Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: TUESDAY, March 13, 1990 TAG: 9003133108
SECTION: NATIONAL/INTERNATIONAL PAGE: A3 EDITION: METRO
SOURCE: Associated Press
DATELINE: WASHINGTON LENGTH: Medium
The tentative orders came eight months after a United DC-10-10 crashed in Sioux City, Iowa, killing 112 of the 295 people aboard.
Investigation into the crash continues, but pilots said they lost hydraulic steering control after the plane's tail engine exploded.
The Federal Aviation Administration's proposed "airworthiness directive" follows changes recommended in the airliner by its manufacturer, McDonnell Douglas Corp.
"The change would preserve enough hydraulic fluid following damage to the system to enable the flight crew to safely fly and land the airplane," the FAA said.
After the order goes into effect, after several weeks for comment, airlines would have six months to make the modifications in DC-10-10s and a year for all other DC-10 models.
Investigators into the July 19 Iowa crash have said they believe flying debris from the explosive tail engine failure severed all three of the jetliner's independent hydraulic systems that control flight.
A final National Transportation Safety Board report on the accident is expected in a few months.
The FAA-imposed modification would involve installing devices in the hydraulic system that would keep fluid from leaking out in the event the lines in the tail section, where the hydraulic systems come the closest together, are cut.
With the change, the pilot would still lose control over the rudder, which turns the airliner, and the elevators, which control climb and decent.
But other control surfaces, including the ailerons, which make it possible to keep the wings level, would remain operable, the FAA said.
If the separate system that controls the horizontal stabilizer trim was left intact, the crew also could control the angle of decent, the FAA said.
Pilots of the United plane said their only means of steering the aircraft and controlling decent was to selectively accelerate the remaining wing engines.
by CNB