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The Air India tragedy, in which at least 270 people died, involved one of Boeing's most innovative and popular planes. Until now, it was considered one of its safest too.

We still do not know why flight 171 crashed just 30 seconds after take-off. Investigators have now recovered flight recorder data and are working hard to find out. But the incident has drawn attention to the aircraft involved: the 787 Dreamliner, the first of a modern generation of radical, fuel-efficient planes.

Prior to the accident, the 787 had operated for nearly a decade and a half without any major accidents and without a single fatality. During that period, according to Boeing, it carried more than a billion passengers. There are currently more than 1,100 in service worldwide.

However, it has also suffered from a series of quality control problems.

Whistleblowers who worked on the aircraft have raised numerous concerns about production standards. Some have claimed that potentially dangerously flawed aircraft have been allowed into service – allegations the company has consistently denied.

It was on a chilly December morning in 2009 that a brand-new aircraft edged out onto the runway at Paine Field airport near Seattle and, as a cheering crowd looked on, accelerated into a cloudy sky.

The flight was the culmination of years of development and billions of dollars worth of investment.

The 787 was conceived in the early 2000s, at a time of rising oil prices, when the increasing cost of fuel had become a major preoccupation for airlines. Boeing decided to build a long-haul plane for them that would set new standards in efficiency.

"In the late 1990s, Boeing was working on a design called the Sonic Cruiser," explains aviation historian Shea Oakley.

This was firstly conceived as a plane that would use advanced materials and the latest technology to carry up to 250 passengers at just under the speed of sound. The initial emphasis was on speed and cutting journey times, rather than fuel economy.

"But then the effects of 9/11 hit the world airline industry quite hard," says Mr Oakley.

"The airlines told Boeing what they really needed was the most fuel-efficient, economical long-range jetliner ever produced. They now wanted an aeroplane with a similar capacity to the Sonic Cruiser, minus the high speed."

Boeing abandoned its initial concept, and began work on what became the 787. In doing so, it helped create a new business model for airlines.

Instead of using giant planes to transport huge numbers of people between "hub" airports, before placing them on connecting flights to other destinations, they could now fly smaller aircraft on less crowded direct routes between smaller cities which would previously have been unviable.

At the time Boeing's great rival, the European giant Airbus, was taking precisely the opposite approach. It was developing the gargantuan A380 superjumbo – a machine tailor-made for carrying as many passengers as possible on busy routes between the world's biggest and busiest airports.

In hindsight, Boeing's approach was wiser. The fuel-thirsty A380 went out of production in 2021, after only 251 had been built.

"Airbus thought the future was giant hubs where people would always want to change planes in Frankfurt or Heathrow or Narita," explains aviation analyst Richard Aboulafia, who is a managing........

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