a speed of not more than 80 knots

with not less than 2000 feet runway remaining.

The fundamental principle of strategy planning is: plan for the worst – hope for the best. This principle allows for the maximum margin for error.


43

43

Stabilized Landing Criteria

A landing that is not stabilized at the threshold; or,

has not touched down in the landing zone; or,

has an adverse or an unintended hazardous touchdown event shall

Execute an immediate go-around.


44

44

Bracketing and Tolerances

It should be anticipated that variations may be present due to environmental conditions, pilot performance or other unexpected conditions

Pilots must consider the effects of deviations as they relate tothe increase in landing distance

Prior to touchdown, pilots should never continue the landing should they assess that they will not have sufficient runway available, including reasonable safety margins to account for unexpected conditions – immediately go-around

If a pilot experiences an adverse or unintended hazardous touchdown – immediately go-around

While pilots should seek to achieve precise stabilized landing parameters when transitioning to the landing phase at the 50 TCH, it should be anticipated that variations may be present due to environmental conditions, pilot performance or other unexpected conditions. When considering acceptable deviation tolerances, pilots must consider the effects of deviations as they relate to the increase in landing distance as previously described. Pilots should never continue the landing should they assess that they will not have sufficient runway available, including reasonable safety margins to account for unexpected conditions.


45

45

Target Airspeed = Vref to Vref + 5 knots

– At Vref + 5 to Vref + 10 knots – CAUTION –increased speed condition exists – pilots should touchdown in the landing zone without delay and aggressively transition to the full braking configuration (commensurate with the available runway and runway conditions); and

– At Vref + 10 knots or greater – WARNING Excess speed condition exists – requires immediate go-around

Examples of Bracketing and Tolerances

Note: The full braking configuration is meant to be commensurate with the available runway and runway conditions and should be in accordance with the planned and briefed braking performance. This planned and briefed braking performance forms part of the braking strategy which also includes “what if”conditional plans. In some cases, when runway distances are limited, this may mean maximum braking effort.


46

46

Target Threshold Crossing Height = 50 – 80 feet

– At TCH 80 - 100 feet – CAUTION – increased landing distance condition exists – pilots should touchdown in the landing zone without delay and aggressively transition to the full braking configuration (commensurate with the available runway and runway conditions); and

– At Threshold Crossing Height 100 feet or greater -WARNING Excess altitude condition exists –requires immediate go-around




47

47

Target Landing Zone – 1000 – 1500 feet from the threshold – At 1500 – 2500 feet from threshold, or approaching

the end of the first third of the runway - CAUTION –increased landing distance condition exists – pilots shall touchdown immediately and aggressively transition to the full braking configuration (commensurate with the available runway and runway conditions); and

– At 2500 feet or greater from the threshold, or at the end of the first third of the runway - WARNINGExcess landing distance condition exists –requires immediate go-around




48

48

Outline








49

49

Stabilized Landing Monitoring

The C-FOQA program has been in effect since early 2006 and has monitored in excess of twelve thousand flights

The following slides have been published by Austin Digital, and may contain proprietary information protected by patent.

FSF has approved the use of these slides to demonstrate the capabilities of the C-FOQA program when considering the stabilized landing criteria

The distributions depicted represent the best estimate for accuracy

The program capabilities have been widely publicized and include monitoring of approach conditions, aircraft limitations and flight operations


50

50

C‐FOQA Annual Unstable Approach Event Rates

*Error Bars Calculated with 90% confidence intervalThis slide is published by Austin Digital, Inc and may contain This slide is published by Austin Digital, Inc and may contain proprietary information protected by patent.proprietary information protected by patent.

The unstable approach event rate decline has been remarkable and demonstrates the potential for the C-FOQA program to bring awareness to the landing environment as well. Given the awareness, pilots seek to achieve more precise flight parameters.

50


51

51

Percent of Unstable Approaches that end in a Go-Around

*Error Bars Calculated with 90% confidence interval

This slide is published by Austin Digital, Inc and may contain This slide is published by Austin Digital, Inc and may contain proprietary information protected by patent.proprietary information protected by patent.


5252

52

Unstabilized Approachesand Initiation of Go-Arounds

Unstabilizedapproaches

Go‐around notconducted when

warranted

19% 20%

The coding scheme developed for data analysis in the original (1999) approach and landing accident (ALA) study — and adapted for the 2009 study — did not provide for explicitly counting accidents that involved unstabilized approaches. Similarly, there was no causal factor citation for failure to initiate a go-around. The data shown in this slide are lower-bound estimates (i.e., these are the minimums) for the 1,007 accidents that occurred in 1995 through 2007. These data were compiled by evaluating two subsets of ALAs: runway excursions and undershoots. It is likely that the values for the entire ALA data set are somewhat higher.


