Commercial Certification (FAA)
25.109
Accelerate - Stop Distance
Rejected Takeoff (RTO)
See AC 25-7A Section 2 Para 11 25.109 1. Brakes must be at wear limit. 2. Wet runway test req'd as well. 3. Distance equivalent to 2 seconds @ V1 to be added. 4. Thrust reversers allowed only on wet runway rests- "explicitly denied" on dry runway tests. 5. At least 6 tests required. 6. Heavy to light weight. 7. Most critical CG. 8. Flaps in T/O position. 9. Cold tire pressures.
Aircraft departs runway
Inhabited Aircraft Only
High
1. Loss of directional control due to OEI, asymmetric reverse thrust, flight control failure, NWS failure or single brake failure. 2. Brake failure due to excessive heating or brake system failure.
1. All testing to be conducted on hard surfaced, dry runway (except for wet runway tests) 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 positioned a minimum of 400 feet from the runway centerline.
4. Minimum essential crew on board.
5. Flight crew 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 test. Service to recommended limits.
8. Monitor for excessive yaw tendencies. Stow reversers if necessary to maintain control.
9. Monitor brake and tire temperatures. Adhere to established test limits.
10. Equip ground crew with fire extinguishers, fire axe, extra wheel/tire and brake assemblies, cooling fans and heat resistant gloves.
11. Remain clear of fuse plug pressure relief area while tires/brakes are hot.
12. Ground crew to observe applicable brake restrictions related to inspecting brakes and checking temperatures. When cleared per the restrictions, MLG to be approached from directly in front or behind, avoiding exposure to sidewalls.
13. Have spin chute available for use and armed.
14. If wheel lock-up occurs, discontinue maximum braking and use any other available means of deceleration: thrust reversers, light pedal braking and spin chute. Use NWS for directional control at lower speeds.
15. Analysis of maximum KE capacity of brakes, brake dynamometer tests and fuse plug tests completed prior to flight tests.
16. Testing will be conducted using throttle chops to idle thrust.
17. Light weight testing will be completed prior to heavy weight and lower V1/Vr prior to 1.0 V1/Vr.
