Evidence Points to Pilots’ Failure to Deploy Flaps : New Data on Detroit Jet Crash Released

Federal investigators disclosed additional evidence Friday that the pilots’ failure to deploy wing flaps on takeoff may have caused the Aug. 16 crash of a Northwest Airlines jetliner in Detroit that claimed 156 lives.

The evidence included:

--A transcript of the cockpit conversations that shows Flight 255--a twin-engine MD-80 bound for Phoenix and Orange County’s John Wayne Airport--was in trouble almost immediately after lifting off from Detroit’s Metropolitan Airport.

--Examination of the wreckage confirms earlier readouts from the plane’s “black box” flight data recorder indicating that the flaps, which give the plane additional lift on takeoff, were in an “unusual” retracted position.

--Tests show that a lack of electrical power caused the failure of a warning alarm to alert the cockpit crew that the flaps were not deployed. The seemingly amazing coincidence of the failure to deploy the flaps and the apparently unrelated failure of the flap deployment warning system had been revealed earlier, but investigators had not previously disclosed the power loss.

--The transcript from the plane’s cockpit voice recorder shows the pilot and co-pilot apparently failed to set the plane’s thrust computer indicator (TCI), evidence that they ignored standard preflight procedures. However, investigators say the apparent failure to set the indicator, which prevented the automatic throttle system from engaging, apparently did not contribute to the accident.

Omitted Mention

The National Transportation Safety Board had revealed earlier that preliminary studies of the transcript showed that when the pilot and first officer went through their mandatory preflight check, they omitted mention of the flaps, which are included on the checklist.

The safety board has yet to complete its investigation or determine a precise cause or causes for the crash. While attention has focused on the undeployed flaps, dangerous wind conditions caused by nearby thunderstorms have been suggested as a contributing factor.

Several witnesses said they thought the plane’s left engine was on fire seconds after takeoff, but the board has found no evidence to support this, and Federal Aviation Administration experts said “backfires” can create the false impression that an engine is aflame.

The full transcript released Friday showed that Flight 255--carrying 149 passengers, four flight attendants, pilot John Maus and co-pilot David Dodds--began accelerating down the runway about 16 seconds after being cleared by the airport control tower for takeoff.

Seven seconds later, Maus complained to Dodds that the automatic throttle “won’t stay on.”

“Won’t go on?” Dodds replied.

“But they won’t stay on,” Maus said.

A second later, Dodds announced, “OK, power’s normal.”

“TCI was unset,” Maus explained.

“There, on now,” Dodds said.

Fourteen seconds later, Dodds announced that the plane had rotated into the nose-up attitude that immediately precedes liftoff.

About three seconds after the sounds of liftoff, the harsh rattle of the plane’s stall alarm could be heard echoing through the cockpit, joined an instant later by the sound of a secondary alarm that issues a verbal warning generated by computer.

Dodd’s voice can be heard in an apparent call for more thrust to climb out of the stall. After that, there is only one more intelligible word from the cockpit--a single expletive, shouted by the co-pilot.

Separate Sounds

Seven separate sounds of impact were picked up on the tape in the five seconds before the recording came to an end.

The plane disintegrated in a fireball that exploded down a four-lane highway, killing two people in vehicles on the roadway and injuring at least seven.

There was one survivor from the plane--4-year-old Cecilia Cichan, who continues to recover from severe burns sustained in the crash.

Rachel Halterman, a spokeswoman for the safety board, said Friday that tests show that in the seconds prior to the crash there was no electrical power for a backup system in the cockpit that could have warned the pilots that the flaps were not deployed.

“Why there wasn’t any power has yet to be determined,” she said.

However, speculation still centers on the possibility that some of the circuit breakers in the power system may have “popped” into the “off” position prior to the crash.