# SDR 99UAL900634

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: December 6, 1999
- Submitted: March 26, 2000
- Operation: Air carrier
- Aircraft: N547UA
- Make and model: Boeing 757222
- Aircraft serial: 25368
- Engine: Pwa PW2037
- System (JASC): [2421 · AC Generator-Alternator](https://openairdocs.org/jasc/2421)
- Part: Generator
- Condition: Failed
- Location: Lt Engine
- Component: Hamilton Sun, 729825G
- Stage of operation: NR
- Nature of condition: J
- Precautionary procedure: A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/99UAL900634

## Discrepancy

AIRCRAFT RETURNED TO ORD, DUE TO LEFT ENGINE GENERATOR PROBLEM.  REPLACED LEFT (NR 1) INTEGRATED DRIVE GENERATOR (IDG).  THE IDG HAD AN INTERNAL DIODE FAILURE.

---
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, except the copies of manufacturers’ service documents, which belong to their rights holders.