What was found
APU BLEED AIR DUCT PRESSURE IS VERY LOW (8 PSI) AND NOT COOLING THE MAIN CABIN SUFFICIENTLY. GROUNDED - YES. TROUBLESHOT PER FIM 49-53. WIRING CHECKS GOOD. REMOVED AND REPLACED APU ECU, REF AMM 49-61-12. OPS CHECKS GOOD.
- Difficulty date
- September 25, 2017
- Submitted
- September 27, 2017
- Operation
- Air carrier
- Aircraft
- N435AS
- Make and model
- Boeing 737990ER
- Aircraft serial
- 43292
- Aircraft time
- 15,641 hours, 5,157 cycles
- System (JASC)
- 4960 · APU Controls
- Part
- Ecu
- Part number
- 707208601
- Part serial
- 6505150200338
- Condition
- Failed
- Location
- Apu
- Part time
- 15,660 hours, 5,161 cycles
- Stage of operation
- NR
- How discovered
- O
- Nature of condition
- O
- Precautionary procedure
- K
As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.