Soutik Biswas
India Correspondent

The Air India 787 was destroyed after crashing into multiple buildings outside the airport in Ahmedabad after take-off in June.

Here's what the preliminary report reveals:

• The aircraft hit the BJ Medical College hostel, about 0.9 nautical miles from the runway
• It clipped trees and a chimney, then crashed into a building with a slight nose-up
• Five buildings were damaged in total, with major structural and fire damage. Wreckage was scattered across a 1000ft x 400ft area
• The debris pattern shows the aircraft broke apart as it tore through structures - giving investigators some clues about its final moments

Image source, Getty Images

Ishadrita Lahiri
BBC Hindi

Image source, Lamnunthem Singson's family

Family members of the crash victims are continuing to grapple with what the release of the preliminary investigation means to them.

The cousin of Lamnunthem Singson, a crew member killed in the crash, says he is not sure if knowing the reason for the crash will change the way they are grieving.

"We are still wading through our own feelings at this point, trying to make sense of our loss," says Ngamlienlal Kipgen.

"I believe closure comes from saying our goodbyes in our own way and living in a way that honours and celebrates them. Her story will live on through us and the many loved ones she left behind," he adds.

Soutik Biswas
India Correspondent

The preliminary report has brought fresh attention to the two pilots in control of the ill-fated Air India flight.

Just seconds after take-off, cockpit audio captured one pilot asking the other, “Why did you do the cut-off?”- referring to the fuel switch that starved the engines. The other replied, “I didn’t.” It's still unclear who asked the question - and who answered.

Here’s what we know about the crew.

Capt Sumeet Sabharwal, 56, was a veteran with 30 years of experience at Air India. He had logged 15,638 flying hours, including 8,596 on the Boeing 787. Based in Mumbai, he lived with his elderly father and was looking forward to retirement.

First Officer Clive Kunder, 32, had 3,403 total flying hours, with 1,128 on the Dreamliner. He joined Air India in 2017 and had dreamed of flying since school.

Both were based in Mumbai and had arrived in Ahmedabad the day before the flight, with adequate rest, the report says. Kunder was the pilot flying, while Sabharwal was the pilot monitoring, it says.

The crew had passed pre-flight breathalyser tests and were seen at the gate on CCTV before they took off, the report adds.

Most of the families of those killed in June's crash had to wait for days to get the bodies of their loved ones.

Medical teams worked arduously to match DNA samples to identify victims.

The civil hospital in the city witnessed heart-breaking scenes for several days after the crash.

In a statement following the release of the report, Boeing - the maker of the Dreamliner that crashed in June - has released a statement saying "our thoughts remain with the loved ones of the passengers and crew on board Air India Flight 171, as well as everyone affected on the ground in Ahmedabad."

The US aviation giant adds that it continues to "defer" to India's Aircraft Accident Investigation Bureau - which is leading the investigation - to provide information about the crashed plane in line with international protocol.

Roxy Gagdekar
BBC Gujarati, Ahmedabad

Image source, Pavan Jaishwal/BBC

A month after the incident, the Air India crash site in Ahmedabad, western India, remains deserted.

The road passing through the area has been closed to commercial activity since the day of the crash.

A police checkpoint has come up nearby and no-one is allowed to enter the site.

Even after a month, scorched trees and damaged buildings stand witness to the devastation caused by the deadly accident.

The Air India plane crashed into a densely-populated residential area in the Indian city of Ahmedabad in June, killing 260 people.

Footage taken shortly after the crash shows debris from the plane sticking out of buildings.

Report sets out what happened - but not whypublished at 04:01 British Summer Time

04:01 BST

Theo Leggett
BBC International Business Correspondent

The preliminary report sets out what happened. What we don’t know is why.

The fuel control switches are designed not to be moved accidentally. Shifting them from RUN to CUT OFF is a two-stage process. Each switch has to be lifted before it can be moved down, and there are two of them, one for each engine.

The conversation between the two pilots appears to show that one of them was aware the switches had been moved. The other pilot replied that he had not done so.

