1 Training for First Flight 12 Nov 09 Air Force Flight Test Center Mr David Vanhoy Mr Karl Major USAF Test Pilot School (661) 277-3000 I n t e g r i t.

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Training forTraining for

First Flight First Flight 12 Nov 0912 Nov 09

Air Force Flight Test CenterAir Force Flight Test Center

Mr David Vanhoy

Mr Karl Major

USAF Test Pilot School

(661) 277-3000

I n t e g r i t y - S e r v i c e - E x c e l l e n c e

Approved for public release; distribution is unlimited.AFFTC-PA No.: 09462

War-Winning Capabilities … On Time, On Cost

Scientia est Virtus

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Roadmap

• USAF TPS Course Overview• 1st Flt Course Objectives

– PA HQ– Model Validation– ASE

• 1st Flight Checkride– Purpose / Scenario– Planning Elements– Key Questions

• Summary

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J F M A M J J A S O N D J F M A M J J A S O N D

TEST MGMT 600 TEST MGMT 600

TEST MGMT 900 TEST MGMT 900

QUAL EVAL 900 QUAL EVAL 900

PERF 600 PERF 600 FLYING QUALITIESFLYING QUALITIES 600600

SYSTEMS 600 SYSTEMS 600 FLYING QUALITIESFLYING QUALITIES 700 700

FLYING QUALITIESFLYING QUALITIES 800 800

FLYING QUALITIESFLYING QUALITIES 900 900

PERF 700PERF 700

PERF 800 PERF 800

SY STEM S 700 SY STEM S 700

SYSTEMS 800 SYSTEMS 800

GR

AD

UA

TIO

NG

RA

DU

AT

ION

AN

500

/CF

500

AN

500

/CF

500

FIE

LD

TR

IPF

IEL

D T

RIP

TPS Course Layout

Motivation!!!!

Who wants to be this guy????

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Or this guy????

6Video courtesy of Gary Aldrich

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Objectives

1. List the 3 kinds of FQ testing that should be conducted during the First Flight of an airplane

2. Describe the types of powered approach Handling Qualities testing that should be conducted on a First Flight

3. Describe the flight conditions at which First Flight powered approach HQ testing should be conducted

4. Name the 3 test methods that can be used to evaluate the Aero-Servo-Elastic stability of the landing configuration

5. State the fundamental principle of test point selection for First Flight Aero-Servo-Elastic testing

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Risks & Risk Reduction

• Ground Testing– Verified and Validated FCS– Nearly Validated Structure

• Uncertainty in Predicted Aero– Unavoidable– Design for Robustness

• Uncertainty in Predicted Handling Qualities– Simulator: Lack of Fidelity– Incomplete Evaluations– Biased Evaluations

GVTSCTLoad Proof & CalFMET

Design PrinciplesPiloted Sim

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Block Diagram of Simple Pitch Axis Control System

GVTGVT

StructuralStructural CouplingCoupling

HIL Gnd TestHIL Gnd Test

Design &Sim Design &Sim Sensitivity StudiesSensitivity Studies

StructuralStructural CouplingCoupling

HIL Gnd TestHIL Gnd Test

UNKNOWNUNKNOWN

Primary Objective:

LAND SAFELY!!

Secondary Obj: Don’t hit chase plane and get cool pics10

Primary Objective:

LAND SAFELY!!

Secondary Obj: GET AWAY FROM THE GROUND and Sample PA HQ 11

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3 Kinds of FQ Testing for 1st Flights

1. Handling Qualities

– Primarily in PA Config

2. Aero Model Validation

3. ASE

OBJ 1

Predict – Test – Validate and use the Build-up Approach

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1. Handling QualitiesPowered Approach

Photo from vets-helping-vets.com

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1st Flt Handling Qualities Tests

• Open Loop and Semi-Closed Loop FTTs

• Closed Loop Elevated Gain FTTs

• Closed Loop Ops Representative

OBJ 2

Photo from skyscrapercity.com

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1st Flt Handling Qualities Tests

• Static Stability Trim Shot• Time Delay and ASE Raps• Dynamic Stability 3 Axis Doublets • Initial Response and Steady State Resp Small Steps

• Directional Stability and R Control Power Sideslips

• Lateral Stability & a Control Power Stabilized Turns & Bank-to-bank Rolls

• “Elevated” g Stabilized Turns • Predictability Attitude Captures • Higher Gain PA HQ & Throttle Response Simulated App

& Go-Arounds

Open Loop and Semi-closed Loop FTTs

LIMIT AMPLITUDE of PILOT INPUTS

OBJ 2

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• Workload Build-up

– Increase aggressiveness to something

greater than anticipated for landing

– Tracking a Target (real or simulated)

• Longitudinal and Lateral/Directional Axis

– Tracking pitch attitude or flight path angle

or AOA

Closed Loop Elevated Gain FTTS

OBJ 2

1st Flt Handling Qualities Tests

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• There generally aren’t any

• Exceptions could be for modified a/c

versus actual 1st flights of new a/c

Closed Loop Ops Representative Tasks

Do NOT make 1st landing a Closed Loop Ops Representative task!!!!!!

