SDR ASAA2023041242836

Service difficulty report · Unknown · Boeing 737990ER

Difficulty date: April 12, 2023
Submitted: April 14, 2023
Operation: Air carrier
Aircraft: N477AS
Make and model: Boeing 737990ER
Aircraft serial: 40716
Aircraft time: 28,074 hours, 8,700 cycles
System (JASC): 2210 · Autopilot System
Part: Unknown
Part number: UNKNOWN
Condition: Unknown
Location: Unknown
Stage of operation: CR
How discovered: V
Nature of condition: J
Precautionary procedure: K

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

AT FL360 ENGAGGED "A" AUTOPILOT. AFTER 5 MINUTES, AUTOPILOT DISENGAGED. RE-ENGAGED "A" AUTOPILOT, AND AFTER 5 MINUTES, AUTOPILOT DISENGAGED AGAIN. ENGAGED "B" AUTOPILOT, "B" WORKS FINE. GROUNDED - YES. ACCOMPLISHED DFCS BITE B737-900 FIM 22-11 TASK 801. FOUND FAULT " 22-11186 TRIM CMD RESPSE MON" ON CHANNEL A FLIGHT LEG 1 @ 36000 FT. ACCOMPLISHED FIM 22-11 TASK 854. ALL TESTS PASS. NO HISTORY PAS 30 DAYS.