Was this a simple mistake made by a pilot under pressure, or was there another reason? The report baldly sets out the precise times when the switches were moved, but there is no other context given – except for that brief exchange between the pilots.

The report itself does not highlight any technical problem that could have led to confusion in the cockpit, before the engines lost thrust.

Some experts also say the possibility that this action was premeditated should be taken seriously, though more of the conversation between the two pilots needs to be released before it is possible to determine what happened.

The report itself is careful not to draw any conclusions – and the investigation (which has been criticised by some for its lack of urgency and transparency) is ongoing.

It is highly likely the "human aspect" – the personal circumstances of the flight crew – will form part of that process.

Image source, Reuters

As we've been reporting, the preliminary investigation into the Air India Flight 171 crash has been released.

If you are just joining us, here's what we know so far:

• According to data from the flight recorder, both the fuel control switches were moved from the run to the cut-off position shortly after take-off, causing both engines to lose thrust and the plane to sink down
• In a voice recording of the cockpit, one of the pilots is heard asking the other why he “did the cut-off” - the other pilot is heard saying he did not do so - it was not clear which pilot made the respective remarks

• The switches were then moved back into their normal in-flight position, something which would automatically start the process of relighting the engines
• One engine was able to restart, while the other relit but failed to regain thrust
• CCTV footage from the airport showed no "significant bird activity"
• The report does not draw any conclusions, and points out that the investigation is continuing

Soutik Biswas
India Correspondent

Investigators are zeroing in on what they describe as an interesting point in the report.

The report says in December 2018, the Federal Aviation Administration (FAA) issued a Special Airworthiness Information Bulletin (SAIB) highlighting that some Boeing 737 fuel control switches were installed with the locking feature disengaged.

While the issue was noted, it wasn’t deemed an unsafe condition requiring an Airworthiness Directive - a legally enforceable regulation to correct unsafe conditions in a product.

The same switch design is used in Boeing 787-8 aircraft, including Air India’s VT-ANB, which crashed. As the SAIB was advisory, Air India did not perform the recommended inspections.

Shawn Pruchnicki, a former airline accident investigator and aviation expert at Ohio State University, tells the BBC he’s wondering whether there was a problem with the fuel control switches.

“What does this [bit in the report] exactly mean? Does it mean that with a single flip, that switch could shut the engine off and cut the fuel supply?" he says.

"When the locking feature is disengaged, what exactly happens? Could the switch just flip itself to OFF and shut down the engine? If that’s the case, it’s a really serious issue. If not, this also needs to be explained."

12 June Air India Flight 171 plane crashes shortly after take off, killing 260 people, including 241 of the 242 people on board

13 June The Indian Ministry of Civil Aviation’s investigation into the cause of the crash begins, as UK and US investigators arrive at the crash site - the first black box is also recovered on this date

16 June Second black box found in the debris at the crash site, though the exact location has not been shared

24 June Both black boxes are transported to Delhi by the Indian Air Force as the data extraction process begins

25 June Memory module and data from the black boxes is successfully downloaded and analysis to reconstruct events leading to the incident begins

12 July Thirty days on from the crash, and after 16 days of analysing the black box data the initial report is released, as outlined under international aviation rules. It finds that the fuel control switches were moved to cut-off position moments before the plane crashed

Cause of plane crash remains unresolvedpublished at 02:57 British Summer Time

02:57 BST

Soutik Biswas
India Correspondent

Investigators say there are two main takeaways from the preliminary report on Air India Flight 171.

First, both engine fuel cut off switches moved from run to cut off within seconds of take-off, abruptly cutting the plane's thrust at 180 knots.

Cockpit voice recordings capture one pilot asking the other why they'd shut the engines down, only to be met with a denial - heightening suspicion that this wasn’t a routine or accidental action. Engineers note these switches are specifically guarded and require deliberate operation, typically reserved for emergencies like engine fire - not mid-flight manoeuvres.

Second, the preliminary findings reference a 2018 Federal Aviation Authority bulletin alerting operators to the possible disengagement of the fuel switch locking mechanism.

