A piece of luggage adrift in the Mediterranean Sea. Floating nearby, a passenger seat from a plane. Scraps of metal, scattered personal belongings and, finally, the grim discovery of human remains.
As the investigation continued Friday into what caused an EgyptAir flight from Paris to Cairo to suddenly and violently plunge from the sky, the discovery of the debris allowed search crews to home in on the location of the crash - an area about 180 miles north of Alexandria, Egypt - even as its cause remained a mystery and the subject of intense speculation.
Data that was transmitted from the aircraft to operators on the ground, published Friday by a respected aviation journal, revealed a rapid loss of control, with alarms and computer-system failures in the seconds before the plane was lost from radar.
The transmissions are evidence of a catastrophic failure, but do not answer the crucial question: What caused it? Why would a plane with a good safety record and experienced pilots fall from the sky on a clear spring night?
No bulk wreckage has been found, and the parts of the aircraft most likely to provide clues for investigators - including the voice and data recorders - are also the ones most likely to quickly sink to the seafloor.
An Egyptian official has said that investigators consider terrorism to be one possible cause of the disaster, but no terrorist group has claimed responsibility. Officials cautioned that there was no direct evidence to suggest a bomb aboard the plane, or any other deliberate act of sabotage.
The plane, a twin-engine Airbus A320 jet, went down Thursday while flying through a cloudless night sky en route to Cairo from Paris.
The Hellenic Civil Aviation Authority provided what a spokesman called a definitive timeline on the disaster. The agency reported that the flight was proceeding normally at 1:48 am Cairo time on Thursday, when Greek traffic controllers last spoke with the pilot, who seemed in good spirits.
At 2:27 am, when the plane was passing from Greek to Egyptian-supervised airspace, the controllers in Athens tried and failed repeatedly to reach the pilots by radio. Even attempts on an emergency frequency failed.
At the same time, technical data was being transmitted from the plane automatically through its Aircraft Communications Addressing and Reporting System, or Acars, which modern jetliners use to provide status updates to maintenance and operational centres on the ground.
Representatives of Airbus and the Federal Aviation Administration said they could not confirm the authenticity of the technical signals. Dina El-Fouly, a spokeswoman for EgyptAir, declined to comment on the apparently leaked data.
Finally at 2:29, there were two more alerts having to do with the plane's flight control computer systems.
"The last two are troubling," Mann said. "You are starting to really see things rapidly degrade."
First, there was a problem with the autoflight control computer. The jet would have been flying near its maximum speed and elevation at that time. That is the most efficient way for jetliners to fly, and it is safe, but pilots prefer to rely on autopilot systems in those conditions because if they were to ever lose control of the plane, it could be hard to regain, Mann said. That is why pilots sometimes call those conditions the "coffin corner."
The last message had to do with the spoiler elevator controller, which essentially controls the flaps responsible for pitch and roll control. The computer controlling these failed as well.
"It looks to me like you have a progressive flight control system failure," Mann said. It is over the course of two minutes, which might have seemed like an eternity on that plane, but is relatively fast.
This is also the moment that the plane left Greek airspace, and at 2:29:40 am, Greek controllers lost the aircraft's trace, just inside Egyptian airspace, about halfway between Crete and Egypt.
Around this time, the plane made a 90-degree turn to the left and then a full circle to the right, dropping precipitously to 15,000 feet from 37,000 and then plunging again to 9,000 feet before it disappeared from radar.
"We cannot say anything, because we have already launched a committee to investigate the crash," she said. "It hasn't told us anything until now."
The data, first reported on AVHerald.com, is written tersely in abbreviations and codes. Robert W. Mann, a former airline executive and an industry analyst, said the jargon in the messages told a compelling, although incomplete, story.
At 2:26 am, a message indicated that the right cockpit window had been opened. This could have been done to vent smoke, Mann said, or something else could have caused the breach.
Over the next two minutes, there were two smoke indications, one in a bathroom and another in the avionics bay, the part of the plane where much of its electronic equipment is housed.
Mann cautioned that these messages did not necessarily mean that there was a fire. The messages could also have been prompted by rapid decompression of the aircraft, which can produce condensation that the plane's sensors could mistake for smoke.
Finally at 2:29, there were two more alerts having to do with the plane's flight control computer systems.
"The last two are troubling," Mann said. "You are starting to really see things rapidly degrade."
First, there was a problem with the autoflight control computer. The jet would have been flying near its maximum speed and elevation at that time. That is the most efficient way for jetliners to fly, and it is safe, but pilots prefer to rely on autopilot systems in those conditions because if they were to ever lose control of the plane, it could be hard to regain, Mann said. That is why pilots sometimes call those conditions the "coffin corner."
The last message had to do with the spoiler elevator controller, which essentially controls the flaps responsible for pitch and roll control. The computer controlling these failed as well.
"It looks to me like you have a progressive flight control system failure," Mann said. It is over the course of two minutes, which might have seemed like an eternity on that plane, but is relatively fast.
