AP HOLDING LWD
(Caution)

The amber 'AP HOLDING LWD' caution CAS message indicates the autopilot roll servo is holding control force on the Left Wing Down.

• The roll servo is drawing excessive current to maintain a steer to command or there is no feed back from the servo tach after position change commanded.
• Usually this message will post when the aircraft is out of trim, or over time if the aircraft has been flown out of trim more voltage is required for the servo motor to maintain level flight. Assure that the aircraft has been trimmed by the flight crew at cruise flight level to reduce nuisance messages. The aircraft flight control configuration can be monitored in degrees through the Pilot STALL TEST PAGE. On the CCP push A/ICE, ECS and HYD buttons simultaneously. Aileron trim displacement > 3°, more than likely will exhibit this condition.

• Aileron Servo (A126)
• Servo Clutch
• Integrated Avionics Processor System (IAPS) (A4)
• Flight Guidance Computer (FGC) (A4-FGC)
• Associated Wiring

Advisory Wire/Service Bulletin:

• AW300-22-0372 - Autopilot Troubleshooting Data
• AW300-27-0285 - Replacement of the Rivets on the Trailing Edge of the Aileron
• AW300-27-0409 - Autopilot (AP) Trim Airplane Flight Manual (AFM) Procedures

Full Throttle Blog/Forum Articles/Infoservice/Newsletter:

• RIL BD-0023 - Aileron Rigging Instructions (Aerodynamic) & Maintenance Check Flight.

Flight Operation Notifications Manual (FONM): None

1. Check control freedom of movement, servo and servo clutch / mount for possible binding and servo tach feed back wiring to IAPS FCC per AMM 27-11-00-710-802. Verify the cable system tension per AMM 27-11-00-720-801.
2. Perform the functional test of the linkage backlash for the aileron balanced geared tab per AMM 27-11-21-720-801.
   NOTE: Some aircraft have had factory adjustments performed during initial flight test, these adjustments to the balanced geared tab may vary from AMM 27-11-21-820-801 and need to remain for aircraft level flight.
3. Check the servo motor for proper operation IAW AMM 22-11-17-710-801, pay particular attention to the movement and strength of the aileron motor when driven with the heading bug. The motor should drive the controls to the stop fully and not be easily overridden. An Aileron Servo Test procedure can be done, this is not a permanent fix, however may temporarily fix an issue with the servo motor after prolonged usage may have resulted in a "dead spot" in the tach/motor position.

• To identify the aircraft flying characteristics, it is recommended under full fuel (8,500 lbs), the following worksheet is filled out Aileron Trim & Control Worksheet, email the worksheet in to the Montreal CRC for possible SRPSA disposition.