Service difficulty report · Autopilot Sys · Boeing 737890

Difficulty date
November 23, 2012
Submitted
November 27, 2012
Operation
Air carrier
Aircraft
N570AS
Make and model
Boeing 737890
Aircraft serial
35185
Aircraft time
22,375 hours, 6,712 cycles
Part
Autopilot Sys
Condition
Unknown
Stage of operation
AP
How discovered
O
Nature of condition
F
Precautionary procedure
O

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

What was found

ON APPROACH, WITH AUTOPILOT B ENGAGED. WHEN ACFT INTERCEPTED LOCALIZER 16R BOTH AUTOPILOT AND AUTOTHROTTLES DISENGAGED AND F/OS GLIDE SLOPE AND FLIGHT DIRECTORS HID FROM VIEW. ATTEMPTED TO ENGAGE AUTOPILOT AGAIN, BUT SYS WOULD NOT ACCEPT. FLEW APPROACH FROM CAPTAINS HUD. CAPTAINS INSTRUMENTS OK. ON LANDING RECIEVED MASTER CAUTION WITH PSEU LIGHT-ON. ACCOMPLISHED LAND VERIFY, AND AUTOPILOT TEST WITH NO DISCREPANCIES. BITE CHECK OF MMR AND RAD ALT BOX GOOD, NO FAILURES. CHECKED NAV OPS WITH IFR 4000 TESTER - ALL SYS OPS NORMAL. CAN NOT DUPLICATE. ACCOMPLISHED LAND VERIFY, BITE GROUP NR 49, DFCS LRU REPLACEMENT TEST FOR LRRA, BITE GROUP NR 40, DFCS LRU REPLACEMENT TEST FOR MMR/ILS, BITE GROUP NR 38, HGS SENSOR TEST FOR RAD ALT, AND MMR/ILS. ALL TEST PASS. ACFT REMAINS CAT III A AUTOLAND AND HGS QUALIFIED. STATUS SCREW REFLECTS SAME.