EMBRAER – Safety Review Board

Three Flags Test Point Execution Scale

Proposal for Flight Test Risk Assessments

EMBRAER – Safety Review Board

Objective

• Propose an alternative method to evaluate Flight Test Point Execution during Risk Assessments

EMBRAER – Safety Review Board

• Risk Assessment Present Day Concept

• Cooper Harper Application to Test Point Execution

• Three Flags Application to Test Point Execution

Agenda

EMBRAER – Safety Review Board

Test Point Execution System Failure Flight Envelope

Greater of All Three

Final Risk Classification

OBS: Each one of them are analyzed separately and considered mutually exclusive.

Risk Assessment Present Day Concept

EMBRAER – Safety Review Board

Final Risk Classification

Risk Assessment Present Day Concept

Minimizing Risk Procedures

Mitigation Procedures

-simulation-training-systems improvements-analysis…etc

-helicopter standing by-ambulance-firefighters-helmetsparachutes-Tailchute…etc

EMBRAER – Safety Review Board

Methodology came from past experience and was based on the FAA and ANAC (Brazilian Certification Authority) approved Risk Assessment Methodology

Nowadays, at Embraer, the CH is used to evaluate TPE Risk along with Three Flags Scale

Focused on TPE point of view only

Risk Assessment Present Day Concept

EMBRAER – Safety Review Board

• Risk Assessment Present Day Concept

• Cooper Harper Application to Test Point Execution

• Three Flags Application to Test Point Execution

Agenda

EMBRAER – Safety Review BoardCooper Harper Application to Test Point Execution Risk

According to the Methodology:

EMBRAER – Safety Review BoardCooper Harper Application to Test Point Execution Risk

Few more points to take into account

• Cooper-Harper scale is intended to evaluate the Flying Qualities of an aircraft for a specific MISSION.

• Cooper-Harper scale is supposed to be applied to a defined TASK. This task should define what is DESIRABLE and ADEQUATE flying performance. The CH rate is obtained AFTER the maneuver is done by the test pilot.

• A high Cooper Harper grade DO NOT necessarily mean a HIGH Risk maneuver.

EMBRAER – Safety Review Board

• Risk Assessment Present Day Concept

• Cooper Harper Application to Test Point Execution

• Three Flags Application to Test Point Execution

Agenda

EMBRAER – Safety Review Board“Three Flags” Application to Test Point Execution

1. Alternative way to go

2. Participation of several test pilots and FTEs

3. Focus on what a test pilot should consider

4. DETECT if certain risks are present

5. Designed ONLY for test point execution risk evaluation

EMBRAER – Safety Review BoardTHREE FLAGS

Test Point Execution SCALE

I – Detect training or gradual approach necessitiesTraining

Try-outs

Gradual Approach

Can the lack or necessity of these affect Safety ?

Is Needed ? And

III – Detect Recovering or Discontinuing possibilitiesRecovering

DiscontinuingWhen The maneuver, is there a probable chance to get

into unsafe situation ?

II – Detect Errors TolerancesTest Tolerances

Positioning TolerancesDo Affect safety if

exceeded or disregarded ?

AndCan be Considered to be tight ?

EMBRAER – Safety Review BoardQUESTION 1 RATIONALE

- Indication of increased execution risk

- Focus ONLY on the safety point of view (NO performance aspects)

QUESTION 2 RATIONALE

- How close to the aircraft limits X margins for errors

- Area Restriction

QUESTION 3 RATIONALE

- “Difficult to handle”

- Robustness and easiness of the recovering

- Experience on the type of aircraft and lessons learned HELPS !!

“Three Flags” Application to Test Point Execution“Three Flags” Application to Test Point Execution

EMBRAER – Safety Review Board“Three Flags” TPE was successfully applied during the Embraer Phenom 100 development

phase for the following Flight Test Campaigns:

1. Automatic Flight Control System2. Controllability and Maneuverability3. Stability4. Autopilot Servo Sizing5. Takeoff Transition6. Minimum Control Speeds7. Fuel Heat Management8. Steering Test Without Shimmy Damper9. In-Flight Thrust Determination10. Engine In-Flight Start11. Engine Inlet Distortion12. ANAC Familiarization Flight

“Three Flags” Application to Test Point Execution“Three Flags” Application to Test Point Execution

EMBRAER – Safety Review BoardExample:

Test Point – Maximum Dive Speed Demonstrated in Flight (Vdf) Determination

Aircraft: Choose an aircraft you are currently flying.Configuration: UP/0Initial Altitude: 15.000 ±1000 ftTrim Speed: VmoMinimum Recovery Altitude: 10.000 ft

1. TRIM aircraft at Vmo/Mmo during 10 seconds;

2. ESTABLISH a pitch attitude 7.5° (pushover maneuver Nz=0.5g) below the trimmed attitude and maintain during 20 seconds. Do not reduce thrust;

3. PERFORM a pull up maneuver with load factor 1.5g. After start pull up, THRUST REDUCTION may be used, if required.

“Three Flags” Application to Test Point Execution“Three Flags” Application to Test Point Execution

EMBRAER – Safety Review Board

MANEUVERQUESTIONS

FLAGS TPE1 2 3

Vdf/Mdf Determination 2 MEDIUM

Example:

Vdf is the maximum speed demonstrated in dive flight.

EMBRAER – Safety Review Board

CH Based Three Flags Based (1)Three Flags Based (2)Three Flags BasedVdf/Mdf Determination M M M MOut-of Trim M M M LCG Shift L L L LInadvertent Speed Increase M M M LLateral Gust Upset L L L LLongitudinal Gust Upset L L L LTwo Axis Gust Upset M L L LLeveling Off From Climb L L L LDescent From Mach Airspeed Limit Altitude L L L LSpeed Excursion to Vdf/Mdf M M M MPower on Stall L M M MStall with Slam Acceleration M M M MWind Up Turn M M M MContinuous Steady Heading Sideslip L M M LHigh Altitude Pushover L M M LHigh Altitude Pull Up L M M LTakeoff with Max Crosswind (target 20 kt) L M M MTakeoff with Max Tailwind (target 10 kt) L M M LLanding with Max Crosswind (target 20 kt) M M M MLanding with Max Tailwind (target 10 kt) L M M LClimb AEO L L L LClimb OEI M L L LServo Sizing (Roll, Pitch And Yaw) L L L LAFCS Malfunction L L L MStatic Longitudinal Stability (LSS) L L L MDynamic Longitudinal Stability (SPO) L L L LDynamic Longitudinal Stability (LP) L L L LDynamic Lateral-Directional Stability (DR) below Vmo L L L LDynamic Lateral-Directional Stability (DR) above Vmo M L L LStatic Lateral-Directional Stability (SHSS) below Vmo L M M MStatic Lateral-Directional Stability (SHSS) above Vmo M H H MContinuous Takeoff Sim OEI L L L M

TEST POINT EXECUTION ANALYSIS

Embraer Phenom 100 Aircraft

EMBRAER – Safety Review Board

CONCLUSIONS

“Three Flags” Test Point Execution Scale

• R.A. Easier and Straight to the Point

• Focused on what WILL be done (future)

• Simple to use

• Consistent grades attribution

EMBRAER – Safety Review Board

“Flying is an unnatural act so be ready.

Prepare yourself till you think you were born that way.”

EMBRAER – Safety Review Board

Three Flags Test Point Execution Scale

Proposal for Flight Test Risk Assessments

Maximilian Kleinübing, B.S.,Flight Test Engineer

maximilian.kleinubing@embraer.com.br