According to former FAA chief of staff Michael Goldfarb, that is "very unusual" and suggests a "catastrophic" incident, as opposed to engine failure.
An airliner should be able to keep flying even if one engine fails, which means pilots normally have time to communicate and recover the aircraft.
"When the data is lost at 8,000 feet suddenly that implies something catastrophic happened to that airplane and they could no longer communicate with the ground control," Goldfarb told CNN.
There is no indication at this stage of what may have caused a catastrophic incident on board the plane, and all options are still on the table.
Goldfarb said an "uncontained" engine failure -- which would create the type of large fire ball reported by witnesses -- could be to blame, but it was too early to tell. An uncontained engine failure, in which pieces of the engine break apart, releases shrapnel that can destroy the plane.
"Under terrorism, of course, any type of explosive device would obviously cause catastrophic loss of the hull," Goldfarb added.
Alan Diehl, a former accident investigator for the US National Transportation Safety Board, Federal Aviation Administration and Air Force, said that that engine failure would naturally be one of the main focuses of any investigation into the crash, considering the aircraft lost contact just minutes after takeoff.
"That's the second-most dangerous phase of flight, the most dangerous being the approach of landing, statistically speaking. That's when the engines are under maximum stress."
He said investigators always looks at four main causes in a crash -- mechanical, human, environment and lastly hostile actions. "All of those are certainly on the table."
коротко
бывший глава FAA и друние предполагают что основная версия это двигатель
