PARIS — Accident investigators examining flight data from the doomed Air France Concorde discovered Thursday that both engines on the port side of the supersonic jet failed during takeoff and that the cockpit crew was unable to retract the plane's landing gear once it was airborne.
The latest clues to the cause of a crash that shattered Concorde's fatality-free safety record of 30 years were contained in a preliminary report by the French Accident Investigation Bureau, or BEA, and provide a more thorough picture of the ill-fated flight's harrowing final seconds.
Those details emerged shortly after the latest and largest memorial to honor the 113 victims of Tuesday's crash--the first involving the elite delta-winged jets since they began ferrying the rich, famous and adventurous across the Atlantic more than 20 years ago. At least 1,000 mourners gathered at Paris' imposing 19th century Madeleine church to light candles, lay wreaths and remember the victims.
Communications between the Concorde pilot and air-traffic controllers released a day earlier focused suspicion on failure of the No. 2 engine as the likely cause of the disaster whose victims were mostly German tourists headed for a luxury cruise in the Americas.
But new details emerging about the last moments of the oldest of 13 Concordes that had been in commercial service suggest that the accident was preceded by a broader array of breakdowns that left a trail of debris along the flight path.
Not only the No. 2 engine--the innermost of the two on the Concorde's left wing--but the No. 1 engine next to it lost power twice during takeoff, the BEA concluded from the recorded flight data.
"During takeoff, when the aircraft had passed the point where it could no longer abort, the control tower signaled to the crew that there were flames at the rear of the plane," the BEA reported.
"In the sound recording, we noted that the crew announced a problem in engine No. 2, and a little later they said the undercarriage would not come up," the flight-data analysis continued. It also noted that the pilot had been informed that flames were trailing his aircraft while it accelerated on the runway.
Although cockpit crew members were aware that their jet was in trouble as it left the ground, they might have sought to retract the landing gear to reduce drag as it struggled, unsuccessfully, to gain altitude and speed.
"Debris was discovered all along the trajectory of the aircraft. In particular, we have found remains of tires on the runway," investigators reported.
Shortly after the No. 2 engine failed, the BEA report said, the other port engine lost power twice in the short period--less than a minute--between takeoff and the fiery crash.
Investigators emphasized that their report was preliminary and that many other factors coded into the flight data recorder require further analysis that will take at least a month.
Authorities cautioned aviation analysts against drawing premature conclusions about the cause of the crash. Many have speculated since disclosure Wednesday of preflight repairs to the No. 2 engine that the problem prompting that last-minute maintenance to fix a failed thrust reverser might have caused the engine to explode.
"Let the investigators do their work," national civil aviation director Pierre Graf appealed amid the profusion of theories on the cause of the crash.
French media reports carried detailed interviews with pilots and other aviation experts speculating that the explosion and fire might have been caused by a foreign object--perhaps a bird or a scrap of tire--getting into the engine.
Technicians have been focusing on turbine blades that draw air into the plane's Rolls-Royce engines. Six of the remaining 12 Concordes have been restored to active service by their owner, British Airways--while one remains grounded--and the five surviving Air France supersonics have been grounded pending the investigations.
Those searching for the cause of the crash were also examining an amateur video that was brought to public attention the day after the disaster. The film was made by the wife of a truck driver as the vehicle passed near Charles de Gaulle Airport and captures the last seconds of the Concorde's flight as it trailed flame and smoke across the horizon.
As investigators combed the charred wreckage and the flight path to reconstruct the disaster, forensic investigators retrieved the last of the bodies from the crash scene and transferred them to a Paris morgue.
They also gathered relatives of the victims to explain that it will be days, if not weeks, before the bodies of their loved ones can be released for burial or cremation. Many of the dead were burned beyond recognition, and dental or DNA records will be needed for positive identification.