THE VIRGINIAN-PILOT
Copyright (c) 1996, Landmark Communications, Inc.
DATE: Wednesday, June 26, 1996 TAG: 9606260435
SECTION: LOCAL PAGE: B5 EDITION: FINAL
SOURCE: ASSOCIATED PRESS
DATELINE: RICHMOND LENGTH: 48 lines
Federal investigators have begun test flights in an effort to discover what caused a Boeing 737 to make an unexpected roll while making its approach this month at Richmond International Airport.
The Eastwind Airlines jet, carrying 53 passengers and crew members from Trenton, N.J., to Richmond, rolled 20 degrees to 30 degrees shortly before landing June 10, according to the National Transportation Safety Board.
The plane landed safely with no injuries or damage to the aircraft. It has since been removed from service.
Investigators are trying to pinpoint the cause of the ``uncommanded roll,'' which may be the cause of at least two fatal crashes involving 737s.
Julie Beal, a NTSB spokeswoman, said Monday that no cause for the roll has been established. She did not know how long the investigation would last or when the plane would return to service.
The NTSB, the Federal Aviation Administration, the Boeing Co., Eastwind, and USAir - which owns Eastwind - are all taking part in the investigation.
The 737 is the world's most popular passenger jet with more than 1,000 in service. Despite its good safety record, investigators have been concerned by the string of unexplained incidents.
A USAir 737 rolled over on approach to Pittsburgh in 1994 and crashed, killing all 132 on board. In 1991, a United Airlines 737 crashed on approach to Colorado Springs, killing 25. Both accidents occurred on clear, calm days and remain unexplained.
There have been dozens of other incidents involving 737s that did not result in crashes. Much attention has focused on the plane's rudder, which controls side to side movement, or yaw. A sudden swing of the rudder, either through pilot error or mechanical problem, could cause the plane to roll, aviation experts say.
Bud Sawatsky, an aviation consultant and a former 737 pilot and instructor, said he suspects a mechanical problem with the 737's yaw damper as a culprit in the string of incidents. The yaw damper is a device that automatically adjusts the rudder to make for a smooth flight.
Sawatsky said the 737 is built with backup systems and that it usually takes several rare mishaps occurring in unison to cause a disaster.
Sawatsky, who lives in Vancouver, British Columbia, said he's spent 5,000 hours in 737s, landed them on ice fields and short gravel runways, and can attest to their overall safety.
``I'd fly that thing anywhere. It's a beautiful little plane,'' he said. by CNB