On a static takeoff procedure when are the brakes released?

On a static takeoff procedure when are the brakes released?

• A. After PF advances the thrust levers to approximately 70% N1 and verifies N1 is stable
• B. At liftoff speed
• C. When engines reach idle
• D. After positive rate of climb is established

Answer: (A)

In a static takeoff, you want to ensure the engines are spooling up normally and the airplane is ready to move under controlled conditions before releasing the brakes. The moment to release is after the pilot flying advances the thrust levers to about 70% N1 and verifies that N1 is stable. This initial spool-up gives a predictable, supervised push of power and lets you confirm there are no abnormal indications before the airplane starts to roll. Releasing brakes at liftoff speed would mean you’re already moving and not in the controlled, brake-held phase of the procedure. Letting go after idle would have no thrust to start moving, and releasing after a positive rate of climb happens once you’ve already departed the ground, which isn’t part of the static takeoff procedure.

In a static takeoff, you want to ensure the engines are spooling up normally and the airplane is ready to move under controlled conditions before releasing the brakes. The moment to release is after the pilot flying advances the thrust levers to about 70% N1 and verifies that N1 is stable. This initial spool-up gives a predictable, supervised push of power and lets you confirm there are no abnormal indications before the airplane starts to roll.

Releasing brakes at liftoff speed would mean you’re already moving and not in the controlled, brake-held phase of the procedure. Letting go after idle would have no thrust to start moving, and releasing after a positive rate of climb happens once you’ve already departed the ground, which isn’t part of the static takeoff procedure.