1st Flt Handling Qualities Tests

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2. Aero Model Validation

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Types of Tests

• Trim Shot• Raps• 3-axis Doublets• Small Steps• Sideslips• Bank-to-bank Rolls

Open Loop FTTs

PTI for Individual Surfaces if required

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Types of Tests

• Trim Shot• Raps • 3-axis Doublets • Small Steps• Sideslips • Bank-to-bank Rolls

PTI for Individual Surfaces if required

Open Loop FTTs

These are the same maneuvers previously

shown for open loop HQ

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ElasticityAero

Servo

Structural CouplingR

igid

Bod

y L

imit

Cyc

le

Flutter

3. ASE

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• Identify the points where the stability margins are the smallest– If there is a chance you may reach one of these

points during approach, you need to test this at altitude first

– If you will not get anywhere near your lowest stability margin points on first flight, then STAY AWAY from them

– Use Raps as appropriate to verify ASE stability

OBJ 5

Test Pt Selection for ASE Testing

Course Evaluation

C-12 First Flight23

Purpose

Level of Learning Objective

Application - Appropriate execution of Flying/Handling Qualities Test Techniques- Appropriate management of Chase

Analysis - Discern effectiveness of mission conduct

Synthesis - Develop appropriate plan for first flight

Evaluation - Assess test results in-flight and post-flight

Develop and Execute a 1Develop and Execute a 1stst Flt Profile with Emphasis on FQ Flt Profile with Emphasis on FQ

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Scenario

C-90 King Air

Make suitable for Special Ops mission25

C-12 Special Ops Prototype

The Answer?

Scenario

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Assumptions

• Ground Tests and Taxi Tests– Successfully completed

• Same engines as C-90 King Air• Same system components, but application

new– fuel lines different, tanks different, pump

locations different, etc

• Performance model: Flight manual • Initial starting envelope given

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Goal

• Effectively determine ability to land safely– Via long, low gain straight-in approach &

landing

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Planning Elements

• How best to get away from ground?

• Basic instruments confidence

• How to expand the envelope?

• Test point selection– Flying / Handling Qualities– Aero Model Validation– Aeroelastic considerations

• Test point prioritization

• System operations

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Mission Variables

• Potential System Failures– Mock aircraft write-ups– Airspeed, pressurization, flaps, DAS, etc.

• MIL-STD 1797, Flying Qualities of Piloted Vehicles – Team Unique Compliance Checks– Program office special interest item

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Key Questions

• First flight objectives and priorities?

• Test point purpose?

• Best envelope expansion approach?– How slow, what increment?– How much sideslip, roll rate?

• Minimum maneuvers to attempt landing?

• What if something goes wrong?

• How do mitigate first landing risks?– Configuration changes

• How much should you elevate the pilot’s gains?– Cooper-Harper ratings

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First Flight Summary

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• Do Your Homework– Simulation

– Thorough Ground Test

– Team Practice

• Predict, Test, Validate Method + Build-up Approach

• PA Handling Qualities, Aero Model Validation, ASE

• Reduce Unknowns: Start test at Ideal Conditions

• Contingency Plans for Undesirable HQ or Failures

Get Away from the GndEval PA HQ &

Land Safely

First Flight Testing

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BACKUPS

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It’s Just a Minor Mod……

V∞ 35

Starting Envelope

• 140-160 KCAS• 15,000 ft PA• ½ Maximum Aileron Input• 0.8G to 1.5G Load Factor• 5° Sideslip• Flight Manual Limits for

A/C Systems• Takeoff designed for 40%

flaps

Heart of the Envelope, then where?

