SDR ASAA2016082017752

Service difficulty report · Modulating Valve · Boeing 737990ER

Difficulty date: August 20, 2016
Submitted: August 24, 2016
Operation: Air carrier
Aircraft: N409AS
Make and model: Boeing 737990ER
Aircraft serial: 41733
Aircraft time: 14,429 hours, 4,693 cycles
System (JASC): 2160 · Cabin Temperature Control System
Part: Modulating Valve
Part number: 3989083
Part serial: 1603
Condition: Failed
Location: Ac Bay
Part time: 68,822 hours, 37,715 cycles
Stage of operation: NR
How discovered: O
Nature of condition: J
Precautionary procedure: K

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

What was found

CONTROL CAB ZONE TEMP ILLUMINATED AFTER RECALL, EXTINGUISHES WITH RECALL. ACFT GROUNDED. PERFORMED NR 2 PACK ZONE TEMP CONTROL BITE, REF FIM 21-62, TASK 801. FOUND CONTROL CABIN TRIM AIR VALVE FAULT IN CURRENT, HISTORY, AND VERIFY. R & R CONTROL CABIN TRIM AIR MODULATING VALVE, REF AMM 21-61-21. OPS CHECK GOOD, NO FAULTS FOUND AFTER REPLACEMENT.