Inside Singapore Airlines Flight SQ321 - where Brit tourists sent desperate ... trends now

When Singapore Airlines Flight SQ321 departed on Monday night, the people on board were starting what they hoped would be a dream trip.

A total of 211 passengers from countries such as the United Kingdom, Australia, New Zealand, Singapore and Ireland settled down for a stress-free 13-hour flight to the Far East.

Among them was 73-year-old Geoffrey Kitchen, a musical theatre director from Gloucestershire who was taking the six-week holiday of a lifetime with his wife Linda to South East Asia, Indonesia and Australia.

The route is a common one, with flights making the near-11,000-mile journey safely every single day, despite skirting near active war zones and flying over some of the world's biggest mountain ranges.

All appeared well when the Boeing 777 aircraft left Heathrow Airport at 10.38pm, quickly passing over English Channel and through Europe on its way to Singapore.

Many of those on board will have rested their eyes and tried to get to some sleep as the plane travelled through Asia, traversing the Hindu Kush mountain range with little problem before moving down into India.

Some would have been opening their eyes for the first time as the plane travelled over the Bay of Bengal, while others were walking about the cabin to stretch their legs.

However, their relaxing journey was about to turn into a nightmare after 11 hours in the air.

At around 3.30pm local time, the plane suddenly lurched as it hit an area of severe turbulence as it travelled through an area of strong thunderstorms in the skies over Myanmar.

Some passengers said they realised the plane had started to tilt upwards, with the fuselage trembling under the conditions outside, although it was slight enough that not all on board noticed it.

It is claimed the fasten seatbelt sign had not been switched on and some people were still standing in the aisle - one traveller is even believed to have been in the toilet. 

Others claimed the signal had been illuminated, but only moments before the plan was engulfed in chaos as the aircraft dropped without warning.

Passengers who did not have their seatbelts on, or had the bad fortune to be stood up at the time, were thrown upwards into the cabin's ceiling with horrific force.

Luggage came crashing out of the overhead lockers, slamming onto people's heads below, while loose objects like water bottles, food trays and cutlery were thrown about like missiles.

As the pilots fought to regain control of the aircraft oxygen masks fell from the overhead compartments into the laps of terrified passengers.

The aircraft carrying more than 200 people dropped hundreds of feet in the space of 90 seconds. 

Bones were broken, blood was left smeared on the fixtures, while the injured were left lying on the floor.

The scene resembled a war zone - one woman was seen screaming in pain, while other travellers were left with head wounds and bleeding ears.

One British traveller said there had been no warning and then he was 'hitting the roof', while his son was left sprawled on the floor two rows behind him.

A person who was in the cramped toilet was seriously injured, while the cabin crew were unable to escape either - they had been checking on passengers to make sure they were complying with the fasten seatbelt sign when the plunge happened.

One female stewardess was seen with a red mark on her face, while a male co-worker was left dishevelled and in a great amount of pain.

In the midst of the chaos Mr Kitchen, who had been so eagerly looking forward to his holiday, collapsed after suffering a suspected heart attack which would prove to be fatal.

The damage was not confined to people -  photos showed people's belongings strewn on the floor, while the ceiling in part of the cabin collapsed entirely leaving wires, piping and debris exposed.

After wrestling the plane back under control and realising the hellish scenario the incident had left behind, the pilot declared a medical emergency and told air traffic controllers he needed a mayday landing in Bangkok, the nearest airport.

One Briton texted his family to say he loved them, fearful that the damaged aircraft might not make it to their hastily rearranged destination. 

As the plane descended desperate passengers performed CPR on Mr Kitchen in a bid to save his life, while people with medical training attempted to help the wounded.

When the aircraft landed at Suvarnabhumi International Airport, shortly before 4pm local time, passengers appeared shell-shocked as paramedics and staff helped them off the plane in wheelchairs and on stretchers.

A convoy of more than a dozen ambulances were lined up on the tarmac. The general manager at the airport in Bangkok described a scene of 'panic and chaos'.

Of the 211 passengers and 18 crew on board, Thai authorities said 71 people had been sent for treatment, six of whom were seriously injured, with many sustaining lacerations to the head as they were thrown upwards. 

On the ground, shaken passengers revealed their shock and horror at the traumatic event.

A British man who was travelling with his family on the flight said 'there were people walking around' when the turbulence hit, and claimed that 'there was no sign to put the seat belts on.'

'There was no turbulence prior to that. It went from no turbulence to this one turbulence. No plane shaking at all and then I was hitting the roof. All of a sudden, I was up like that,' he told the BBC.

'My son was thrown down on the floor two rows behind me. I heard that there was a guy hitting the roof in the toilet and he was injured quite badly, too.' 

Dzafran Azmir, a 28-year-old student on board, told Reuters: 'Suddenly the aircraft starts tilting up and there was shaking so I started bracing for what was happening, and very suddenly there was a very dramatic drop so everyone seated and not wearing seatbelt was launched immediately into the ceiling.

'Some people hit their heads on the baggage cabins overhead and dented it, they hit the places where lights and masks are and broke straight through it.'

Andrew Davies, from Lewisham, London, wrote that he and other passengers who were not injured in the turbulence were currently waiting in a holding area at the airport.