# SDR 97UAL900178

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: March 5, 1997
- Submitted: March 26, 2000
- Operation: Air carrier
- Aircraft: [N779UA](https://openairdocs.org/aircraft/N779UA), registered now
- Make and model: Boeing 777222
- Aircraft serial: 26941
- Engine: Pwa PW4077
- System (JASC): [4950 · APU Bleed Air System](https://openairdocs.org/jasc/4950)
- Part: Check Valve
- Part number: 32026104
- Condition: Damaged
- Location: Apu
- Part time: 2,700 hours
- Stage of operation: TX
- Nature of condition: O
- Precautionary procedure: D
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/97UAL900178

## Discrepancy

AIRCRAFT RETURNED TO BLOCKS WITH LOUD BANGING NOISE.  FOUND VIBRATION IN DUCTING FROM LEFT PACK TO THE APU.  *S/D*  LOUD BANGING AND FLAMES OUT OF EXHAUST WHILE MOTORING APU.  FOUND .125 INCH DIAMETER OVAL HOLE IN APU CHECK VALVE (P/N 3202610-4).  APU REPLACED.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.