AHMEDABAD, India — In one of India’s rarest aviation disasters in recent memory, Air India Flight 171 was airborne for less than 40 seconds before it tragically plunged into a densely populated neighbourhood in Ahmedabad.
Investigators now face the grim and meticulous task of sifting through the wreckage and decoding the cockpit voice and flight data recorders of the Boeing 787 Dreamliner to piece together precisely what went catastrophically wrong in the moments after take-off.
Under international regulations set by the UN aviation body ICAO, a preliminary investigation report is expected within 30 days, with the final report ideally completed within 12 months.
The London Gatwick-bound aircraft, piloted by Captain Sumeet Sabharwal and co-pilot Clive Kundar, lifted off from the western Indian city of Ahmedabad at 13:39 local time [08:09 GMT] on Thursday, carrying 242 people and nearly 100 tonnes of fuel.
Within moments, a mayday call crackled from the cockpit—the last transmission received before a rapid loss of altitude and a crash engulfed in flames. Captain Kishore Chinta, a former investigator with India’s Aircraft Accident Investigation Bureau (AAIB), described this incident as “the rarest of the rare” crashes – a controlled flight into terrain just 30 seconds after take-off. “To my knowledge, nothing quite like this has ever happened,” he said.
Investigators will meticulously probe a range of possibilities: did both engines fail due to bird strikes or fuel contamination? Were the flaps improperly extended, reducing lift on a heavily loaded jet in extreme heat? Was there a maintenance error during engine servicing? Or did an inadvertent crew action cut off fuel to both engines?.
Air crash investigations rely on a rigorous process of triangulation and elimination—matching physical evidence from the wreckage with recorded aircraft performance data to construct a coherent picture of the events.
Every scorched cable, every damaged turbine blade, airplane maintenance log, and signals and sounds from the flight data and cockpit voice recorders—colloquially known as the “black boxes”—will be painstakingly examined.
According to accident experts, the initial clues on the ground are likely to emerge from the wreckage of the two engines. Peter Goelz, a former managing director of the US’s National Transportation Safety Board (NTSB), explained: “You can tell from the damage whether the engines were generating power at impact – turbines fracture differently when spinning at high speed. That’s the first clue to what went wrong.”
Turbines are crucial rotating components essential for generating thrust. Goelz added, “If the engines weren’t producing power, investigators have a serious case on their hands – and the focus will shift sharply to the cockpit.”
What transpired within the cockpit will be primarily revealed by the Boeing 787’s Enhanced Airborne Flight Recorders (EAFRs)—the “black boxes”—which Indian officials confirmed have been recovered from the crash site. These advanced devices capture extensive flight data and cockpit audio, ranging from pilot radio calls to ambient sounds within the cockpit.
Voice recordings are sourced from individual pilot microphones, radio transmissions, and an area microphone that picks up background noise. Data recorders meticulously track parameters such as gear and flap lever positions, thrust settings, engine performance, fuel flow, and even fire handle activation with high precision.
Goelz further elaborated: “If the flight data recorder shows the engines were making full power, then the attention will move to the flaps and slats. If they are found to be extended as needed, then it becomes a very difficult investigation.”
Flaps and slats are critical for increasing lift at lower speeds, enabling safe take-off and landing by preventing stalling. Should the investigation point to a problem within the flight management control system, Goelz warned, “that would raise serious concerns – not just for Boeing, but for the entire aviation industry.”
The Boeing 787’s flight management control system is a highly automated suite managing navigation, performance, and guidance, integrating sensor data to optimize flight path and fuel efficiency.
With over 1,100 Boeing 787s operating globally since 2011, experts emphasize the critical need for investigators to determine whether this was a systemic issue affecting the entire worldwide fleet or a one-off failure unique to this particular flight. “If it points to a system problem, then the regulatory bodies have to make some tough decisions very quickly,” Goelz stated.
So far, there is no indication of fault on anyone’s part. India’s civil aviation ministry announced on Tuesday that a recent inspection of Air India’s Boeing 787 fleet – comprising 24 out of 33 aircraft checked thus far – “did not reveal any major safety concern,” asserting that both the planes and their maintenance systems complied with existing standards.
Boeing President and CEO Kelly Ortberg, in a statement on June 12, affirmed that “Boeing will defer to India’s Aircraft Accident Investigation Bureau (AAIB) for information on Air India Flight 171, in line with UN ICAO protocol.”
The decoding of the flight data at the AAIB lab in Delhi will be led by Indian investigators, with the participation of experts from Boeing, engine-maker GE, Air India, and Indian regulators. Investigators from the US National Transportation Safety Board (NTSB) and the UK will also contribute to the analysis. “In my experience, teams can usually determine what happened fairly quickly,” Mr. Goelz observed. “But understanding why it happened can take much longer.”
The wreckage itself is expected to yield other crucial clues. “Every part – wire, nut, bolt – will be meticulously collected,” said Mr. Chinta. Typically, wreckage is moved to a secure facility, laid out to identify major sections, and then meticulously pieced together.
However, investigators suggest that depending on the clarity of the flight data and voice recorder revelations, a full reconstruction may not be necessary in this particular case. The importance of wreckage varies significantly by accident, as exemplified by Malaysia Airlines flight MH17, where reconstruction of the nose was crucial in revealing shrapnel damage from a missile.
Investigators will also examine fuel filters, lines, valves, and residual fuel within the wreckage to check for contamination—a factor that is relatively easy to detect or rule out, according to a crash investigator who preferred to remain unnamed. He also believed that the refuelling equipment used before departure “has likely been quarantined and already inspected.”
Beyond physical evidence, investigators will gather comprehensive maintenance and fault history records from Air India and Boeing’s ACARS (Aircraft Communications Addressing and Reporting System), which transmits data via radio or satellite to both manufacturers and airlines, as explained by Mr. Chinta.
They will review all flights operated by the aircraft and the crew over recent months, along with the technical log detailing pilot-reported faults and corrective actions taken before the aircraft was released for service.
Pilot licenses, training records, simulator performance, and instructor remarks—including how pilots handled scenarios like engine failures in advanced flight simulators—will also be thoroughly examined.
“I reckon Air India would have already provided these records to the investigation team,” Mr. Chinta speculated.
Furthermore, investigators will review the service history of all components that were removed and replaced on the aircraft, scrutinizing reported defects for any recurring issues or signs of problems that could have affected this flight.
“These investigations are extraordinarily complex. They take time, but there will be early indicators of what likely went wrong,” Mr. Goelz affirmed. He highlighted the transformative impact of technology on accident investigation: “One of the first accidents I investigated in 1994 had a flight data recorder tracking just four parameters. Today’s recorders capture hundreds – if not thousands – every second. That alone has transformed the way we investigate crashes.”