OBJ 336

Brief Items

• Objectives• Priorities• A/C Status / Mods /

SI• Go / No-Go• Safe Envelope• Envelope

Expansion Plan• Predictions• Time / Fuel Line

• Wx• Area

Considerations• Safety Brief• Limits• Terminology• Com Plan• Duties• Contingency Plans

Test Limits• 60° Max Bank Angle

• 0.5G to 2.0G Load Factor

• Recover from stall at first indication of BUFFET

• All minimum speed maneuvers (VMCA) will be terminated not later than first indication of stall (horn or buffet, whichever occurs first)

• Maximum pressure altitude of 17,000 ft PA

• No High Gain Aggressive tracking in wingtip formation

• Flight Manual Limits

– Engine Parameters, pressurization, yaw damper, etc

It’s the crew’s re

sponsibility to keep

It’s the crew’s re

sponsibility to keep

the aircraft within the test lim

its

the aircraft within the test lim

its

Questions You Should Ask• What can go wrong?

– engines, fuel, configuration, etc.• How are you going to minimize risk?• What are the contingency plans?

– Include those plans (or the philosophy) in the brief & be able to apply to your cards

• How far do you go looking for PIO??• How do you accomplish higher gain PA tasks?

Questions You Should Ask• How Slow should you go?

– Vapp???– Stall Warning??– Stall??

• How much Sideslip should you generate?

• How far should you expand roll rate?

– How do you expand roll rate?

• Do you Evaluate Engine Out?

– Power settings / Airspeeds / Maneuvers?

Questions You Should Ask

• Do you raise the gear?? – ALL Config Changes should be dedicated events

• What tasks are best to simulate landing?• What axis is the most critical?• What do you track?• What are the desired and adequate criteria?• How important are Cooper-Harper Ratings? –

Don’t make the landing a C-H Task!!!

It was Built to Specs……

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Course Academic Topics Labs, Sims & Checks Reports

FQ 600Unaugmented Airplane Motion

Equations of MotionTrim & StabilityParameter Estimation

C-12 Long-Stat & Lat-DirLJ-24 Long-Stat & Lat-DirT-38 Long-Stat & Lat-DirT-38 Dynamics

T-38 Long-Stat 5314T-38 Long-Stat TRT-38 Lat-Dir 5314T-38 Lat-Dir TR

FQ 700Flight Control SystemTesting

Intro to FCSAnalog & Digital FCSAero-Servo-ElasticityCriteria for FCS DesignFreq Content, Aliasing, FiltersFreq Response EstimationRedundancy Mgmt SystemsFCS Ground TestingFlight Test Simulators

FQ & HQ SimulatorsVISTA HQ DemoLJ-24 FCS Project

VISTA HQ 5314

FQ 800Stall, Departure, Spin,& Failure State Testing

Stall-Departure-Spin TestingFailure State Testing

Glider SpinT-38 Stall & HQC-12 & KC-135 Eng-OutF-16 Departure

T-38 HQ/Stall 5314T-38 HQ/Stall Oral PRREng-Out Expanded 5314F-16 Departure Oral PRR

FQ 900Handling Qualities (HQ)& Envelope Expansion

FQ Testing Config & OverviewTaxi testingFirst-Flight FQ TestingHandling Qualities EvaluationOne-Flight FQ EvaluationStores CertificationStructures

F-16 limit Cycle OscillationKC-135 & Glider FQC-12 First-Flight CheckF-16 HQF-15 CFP & Asymmetric StoresAT-38 FQ CheckF-16 Structural Loads Check

Flying Qualities Phase

Risks & Risk Reduction

• Prepare the Aircraft

• Prepare the Pilot

• Plan the Envelope Expansion Profile

• Plan for Emergencies

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First Flight: Short and Cautious

• Riskiest parts– Take-off

• Close to Ground• No Build-up

– Landing

• Risk Reduction– Low Bandwidth Take-off and Landing – Good Weather– Long, Smooth Runway– Controlled Airspace– Crash and Rescue

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Test Conditions

2 1 3 4

OBJ 3

Heart of the Envelope, Approach Speeds

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Generic Profile

• GET AWAY FROM THE GROUND• Heart-of-the-envelope Trim Shot• Air Data Checks• ASE if required• Open Loop PA HQ - compare to predictions• Closed Loop PA HQ - compare to predictions• Engine Checks• System Checks • Expand envelope to meet primary objective:

LAND SAFELY• Long Straight-in approach /low gain landing

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• Trim Shot (Accel into to eval Static Stability)• Raps (Time Delay and ASE)• 3-axis Doublets (Dynamic Stability) • Small Steps (Initial Response and Steady State Resp)

• Sideslips (Directional Stability and R Control Power)