53

53

C‐FOQA Seasonal Unstable Approach Event Rates (All Years)

*Error Bars Calculated with 90% confidence intervalThis slide is published by Austin Digital, Inc and may contain This slide is published by Austin Digital, Inc and may contain proprietary information protected by patent.proprietary information protected by patent.

Q3 event rates are higher.

53


54

54

Stabilized Landing Distribution Examples

Speed at Threshold

Height at Threshold

Tailwind on Landing

Landing in the Touchdown Zone

Runway remaining with 80 knots

Comparison of events following unstabilized approaches versus stabilized approaches

The development of stabilized landing criteria and monitoring of event rates will serve to bring awareness to aircraft performance of the landing phase; including, both the airborne and ground landing distance.


55

55

Speed at Threshold

Caution Limit

Warning Limit


Vref – Vref + 5

Vref + 5-10 is the highest distribution.


56

56

Caution Limit

Warning Limit

Threshold Crossing Heights


TCH 50 ft

While runway excursion does not include short landings – this slide indicates that the hazard is real.


57

57

Threshold Crossing Heights


TCH 50 ft

Another depiction using different bin sizes – presented to demonstrate that C-FOQA is versatile.


58

58

Tailwind on Landing

Caution Limit

Warning Limit


Tailwinds - Headwinds

Indicates a low incidence of high tailwind landings


59

59

Tailwind on Landing

This slide is published by Austin Digital, Inc and may contain proprietary information protected by patent.

Scatter chart showing a clear depiction of incidence of tailwinds.


60

60


Caution Limit

Warning Limit


1000-1500 feet

2500 +

Clearly depicts the average is 1500-2000 – there is a high incidence of long landings


61

61



Above is a depiction of the best estimate of the distance from threshold of the first touchdown, grouped by landings on various runway lengths. It is interesting to note that when faced with runways of 6000 feet or less, pilots can consistently achieve touchdowns in the 1500 foot range; however, as the runway length increases as do the touchdown distances.


62

62

Runway Remaining at 80 Knots

Caution Limit

Warning Limit


2000 feet


63

63

Runway Remaining at 80 Knots


The chart above is the best estimate of runway remaining when slowed to 80 knots, grouped by landings on various runway lengths.


64

64

Unstabilized vs. Stabilized


The Common Culprit

When stabilized landing criteria are used in conjunction with stabilized approach criteria, it will be possible to assess if the decision to continue an unstabilized approach resulted in an unstabilized landing. This should serve to be a strong indicator of the overall risk of the approach and landing.


65

65

Recommendations - Operators

Operators should develop, publish, train and monitor stabilized landing criteria

Operators should provide pilots with quick and easy cockpit access to aircraft performance data pertinent for both anticipated and unanticipated landing and runway conditions

Operators should manage the risks associated with runway excursions in their operations by implementing a FOQA program. This program should include performance measurements for: height, airspeed and tailwind at threshold crossing, touchdown point, and landing roll


66

66

Recommendations - Pilots

Pilots should reaffirm their commitment to adhere to stabilized approach criteria and go-around should approaches become unstabilized below 1000 feet IMC or 500 feet VMC

Pilots should plan and brief a stabilized landing strategy and go-around should landings be assessed as unstabilized at the threshold, or become unstabilized

Pilots should incorporate the runway excursion risk awareness tool into their flight risk awareness program


67

67

Recommendations - All

Must read!!!!


68

68

Recommendations - Other

The FSF should endorse and promote the concept of stabilized landing criteria


69

69

Summary – Stabilized Landings

A landing is stabilized when the aircraft is positively controlled from a point 50 feet above the threshold to a full stop on the landing surface, without any unintended or adverse aircraft deviations from the planned and briefed maneuver.


70

70

Summary - Criteria

Assess, plan and brief a landing strategy

Achieve threshold parameters for height and speed

Touchdown firmly in the landing zone

Brake effectively to stop safely

And finally……..


71

71

Know when to Go-Around

A landing that is not stabilized at the threshold; or,

has not touched down in the landing zone; or,

has an adverse or an unintended hazardous touchdown event

Shall execute an immediate go-around.


72

72

Acknowledgements

Mr. Jim Burin – Flight Safety Foundation– Leading the charge on Runway Excursions

Mr. Ted Mendenhall – Flight Safety Foundation– Painstaking efforts to promote and develop C-FOQA

Mr. Andy Rector – Austin Digital– Providing excellent technical analysis


73

End

[email protected]

Date post:	13-Apr-2018
Category:	Documents
Upload:	buibao
View:	221 times
Download:	7 times

Stabilized Landing Concept - NBAA · Stabilized Landings - Charbonneau CASS 2010 4 4 Major...

Documents