# SDR MEX2002245

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: July 29, 2002
- Submitted: August 14, 2002
- Operation: Air carrier
- Aircraft: N491SH
- Make and model: Doug DC-9-82
- Registry model: [Doug DC-9-82](https://openairdocs.org/model/mcdonnell-douglas-dc-9-82) (OpenAirDocs)
- Aircraft serial: 49150
- System (JASC): [3441 · Inertial Guidance System](https://openairdocs.org/jasc/3441)
- Part: Flow Valve
- Part number: 2587794
- Condition: Failed
- Location: Compass
- Stage of operation: NR
- How discovered: O
- Nature of condition: J
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/MEX2002245

## Discrepancy

PILOT REPORTED A DIFFERENCE OF 6 DEGREES BETWEEN COMPASS AND RADAR WITH AN INDICATION FAILURE AND FLIGHT DIRECTORS OUT OF SERVICE IN TAKE OFF.  DUE TO SUCH A FAILURE,  A CHANGE OF EQUIPMENT WAS REQUESTED.  THE FLOW VALVE OF THE COMPASS SYSTEM WAS REPLACED, IAW MM, TEST OK.

---
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.