Thrust Reverser
Each engine is equipped with a hydraulically operated thrust reverser, consisting
of left and right translating sleeves. Aft movement of the reverser sleeves causes
blocker doors to deflect fan discharge air forward, through fixed cascade vanes,
producing reverse thrust. The thrust reverser is for ground operations only and is
used after touchdown to slow the airplane, reducing stopping distance and brake
wear.
Hydraulic pressure for the operation of engine No. 1 and engine No. 2 thrust
reversers comes from hydraulic systems A and B, respectively. If hydraulic
system A and/or B fails, alternate operation for the affected thrust reverser is
available through the standby hydraulic system. When the standby system is
used, the affected thrust reverser deploys and retracts at a slower rate and some
thrust asymmetry can be anticipated.
The thrust reverser can be deployed when either radio altimeter senses less than
10 feet altitude, or when the air/ground safety sensor is in the ground mode.
Movement of the reverse thrust levers is mechanically restricted until the forward
thrust levers are in the idle position.
When reverse thrust is selected, an electro–mechanical lock releases, the
isolation valve opens and the thrust reverser control valve moves to the deploy
position, allowing hydraulic pressure to unlock and deploy the reverser system.
An interlock mechanism restricts movement of the reverse thrust lever until the
reverser sleeves have approached the deployed position. When either reverser
sleeve moves from the stowed position, the amber REV indication, located on the
upper display unit, illuminates. As the thrust reverser reaches the deployed
position, the REV indication illuminates green and the reverse thrust lever can be
raised to detent No. 2. This position provides adequate reverse thrust for normal
operations. When necessary, the reverse thrust lever can be pulled beyond
detent No. 2, providing maximum reverse thrust.
Downward motion of the reverse thrust lever past detent No. 1 (reverse idle
thrust) initiates the command to stow the reverser. When the lever reaches the
full down position, the control valve moves to the stow position allowing hydraulic
pressure to stow and lock the reverser sleeves. After the thrust reverser is
stowed, the isolation valve closes and the electro–mechanical lock engages.
Each engine is equipped with a hydraulically operated thrust reverser, consisting
of left and right translating sleeves. Aft movement of the reverser sleeves causes
blocker doors to deflect fan discharge air forward, through fixed cascade vanes,
producing reverse thrust. The thrust reverser is for ground operations only and is
used after touchdown to slow the airplane, reducing stopping distance and brake
wear.
Hydraulic pressure for the operation of engine No. 1 and engine No. 2 thrust
reversers comes from hydraulic systems A and B, respectively. If hydraulic
system A and/or B fails, alternate operation for the affected thrust reverser is
available through the standby hydraulic system. When the standby system is
used, the affected thrust reverser deploys and retracts at a slower rate and some
thrust asymmetry can be anticipated.
The thrust reverser can be deployed when either radio altimeter senses less than
10 feet altitude, or when the air/ground safety sensor is in the ground mode.
Movement of the reverse thrust levers is mechanically restricted until the forward
thrust levers are in the idle position.
When reverse thrust is selected, an electro–mechanical lock releases, the
isolation valve opens and the thrust reverser control valve moves to the deploy
position, allowing hydraulic pressure to unlock and deploy the reverser system.
An interlock mechanism restricts movement of the reverse thrust lever until the
reverser sleeves have approached the deployed position. When either reverser
sleeve moves from the stowed position, the amber REV indication, located on the
upper display unit, illuminates. As the thrust reverser reaches the deployed
position, the REV indication illuminates green and the reverse thrust lever can be
raised to detent No. 2. This position provides adequate reverse thrust for normal
operations. When necessary, the reverse thrust lever can be pulled beyond
detent No. 2, providing maximum reverse thrust.
Downward motion of the reverse thrust lever past detent No. 1 (reverse idle
thrust) initiates the command to stow the reverser. When the lever reaches the
full down position, the control valve moves to the stow position allowing hydraulic
pressure to stow and lock the reverser sleeves. After the thrust reverser is
stowed, the isolation valve closes and the electro–mechanical lock engages.
