Panel to Review Design of Wide-Body Jets

The Federal Aviation Administration, citing last month’s DC-10 crash in Sioux City, Iowa, and two other jumbo jet accidents, called Thursday for a design review and a possible redesign of wide-body aircraft to improve their ability to survive in-flight damage.

While investigators continued to comb the Sioux City cornfields for clues to explain the unprecedented explosion of the tail engine on the United Airlines jet, the FAA announced the formation of a task force to explore ways to better protect the control systems of DC-10s, Boeing 747s, Lockheed L-1011s, Airbus 300s and other wide-body jets.

Officials said they are not questioning the safety of the jumbo jets but are looking for ways to improve the margin of safety in unusual in-flight accidents.

Jets Termed Safe to Fly

“All jumbo jets that fly today and are certified by the FAA are safe to fly and provide the safest form of transportation available,” said Anthony J. Broderick, FAA deputy administrator for regulation and certification. “The task force will be charged with improving them even further.”

The task force, modeled on another panel formed to study aging aircraft, will include representatives of airlines, aircraft manufacturers and domestic and foreign government agencies.

The group will look at ways to protect the control lines by providing more, different or better backup systems and devices. That could mean more valves to prevent the loss of hydraulic fluid, or different placement of the valves and hydraulic lines or stronger materials.

A subgroup already has scheduled a meeting for Monday. Results will be reported as they are determined, with conclusions expected in two to four months, Broderick said. Although the task force does not have the power to order design changes, its recommendations would have significant weight with the FAA in any decision to formulate new design regulations.

Design changes could affect the 2,030 wide-bodies in service worldwide, said Avmark Inc., an aviation consulting firm. The changes, which could cost hundreds of millions of dollars, also would affect future aircraft such as the MD-11, the successor to the DC-10 planned by McDonnell Douglas.

McDonnell Douglas Corp. “supports the action of the FAA in setting up the task force,” spokesman Don Hanson said. “We are confident the results would benefit the entire commercial transportation industry.”

Boeing said it would participate in the task force but issued a statement suggesting that it already has accomplished what the task force seeks to do: “By design, the Boeing fleet is protected so that sufficient flight control power would be available to vital functions in the event of any uncontained engine or auxiliary power unit burst.”

A Lockheed spokesman said it would be premature to comment on the task force. He noted that Lockheed stopped producing commercial aircraft in 1983 but could be affected by any ordered retrofit.

FAA officials cited the July 19 crash in Iowa as the third accident in which major in-flight damage caused, or nearly caused, the total loss of control of an aircraft.

In the Iowa accident, the tail engine blew apart, spraying shrapnel that ruptured the three hydraulic systems that provide the pressure to control the flaps, slats, rudder and other parts that steer the plane.

In 1985, a Japan Air Lines Boeing 747 lost all four hydraulic systems after the aft bulkhead ruptured and a rush of air from the cabin knocked off part of the jet’s rudder and vertical stabilizer. After that accident, the FAA ordered Boeing to better separate the hydraulic lines in the tail.

In the third incident cited, an Eastern Air Lines L-1011 landed safely at John F. Kennedy International Airport in New York after part of the center engine broke in flight. The engine shaft broke, allowing the fan section to move into the fuselage.