Login
Register
| Contents [show] |
Spoilers
There are 6 spoiler panels on each wing (count from inboard to outboard). They have several functions:
- speed brakes, using all the spoilers
- roll control, using the 5 outer spoilers
- ground spoilers, using all spoilers
Spoiler deployment is shown on both the WHEEL page and the F/CTL page.
Spoiler control is shared by the PRIM and the SEC computers.
Speed brakes
Extension is inhibited when:
- MLA activated
- AOA or alternate AOA protection active
- flaps in configuration FULL
- at least 1 thrust lever above MCT
- alpha floor activation
If an inhibition occurs with speedbrakes extended, they automatically retract until the inhibition disappears and the lever is reset.
Ground spoilers
The ground spoilers should be armed manually for takeoff and landing. Deploy when:
- during an RTO at >72 kts, or during landing when both landing gear have compressed; and
- both thrust levers idle with ground spoilers armed; or
- reverse selected on 1 engine with the other idle.
Partial extension occurs when:
- 1 landing gear is compressed; and
- reverse selected on 1 engine with the other idle.
Automatic retraction occurs when:
- 1 thrust lever above idle; or
- both thrust levers at forward idle and the speedbrakes lever is pushed down.
Servojacks
A servojack positions each spoiler.
Failures
Spoilers are generally automatically retracted when faulty or not electrically controlled. If the hydraulic system controlling the spoiler actuator is lost, the affected spoiler remains at its current deflection unless pushed down by aerodynamic forces.
| F/CTL SPLR FAULT | - the failed spoiler is shown as Δ - the symmetrical one on the other wing is automatically inhibited, except for spoilers 4 and 6 |