What caused Air India Flight AI171 to crash? The key information we know so far

Yahoo

12 hours ago

The Indian government is reportedly looking at a number of factors that may explain why Air India flight AI 171 crashed shortly after take-off from Ahmedabad Airport on Thursday, killing all but one of its 242 passengers.
The London Gatwick-bound plane - which was carrying 53 British passengers, 169 Indian nationals, seven Portuguese and one Canadian - crashed into a medical college and erupted in a huge fireball on Thursday.
The sole survivor was Briton Vishwash Kumar Ramesh, 40. At least 24 more people on the ground died.
One of two black boxes has reportedly been found in a bid to help piece together vital clues that could shed light on the cause of the accident.
On Friday, it was reported that Air India and the Indian government were looking at several aspects of the crash, including issues with the jet's engine thrust, its flaps, and why its landing gear remained open. The government is also looking at whether Air India was at fault, including looking at maintenance issues, a source told Reuters.
Experts have also raised questions about the plane's landing gear, which was down when it should have been up, as well as the wing flaps. Some have raised the possibility of a power failure or bird strike.
Here, Yahoo News UK looks at what investigators are likely to be considering.
The Reuters news agency has reported two police sources as saying one of two black boxes from the plane has been found.
They did not say whether it was the flight data recorder or the cockpit voice recorder that had been recovered.
The black boxes, which are coloured orange to make them easier to find in the event of a crash, will be critical in establishing what happened.
There are normally two recorders: a Cockpit Voice Recorder (CVR) for pilot voices or cockpit sounds, and a separate Flight Data Recorder (FDR).
They are mandatory on civil flights, but their aim is not to determine any wrongdoing or fault - they are designed to preserve clues from cockpit sounds and data to help prevent future accidents.
According to Reuters, investigators say the FDR helps them analyse what happened, and the CVR can start to explain why, though no two investigations are the same.
According to Airbus: "Flight recorders store data (aircraft parameters) and sound (pilot, copilot, radio communications and the cockpit ambient noise). The recording device is crash-protected up to a certain level. It is resistant to fire, explosion, impact and water immersion."
Video of the plane before the crash has shown its landing gear was down. Usually, this folds back into the aircraft immediately after it becomes airborne.
Former British Airways pilot Alastair Rosenschein told Sky News: "It's clearly got its [landing] gear down and that is not correct... it should have been up."
Watch: Moment Air India flight crashes after take-off
He added: "I cannot understand why the [landing] gear would have been down... [and] left down. That would suggest, perhaps, a hydraulic problem because it's hydraulics that raise the gear." However, he made clear this was speculation.
US aerospace safety consultant Anthony Brickhouse also said of the landing gear being down: "If you didn't know what was happening, you would think that plane was on approach to a runway."
Steve Scheibner, an American Airlines pilot, also suggested there were abnormalities with the plane's wing flaps and linked this to the landing gear being down.
Pilot Sumeet Sabharwal and his co-pilot Clive Kundar cried 'mayday' as the plane lost altitude, saying the engine was 'losing power'.
According to reports, Sabharwal, who had more than 8,000 hours of flying experience, said he had 'no thrust' and was 'unable to lift'.
And the Wall Street Journal reported on Friday, citing unnamed sources, that an investigation into the crash was focusing on "whether the aircraft had a loss or reduction in engine thrust".
Dr Jason Knight, a senior lecturer in fluid mechanics at the University of Portsmouth, told The Telegraph: 'It appears from the video there is a cloud of dust just after take-off.
'I'm not sure, but it appears as though the cloud of dust could be from the engines as they both fail.'
A twin-engine failure is extremely rare.
The BBC reported experts familiar with Ahmedabad Airport as saying it is "notorious for birds", which can cause engine failures.
Dr Knight also said "the most likely [reason] is a bird strike in both engines".
But Scheibner said he didn't think a bird strike is a "likely theory". "We don't see any birds in the picture. It would have to be a lot of birds to foul out both engines and we don't see any indications coming out of the back of the engine that that happened: you'd see flames, you'd see sparks."
Who were the British victims of the Air India plane crash? (The Guardian)
Heartbreaking final selfie of doctor's young family starting a new life in Britain (The Telegraph)
'She was a ray of sunshine': First British victims of Air India plane crash named after 241 killed (The Independent)