SDR AALA201904229003

Service difficulty report · Computer · Boeing 737823

Difficulty date: April 21, 2019
Submitted: April 22, 2019
Operation: Air carrier
Aircraft: N929AN
Make and model: Boeing 737823
Aircraft serial: 30078
Aircraft time: 57,210 hours, 23,605 cycles
System (JASC): 2210 · Autopilot System
Part: Computer
Condition: Faulty
Location: Nav
Stage of operation: DE
How discovered: 9
Nature of condition: O
Precautionary procedure: O

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

What was found

AIRCRAFT WAS GROUNDED: DURING DECENT IN VNAV MODE AIRCRAFT SUFFERED UNCOMMANDED ELEVATOR INPUTS FROM THE AUTO PILOT. THESE UNCOMMANDED INPUTS WERE MODERATE, AUTO PILOT CMD - A THE FIRST ONE WAS PASSING 25,000 FEET THE SECOND ONE WAS PASSING 18,000 FEET. ACCOMPLISHED DFCS BITE FAULT HISTORY AND CURRENT FAULTS IAW FIM 22-11-00 ,NO FAULTS FOUND. REMOVED AND REPLACED FCC-A IAW MM 22-11-33.ALL CKS NORMAL ACCOMPLISHED AND VERIFY IAW MM 22-11-00 AND BITE TEST IAW MM 34-36-00. ALL CKS NORMAL.