SDR ASAA2017121722924

Service difficulty report · Computer · Boeing 737990ER

Difficulty date: December 17, 2017
Submitted: December 19, 2017
Operation: Air carrier
Aircraft: N494AS
Make and model: Boeing 737990ER
Aircraft serial: 41729
Aircraft time: 7,388 hours, 2,422 cycles
System (JASC): 2210 · Autopilot System
Part: Computer
Condition: Malfunctioned
Location: Llm
Stage of operation: IN
How discovered: 9
Nature of condition: O
Precautionary procedure: K

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

What was found

WHILE ACCOMPLISHING LLM UPDATE BITE LIBRARY TEST FOR AILERON FAILED. 2 FAULTS AIL POS FAIL & R SENSOR EXC INV CHANNEL B. REPEATED TEST, NO HELP. CHANNEL A TEST PASSED. ACFT GROUNDED. TROUBLESHOT IAW FIM 22-12 TASK 813. NO MAINTENANCE MESSAGES SHOWN AFTER DFCS BITE CHECK ACCOMPLISHED. PERFORMED DFCS LRU REPLACEMENT TEST FOR FCC IAW AMM 22-11-33, LAND VERIFY TEST IAW AMM 22-11-00/201 BOTH TESTS PASSED. NO HISTORY LAST 30 DAYS.