However, there’s no clear explanation of how this mechanical issue could have caused both switches to flip nearly simultaneously. The bulletin was advisory and inspections by Air India were skipped. The airline’s past maintenance included throttle module replacements in 2019 and 2023. None of these replacements were linked to the fuel control switches.

Until further investigation digs into whether this was human error or a rare mechanical malfunction, the cause remains unresolved.

Footage taken after the Air India plane crash in June shows smoke billowing into the air following the incident.

The London-bound Boeing 787-8 Dreamliner crashed less than a minute after taking off on 12 June from Ahmedabad airport in western India, killing 260 people, most of them passengers.

Samira Hussain
Reporting from Delhi

Two days ago, I met Shweta Parihar, 41, who lost her husband Abhinav Parihar in the crash. He was returning home to London where she and her 11-year-old son were waiting for him.

Parihar, a former NHS worker, said the ongoing investigation offers her little comfort. “We are normal people. We trusted the airline. What is the point of the investigation now?” she said, choking back tears. “We are finished.”

What pains her are the questions asked by her son. "Did he suffer when he died? How much pain was he in? Did he burn?"

Parihar says her son will never fly with Air India, who he blames for killing his father, again.

British national Vishwashkumar Ramesh was the sole survivor of the Air India crash. He escaped the wreckage through an opening in the fuselage.

After the crash, he said: "I still cannot believe how I made it out alive."

This is the moment he walked away from the crash site:

Soutik Biswas
India Correspondent

Peter Goelz, a former managing director of the US's National Transportation Safety Board (NTSB), says he’s impressed by the preliminary report.

Goelz, who has led several accident investigations, says India's Aircraft Accident Investigation Bureau, responsible for the report, "needs to be praised for preparing such a detailed preliminary report.”

“Oftentimes when dealing with such a high-profile former flag carrier of a nation, the reports are far less detailed and candid.”

“This was a very detailed report. For that the AAIB should be praised.”

As we've been reporting, India's Aircraft Accident Investigation Bureau (AAIB) has published a 15-page preliminary report. It details what happened to the Air India plane that crashed within seconds after takeoff.

"The aircraft achieved the maximum recorded airspeed of 180 Knots IAS at about 08:08:42 UTC and immediately thereafter, the Engine 1 and Engine 2 fuel cutoff switches transitioned from RUN to CUTOFF position one after another with a time gap of 01 sec," the report says.

Then, "in the cockpit voice recording, one of the pilots is heard asking the other why did he cutoff. The other pilot responded that he did not do so."

At 08:08:52 UTC, "the Engine 1 fuel cutoff switch transitioned from CUTOFF to RUN", and four seconds after that, "the Engine 2 fuel cutoff switch also transitions from CUTOFF to RUN." It was now 08:08:56.

At 08:09:05, nine seconds later, one of the pilots transmitted "MAYDAY MAYDAY MAYDAY" to the Air Traffic Control Officers on the ground. The officers received no response, and shortly afterwards, they saw the plane crashing.

Here is a link, external to the preliminary report.

Archana Shukla
India business correspondent

One thing that stands out from the report is that so far there has been no advisory issued for the Boeing Dreamliner 787 or the GE GEnx-1B engine operators used in this aircraft.

At the moment mechanical fault has been ruled out but we need to wait for more information to come out as these are just preliminary findings.

The content of the report is, however, quite shocking, especially the fact that both the fuel control switches were moved from the run position to the cut-off position.

But many questions are still swirling around.

Was it a technical issue? Was it a software issue? Was it a human error?

The findings of this report are being closely watched as families of this devastating crash seek closure.

Air India has released a statement on the report. It says that the airline "stands in solidarity with the families and those affected" and that it is cooperating fully with authorities investigating the crash.

It does not address specific findings in the report.

Here is the statement:

Prior to boarding Air India Flight 171, the crew and two pilots of the flight all underwent testing to ensure they were capable of operating the aircraft.

The report states that both pilots, who were based at Mumbai, had arrived at Ahmedabad the day before the flight and had an "adequate rest period".

The crew and pilots all also underwent a breathalyser test at 06:25 local time and were found "fit to operate the flight", it added.