• Bank-to-bank Rolls (Roll mode time constant & a Control Power)

• Stabilized Turns (Spiral Stability and “elevated” g)• Attitude Captures (Predictability)• Simulated App & Go-Arounds (Higher Gain PA HQ &

Throttle Response)

LIMIT AMPLITUDE of PILOT INPUTS

Open Loop and Semi-closed Loop FTTs

OBJ 2

1st Flt Handling Qualities Tests

CASE STUDY:ADAM AIRCRAFT M309

CASE STUDIES

Adam Aircraft Industries Photo

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RecapRecap

Photo from sodahead.com

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Figure 28-37

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Cme CN0

CNe Cm0

Cme

Analytical Determination of Trim

trim =

mgq S

Cm0 Cm

e trim =

Cme

trim

CNe Cm

Cme CN

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Pitch Doublet Time History

Figure 28-16

act = 11.3pred = 14.1

eact = -13.5epred = -10.6

= Aero Parameter Identification

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Flight Test Estimated vs Predicted Stability Derivatives

Figure 28-17

57Figure 28-27

Flight Test vs Updated Simulator Comparison

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Structural Coupling Ground Test Results

Figure 28-39

Min Damping for Flt Test

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3 Methods to Evaluate ASE

• Pulse and Go (= Stick / Pedal RAP or PTI)

• Increasing Loop Gain

– If stability margin will get small near approach

speed, then need to verify margin at a higher speed

(model validation approach)

• Frequency Response (= Freq Sweep)

OBJ 4

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Increasing Loop-Gain Method

1) Begin at Nominal Gain

2) Small, Sharp Input

3) Observe Control Surface: Stop or go to 4

4) Large, Sharp Input

5) Observe Control Surface: Stop or Increase

Gain

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Time Histories of Elevator Input

Figure 28-40

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Flight Test vs Predicted Damping

Figure 28-41

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Taiwanese Indigenous Defense Fighter (IDF)

Photo from skyscrapercity.com

Mission Objective

R1. Increase size of cargo bay to accommodate required payload.R2. Correct Roll PIO problem found during high gain Special Ops tasks.R3. Improve directional stability margin to allow for safe recovery following battle damage.R4. Redesign tail to prevent parachute/static line entanglement during low altitude jumps.R5. Improve formation flying qualities, specifically concerning Dutch-roll damping.R6. Reduce rudder force required during rapid speed changes.

General Information

• C-12 Test Aircraft– Pilot/Engineer Test Teams Assigned in Advance– Each team given a SPO MIL-STD-of-Interest

• Chase Aircraft (C-12 or other low speed aircraft)– Random Crews Assigned by Scheduling

• Data– Hand Held and DAS as available– Test Day Only (No Standardization)

Mission Profile

• Designed by the FTE/Test Team• The Following Profile OPTIONS are just

SUGGESTIONS– Not a minimum list or an all inclusive list of

FTTs

• YOU find a BALANCE between safety, envelope expansion, and program requirements

Mission Profile Options

Ground Block Flying QualitiesTakeoff Check Dash-1 normal procedures

Airborne pick-up /w photo

Climb Pitch capturesLongitudinal stabilityFlight Manual SchedulePower effectsAir Data

“Cruise” Data Trim Air DataLong and Lat/Dir flying qualitiesConfiguration changesHandling Qualities (PA and UA)Model ValidationASE

Mission Profile Options (cont’d)

“Cruise” Data Approach to stallcont. Simulated single engine

Simulated go-around

Mil-Std Compliance Maneuvers as required

Descent Flight Path StabilityFight Manual SchedulePower effects

Landing Stick forcesConfiguration changes

Ground Block Flying Qualities

Instrumentation

• Handheld data• Production gauges• Whatever you want to bring

– g-meter– Voice recorder– Tape Measure– Markers

• Simulated DAS

Test Conduct

• Data from all phases of flightData from all phases of flight– Don’t focus so much on gathering handheld data that Don’t focus so much on gathering handheld data that

you neglect other test conductor dutiesyou neglect other test conductor duties

• Use the chase/target as requiredUse the chase/target as required– Don’t forget potential photo usesDon’t forget potential photo uses

• Cautious, but accomplish somethingCautious, but accomplish something– Controlled, intentional build-upControlled, intentional build-up

• Safe Envelope DefinitionSafe Envelope Definition

• Landing Option BreakpointsLanding Option Breakpoints– Land Now or Accomplish a Test Pt First?Land Now or Accomplish a Test Pt First?