From eyewitnesses and videos to the actual wreckage itself, those probing the crash of Air India Flight 171 on Thursday will try to get the “full picture” into what happened, plane crash investigation experts say, though it may take some time for the cause to be known.
That investigation is already underway, with investigators having collected one of the plane’s black boxes — the flight data recorder — as the search for more victims in the crash that killed at least 241 on board and more on the ground continues.
One man on board the plane survived the crash.
“I think it’s like any investigation … you start with the easiest, most obvious stud and then you dig down accordingly,” said Nigel Waterhouse, an aeronautical engineering aircraft certification expert.
“They’ll try to get the full picture.”
Waterhouse said the first thing investigators will do is interview witnesses “as soon as possible.”
They will try to get information such as if smoke was coming from an engine or loud noises were heard, as well as asking if the plane was climbing, diving or other “obvious things that people would notice.”
Videos taken of the plane and airport will also be looked at as it could give insight into what was happening at the time.
Anthony Brickhouse, a U.S.-based aerospace safety consultant, told Global News on Thursday that the goal of the investigation is to answer three questions.
“What happened, why did it happen, and most importantly, what can be done to prevent it from happening again,” he said.
Investigators will also look at the conditions at takeoff, including the airport and weather, for potential impacts.
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Though interviews play a key role, examination of the airplane and the black boxes — the flight data recorder and cockpit voice recorder — will be “very important” in determining the causes.
According to Brickhouse, the data recorder can provide information on the operation of the aircraft. The voice recorder records voice and sounds and can not only pick up communication between the pilot and co-pilot, including signs of stress in their voices.
“So the cockpit voice recorder is going to record voice and sounds and then we have what’s called the digital flight data recorder, which has a capability to record well over 1,000 different parameters,” Brickhouse said.
“So anything you would like to know about the operation of that aircraft it is probably going to be on the flight data recorder.”
The data and voice recorder also work in partnership, Waterhouse notes, as investigators can listen to the pilot and co-pilot going through their checklist for takeoff and then cross-reference it to what the data recorder shows the controls were set to.
He added that examining the remnants of the aircraft will also help in the probe, with the wreckage being taken away and analyzed to determine what was happening at the time of impact.
“So the data recorders will give the clues of where to start to look, and then they’ll verify with the actual wreckage and whatever they can see from the aircraft systems,” Waterhouse added.
How long until an answer?
Even with all the data and interviews conducted, it’s difficult to say exactly how soon information on the cause of the crash will be available.
If the cause of the flight was due to just one issue, information could be known within two to three days, but delays could occur if the process is not as clear cut.
The U.S. is also participating in the investigation with the National Transportation Safety Board, Federal Aviation Administration, Boeing and General Electric involved.
Waterhouse said if the data recorders need to be sent to the U.S. for further examination, it could lead to logistical delays. Also, discussions between India and the U.S. bodies to confirm results could add to that.
Damage to the black boxes could also create difficulties to the investigation, though he noted the devices are built to withstand a fairly significant impact, so it’s unlikely the data would be lost.
While the data could be known within a short amount of time, the process of releasing the findings could add to the time as discussions may be needed around things like liabilities and fault, prompting legal conversations.
Brickhouse told Global News the work being done should help determine what caused the crash which, in turn, could help prevent future incidents from happening.
“I’m confident the second they come across something that could have caused this accident, the world will know about it and appropriate changes will be made,” he said.
— With files from The Associated Press
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