What is the maximum permissible tailwind component for engine start?

What is the maximum permissible tailwind component for engine start?

• A. 10 kts
• B. 12 kts
• C. 14 kts
• D. 16 kts

Answer: (D)

Tailwind during engine start is limited because wind along the runway can push the aircraft if it isn’t perfectly held in position, affecting the start sequence and ground handling. The engine start procedure assumes the airplane will remain effectively stationary while the engines spool up, and the brakes, nosewheel steering, and APU/start sequence are designed around a certain amount of crosswind/tailwind allowance. If the tailwind component is too high, the airplane can drift or be harder to manage during start, which could compromise safety on the ramp and complicate the start procedure. The published limit for this aircraft is 16 knots, which balances allowing a moderate tailwind to exist on some runways with the need to keep the airplane controllable and stationary during start. So, 16 knots is the maximum permissible tailwind component for engine start. If conditions exceed this, engine start should be deferred until the wind subsides.

Tailwind during engine start is limited because wind along the runway can push the aircraft if it isn’t perfectly held in position, affecting the start sequence and ground handling. The engine start procedure assumes the airplane will remain effectively stationary while the engines spool up, and the brakes, nosewheel steering, and APU/start sequence are designed around a certain amount of crosswind/tailwind allowance. If the tailwind component is too high, the airplane can drift or be harder to manage during start, which could compromise safety on the ramp and complicate the start procedure.

The published limit for this aircraft is 16 knots, which balances allowing a moderate tailwind to exist on some runways with the need to keep the airplane controllable and stationary during start. So, 16 knots is the maximum permissible tailwind component for engine start. If conditions exceed this, engine start should be deferred until the wind subsides.