Image source, Reuters

We now know from the report that at least five buildings were destroyed when Air India Flight 171 crashed into a densely-populated residential area in the west Indian city of Ahmedabad.

"The aircraft was destroyed due to impact with the buildings on the ground and subsequent fire," the report said.

We previously reported that about 20 people also died on the ground after the plane hurtled down and crashed into a hostel for medical students outside the airport in Ahmedabad.

One section of the report explains how one of the engines was able to restart after transitioning to cutoff, but could not reverse the plane's deceleration.

Engine 1’s core deceleration stopped, reversed and started to progress to recovery, the report says, while Engine 2 was able to relight but "could not arrest core speed deceleration".

The CCTV obtained from the airport showed that there was no "significant bird activity" observed in the vicinity of the flight path, the report said.

Experts had previously speculated that a bird striking the airplane could have caused the plane to crash, but the report released today suggests that was likely not the case.

In its 15-page report, the Aircraft Accident Investigation Bureau (AAIB) says the wreckage site activities, including drone photography and videography, have been completed.

The wreckage itself has been moved to a secure area near the airport.

"Both engines were retrieved from the wreckage site and quarantined at a hangar in the airport," the report said.

"Components of interest for further examinations have been identified and quarantined," the report added.

Report does not draw conclusions - but details provided on pilots' actionspublished at 21:30 British Summer Time 11 July

21:30 BST 11 July

Theo Leggett
BBC International Business Correspondent

The preliminary report from India’s Air Accident Investigation Bureau into the loss of Air India flight 171, which killed 260 people, has cast attention firmly on the actions of the pilots.

As we just reported, the report says that according to data from the flight recorder both the fuel control switches, which are normally used to switch the engines on or off when on the ground, were moved from the run to the cutoff position shortly after takeoff.

This caused both engines to lose thrust.

It says that in the cockpit voice recording, one of the pilots is heard asking the other why he “did the cutoff”. The other pilot, it says, responded that he did not do so.

It is not specified which voice is which. At the time the aircraft took off, the co-pilot was flying the plane, while the captain was monitoring.

The switches were then moved back into their normal inflight position, something which would automatically start the process of relighting the engines.

One engine, according to the report, was in the process of regaining thrust at the time the aircraft crashed. The other was relit but was not yet regaining thrust.

The report says: "At this stage of investigation, there are no recommended actions to B787-8 and/or GE GEnx-1B engine operators and manufacturers," suggesting that no significant fault has been found with the plane or its engines.

The report does not draw any conclusions, and points out that the investigation is continuing, but it is clear attention is now being focused on the actions of the pilots.

One of the findings from the report outlines how a pilot could be heard asking the other pilot in a voice recording of the cockpit in the moments before the crash: why did you cut off?

The report says that both engine fuel cut off switches were turned to "cut-off" with a time delay.

Below is an excerpt of that finding from the preliminary report:

"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 Engine N1 and N2 began to decrease from their take-off values as the fuel supply to the engines was cutoff.

"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."

Image source, EPA

• Air India Flight 171 was travelling from Ahmedabad to London on 12 June and crashed shortly after take off, killing 241 of 242 people on board
• In total, officials say 260 people were killed in the incident, after the plane plunged into a densely populated neighbourhood
• The Boeing 787-8 Dreamliner gave a mayday signal to air traffic control before crashing into a building that was used as doctors' accommodation at the Byramjee Jeejeebhoy Medical College and Civil Hospital
• The sole survivor on board the plane, British national Vishwashkumar Ramesh, said: "I still cannot believe how I made it out alive"
• There were 169 Indian nationals, 53 British citizens, seven Portuguese nationals, one Canadian and 12 crew on board
• A formal investigation was launched by India’s Aircraft Accident Investigation Bureau (AAIB) into the cause of the crash

A preliminary report into the Air India Flight 171 crash that killed 260 people, including 241 people on board, has been released.

The London-bound aircraft, a Boeing 787-8 Dreamliner, crashed soon after taking off from the western Indian city of Ahmedabad on 12 June.

Under International Civil Aviation Organization (ICAO) rules, investigating states are obliged to file a preliminary report within 30 days of a crash, detailing any initial findings.

We're taking a closer look at the report and will bring you the key lines. Stay with us.