Commercial Certification (FAA)
25.107(d)
Takeoff Speeds
Vmu Demonstration
See AC 25-7A Section 2 Para 10 b 1. Start with full aft yoke at start of T/O roll (may wait till 40-60 knots). Maintain pitch attitude at liftoff. 2. For low T/W test, with the airplane static and lined up for takeoff, set the desired EPR and place a strip of masking tape across the throttle quadrant immediately aft of the throttle levers. Set TO EPR to initiate the takeoff roll and at 60 KCAS retard the throttles to the marked position. If a takeoff abort is necessary, the masking tape can be easily broken while retarding the throttles to the IDLE position.
3. If the aircraft is airborne and an engine fails, decrease pitch attitude, establish a stable bank angle and advance the operative engine throttle so aircraft will accelerate and climb. Minimize asymmetric thrust when possible. Make all turns into the operative engine and climb at no less than V2 until 1500 feet AGL.
4. If the aircraft is over-rotated, or rotated early and stalls, decrease pitch attitude, maintain wings level, advance throttles, accelerate and climb.
Aircraft departs runway / Inadvertent ground contact.
Inhabited Aircraft Only
High
1. Excessive rotation force / over-rotation at low speed, low altitude stall.
2. Engine failure at low T/W test conditions.
1. All testing to be conducted on hard surfaced, dry runway under day VFR conditions.
2. Minimum runway length and width must be established.
3. Crash and rescue crews to be briefed on conduct of the tests, aircraft familiarization and rescue procedures. Equipment and crews to be positioned a minimum of 400 feet from the runway centerline during the tests.
4. Minimum essential crew on board.
5. Flight crews will wear protective clothing and helmets.
6. Wind speed must be 5 knots or less from any direction except no tail wind is permitted.
7. Inspect tires, struts and brakes prior to the test. Service to recommended limits.
8. Stall barrier system will remain active during the testing. The stall barrier system must be validated by flight test prior to conducting testing.
9. Vmu assurance testing will be approached in a build up manner. Tests will begin AEO at high T / W conditions and proceed to the lower T / W conditions required. The number of required buildups and repeat testing will be determined by the test team.
10. OEI testing will be conducted by simulating the OEI condition, using the equivalent OEI total thrust divided symmetrically between all engines.
11. Pitch attitude will be limited to xx degrees. (AOA at Pusher = xx.x deg, AOA at Shaker = xx deg).
12. For low T / W test, the accel-stop / accel-go distance will be calculated and provided to the test crew prior to the conduct of the test.
13.APU will be ON.
14. Pilots will be familiar with AFM Engine Failure Procedures.
15. Experimental Tail Bumper & Proximity Warning must be operational.
16. Critical Flight Test Instrumentation parameters will be monitored by telemetry and displayed to flight crew.
17. Review procedures in event of test abort- continue flight or RTO.
