MD-11 Flight Crew Operations Manual
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Flight Controls -
Description and Operation
Flt.10.5
On the ground, with nose gear strut compressed, pulling the SPOILER handle up
and aft to the GROUND SPOILER position extends all ten spoilers to maximum
deflection. When in the full aft position, pulling the handle up locks it in that
position.
Spoiler extension is accomplished automatically by an Auto Ground Spoiler
(AGS) actuator. This provides an increase in drag and a rapid transfer of weight
to wheels during landing or Rejected Takeoff (RTO). The FCCs control power to
the AGS actuator.
An electrical control system provides operation logic in the automatic mode.
Additional logic is provided by arming the SPOILER handle. An ARM flag,
integral to the handle on each side, is exposed when the handle is placed in the
ARM position.
Disarming the SPOILER handle may be initiated at any position during AGS
actuation by pushing the T-handle down. The SPOILER handle then moves fully
forward to the spoiler retracted (RET) position, drops down to disarmed position,
and automatically latches.
After landing, all ten spoiler panels may be extended to maximum deflection by
automatic operation of the SPOILER handle. In order for this to occur, the
SPOILER handle must be armed and the flaps 31 degrees or more. After main
wheel spinup, spoilers extend between the 2/3 and FULL speed brake position.
After nose gear touchdown spoilers move to the GROUND SPOILER position or
in case no nose wheel spinup is detected, ground spoilers extend after nose gear
touchdown with any two throttles moved into reverse thrust. Maximum ground
spoilers are then deployed.
If an RTO is necessary, ground spoilers automatically extend as a function of
indicated airspeed when:
• Groundspeed is less than 80 knots, with auto spoilers armed, and any two
of the three throttles is moved to reverse thrust.
• Groundspeed is greater than 80 knots, with auto spoilers armed, and any
two of the three throttles is moved to idle.
The USE MANUAL SPOILERS alert or DISARM SPOILERS alert, if the spoiler
handle is armed, warns the flight crew that the handle is armed and the AGS
system has failed. In this case, manual ground spoiler deployment is required.
AGS is not affected by the (automatic flight system) AFS OVRD OFF switches
on the auto flight control panel. After spoiler extension, advancing throttle 2
automatically moves the SPOILER handle to full forward, retracting the spoilers.
If the number 2 engine throttle is not at idle at main gear wheel-spinup it is
possible that the AGS will initiate deployment and will then immediately retract
the spoilers. If this occurs, ground spoilers must be manually extended.
October 02, 2006
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