WASHINGTON -- The pilot of a mystery 'third airplane' that might have figured in a 1978 collision of two planes over San Diego that killed 144 people has been located and will testify to federal investigators, a government spokesman said Friday.
Brad Dunbar, spokesman for the National Transportation Safety Board, said the pilot, who was not identified, will give sworn testimony to board investigators in Hawthorne, Calif., on Monday.
The results could force the board to reopen its investigation of the disaster, which was blamed on the crew of the Pacific Southwest Airlines jetliner that collided with a Cessna 172 over San Diego's North Park residential area on Sept. 25, 1978.
It was the nation's worst air disaster up to that time.
The development fuels persistent speculation during the past two years that another Cessna had drawn the attention of the PSA cockpit crew, which had been advised by air controllers to watch out for a Cessna.
According to the speculation, spotting of the third aircraft could have lulled the PSA crew into a false sense of safety.
The jetliner was approaching Lindbergh Field as the Cessna 172 was ascending from Montgomery Field, a small airfield in San Diego, when the smaller plane grazed the jetliner's wing and sent it plunging to earth.
Dunbar said a student pilot in a Cessna 150 about the time of the PSA collision was located by an investigator in the board's Los Angeles field office.
On the basis of his testimony, Dunbar said, the safety board will decide whether to formally reopen its investigation of the accident. The NTSB's accident report after the crash concluded the PSA crew should have maintained separation of the two aircraft by visual means.
The Hawthorne hearing is the result of a petition by the Air Line Pilots Association, the nation's largest pilot's union, to reopen the case. The 'third plane' theory was raised during the board's formal investigation of the accident, but was dismissed for lack of evidence.
Harold Marthinsen, manager of accident investigation for the Air Line Pilots Association, disclosed earlier this week that he found the third plane, a Cessna 150, by tracing radar data from the Federal Aviation Administration and air traffic controllers.
Marthinsen said the PSA crew may have mistakenly acknowledged the Cessna 150 as the student-flown Cessna 172 they were advised to monitor. The pilot may never have seen the Cessna 172 before the crash, the investigator said.
He said he traced the aircraft to a flying club, but was unable to identify the pilot.
In its Nov. 5 letter, ALPA noted it submitted evidence earlier showing the radar track of a small craft that crossed the path of PSA Flight 182, but that the craft had been incorrectly identified as a Beech Baron.
The pilot of the Baron apparently incorrectly thought he saw the jetliner pass over him when he actually observed another PSA flight, adding to the confusion.
'We have now determined that the radar track was, in fact, the track of another Cessna and not the Beech Baron,' the letter said.
'The radar data and ATC transcript comments, when properly correlated, show that the crew of PSA 182 did in fact see a Cessna aircraft other than the one involved in the mid-air (collision),' the letter said.
'We have included the radar track of the Beech Baron because the pilot of that aircraft believed PSA 182 had passed over him as he proceeded to Montgomery Field. The data shows that he, in fact, observed PSA 766, which preceded PSA 182 into the Lindbergh area by several minutes.'