3. DESCRIPTION
A. A82 flight computer
A82 flight computer consists of an electronic box enclosing the processing circuits and the two modules storing the values determined upon system certification. These replaceable modules are installed on the top and bottom boards.
A82 flight computer receives data from the following components :
- control switches and push-buttons located on the pilot control wheel,
- the attitude director indicator (roll and pitch attitude data),
- the heading reference system (selected course and heading data),
- radionavigation system (VOR or GPS, LOC, GS and MKR data),
- A81 altitude / vertical speed selector (vertical speed and preselected altitude data).
A82 flight computer processes these data and generates command signals which are sent to the roll servo-actuator when the autopilot mode is engaged.
A82 flight computer also ensures system monitoring and disables autopilot engagement when the pre-flight test has not been successfully completed.
When the autopilot is disengaged for whatever reason, it sends a signal to the autopilot sonalert and flashes "AP" annunciation.
A82 flight computer is electrically supplied by BJ6 bus bar and protected by "A / P" circuit breaker. It is mounted on the radio rack.
B. B35, B36 and B38 pitch, roll and pitch trim servo—actuators
The servo actuators provide a means to transmit the piloting commands computed by A82 flight computer to the flight controls.
Each servo actuator consists of a CW/CCW electric motor, a clutch mechanism and a capstan on which a cable attached to the main flight control is wound.
As long as the autopilot is engaged, the capstan remains integral with the electric motor, the commands from A82 flight computer are transmitted to the flight controls.
When the autopilot is disengaged, the drive capstan rotates freely.
NOTE : Each capstan is equipped with a calibrated slip clutch that enables the pilot to manually override the autopilot with flight controls when the autopilot is engaged.
B38 pitch trim servo—actuator is electrically supplied by BJ6 bus bar and protected by "TRIM" circuit breaker.
B36 and B35 roll and pitch servo—actuators are electrically supplied by BJ6 bus bar and protected by "NP" circuit breaker.
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