How is the Boeing Dreamline’s crash investigation unfolded

Less than 40 seconds.

This is how long the Air India Flight 171 was in the air before immersing in a densely populated neighborhood in Ahmedabad in one of the most aviation disasters in India in recent memory.

Investigators are now confronted with the gloomy task of sifting through the remains and decoding the voice of the cockpit and records of data on the Boeing 787 Dreamliner flight to collect what went crazy in the seconds after the departure. According to International Rules set by the UN Aviation Authority IcaoA preliminary investigation report should be published within 30 days, with the final report ideally completed within 12 months.

The London Gatwick Air Force, piloted by Captain Sumeth Sabhawal and Pilot Clive Kundar, rose from the western Indian city of Ahmedabad at 13:39 local time (08:09 GMT) on Thursday, with 242 people and nearly 100 tonnes of fuel on board. Within moments, the call of Mayday was bursting from the cockpit. This will be the last show. This was followed by a loss of altitude and a crash absorbed by flames.

Captain Kishore Chinta, a former investigator at the Air Aviation Investigation Bureau in India (AAIB), calls this “the most rare” crashes – a controlled flight in the terrain just 30 seconds after the departure. “To the best of my knowledge, nothing like this has never happened,” he told the BBC.

Both engines failed due to bird strikes or fuel pollution? Were the valves lengthened incorrectly, reducing the lift to a highly loaded jelly with exceptional heat? Was there an error in the maintenance while servicing the engine? Or the involuntary crew action cut the fuel of both engines?

Investigators will study all these opportunities – others. Air catastrophe studies rely on triangulation and elimination – corresponding to the physical evidence of the remains of recorded data on the productivity of the aircraft to build a coherent picture of what went wrong.

Any burned cable, damaged turbine blade, aircraft maintenance diary and sounds from flight data and voice records of the cockpit – the so -called “black box” – will be considered. The BBC talk to accident experts to find out how the investigation will continue.

It is critical that the first clues on Earth can come from the remains of the two engines, at least three investigators said.

“You can find out from the damage whether the engines generate energy when the turbines break differently when they rotate at high speed,” says Peter Gölz, a former managing director of the US National Transport Safety Council (NTSB). “This is the first clue to what went wrong.”

Turbines are decisive rotating components that play a key role in energy extraction to generate thrust.

“If the engines did not produce energy, investigators have a serious case of their hands – and the focus will move sharply to the cockpit.”

What happened in the cockpit will be revealed by the improved Boeing 787 (EAFRS) flying records – or “black boxes” – which, they say, investigators will help tell the story. (Indian officials claim that recorders were restored from the site of the crash.)

These devices capture extensive data on flights and audio in the cockpit – from pilot radio hinges to atmospheric sounds of the cockpit. Voice records come from individual pilot microphones, radio broadcasts and microphone in the area that raises the background noise in the cockpit.

Tracking data records With high accuracy, the position of gears and valve levers, traction settings, engine operation, fuel flow and even activation of the fire handle.

“If the flight recorder shows that the engines have made full power, then the attention will move to the valves and slats. If it is found to have been expanded as needed, then it becomes a very difficult investigation,” says G -N -Gaelz.

The valves and slats increase lifting at shorter speeds, helping the aircraft to take off and land safely, allowing it to fly more slowly without asserting itself.

“If (the path leads) to a problem in the flight control system, it would cause serious concerns – not only for Boeing, but for the entire aviation industry.”

The Boeing 787 flight control system is a highly automated package that manages navigation, performance and guidance. It integrates data from a number of sensors to optimize the flight path of the aircraft and fuel efficiency.

With over 1,100 Boeing 787s have been flying around the world since 2011, investigators have to determine whether it is a systemic problem that can affect the global fleet – or a single failure unique to this flight, experts say. “If this indicates a systemic problem, then the regulatory authorities have to make some difficult decisions very quickly,” says G -n Goelz.

So far, there is no indication of guilt on the part of anyone. The Ministry of Civil Aviation in India said on Tuesday that Air India’s Boeing 787 Fleet inspected – 24 of the 33 aircraft have been checked so far – “does not reveal great safety care”, adding that aircraft and maintenance systems have complied with existing standards.

Boeing President and CEO Kelly Ortberg said on June 12: “Boeing will postpone the AAIB Investigation Bureau (AAIB) for Air India Flight 171, in accordance with the UN ICAO protocol.”

AAIB data decoding The Delhi Laboratory will be led by Indian investigators, such as Boeing experts, engine manufacturer GE, Air India and Indian regulators. NTSB and UK investigators will also participate.

“According to my experience, the teams can usually determine what happened quite quickly,” says G -n Gaelz. “But understanding why it could take a lot more time.”

Rainings can give other clues. “Every part – wire, nut, bolt – will be thoroughly collected,” says G -n Chinta.

Usually the remains are moved to the nearby hangar or a secure facility located to identify the nose, tail and wings and then cut together. In this case, depending on what the flight data and the recorders of the voice reveal, complete reconstruction may not be required, investigators say.

The importance of the remains varies by accident, investigators say. For Flight Malaysia Airlines MH17Downloaded Eastern Ukraine in July 2014, it was crucial – the nasal reconstruction revealed clear damage to a rocket made by Russian.

In the remains, investigators will also look at fuel filters, lines, valves and residual fuel to check for pollution – something that is easy to detect or exclude, said an investigator from a crash that prefers to remain unnamed. He also believed that the fuel charging equipment used before departure was “probably quarantine and already inspected.”

That’s not all. Investigators will collect entries and history of ACARS from ACARS and Boeing (Aircraft Communications Additing and Reporting System), which transmits data via radio or satellite to both Boeing and Air India, says Chinta.

They will inspect all flights operated by the aircraft and crew in recent months, together with the technical diary of the business, reported by the pilot and corrective actions taken before the service was launched.

Investigators will also consider pilot licenses, training records, simulator execution and instructor’s remarks – including how pilots process scenarios such as engine damage in advanced flight simulators. “I think Air India would have already provided these records to the investigative team,” says G -n -Chinta.

Investigators will inspect the history of service of all components of the aircraft that have been eliminated and replaced, considering reported defects for any recurring problems – or signs of problems that could affect this flight.

“These investigations are extremely complicated. They take time, but there will be early indicators of what has probably gone wrong,” says G -n Gaelz.

The big reason is how far the technology has come. “One of the first accidents I investigated in 1994 had a flight data tracking that followed only four parameters,” he says.

“Today’s recorders capture hundreds – if not thousands – every second. This alone has transformed the way we investigate catastrophes.”

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