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| Title: | Flight control system oddities, McDonnell Douglas MD-82, April 11, 1998 |
| Micro summary: | This McDonnell Douglas MD-82 experienced a series of unusual flight control system behaviors. |
| Event Time: | 1998-04-11 at 645 EST |
| File Name: | 1998-04-11-US.pdf |
| Publishing Agency: | National Transportation Safety Board (NTSB) |
| Publishing Country: | USA |
| Report number: | CHI98IA167 |
| Pages: | 5 |
| Diversion Airport: | Washington Dulles International Airport, Washington, DC, USA |
| Site of event: | Washington, DC |
| Departure: | Ronald Reagan Washington National Airport, Arlington County, Virginia, USA |
| Destination: | Lambert Saint Louis International Airport, St. Louis, Missouri, USA |
| Airplane Type(s): | McDonnell Douglas DC-9-82 (MD-82) |
| Flight Phase: | Takeoff |
| Registration(s): | N951U |
| Operator(s): | Trans World Airlines |
| Type of flight: | Revenue |
| Occupants: | 84 |
| Fatalities: | 0 |
| Serious Injuries: | 0 |
| Minor/Non-Injured: | 84 |
| Other Injuries: | 0 |
| Diverted to: | Washington Dulles International Airport, Washington, DC, USA |
| Executive Summary: | NTSB short summary: The failure of the Dual Axis Accelerometer. NTSB synopsis: The Douglas MD82 experienced a flight control malfunction after takeoff and diverted to Dulles International Airport. The crew reported that they lost the autopilot, there were in-flight kicks on the rudder and the rudder tab was moving uncommanded on the ground. The Yaw Damper Actuator, Digital Flight Guidance Computer, and Dual Axis Accelerometer were removed for further testing. The Yaw Damper Actuator and the Digital Flight Guidance Computer passed testing. The Dual Axis Accelerometer was bench tested using test manual #22-19-01, Rev 1 at the avionics test center. The unit failed an original test and failed a second test after a metal sliver imbedded in the pins was removed. NTSB factual narrative text: On April 11, 1998, at 0645 est, N951U, a McDonnell Douglas MD82, being operated as Trans World Airlines flight number 235, from Washington National Airport to Saint Louis, Missouri, experienced a flight control malfunction after takeoff and diverted to Dulles International Airport. There was no damage to the aircraft and there were no injuries to the crew of 5 or 79 passengers. The flight was on an IFR flight plan and visual meteorological conditions prevailed. The crew reported that they lost the autopilot, there were inflight kicks on the rudder and the rudder tab was moving uncommanded on the ground. The aircraft was an MD-82, S/N 49245. The Yaw Damper Actuator, Digital Flight Guidance Computer, and Dual Axis Accelerometer were removed for further testing. The Yaw Damper Actuator and the Digital Flight Guidance Computer passed testing. The Dual Axis Accelerometer from the aircraft, PN 4034239-901, SN 8303033, was taken to the Honeywell Support Center in Dallas, Texas for further investigation. The part was bench tested using test manual #22-19-01, Rev 1 at the avionics test center. The unit failed an original test and failed a second test after a metal sliver imbedded in the pins was removed. See attached test report of the inspection conducted July 8, 1998. |
| Learning Keywords: | Operations - Maintenance |
| Operations - Upset - Uncommanded or excessive Yaw | |
| Systems - Flight Control System |
| Close match: | Uncommanded roll and yaw, Douglas DC-9-34, April 30, 1998 |
| Rudder hardover, Boeing 747-400, October 9, 2002 |
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