ADIRS -SAARU BACKUP NAVIGATION
Calculate Flight Path Acceleration
The calculate flight path acceleration logic uses these inputs:
*
Along track horizontal acceleration
*
Ground speed
*
Vertical speed
*
Vertical acceleration.
SAARU Backup Navigation Outputs
The SAARU backup navigation outputs go to the autopilot flight director computers (AFDCs) and the primary flight computers (PFCs). These are the SAARU backup navigation outputs:
*
Roll angle
*
Pitch angle
*
Magnetic heading
*
Magnetic track
*
True heading
*
Along-track horizontal acceleration
*
Cross-track horizontal acceleration
*
True track angle
*
Ground speed
*
Flight path acceleration.
EFFECTIVITY BEJ ALL
Training Information Point
The autopilot flight director system (AFDS) can use ADIRU or SAARU data. The AFDS uses ADIRU data first. If the ADIRU fails, the AFDS uses SAARU data. Some AFDS modes do not operate when the ADIRU fails and SAARU backup navigation is not available. These are the AFDS modes that do not operate in this condition:
*
Approach (APP)
*
Flight path angle (FPA)
*
Takeoff/go-around (TO/GA)
*
Track hold (TRK HLD)
*
Track select (TRK SEL)
*
Vertical navigation (VNAV)
*
Lateral navigation (LNAV).
If the ADIRU fails when the APP mode is armed or engaged, the AFDS automatically selects the SAARU backup navigation data. If the airplane does not land within 3 minutes, the autopilot pitch and roll modes fail. The flight crew must select another autopilot mode or disengage the autopilot.
If the ADIRU fails when the FPA mode is engaged, the AFDS will automatically select the SAARU backup navigation data. If the autopilot does not go into another mode or if the flight crew does not select another mode within 3 minutes, the autopilot pitch mode fails. The flight crew must select another autopilot mode or disengage the autopilot.
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ADIRS -SAARU BACKUP NAVIGATION
If the ADIRU fails when the TO/GA mode is engaged, the AFDS will automatically select the SAARU backup navigation data. If the autopilot does not go into another mode or if the flight crew does not select another mode within 3 minutes, the autopilot roll mode fails. The flight crew must select another autopilot mode or disengage the autopilot.
If the ADIRU fails when the TRK HLD or TRK SEL mode is engaged, the AFDS will automatically select the SAARU backup navigation data. If the flight crew does not select another mode within 3 minutes, the autopilot roll mode fails. The flight crew must select another autopilot mode or disengage the autopilot.
VNAV and LNAV are not AFDS modes. VNAV and LNAV are flight management computing system (FMCS) modes that go through the AFDCs. VNAV and LNAV do not operate when the FMCS does not have valid ADIRU data. If the ADIRU fails, the autopilot pitch and roll modes immediately fail. The flight crew must select another autopilot mode or disengage the autopilot.
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ADIRS -SAARU BACKUP NAVIGATION
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ADIRS -STANDBY ATTITUDE INDICATOR
Purpose
The standby attitude indicator shows attitude data. The attitude data comes from the secondary attitude air data reference unit
(SAARU). The standby attitude indicator is display (LCD). a liquid crystal
Program Pin Configuration
Program pins determine the function of the standby
instruments. Install the standby instrument in the standby attitude indicator position to show the standby attitude indicator format.
If you replace the normal standby attitude indicator with an indicator that has a push-button and rotating knob, the knob has no function. The push-button and the rotating knob are active only when you install the standby instrument in the standby airspeed indicator position or the standby altimeter position.
Integral Light Sensor
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