SmartCockpit Fokker 50, Руководство пользователя

Страница: 2 / 18

switching panel. Once switched OFF, the system cannot be reinstated from the flight deck. If
the system is switched OFF, or has failed, the elevator operation is not affected. The elevator
control forces will now be defined by the position in which the feel control unit ceased
operation. On the ground an automatic self-test of the system is initiated when the flight
control lock is engaged, and the system is placed into a parked condition.
Type II
The Longitudinal Stability Augmentation System (LSAS) is provided to correct for the
dynamic out of trim farces caused by changes in engine power, flap position and aircraft
speed, and to augment the longitudinal stability at forward CG in flight. System operation is
automatic and active during flight only. Inputs are provided by:
• Both Electronic Engine Control (ENG EC) units.
• Attitude and Heading Reference System no 1 (AHRS 1).
• Flap drive unit.
• Air Data Computer (ADC).
NOTE: For those aircraft equipped with two ADC’s, ADC 1 is used as input for this
system.
The system uses the inputs to vary the bungee spring tension. Controls and indicators are
installed at the general switching panel, located at the overhead panel. A DEGRADED light
indicates a system input failure (flap position, airspeed or pitch). A FAULT light in the STAB
AUG pushbutton indicates a complete system failure. In this case LSAS will freeze in its last
position. The system can be switched OFF by depressing the STAB AUG pushbutton. With
the DEGRADED or FAULT lights illuminated, or the system switched OFF, the elevator
control forces during manual flight may be slightly higher or lower than normal, depending on
flight phase. Some system input failures (power lever and flap positions) detected in flight will
result in a system failure alert after landing (15 seconds after touch down). On the ground an
automatic self-test of the system is initiated when the flight control lock is engaged, and the
system is placed into a parked condition.
Pre-stall warning
If the aircraft attitude approaches a stall condition, a stick shaker at the LH control column is
activated. Shaker activation will disengage autopilot and yaw damper. The angle-of-attack
vane is located on the RH side of the fuselage nose. The pre-stall warning, which operates
independent of the integrated alerting system, is armed in flight only.
Flight control lock
A mechanically operated system of locks is provided for the ailerons, the rudder, and the
elevators. This system locks the ailerons and rudder in neutral position and the elevators in
down position. Each lock is spring loaded to the unlocked position. The EFCS or LSAS
control unit is commanded to a parking position. When the flight controls are locked, then the
power levers are prevented from being set to take-off power simultaneously. The flight
control lock lever is located at the rear LH side of the pedestal.
Fokker 50 - Landing Gear & Flaps
Page 2