WASHINGTON -- The National Transportation Safety Board called yesterday for immediate inspections and, if necessary, repairs of the rear-exit handles on DC-9s and MD-80s, warning that the devices had "serious deficiencies."
Federal Aviation Administration officials said that an order would be issued no later than tomorrow to all airlines to make the checks and fixes, an action that would affect more than 900 DC-9s and more than 800 MD-80s worldwide.
On many models of older DC-9s, the tail exit -- which requires passengers to open a door, then pull on a handle that opens up part of the aircraft's tail -- is the only escape route in the rear of the aircraft.
John Thom, spokesman for Douglas Aircraft Co. in Long Beach, Calif., maker of the jetliners, said his company already has alerted airlines to inspect the tail-cone release handles for possible problems.
However, Mr. Thom said, "In 25 years of service by DC-9s, we have had no other instances reported of a broken handle."
The government action follows an NTSB investigation that essentially concluded that a faulty handle caused the deaths of two people aboard a Northwest Airlines DC-9,which was hit by a Northwest Boeing 727 at Detroit Metropolitan Airport.
The NTSB said that the two people -- a flight attendant and a passenger -- died of smoke inhalation after they were trapped near the closed rear exit in the tail-cone area of the plane.
The NTSB said the tail cone did not open because the release handle was broken.
To leave a DC-9 or MD-80 at the rear, passengers must open a door at the end of the aisle, walk through a tunnel-like area, then pull a handle to release the aircraft's tail cone. The tail cone must pop off for a stairway or slide to deploy.
"The safety board's continuing investigation has found serious deficiencies with the manual release mechanism on the inside of the DC-9 tail cone," NTSB Chairman James Kolstad wrote to FAA Administrator James B. Busey.
Investigators found that the handle can break if it is pulled too hard or in the wrong direction.
The handle also can be jammed, they said.
The NTSB also found that the Detroit DC-9's tail-cone assembly had been reinstalled improperly by Northwest after an inspection, although "this rigging discrepancy alone would not have prevented the tail cone from being jettisoned."
Investigators said the tail cone had been jettisoned during a Nov. 6, 1990, inspection, and mechanics had not detected any problem with the release handle. But the NTSB also said that neither the mechanics nor the inspector who watched their work had been trained in installing a tail cone and that Northwest did not follow the inspection guidelines recommended by Douglas.
Other NTSB recommendations the FAA is expected to incorporate in its order include:
* A required redesign by Douglas of the tail-cone release mechanisms.
* A directive that airlines periodically inspect the tail-cone assemblies and release mechanisms.
* Immediate changes in maintenance manuals to detail how the release handles should be examined for damage.
* Immediate training for flight crew and flight attendants to make them more aware of how the tail-cone release handles operate and could be damaged.
Mr. Thom, who said Douglas has been working with the NTSB and the FAA on the tail-cone release issue, said that "if we determine that improvements are called for, we will take the necessary steps."
At the moment, Douglas was still studying the NTSB's findings, he said.