SDR ASAA2015072212545

Service difficulty report · Filter · Boeing 737990ER

Difficulty date: July 22, 2015
Submitted: July 24, 2015
Operation: Air carrier
Aircraft: N419AS
Make and model: Boeing 737990ER
Aircraft serial: 41734
Aircraft time: 9,185 hours, 2,978 cycles
System (JASC): 2160 · Cabin Temperature Control System
Part: Filter
Part number: 412A160041
Condition: Dirty
Location: Cabin Air
Stage of operation: DE
How discovered: O
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

DURING DESCENT CONTROL CABIN TEMP WENT FULL COLD. TEMP SELECT KNOB HAD NO EFFECT ON DUCT TEMP. SELECTING KNOB TO OFF AND TEMP ROSE RAPIDLY TO HOT TEMP 60 DEG DUCT TEMP. ACFT GROUNDED. PERFORM PACK ZONE TEMP CONTROLLER BITE TEST. NO FAULTS NOTED. RAN CONTROL CABIN AIR, COULD NOT DUPLICATE. CLEANED CABIN TEMP SENSE FILTER PRECAUTIONARY REF AMM 21-61-00-700-806-002 AND AMM 21-61-06-000-801. ACFT OK FOR SERVICE.