SDR ASAA2020012281899

Service difficulty report · Sensor · Boeing 737990ER

Difficulty date: January 18, 2020
Submitted: January 29, 2020
Operation: Air carrier
Aircraft: N494AS
Make and model: Boeing 737990ER
Aircraft serial: 41729
Aircraft time: 15,752 hours, 4,952 cycles
System (JASC): 2150 · Cabin Cooling System
Part: Sensor
Part number: 51090306002
Condition: Faulted
Location: Lt Pack Flow
Stage of operation: NR
How discovered: V
Nature of condition: J
Precautionary procedure: O

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

What was found

LEFT PACK LIGHT ILLUMINATES ON RECALL AND EXTINGUISHES ON RESET. GROUNDED - YES. BITE OF LEFT PACK FLOW TEMP CONTROLLER PER B737-900 FIM 21-62 TASK 801 SHOWED FAULT 21-51246, PACK FLOW SENSOR. ACCOMPLISHED T/S FOR FAULT 21-51246 PER FIM 21-62 TASK 860, CLEARED FAULT AND OPERATED LEFT PACK, FAULT 21-51246 CAME BACK. SUSPECT LEFT PACK FLOW SENSOR HEATER ELEMENT OPEN. REMOVED & REPLACED LEFT PACK FLOW SENSOR IAW AMM 21-51-43, OPS CHECK GOOD.