EgyptAir: What the wreckage can tell us


May 21, 2016

The discovery of floating debris from EgyptAir flight 804 on Friday marks the beginning of a recovery and an investigation that past experiences show could take years, experts say.

May 21, 2016

The discovery of floating debris from EgyptAir flight 804 on Friday marks the beginning of a recovery and an investigation that past experiences show could take years, experts say.

Searchers have combed the vast Indian Ocean floor for Malaysia Airlines flight 370 for more than two years since its disappearance in March 2014 without locating the bulk the wreckage. It took two years for investigators to locate the wreckage and recorders of Air France flight 447 even though they knew about where the aircraft flopped into the Atlantic Ocean in June 2009.

In January 2010, Ethiopian Airlines flight 409 crashed just five miles away from Beirut airport, but it took 13 days to find the data recorder and three more days to find the voice recorder.

In the case of EgyptAir 804, which carried 56 passengers and 10 crew, when it plunged into the sea Thursday, investigators desperately want to recover the data recorder, voice reporter and physical remains of the plane. Each element holds critical clues to the final moments of EgyptAir 804.

 But if the Airbus A320 broke up in flight, either due to a bomb or a mechanical problem, debris could be spread over miles.

And the clock is ticking. The recorders so critical to the investigation will stop transmitting electronic location 'pings' after about a month.

“This may be a very long search and even longer accident reconstruction,” said Al Diehl, a former crash investigator for the National Transportation Safety Board.

“We could have an underwater search and recovery effort that is orders of magnitude more complicated” than Air France flight 447, Diehl said.

The data recorder gives a detailed description of how hundreds of systems in the plane operated in the moments before the crash. The voice recorder reveals what the pilots said and can pick up unusual noises in the cockpit. The wreckage offers clues about whether a mechanical problem, human error or terrorism were to blame.

The flight recorders are stowed in the tail. If the tail came off, which could explain the plane's wild spin before plummeting, as observed by Greek radar tracking, it could have carried the recorders far from the rest of the fuselage.

"Without those, everything else is pure speculation," Anthony Roman, a trained pilot and president of security consultancy Roman & Assoc., said of the flight recorders.

The Mediterranean Sea adds to the challenge. EgyptAir went down in water two miles deep. The flight recorders should emit radio signals nicknamed “pings” at 37 kilohertz for at least 30 days, as required by international standards. But if the precise location isn’t known, it could take longer than that for robotics to scan the ocean floor.

Diehl says the nature of the crash may enable searchers to find the recorders quickly, “but that may only be the beginning of the hunt because the other wreckage could be many miles away.”

In July 1996, TWA flight 800 exploded off the coast of Long Island and witnesses on land saw it go down. But the explosion scattered three major debris fields across an area four miles long and three miles wide. Pieces of the wreckage were recovered for 10 months with robotics and scallop trawlers.

Investigators spent years painstakingly piecing together much of the fuselage. The National Transportation Safety Board ultimately ruled that a short-circuited wire sparked a central fuel tank, which caused an explosion.

Crash investigators make the effort because analyzing the damage can help determine why a plane broke apart.  In the case of Malaysia Airlines flight 17, which crashed in July 2014 in Ukraine, investigators found perforations in the fuselage that confirmed a missile exploded near the plane, knocking it out of the sky.

Residue from explosives could confirm whether EgyptAir succumbed to a bomb. But to determine that, investigators will need the plane pieces closest to where the problem occurred, particularly if the bomb was small. Residue tests revealed a bomb as small as a soda can may have brought down Russian Metrojet flight 9268 in Egypt in October.

Courtesy: USA Today