Whether this - or already existing flaws that had left the Airbus vulnerable to turbulence - caused the plane to break apart is not yet clear.

But wake turbulence can be extremely strong and is known to have caused fatal crashes in the past.

To avoid running into this serious hazard planes are required to leave a gap of at least two minutes - or four nautical miles - before taking-off after the plane ahead of them.

Air traffic controllers did follow this protocol correctly, leaving a gap of two minutes 20 seconds in between clearing two planes to begin their journeys.

But a Japan Airlines jumbo jet seems to have paused slightly before take-off, leaving just one minute and 45 seconds between the two planes.