As the investigation continued Friday into what caused an EgyptAir flight from Paris to Cairo to suddenly and violently plunge from the sky, the discovery of the debris allowed search crews to home in on the location of the crash - an area about 180 miles north of Alexandria, Egypt - even as its cause remained a mystery and the subject of intense speculation.
Data that was transmitted from the aircraft to operators on the ground, published Friday by a respected aviation journal, revealed a rapid loss of control, with alarms and computer-system failures in the seconds before the plane was lost from radar.
The transmissions are evidence of a catastrophic failure, but do not answer the crucial question: What caused it? Why would a plane with a good safety record and experienced pilots fall from the sky on a clear spring night?
No bulk wreckage has been found, and the parts of the aircraft most likely to provide clues for investigators - including the voice and data recorders - are also the ones most likely to quickly sink to the seafloor.
An Egyptian official has said that investigators consider terrorism to be one possible cause of the disaster, but no terrorist group has claimed responsibility. Officials cautioned that there was no direct evidence to suggest a bomb aboard the plane, or any other deliberate act of sabotage.
The plane, a twin-engine Airbus A320 jet, went down Thursday while flying through a cloudless night sky en route to Cairo from Paris.
The Hellenic Civil Aviation Authority provided what a spokesman called a definitive timeline on the disaster. The agency reported that the flight was proceeding normally at 1:48 am Cairo time on Thursday, when Greek traffic controllers last spoke with the pilot, who seemed in good spirits.
At 2:27 am, when the plane was passing from Greek to Egyptian-supervised airspace, the controllers in Athens tried and failed repeatedly to reach the pilots by radio. Even attempts on an emergency frequency failed.
At the same time, technical data was being transmitted from the plane automatically through its Aircraft Communications Addressing and Reporting System, or Acars, which modern jetliners use to provide status updates to maintenance and operational centres on the ground.
Representatives of Airbus and the Federal Aviation Administration said they could not confirm the authenticity of the technical signals. Dina El-Fouly, a spokeswoman for EgyptAir, declined to comment on the apparently leaked data.
Finally at 2:29, there were two more alerts having to do with the plane's flight control computer systems.
"The last two are troubling," Mann said. "You are starting to really see things rapidly degrade."
First, there was a problem with the autoflight control computer. The jet would have been flying near its maximum speed and elevation at that time. That is the most efficient way for jetliners to fly, and it is safe, but pilots prefer to rely on autopilot systems in those conditions because if they were to ever lose control of the plane, it could be hard to regain, Mann said. That is why pilots sometimes call those conditions the "coffin corner."
The last message had to do with the spoiler elevator controller, which essentially controls the flaps responsible for pitch and roll control. The computer controlling these failed as well.
"It looks to me like you have a progressive flight control system failure," Mann said. It is over the course of two minutes, which might have seemed like an eternity on that plane, but is relatively fast.
This is also the moment that the plane left Greek airspace, and at 2:29:40 am, Greek controllers lost the aircraft's trace, just inside Egyptian airspace, about halfway between Crete and Egypt.
Around this time, the plane made a 90-degree turn to the left and then a full circle to the right, dropping precipitously to 15,000 feet from 37,000 and then plunging again to 9,000 feet before it disappeared from radar.
"We cannot say anything, because we have already launched a committee to investigate the crash," she said. "It hasn't told us anything until now."
The data, first reported on AVHerald.com, is written tersely in abbreviations and codes. Robert W. Mann, a former airline executive and an industry analyst, said the jargon in the messages told a compelling, although incomplete, story.
At 2:26 am, a message indicated that the right cockpit window had been opened. This could have been done to vent smoke, Mann said, or something else could have caused the breach.
Over the next two minutes, there were two smoke indications, one in a bathroom and another in the avionics bay, the part of the plane where much of its electronic equipment is housed.
Mann cautioned that these messages did not necessarily mean that there was a fire. The messages could also have been prompted by rapid decompression of the aircraft, which can produce condensation that the plane's sensors could mistake for smoke.
Finally at 2:29, there were two more alerts having to do with the plane's flight control computer systems.
"The last two are troubling," Mann said. "You are starting to really see things rapidly degrade."
First, there was a problem with the autoflight control computer. The jet would have been flying near its maximum speed and elevation at that time. That is the most efficient way for jetliners to fly, and it is safe, but pilots prefer to rely on autopilot systems in those conditions because if they were to ever lose control of the plane, it could be hard to regain, Mann said. That is why pilots sometimes call those conditions the "coffin corner."
The last message had to do with the spoiler elevator controller, which essentially controls the flaps responsible for pitch and roll control. The computer controlling these failed as well.
"It looks to me like you have a progressive flight control system failure," Mann said. It is over the course of two minutes, which might have seemed like an eternity on that plane, but is relatively fast.
© 2016 The New York Times News Service