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SDR ASAA2020012403902

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Service difficulty report · Actuator · Boeing 737990ER

FAA SDR system

Difficulty date
January 20, 2020
Submitted
January 29, 2020
Operation
Air carrier
Aircraft
N468AS
Make and model
Boeing 737990ER
Aircraft serial
41735
Aircraft time
21,907 hours, 7,072 cycles
System (JASC)
2210 · Autopilot System
Part
Actuator
Part number
158300101
Part serial
29873
Condition
Failed
Location
Lt Mlg Ww
Part time
21,985 hours, 7,093 cycles
Stage of operation
NR
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

AUTOPILOT A DISCONNECTED AFTER BEING ON FOR ABOUT 1 MINUTE. WOULD NOT REENGAGE. GROUNDED - YES. FOUND MAINT MSG 22-11143. ACCOMPLISHED FIM 22-13 TASK 804. PIN 2 SHOWS 28VDC. REPLACED PRESSURE SWITCH S774 IAW AMM 22-11-40. NO HELP. AUTOPILOT AILERON ACTUATOR OHMS BAD. FIM 22-13 TASK 804, REMOVED AND REPLACED AILERON A/P ACTUATOR-A M943 IAW AMM 22-11-25/401. PERFORMED AUTOPILOT AILERON ACTUATOR - ADJUSTMENT/TEST IAW AMM 22-11-25/501, ALL TESTS PASSED. DFCS BITE TEST STATUS AUTOPILOT LIBRARY 11.00 TESTS PASSED.