An Air India flight crashed shortly after takeoff from Ahmedabad in northwest India on Thursday afternoon local time, killing more than 260 people.

The Boeing 787-8 Dreamliner, Flight AI171, was carrying 242 people bound for London. Only one passenger, a British man, survived.

The plane crashed less than a minute after takeoff, coming down on top of a college hostel around 1.5 kilometres from the runway. Little is known so far about the cause of the incident.

As an aviation safety expert, it is hard to avoid a sense of disbelief that an event such as this – involving one of the most advanced passenger jets in the world, built on the lessons of many earlier accidents – could happen in the 21st century.

Trouble after takeoff

Air crashes such as this one, in which a plane experiences trouble immediately after takeoff, are now extremely rare. They were more common in the past.

In one infamous 1999 incident, 32 people died when LAPA Flight 3142 crashed during takeoff from Buenos Aires. During the accident investigation, it emerged that the Boeing 737’s wing flaps had not been in the right position for takeoff and the crew had ignored alarms from the plane’s internal warning system.

The 2009 emergency landing of US Airways Flight 1549 on New York’s Hudson River also occurred shortly after takeoff. In that case, the problem was quite different: a collision with a flock of Canada geese shut down both engines, leading to a powerless aircraft.

However, the aviation industry puts a lot of resources into learning from accidents so they don’t happen again. LAPA Flight 3142 led to recommended improvements in pilot training and flight procedures. The rules for engine design were changed after the “miracle on the Hudson”.

So whatever caused the Air India crash, it may not be something we have seen before.

How did one passenger survive?

One passenger survived the crash. We don’t know exactly how.

He was sitting in seat 11A, next to an emergency exit. Reports say the plane “broke in half”, and the passenger found himself in the front half while the rear caught fire. He then walked from the wreckage and was found by rescuers.

Why did he survive when everybody else died? Research suggests that, in general, the seats at the back of the plane are the safest place to be in a crash – but this man was quite close to the front.

Based on what we know so far, my expert opinion is that we have no better explanation than to call it luck or a miracle.

Where to from here?

We won’t have a clear idea of what happened until a full investigation has been carried out. Air crash investigations follow a protocol laid out by an International Civil Aviation Organization document called Annex 14.

India’s Aircraft Accident Investigation Bureau will lead this investigation, putting together a team that will be assisted by representatives from the US National Transport Safety Bureau and the UK Air Accidents Investigation Branch, representing the countries of the plane’s manufacturer and passengers aboard.

Rescuers sift through the wreckage of Flight AI171 in Ahmedabad. Sam Panthaky / AFP via Getty Images
The team will conduct a forensic investigation of the crash site to make sense of what happened. Alongside material evidence found at the site, they will look at the data stored in the plane’s “black box”, which includes data from the flight recorder and cockpit voice recorder, to learn about what happened in the leadup to the crash.

A slow, steady process

Air crash investigations can take a long time. Typically a preliminary report will be published 3 to 6 months after the crash, followed by a final report a year or two later.

The report will provide factual information on the cause of the accident and make recommendations. Depending on the cause, these might be changes to maintenance procedures, pilot and crew procedures, or even the design of parts of the aircraft.

Indian authorities will then disseminate these recommendations to whoever needs them around the world. The process is slow, but it moves in the direction of safer air travel. Everyone will be waiting to find out and learn.

In the meantime, it’s best to remember that we still don’t know what happened or why. Everyone wants answers, but speculation can do more harm than good.