The lone survivor of 242 people aboard a London-bound passenger plane that crashed in the Indian city of Ahmedabad was on Friday struggling to explain how he miraculously walked out alive from the fireball explosion.

"Everything happened in front of me, and even I couldn't believe how I managed to come out alive from that," British citizen Vishwash Kumar Ramesh said from his hospital bed, speaking in Hindi to national broadcaster DD News.

The Air India Boeing 787-8 Dreamliner plane, which was full of fuel as it took off for a long-haul flight to London, exploded into a burst of orange flame on Thursday afternoon just after taking off.

Ramesh – who was in seat 11A according to media reports – was the only one aboard the plane not to be killed, with at least 24 others killed on the ground.

His brother was also on the same flight, his family in Britain said.

"Within a minute after takeoff, suddenly... it felt like something got stuck... I realised something had happened, and then suddenly the plane's green and white lights turned on," Ramesh said.

"After that, the plane seemed to speed up, heading straight towards what turned out to be a hostel of a hospital. Everything was visible in front of my eyes when the crash happened."

Indian Prime Minister Narendra Modi paid a visit to Ramesh on Friday at the hospital where he is being treated for burns and other injuries, footage on his YouTube channel showed.

Ramesh, 40, is from the British city of Leicester, according to Britain's Press Association news agency.

The plane smashed into the buildings just outside the perimeter of the airport.

"Initially, I too thought that I was about to die, but then I opened my eyes and realised that I was still alive," he said.

"I saw the air hostess and aunties and uncles all in front of me," he said, his voice trailing off in emotion, using a term of respect used in India for older people.

"I unfastened my seatbelt and tried to escape, and I did.

"I think the side I was on was not facing the hostel," he added. "Where I landed was closer to the ground and there was space too – and when my door broke – I saw that there was space, and I thought I could try to slip out."

Videos shared on social media showed Ramesh soon after, dressed in a bloodied T-shirt and limping, but walking towards an ambulance.

"My left hand got slightly burnt due to the fire, but an ambulance brought me to the hospital," he said. "The people here are taking good care of me." (AFP)