David GillTeam Leader Airworthiness

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Introduction to Performance and Flying Qualities Flight Testing

Two Week Short Course May 8 – 19, 2006Intended to provide practical experience

in aircraft performance, stability and control handling qualities, flight test instrumentation and data handling

Aircraft Certification Unit – Flight Test Engineering Course Report7th Sept 2007

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This two week short course is designed to satisfy the demand for engineers, pilots and flight test support personnel who require practical experience in aircraft performance, stability and control, handling qualities, flight test instrumentation data handling, as well as a working knowledge of FAA and military specifications pertaining to piloted aircraft.

Classroom academics are tailored to prepare the students for practical in-flight tests.  Seven flights are performed in a medium weight transport aircraft. These aircraft have been instrumented to serve as in-flight laboratories.  On each of the sorties the students participate as flight test engineers, gathering data for post-flight analysis. Four additional sorties are flown in light aircraft to allow the students to give practical hands-on experience in performing the various flight test techniques as a pilot.  At the conclusion of the course, students present their findings and recommendations on both mission suitability and regulatory compliance in an oral report to the staff.

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Basically the course consisted of lectures in the morning on a particular subject, followed by explanation of the flight test exercise to be carried out on that subject.

Each of the two groups would then prepare their test cards for the flight. Each group would be assigned a different aircraft c.g. configuration.

The flight would then be undertaken with each person recording their own results.

After the flight the data would be processed using the NTPS programs and analysed. This was then collated and graphed, and checked against design requirements.

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Test Aircraft – Test Aircraft – Swearingen Merlin IIISwearingen Merlin III840 shp Garrett 311-393G Turboprops

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Pitot-Static Calibration/Position Error Correction (Using a trailing bomb)

Cruise Performance, CL-CD and Drag PolarSawtooth Climb and Level Acceleration

Longitudinal Static Stability (stick-fixed and stick-free), and Neutral Point Determination

Manoeuvering Stability, Turns, Pull-Ups, Pushovers

Lateral/Directional Static StabilityAircraft Dynamics and Stalls

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Cruise Performance Objects: To obtain cruise performance data

and fuel flow information for various configurations.

Determine the specific range and drag polar for the aircraft.

Technique: Stabilize the aircraft at the test

altitude and airspeed by using the “backside” technique.

Record fuel flow, power, altitude and airspeed, along with ambient conditions.

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The bottom of the curve shows denotes speed for best endurance.

Maximum slope of curve, from origin, denotes speed for maximum range.

Top of curve indicates maximum range at standard weight.

99% of maximum Specific Range is the speed for long range cruise.

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Drag Polar extrapolates to CD0 at the y axis.

The slope of the line through the origin indicates maximum lift-to-drag ratio.

As well as the Group exercises in the Merlin all course students had the opportunity to carry out individual “hands-on” flights in the NTPS light aircraft fleet.

This was not intended to teach test pilot techniques, but to introduce the student to the various manouevres, so they could understand what they were asking the pilot to do.

The test exercises were:Position error CorrectionPerformanceFlying QualitiesAsymmetric Power Test Techniques

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Left: Beech 36 BonanzaMiddle: Cessna 150Right: Beech 76 Duchess

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• DH.104 Dove• Cessna 150 and 152• Beech 36 Bonanza• Beech 76 Duchess• Hughes 500• Bell OH-58• MB326 Impala• DHC-1 Chipmunk• Cirrus SR-22

SA226T Merlin IIITurboprop DC-3Cessna 441

ConquestAM-3 BosbokMS-760 ParisNDN-1 FirecrackerSaab J35XD DrakenPiper PA-28

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