Speedbrake Inhibit Function
The speedbrake inhibit function has an effect on the ground spoiler speedbrake commands.
The function receives main landing gear on the ground signal from the PSEU and the pitch attitude from the ADIRU.
The function also monitors the position of the speedbrake lever.
The speedbrake inhibit function operates when the pitch attitude is more than 2 degrees with the airplane on the ground or during the first 1.25 seconds after a main landing gear air to ground transition.
When there is a speedbrake lever command, the outboard spoilers 2, 5, 10 and 13 do not deploy.
The PFCs limit the inboard spoilers 6, 7, 8, and 9 to 20 degrees until the speedbrake inhibit function is no longer active.