The data recorded by onboard sensors point towards an "internal explosion", one professional pilot concluded.
Here are some data that was published by the Aviation Herald.
00:26Z 3044 ANTI ICE R WINDOW
00:26Z 561200 R SLIDING WINDOW SENSOR
00:26Z 2600 SMOKE LAVATORY SMOKE
00:27Z 2600 AVIONICS SMOKE
00:28Z 561100 R FIXED WINDOW SENSOR
00:29Z 2200 AUTO FLT FCU 2 FAULT
00:29Z 2700 F/CTL SEC 3 FAULT
The Telegraph Reporter spoke to a European airline pilot who helped make sense of the data from the ACARS (Aircraft Communications Addressing and Reporting System).
He is an aviation professional who tells a terrifying story of a series of cascading faults before the system stopped transmitting.
The ACARS sends short transmissions from the aircraft's internal systems to receivers on the ground. It is nowhere near as detailed as a blackbox recorder but it gives some sense of what was happening on the plane.
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The European pilot helped decode each entry. Here's what they all mean:
"Each entry begins with a time stamp, like 00:26Z. This is referring to Zulu time, which is the same as GMT, but is used by sailors and fliers across the world to coordinate movements and make sure they are all running to the same schedule. 00:26 Zulu time would have been 02:26am above the Mediterranean."
00:26Z 3044 ANTI ICE R WINDOW: There's a fault in the right cockpit window's heating element. The window should be heated to stave off ice but it isn't working.
00:26Z 561200 R SLIDING WINDOW SENSOR: There's a fault in the co-pilot's sliding window sensor. This sensor tells the crew if a cockpit window is closed or not.
00:26Z 2600 SMOKE LAVATORY SMOKE: Smoke has been detected in one of the lavatories. The smoke detector is an optical sensor and detects if a cloud has come between two points of light. It detects smoke but also fog inside the cabin.
00:27Z 2600 AVIONICS SMOKE: Smoke has been detected in the avionics compartment. Located underneath the cockpit, this area can be entered via a latch in the cockpit or via a latch at the nose wheel. It is a big area where all the aircraft computers are located.
00:28Z 561100 R FIXED WINDOW SENSOR: There's a fault in another cockpit window on the right side.
00:29Z 2200 AUTO FLT FCU 2 FAULT: There's a fault in the Autopilot Flight Control Unit 2. There are two channels in the control unit and losing one will result in the spare one taking over automatically.
00:29Z 2700 F/CTL SEC 3 FAULT: There's a fault in the system that controls the wing's spoilers, the portion of the wing that rises during landing. This is the final entry.
Each entry tells a discrete story about some part of the aircraft breaking down. But what do they mean altogether?
Firstly, they indicate that something catastrophic happened to the plane in the air, which would seem to rule out a deliberate crash by the pilots or a hijacking that forced the plane into the sea.
The pilot who decode data says "internal explosion" seemed the most likely explanation, based especially on the problems with windows in the cockpit. "It looks like the right front and side window were blown out, most probably from inside out," he said.
The fact that the sensors in the cockpit were triggered doesn't mean the explosion came from the cockpit. There are more sensors at the front of the plane so there could be something going wrong in the main cabin but the sensors are not picking it up.
"The two smoke related messages also point to something happening inside of the cabin. The pilot suggested it could be fog suddenly filling the air due to a sudden loss of cabin pressure."
There could have been a fire onboard but the pilot felt that the crew would have had time to notify air traffic control of a fire.
They also would have pointed towards an airport for an emergency landing rather than making a series of drastic spins and turns.
The data on its own is far from definitive. But it seems to point towards a bomb onboard.
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