SDR ASAA2019100753935

Service difficulty report · Adiru · Boeing 737990ER

Difficulty date: October 5, 2019
Submitted: October 8, 2019
Operation: Air carrier
Aircraft: N435AS
Make and model: Boeing 737990ER
Aircraft serial: 43292
Aircraft time: 23,633 hours, 7,645 cycles
System (JASC): 3420 · Attitude and Direction Data System
Part: Adiru
Part number: HG2050AC11
Part serial: 00043208
Condition: Faulted
Location: Left
Part time: 65,158 hours, 25,862 cycles
Stage of operation: CL
How discovered: O
Nature of condition: P
Precautionary procedure: A

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

What was found

SHORTLY AFTER TAKEOFF THE LEFT IRS FAILED COMPLETELY WITHOUT ANY WARNING ANNUNCIATIONS. GROUNDED - YES. AIR TURNBACK. DIVERSION TIME 62 MINUTES - COULD NOT DUPLICATE FAULT. ADIRS BITE REF B737-900 FIM 34-21 TASK 801, SHOWS NO CURRENT FAULTS. CDS BITE REF FIM 31-62 TASK 801. (R) DEU SHOWS: LEG 01, 31-65010 PITCH DISAGREE, 31-65020 ROLL DISAGREE. DFCS BITE REF FIM 22-11-00-810-801. LEG 01 SHOWS: NO ADIRU DATA 22-11040 (L) ADIRU. REF B737-900 AMM 34-21-01/401. REMOVED AND REPLACED (L) ADIRU. OPS TEST NORMAL. ALL REQUIRED TESTS PASSED.