Northwest Minimizes Safety Incidents : Aviation: FAA official claims ‘thread of pilot error.’ Company calls events ‘anomalies’ in testimony at hearing on Detroit runway collision.
A federal official’s concerns about “an inordinate number of pilot-induced safety infractions” at Northwest Airlines in the months before a runway collision between two of the airline’s jets were aired here Wednesday at a hearing about the accident.
The infractions--which included two attempts to land at the wrong airport and three purported attempts to take off with improper flap settings--were listed in documents discussed during the third day of the National Transportation Safety Board’s hearings to determine the cause of the Dec. 3 crash that killed eight and injured 21 at Detroit Metropolitan Airport.
Improper deployment of flaps--slab-like extensions that increase the lifting power of a plane’s wings--has been blamed in several airline accidents, among them the crash of another Northwest jet that was attempting to take off from Detroit Metropolitan on Aug. 16, 1987.
The 1987 crash here killed 154 passengers and two people on the ground. The only on-board survivor was a 4-year-old girl.
A Northwest executive minimized most of the more recent incidents that were enumerated in the documents and characterized them as “anomalies” rather than examples of current systemwide problems.
“There’s no thread here” connecting the infractions cited by the Federal Aviation Administration with the Dec. 3 crash that occurred when a DC-9 strayed into the path of a Boeing 727 that was accelerating down a fog-shrouded runway on takeoff, Stuart L. Henning, Northwest’s vice president for flight operations, said in an interview.
“The (safety) trend has not been downward . . . or level,” Henning said. “The trend has been upward.”
On the other hand, FAA unit supervisor Louis J. Martin testified Wednesday that the incidents cited show “a common thread of pilot error . . . Each and every one of them was a potential accident.”
The documents discussed Wednesday disclosed that on Oct. 29 Martin wrote a letter to Henning asking about Henning’s “plan of action toward correcting what seems to be an inordinate number of pilot-induced safety infractions in the DC-9 fleet . . . .”
“In a relatively short period of time,” Martin wrote, there have been approaches to wrong airports . . . mismanagement of (a) routine CSD (generator) problem . . . attempts at takeoff with improper flap settings and three tail strikes (rubbing of a plane’s tail against the runway while lifting off).”
When asked Wednesday about the incidents cited by Martin, Henning said that a DC-9 attempting to set down in bad weather at Rapid City, N.D., on July 9 almost landed at nearby Ellsworth Air Force Base by mistake. The pilot realized his error about 1,000 feet above the ground, pulled up and continued on to Rapid City.
In a similar incident a month later, another DC-9, scheduled to land at Green Bay, Wis., had to pull up suddenly when the pilot realized he was mistakenly setting down at Appleton, Wis., Henning said. Once again, the pilot pulled up in time and continued on to the proper airfield.
Martin said the mismanagement of the CSD--a “constant speed drive” generator that provides electrical power for the aircraft--occurred in October, 1989, when a DC-9 pilot noted that one of the two CSDs on board was malfunctioning, but mistakenly turned off the one that was operating properly.
CSDs can only be restarted by ground crews, so when the malfunctioning unit failed altogether, the plane was plunged into darkness. Henning’s associates said batteries provided only enough electricity to power a few basic instruments for about 30 minutes, so the pilot had to attempt a landing as quickly as possible, without the aid of most of his navigational equipment.
When trying to land at Colorado Springs, Colo., the pilot mistakenly set down at a smaller nearby airport at Monte Vista, Colo., but the landing was successful and no one was injured.
Henning said of the incident that there is “no doubt that there was an individual crew screw-up there.”
He said two of the no-flap takeoffs cited involved reports by passengers that neither the FAA nor the airline have been able to confirm.
The third, he said, occurred at Minneapolis on Sept. 22, but the pilot caught and corrected his error before actually taking off, and the plane lifted off without incident.
He said the tail strikes involved situations in which the planes tipped upward too steeply on takeoff, scraping the underside of their tail sections on the pavement as they lifted off. DC-9s are equipped with tail skid plates, he said, so no damage was done and the takeoffs were otherwise normal.
“I don’t consider those a problem,” Henning said.
In contrast, Martin said the tail strikes were pilot errors that “should be taken seriously.”
On Dec. 5, Martin wrote Henning’s boss, Northwest board Chairman Alfred A. Checchi, complaining about the lack of response to two letters he had written questioning the airline’s pilot training procedures and record-keeping.
Two days later, Henning sent Martin a letter detailing the actions Northwest had taken in response to his concerns.
Among those actions, Henning said, was appointment of a committee, which has recommended expanded training, formation of a pilot advisory council and formation of a training work group. He said all “will be accomplished.”
