Black box data tells all about deadly flight Air India 171: Full sequence of events that ended in a tragic crash
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Flight AI423 had a Pilot Defect Report (PDR) entry for a status message: 'STAB POS XDCR' in the tech log.
Troubleshooting was carried out, and the aircraft was released for flight.
The pilots had adequate rest, underwent pre-flight breath analyser tests, and were found fit to operate the flight.
Fuel on board was 54,200 kg, and the takeoff weight was 213,401 kg, which was within the maximum allowed limit of 218,183 kg.
No dangerous goods were onboard the aircraft.
The aircraft began its takeoff roll at 08:07:37.
The air/ground sensors transitioned to 'air mode,' consistent with liftoff at 08:08:39.
The aircraft achieved a maximum recorded airspeed of 180 knots IAS at approximately 08:08:42.
Immediately after, Engine 1 and Engine 2 fuel cutoff switches were moved from RUN to CUTOFF positions, one after another, with a one-second gap.
As fuel supply to the engines was cut off, both N1 and N2 values began to decrease from their takeoff values.
In the cockpit voice recording, one pilot is heard asking the other, 'Why did you cut off?'
The other pilot responded that he did not.
CCTV footage from the airport showed the Ram Air Turbine (RAT) deploying during the initial climb, immediately after liftoff.
No significant bird activity was observed near the flight path.
The aircraft began to lose altitude before crossing the airport perimeter wall.
According to EAFR data, both engines' N2 values dropped below the minimum idle speed, and the RAT hydraulic pump began supplying power at around 08:08:47.
At approximately 08:08:52, Engine 1's fuel cutoff switch transitioned back from CUTOFF to RUN.
At 08:08:56, Engine 2's fuel cutoff switch also transitioned from CUTOFF to RUN.
When fuel control switches are moved from CUTOFF to RUN during flight, the Full Authority Dual Engine Control (FADEC) system automatically initiates a relight and thrust recovery sequence, including ignition and fuel reintroduction.
Exhaust Gas Temperature (EGT) began rising for both engines, indicating relight.
Engine 1's core deceleration stopped, reversed, and began recovering.
Engine 2 managed to relight but could not stop the core speed deceleration. It kept reintroducing fuel in attempts to increase acceleration and achieve recovery.
The EAFR recording stopped at 08:09:11.
At around 08:09:05 UTC, one of the pilots transmitted: 'MAYDAY, MAYDAY, MAYDAY.'
Air Traffic Control (ATCO) asked for the call sign but received no response.
ATCO then observed the aircraft crash outside the airport boundary and immediately activated the emergency response.
On June 12, tragedy struck as Air India Flight 171 crashed just moments after takeoff, despite no signs of mechanical issues or external threats like bird strikes. In a shocking chain of events, both engines shut down mid-air, cockpit confusion unfolded, and a desperate Mayday call went unanswered.A detailed sequence reconstructed from technical logs, cockpit voice recordings, and CCTV footage now reveals the terrifying final moments of the flight, offering a chilling look into what caused the deadly crash.Below is the minute-by-minute breakdown of what exactly happened from takeoff to impact.Here is the sequence of events leading to the deadly crash on June 12:
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Time of India
4 days ago
- Time of India
Ahmedabad air crash: Inside the 10-second mystery - What really brought down AI 171?
