What could have led to fatal Air India Ahmedabad crash: Possible scenarios as per experts

A formal investigation has been launched by the Aircraft Accident Investigation Bureau (AAIB) into the deadly crash of Air India flight 171.

The crash of Air India flight 171 from Ahmedabad to London, a Boeing 787 aircraft, just 33 seconds after takeoff from Ahmedabad’s Sardar Vallabhbhai Patel International Airport, has sent shockwaves not just in India but through the global aviation community.

HT spoke to several aviation experts, and what follows is a breakdown of key scenarios that they believe could explain the crash.(Bloomberg)

The 11-year-old plane, which was carrying 230 passengers and 12 crew members, never gained sufficient altitude before it nose-dived and erupted into flames before crashing into a nearby medical college hostel.

This tragedy now sits at the centre of intense scrutiny and speculation. A formal investigation has been launched by the Aircraft Accident Investigation Bureau (AAIB) into the deadly crash of Air India flight 171.

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The Indian agency will be joined by experts from the United States and the United Kingdom to probe the fatal crash.

Experts and investigators are combing through early evidence, including airport surveillance video and radio transmissions. Although just preliminary clues and theories are emerging, a definitive cause remains elusive until the government probe concludes.

HT spoke to several aviation experts, and what follows is a breakdown of key scenarios that they believe could explain the crash, while stressing that only data from the flight recorder will provide conclusive answers.

Scenario 1: Sudden power loss or compressor failure

As per the initial footage, the aircraft initially climbed on a normal trajectory before it suddenly began descending. Experts noted the plane appeared to maintain a nose-up attitude, a posture usually not associated with a normal descent. This, according to them, suggests a significant and sudden loss of engine thrust.

According to officials aware of the matter, a Mayday call was also issued by the pilots shortly after takeoff, supporting the theory of an in-flight emergency.

“A B787 aircraft has extremely powerful engines. It is hard to guess what went wrong. It looks like the pilot could not get adequate thrust and realised the issue immediately after take-off,” said Amit Singh, aviation safety expert and founder of Safety Matters Foundation.

What led the plane to lose power would likely be at the centre of the investigation, said another expert. 

“While nothing can be said by merely looking at the video, it could be possible that the crash was because both engines stalled. Investigations will reveal what led to the situation,” said Sam Thomas, president of the Airline Pilots Association of India (ALPA). That’s an extremely rare event on a 787, with a probability of 1 in a billion flying hours.

A third expert, Mohan Ranganathan, agreed that from the visuals, it appeared there was “a loss of thrust and compressor failure”, referring to the scenario when not enough air enters the engine, reducing thrust.

Scenario 2: Bird strike

One of the other scenarios that HT brought up was a bird strike, which can potentially disable one, or in the extremely rare case of the December 2024 crash of Korea’s Jeju Air Flight 2216, both engines, though experts were sceptical.

Thomas said it was “highly unlikely” a flock of birds disabled both engines. However, Ranganathan noted that bird activity increases during the monsoon season at Ahmedabad airport, which is known for frequent avian presence.

The runway surveillance footage did not have the typical signs of a bird hit, where flames or smoke are momentarily seen from an engine when birds are ingested.

Scenario 3: Unusual aircraft configuration at take-off

A bystander’s video suggested that the plane’s landing gear is still extended, but its flaps – a sort of wing deployed to generate lift – are retracted. “That should not have been the case at all,” said Singh.

A senior pilot, who asked not to be named, also drew attention to the landing gears not having been retracted as a crucial indicator.

“Landing gear is retracted after an average of 35-100 ft of climbing since the aircraft achieves what is known as a positive climb rate. As per Flightradar24, the aircraft achieved a height of 650 ft. The Ahmedabad airport is at an elevation of 180ft, which essentially means aircraft achieved a height of around 400 ft. This indicates that something more systemic could have happened and was detected immediately after take-off,” said this person, suggesting the pilots may have immediately planned for a return.

Scenario 4: Environmental conditions and aircraft load

Some experts highlighted weather and environmental factors. Aviation expert Vipul Saxena said that the aircraft would have had 100,000 litres of fuel for its non-stop flight to London.

Saxena noted that the aircraft took off in clean configuration but faced challenging conditions.

“The aircraft experienced strong cross winds at atmospheric temperatures of above 30 degrees, which in itself could have caused a certain amount of loss of lift,” he said.

Scenario 5: Systemic failure

Saxana also highlighted the unusual landing gear configuration as a critical factor.

“Till the aircraft crashed, the undercarriage was still not retracted, which was very unusual and which too would have required more lift and, thus, more engine power,” he explained.

While the focus remains on mechanical failure, broader systemic or operational issues can’t be ruled out. Experts expressed concern that such a catastrophic failure occurred despite experienced pilots and a proven aircraft.

“The situation seems complicated since the aircraft started sinking in a take-off attitude, which points to failure of one of the controls (may be flaps or elevators) that increased descent in take-off attitude,” Saxena said.