SDR ASAA2017040620383

Service difficulty report · Warning Light · Boeing 737990ER

Difficulty date: April 6, 2017
Submitted: April 10, 2017
Operation: Air carrier
Aircraft: N478AS
Make and model: Boeing 737990ER
Aircraft serial: 44105
Aircraft time: 7,156 hours, 2,384 cycles
System (JASC): 2150 · Cabin Cooling System
Part: Warning Light
Condition: False Activation
Location: Lt A/C Pack
Stage of operation: TX
How discovered: V
Nature of condition: J
Precautionary procedure: D

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

What was found

AFTER BOTH ENGINES STARTED, LEFT PACK LIGHT ILLUMINATED. FOLLOWED QRH PROCEDURE AND THE PACK LIGHT WENT OUT FOR A FEW SECONDS, THEN CAME BACK ON AGAIN AND COULD NOT EXTINGUISH THE PACK LIGHT. THE PACK TEMPERATURE SHOWS OVERHEAT. ACFT GROUNDED. REVERSED IAW AMM 21-00-00-440-801. ACCOMPLISHED BITE CK OF PACK/ ZONE TEMP CONTROLLERS IAW AMM 21-61-00-700-806-002. WITH & WITHOUT BLEED AIR, BITE CK WAS GOOD WITH NO FAULTS. GROUND VERIFICATION SUCCESSFUL. NO LIGHTS ILLUMINATE ON RECALL.