Which of the two events auto-deploys the "armed" speed brakes during landing?
1. The aircraft's "weight-on-wheels" sensors...during touchdown.
or
2. The pilot engaging the thrust reversers as he/she "de-rotates".
2006-09-20 20:50:16 · 9 answers · asked by Fulani Filot 3 in Cars & Transportation ➔ Aircraft
The above answers are correct. Remember, not all aircraft have auto speedbrakes. Besides a Weight on Wheels (WoW) signal, some aircraft require a main wheel spin up signal together with the WoW. My experience on the DC-10 showed many times on a wet runway, combined with soft landing, the auto speedbrakes would not extend, and it was the Flight Engineer's (Second Officer) responsibility to manually extend them.
The Thrust Reversers had nothing to do with the auto speedbrake system as far as I knew.
2006-09-21 00:00:14 · answer #1 · answered by sc0tt.rm 3 · 0⤊ 0⤋
It varies with aircraft type, but it generally takes a combination of things to deploy Ground Lift Dumping. This requirement for several conditions to be met prevents the panels from deploying inadvertently.
On the plane I fly, the following conditions must be met:
- Ground Lift Dumping switches armed
- Both thrust levers at idle position
**plus two of the following**
- Left or right main landing gear weight on wheels
- Radio altimiter less than 5 feet
- Wheel speed greater than 16 knots
2006-09-24 17:46:52 · answer #2 · answered by Anonymous · 0⤊ 0⤋
During landing, #1:
D. The spoiler automatic system is an electrically controlled, hydraulically actuated system, used to reduce lift and increase drag for more effective braking during the landing roll or rejected takeoff roll.
With the speedbrake lever set in the armed position the spoilers will automatically extend when the main landing gear wheels spin up on landing, or the lever may be operated manually to extend the spoilers. With the speedbrake lever armed during takeoff the spoilers will automatically extend when both thrust levers are raised to reverse thrust position. In each case all spoilers on each wing are fully extended simultaneously.
2006-09-20 21:05:03 · answer #3 · answered by Ben 4 · 1⤊ 0⤋
There is a wheel spin-up sensor that sends a signal to the auto-spoiler controller that is it OK deploy them when the aircraft is on the ground
2006-09-21 08:46:55 · answer #4 · answered by Jerry L 6 · 0⤊ 0⤋
Weight on wheels triggers autospeedbrakes......But only if your throttles are retarded (pulled back to idle) This is to keep the aircraft clean in case of a touch and go or aborted landing after touchdown.
Wheel speed signals are only for antiskid/autobrake
2006-09-21 19:36:54 · answer #5 · answered by aer_tech 2 · 1⤊ 0⤋
The weight on wheels sensors deploy the speedbrakes.
2006-09-21 14:05:53 · answer #6 · answered by Fadhl 3 · 0⤊ 0⤋
As soon as the rear main landing gear touches the runway the speed brakes deploy.
2006-09-20 23:05:25 · answer #7 · answered by ZUS 3 · 1⤊ 1⤋
Typically you need both WoW login and a thrust lever angle (TLA) of less than a designated threshold (approximately 30 degrees)
2006-09-23 11:11:37 · answer #8 · answered by Jason 5 · 0⤊ 0⤋
It's almost always weight on wheels.
2006-09-21 06:24:02 · answer #9 · answered by Doc Savage 2 · 0⤊ 0⤋