# Incident 19981010043089I: Doug DC931, Philadelphia, PA, October 10, 1998

- Type: FAA incident report (Accident/Incident Data System), as reported
- Date: October 10, 1998
- Place: Philadelphia, PA
- Airport: Philadelphia International
- Phase of flight: Normal Cruise
- Operating rules: Air carrier (Part 121)
- Operator: USAA
- Location: 39.8721° N, 75.2407° W: Placed by OpenAirDocs at PHILADELPHIA INTL (PHL), within about a mile (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=39.8721&lon=-75.2407&mi=10
- Aircraft: N991VJ, a cancelled registration (https://openairdocs.org/deregistered/N991VJ-2005-02-07) (OpenAirDocs)
- Registry model: Douglas DC-9-31 (registry code 3022065, https://openairdocs.org/model/douglas-dc-9-31) (OpenAirDocs)
- Registry engine: Pratt & Whitney JT8D series (registry code 52053, https://openairdocs.org/engine/pratt-whitney-jt8d-series) (OpenAirDocs)
- Reported make and model: DOUG DC931
- Pilot flight hours: 14,876 total, 10,931 in this make and model, 184 in the last 90 days
- FAA source: FAA Aviation Safety Information Portal (https://asip.faa.gov/)
- Page: https://openairdocs.org/incident/19981010043089I

## Narrative

As the FAA filed it, in capitals; the FAA replaces private details with ^PRIVACY DATA OMITTED^.

(-5) THE FLIGHT CREW STATED THAT THEY WERE ENROUTE FROM WASHINGTON NATIONAL AIRPORT (DCA) TO LOGAN INTERNATIONAL AIRPORT (BOS). THE FLIGHT CREW DIVERTED AND LANDED AT PHILADELPHIA INTERNATIONAL AIRPORT (PHL) ON RUNWAY 27L DUE TO A RUDDER PROBLEM. THE FLIGHT CREW ALSO STATED THAT APPROXIMATELY, TWENTY-THREE MINUTES INTO FLIGHT DURING CLIMB THE AIRCRAFT EXPERIENCED UNCOMMANDED YAW TO THE LEFT. FOLLOWED BY OSCILLATION TO THE RIGHT AND LEFT OF 10 DEGREES. THIS OCCURRED WITH AUTOPILOT IN THE ON AND OFF POSITIONS. THE FLIGHT CREW FOLLOWED ALL PRECAUTIONARY PROCEDURES FOR UNCOMMANDED YAW. THE FLIGHT CREW LANDED THE AIRCRAFT SAFELY WITH 7 DEGREES LEFT RUDDER TRIM, RUDDER POWER CONTROL IN THE MANUAL POSITION, AND THE AUTOPILOT RUDDER SERVO IN THE OFF POSITION. THERE WERE NO INJURY TO THE PASSENGERS OR FLIGHT CREW PERSONNEL DURING LANDING. US AIRWAYS MAINTENANCE PERSONNEL INSPECTED FLIGHT CONTROLS AND FOUND NO FAULTS. MAINTENANCE PERSONNEL DECIDED TO REMOVE AND REPLACE THE YAW DAMPER ACTUATORS. THE SYSTEM WAS ADJUSTED AND TESTED ON THE GROUND BY MAINTENANCE PERSONNEL, SYSTEM OPS CHECKED AND TESTED GOOD. THE FLIGHT CREW WAS TASKED TO FUNCTIONAL CHECK THE YAW DAMPER SYSTEM.                    THE YAW DAMPER SYSTEM MET THE REQUIREMENTS FOR CAT II STATUS AND THE FUNCTIONAL CHECK WAS SATISFACTORY. THE AIRCRAFT HAS BEEN RETURNED TO SERVICE. THE US AIRWAYS PPM AND THE NTSB HAVE BEEN CONTACTED CONCERNING THE ABOVE MATTER. THIS CASE IS CONSIDERED CLOSED.

## Other reports on N991VJ (1)

Matched to the same aircraft by N-number and date.

- [Incident 19910608028609I](https://openairdocs.org/incident/19910608028609I), Jun 8, 1991: Doug DC931 (N991VJ), Omaha, NE. Crew took evasive action when TCAS alert sounded. Other aircraft had defective encoder.

From the FAA Accident/Incident Data System. Reports are matched to registry aircraft by N-number and event date, checked against the reported make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. For accidents, the NTSB's own investigation is the fuller record.

---
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.