# SDR 9508636637

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: May 27, 1995
- Submitted: March 26, 2000
- Operation: Air carrier
- Aircraft: N637US
- Make and model: Boeing 747251B
- Aircraft serial: 23548
- System (JASC): [3441 · Inertial Guidance System](https://openairdocs.org/jasc/3441)
- Part: Ins
- Part number: 7883450041
- Condition: Malfunctioned
- Location: E/E Compartment
- Part time: 22,107 hours
- Stage of operation: CR
- Nature of condition: J
- Precautionary procedure: A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/9508636637

## Discrepancy

DURING CRUISE, THE NR 1 AND NR 2 INS RED WARNING LIGHT ILLUMINATED CONSECUTIVELY.  CREW FOLLOWED COCKPIT OPERATING MANUAL AND DIVERTED FLIGHT TO ANC.  MAINTENANCE REPLACED THE NR 1 INS AND PERFORMED CHECK, CHECK WAS NORMAL.  THE NR 1 INS RED WARNING LIGHT ILLUMINATED.  THE NR 2 INS DID NOT HAVE A PROBLEM.  THE FLIGHT DIVERTED TO ANC, BECAUSE THE FLIGHT COULD NOT USE RUSSIAN AIRSPACE.

---
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.