22-60 Maintenance
22-61 Scheduled Maintenance and Inspections
A. Ground Checks
NOTE
Perform the following ground checks after component replacement
or other repairs have been performed on the autopilot system.
Perform ground checks after an accident or incident that may have
affected autopilot or related equipment prior to return to service.
NOTE
Refer to § 22-62 for troubleshooting if any of the following ground
checks cannot be verified.
1. Turn battery & avionics switches on. Verify four beeps in headset and control
panel LEDS alternate white/green:
FOUR BEEPS
IN HEADSET
LEDs ALTERNATE
WHITE/GREEN
2. Verify SAS enters standby mode approximately 6 seconds after attitude indicator
caging flag exits window (pull and release caging knob if instrument bank angle
exceeds 6 degrees). Verify no sound in headset and control panel SAS LED is
white, other LEDs are dark:
NO SOUND
SAS LED IS WHITE,
OTHER LEDs DARK
3. Visually verify servo assembly arms do not move when moving cyclic.
4. Engage SAS mode (cyclic should feel "energized). Verify no sound in headset and
control panel SAS LED is green, other LEDs are dark:
NO SOUND
SAS LED IS GREEN,
OTHER LEDS DARK
5. Install & activate hydraulic test pump (to simulate hydraulics-on operation) per § 12-34.
a. With SAS engaged, displace cyclic at least 1 inch from neutral position and
verify SAS returns cyclic to neutral within ± 0.25 inch. Perform check for roll
& pitch axes.
b. With SAS engaged, displace cyclic full deflection, and verify 2.5–3.5 lb force
when displaced more than 1 inch from neutral position. Perform check for roll &
pitch axes.
Page 22.8 Chapter 22 Autopilot MAY 2015
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