Representative Image NEW DELHI: The fatal crash of Air India Flight AI 171 has drawn intense attention to a brief but pivotal sequence in the cockpit—ten seconds that may explain how a routine takeoff ended in disaster. As investigators dig into the timeline, a Bloomberg report says that the unexplained actions and delays during this window are now central to understanding what went wrong with Boeing's advanced 787 Dreamliner. On June 12, Flight AI 171 departed Ahmedabad for London with 242 people on board. Both pilots, senior captain Sumeet Sabharwal and junior co-pilot Clive Kunder, were cleared for duty and the aircraft's initial climb appeared normal. But within seconds, a sudden loss of engine power set off a chain of events that the crew could not recover from, despite their efforts. The unexplained 10 seconds • Just three seconds after takeoff, the 787 Dreamliner reached its maximum recorded airspeed. • Both engine fuel switches were inexplicably set to cutoff within a single second, shutting down fuel flow to the engines. • Confusion erupted in the cockpit, with each pilot denying responsibility for moving the fuel switches, according to Bloomberg's reporting. • There was a 10-second delay before the first fuel switch was reset, and another four seconds before the second was restored. • The aircraft was too low and slow for the engines to be reignited in time to regain thrust. •The significance of the ensuing 10-second delay cannot be overstated. As retired FAA inspector Michael Daniel told Bloomberg, 'The 10 seconds are crucial because the aircraft was simply too low and too slow to re-ignite the engines to gain thrust in order to climb.' • The sudden shutdown triggered a barrage of cockpit alarms, possibly causing a psychological 'startle effect' and momentary freeze in pilot response. • Emergency systems like the Ram Air Turbine (RAT) provided minimal power, but only to the captain's controls, forcing a rapid transfer of control from co-pilot to captain. • Despite resetting the switches, the crew ran out of time; a 'Mayday' was sent, but the plane crashed just outside the airport, killing 260 people. The preliminary report, as cited by Bloomberg, has left investigators with more questions than answers. While Air India's CEO said that fleet-wide safety checks found no anomalies, the focus remains on what happened inside the cockpit during those critical seconds. Human factors—including confusion, sensory overload, and psychological shock—are now under close scrutiny, as experts seek to determine whether these played a critical role in the delay that doomed the flight.
NDTV
5 days ago
- NDTV
Air India Crash: We're All Terrified Of Flying Now, Thanks To Conspiracy Theories
The investigation into the tragic crash of Air India flight AI 171 last month has become a subject of intense speculation, memes and long posts on social media. It has also quickly eroded public trust in the investigator as well as the process of investigation. This is a sad state of affairs and also a bit scary, since erosion of trust has triggered apprehensions among the travelling public about air travel. I know of many erstwhile frequent fliers, who thought nothing before taking a flight for work or leisure, now hesitating before making the next flight booking. Some have been barred from flying by families, others remain confused over which aircraft type to fly and whether to risk a long-haul flight, weighing the option of postponing the flight altogether. Took a flight today and the panic post Air India is real - My neighbour was like what's the smoke when they initially spray the disinfectant (I think) - People were extremely attentive to the instructions sitting at the exit door - The air hostess had to literally explain why… — Kirtan A Shah, CFP® (@KirtanShahCFP) June 20, 2025 Speculation Abounds A million theories of what went wrong had already been circulated when the buzz reached a crescendo last week, after the Aircraft Accident Investigation Bureau (AAIB) released a preliminary report. In a poorly worded and somewhat verbose report, the AAIB indicated that the cockpit crew could be responsible for the tragic accident, while seemingly absolving the aircraft manufacturer and other stakeholders. Two specific words or phrases in the report are telling. One, the use of the word "transitioned" in reference to fuel cutoff switches. Second, the report has quoted a part of the conversation between the two pilots, in which one is heard asking the other whether he "cut off". The report says the aircraft "achieved the maximum recorded airspeed of 180 Knots IAS at about 08:08:42 UTC and immediately thereafter, the Engine 1 and Engine 2 fuel cutoff switches transitioned from RUN to CUTOFF position one after another with a time gap of 01 sec". What does "transitioned" mean? Were they moved, or did the switches malfunction? Unless the AAIB was prepared to go further and clarify this, either way, what was the crying need to even mention the 'transitioning' of fuel switches in a preliminary report? The Cost Of Dilly-Dallying As per ICAO (International Civil Aviation Organisation) guidelines, a preliminary report of any accident should ideally be released within 30 days, and the investigator is expected to share "critical initial facts" to enable immediate safety actions globally. The 