AI 171 crash: Since the Ahmedabad-London flight AI 171 crashed on June 12, almost a month ago, aviation experts, former pilots, and investigators have been trying to figure out what went wrong with the Air India flight. Some believe that there was a dual engine failure at the same time, per an NYT report; a Sunday Guardian report suggests that there was a known software glitch in the Boeing 787 aircraft that crashed moments after take-off. FinancialExpress.com got in touch with a US aviation attorney to understand the possible reason behind the tragic crash that shook the entire nation.
‘When both engines fail, cause is usually external’
Mary Schiavo, aviation attorney with the US aviation litigation firm Motley Rice, told FinancialExpress.com that although “dual engine failures are extremely rare”, when that happens, it is usually because of “external causes”.
“We know, based on extensive research and testing, that when both engines fail, the cause is usually external to the aircraft,” she told FinancialExpress.com.
Schiavo said that, based on previous cases where both engines failed, possible causes could include issues with fuel – either it was contaminated or vapour lock; a situation where the pilots had a problem with one engine but shut down the other (good) engine by accident; bird strikes; maintenance issues or both engines flaming out due to weather, water, or hail ingestion.
She said that “none of these issues are present” in the case of the Ahmedabad plane crash. So, what could have been the possible reason behind the dual engine failure?
‘TCMA failure may have caused Boeing 787 crash’
The NYT report, citing investigators and aviation experts, concluded that both engines failed simultaneously, and that the contamination of the fuel source into both engines, or an incorrect input of flight parameters before take-off, could have caused the crash.
However, according to Schiavo, per the previous incidents, the “chief” on the list is TCMA and FADEC.
TCMA is the Thrust Control Malfunction accommodation, and FADEC is the Full Authority Digital Engine Control. The TCMA tells the FADEC, which controls airspeed and thrust on the engines, whether it is on the ground or in the air.
“If the TCMA senses it is on the ground, it throttles back the engines without pilot input,” she further said, before adding, “On the Air India flight the fact that there are known computer problems causes me to suspect the Thrust Control Malfunction accommodation (TCMA) and the Full Authority Digital Engine Control (FADEC).”
Schiavo based this possible explanation for the Air India plane crash on two previous incidents, one of which involved a Boeing 787.
She added, “In early 2025, a United Airlines flight from Nigeria to Washington, DC experienced uncommanded dives (meaning the pilot did not do that). The USA NTSB is still investigating, but we know there was a computer or software problem on that 787.”
“The reason for my suspicion is yet another accident with the 787. In 2019, the TCMA malfunctioned on an ANA (Japan) flight. The USA NTSB concluded the TCMA failed,” she told FinancialExpress.com, before adding that the Flight Data Recorders will reveal if this happened.
‘Dual engine failure is in one in a million range’
Dual engine failure, given today’s advanced technologies in the aviation industry, is in the “proverbial one in a million range”, Schiavo said.
“In commercial aviation, a dual-engine failure is extremely rare. Our engines today are more efficient and reliable than ever,” WSJ, in one of its reports on the AI 171 crash, quoted US-based aerospace safety consultant Anthony Brickhouse as saying.
According to the outlet, Brickhouse also said that pilots activate the RAT (Ram Air Turbine) if they believe both engines have failed, an event that could result from various factors, including bird strikes or fuel-related issues.
Only way to overcome a software glitch is…
Schiavo told us that in the present times, when aircraft are “complicated”, the only way to overcome a software glitch is often to “pull electrical breakers and shut down the system causing the problem”.
She added, “However, when pilots only have seconds to diagnose and correct a problem imbedded somewhere in a million lines of code which has overtaken their control of the aircraft, they don’t have enough time and altitude (and altitude buys you time) to diagnose, trouble shoot and shut down the errant system.”
‘Intelligence chatter has clues’
Ruling out the sabotage angle, Schiavo said that the “intelligence chatter” usually offers clues. She also noted that, upon close examination of the takeoff video, one can actually see the “exact moment the engines are throttled back, right after lift off”.
The US aviation attorney further said that, since Ahmedabad Airport lacks runway overrun areas or arrestor beds, “throttling back the engines right after lift off” would be the last thing the pilots would’ve done.
AI 171 crash: What do we know so far?
The Air India flight, AI 171, departed from Ahmedabad Airport’s runway 23 for London’s Gatwick Airport like any other aircraft, except for one unusual detail – the aircraft used the entire 3.5-kilometre runway before becoming airborne. This is unusual for a Boeing 787, especially one with sufficient fuel and engine power. Just 30 seconds after liftoff, the plane began descending at a rate of 475 feet per minute, after reaching an altitude of only 625 feet.
Pilot Sumeet Sabharwal and co-pilot Clive Kundar issued a “mayday” distress call to Air Traffic Control (ATC), but ATC was unable to establish contact since there was just a 15-second window between the call and the crash, Bloomberg reported, citing people familiar with the investigation.
Captain Sabharwal’s mayday call to ATC reportedly stated: “Mayday… no thrust, losing power, unable to lift.” Mayday is the highest-level distress signal that indicates a life-threatening emergency.
India’s Aircraft Accident Investigation Bureau (AAIB), which is independently probing the crash, is expected to release its preliminary report soon. According to Bloomberg, investigators reconstructed the crash to better understand the sequence of events. They concluded that while the aircraft’s landing gear was down and the wing flaps had been retracted, those factors alone were not responsible for the crash.
This follows a WSJ report suggesting a possible dual engine failure, noting that the aircraft’s emergency power system, known as the Ram Air Turbine (RAT), had been deployed, either manually by the pilot or automatically. The activation of the RAT typically indicates a total or near-total loss of engine power or a complete electrical failure.
The NYT also reported that the aircraft stayed on course and did not veer to either side, suggesting that both engines lost thrust simultaneously. The pilot’s mayday message further confirms the loss of thrust. The report also noted that right-wing slats were in an extended position, photos from the wreckage show. This means that they were deployed to increase surface area and provide additional lift. Investigators also found that the landing gear failed to retract, possibly due to insufficient electrical or engine power.
Reuters report, based on a source, mentioned that there is a focus on the “fuel switch issue” in the preliminary report. However, Captain Rakesh Rai, who has flown the same Boeing 787 aircraft, told Mojo Story that even if the pilots cut off and rerun fuel control switches, there was nothing wrong with it. It is, as per him, the standard operating procedure outlined by Boeing in case of a dual-engine failure.
All 242 but one on board the doomed flight were declared dead. Among them was former Gujarat Chief Minister Vijay Rupani.
One British national, Vishwash Kumar Ramesh, cheated death and survived the crash. He saw bodies scattered around him and described the scene as “unimaginable”.