Autostow Failure Scenario Crew Procedure (1)
Autostow is enabled, but the actuator does not reach the retract position within 2.5 seconds. The SAC turns off the light either when the T.E. flaps are extended or when gross weight is less than 220,000 pounds. The light is inhibited if SAC's Air/Ground logic is in the On-Ground state unless loss of power to SAC. The crew is not to exceed 330 knots. This Flaps-Up procedure for the light is new for airplanes with the Autostow function. With the Autostow function unable to retract the speedbrakes, the new procedure alerts the crew to reduce airspeed, in order to prevent the potential for design loads being exceeded, should a pitch-up maneuver occur.
The SAC is not receiving valid airspeed or T.E. flap position data. SAC turns on the light since loss of either of these parameters results in the Autostow function being inoperative. The light is inhibited if SAC's Air/Ground logic is in the On-Ground state or when gross weight is less than 220,000 pounds.
The SAC pin programs do not indicate a valid program combination. SAC turns on the light since the Autostow function is inhibited. The SAC will be disconnected and dispatched under MMEL. The crew is not to exceed 275 knots.
The SAC has lost input power.
The Autostow actuator is not in its Extend position when the T.E. flaps are extended. Do not use the Auto-Speedbrake function. This procedure is necessary because the Auto-Speedbrake function may only partially extend the speedbrakes on landing if the Autostow function is not completely disengaged. This flaps-extended Autostow procedure is the
same procedure used on all 757-200 airplanes, if the "Auto Speedbrake" light illuminates due to an Auto-Speedbrake failure.
Crew procedures are defined in the APB Operations Manual supplement AP57.2-0605. The "Auto Speedbrake" light's color is amber (caution level).
Any time the SAC commands the "Auto Speedbrake" light to illuminate, the SAC “Speedbrake Do Not Arm” module LED is latched on and a record stored in nonvolatile memory. The “Speedbrake Do Not Arm” light can indicate either a system failure or a SAC failure.
The maintenance light test for the SAC will reset all latches.
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757-200
MAINTENANCE MANUAL SUPPLEMENT
Part I
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