30-day deadline is meant to compel investigators to prioritise the collection and reporting of readily available, verified factual and circumstantial information, rather than waiting for exhaustive analysis. Obviously, then, the deadline is not meant to encourage speculation, which the AAIB seems to have encouraged, knowingly or unknowingly, by using vague terms like fuel switch transition. Besides, experts have pointed out that while the ICAO norms encourage a preliminary report within 30 days, the AAIB charter has no such requirement, and in at least one previous air crash, the AAIB did not release any preliminary report at all. So, the agency actually had the option of not going through the paces and releasing anything at all. That it chose to do so on the 30th day, past midnight, points to myriad pressures on the investigating team. The Western media thereafter made matters worse by speculating further on pilot suicide theories, quoting unnamed sources. Then, the second word or phrase which stands out in the preliminary report is the mention of a part of the conversation in the cockpit. The AAIB has chosen to reveal that one pilot asked the other about why he "cut off," and the latter replied he did not. Without spelling out which pilot posed the question and which one answered, a Pandora's box has been opened. Not only does providing just a sentence of the conversation in the cockpit fail to give the full picture of what transpired, but there is no clarity on what the pilots were actually talking about. Questions With No Answers Was this conversation about fuel cutoff or something else? If it was about fuel cutoff, which pilot posed the question? AAIB has itself said that it recovered two hours of audio from the flight data recorders. The words "cut off" could have referred to anything - engine, instruments, etc, not necessarily fuel switches. What the preliminary report has also done is this: it has provided a virtual clean chit to Boeing & Co. The report says that at this stage of the investigation, "there are no recommended actions to B787-8 and/or GEnx-1B engine operators and manufacturers". No one wants to fly Air India anymore. For years, people tolerated bad service, delays, rats and broken TV systems etc, but now it's about existential threat to life. Brand is badly damaged. Tata took it easy and focused on bells & whistles changes instead of improving customer… — Rajesh Sawhney 🇮🇳 (@rajeshsawhney) June 15, 2025 Again, a mere preliminary report need not have been in such undue haste to absolve either Boeing or any other stakeholder of negligence or faults. The report should have stuck to facts. It should have given out the sequence of events; details of the number of crew involved and their experience (without identifying them); number of casualties and number of injured; and the fact that both aircraft engines flamed out. Nothing else was needed in the preliminary report. Flaws are emerging even in the constitution of the probe team. Until recently, no senior pilot had been included in the team, since only Air India has a fleet of Dreamliners, and the AAIB probably wanted to avoid allegations of any bias. Then, despite more than a month having elapsed, the AAIB has not found the time to launch an appeal for the public to depose with any evidence about the crash. The Buzz In Parliament As the buzz about the crash and the AAIB's insinuations gets louder, Union Civil Aviation Minister Kinjarapu Rammohan Naidu has had to assert in Parliament that the AAIB is unbiased and has been conducting a probe based on rules and regulations. His comments follow an appeal by the AAIB itself, urging the media and the public to refrain from "spreading premature narratives that risk undermining the integrity of the investigative process". There are really only two options now to mend the situation: either AAIB release further details of the cockpit conversation and reasons for the crash, or it follow the dictum of 'Mum's the Word' and carry out further investigation out of public glare. Rebuilding public trust in the probe - and Indian aviation- itself is the need of the hour.
Indian Express
6 days ago
- Indian Express
Cessna trainee pilot in Gujarat lost contact with controller around 10 nautical miles from March 31 crash site: AAIB report
A preliminary report by the Aircraft Accident Investigation Bureau (AAIB) on the March 31 Cessna trainer crash in Mehsana says the aircraft lost contact with the APP (S&P) Controller around 10 nautical miles from the destination. The plane had crashed in a field in Ucharpi village of Mehsana district. The trainee pilot, though injured, survived. Local police had registered the incident. According to the report, the pilot was flying solo for a cross-country training exercise. The planned route was from Mehsana to Banswara, then Deesa, and back to Mehsana. The aircraft, a 1984 model, was owned and operated by Blue Ray Aviation Pvt Ltd. 'There were no abnormal reports from the aircraft until it was inbound to Mehsana after overflying Deesa,' the report stated. 'Ten nautical miles from Mehsana, the aircraft was in contact with Mehsana ATC (Ground VHF, maintained by BRAPL). However, communication was intermittent. As per one Assistant Flight Instructor's statement, the trainee pilot last reported at 4 NM inbound Mehsana at 2000 ft. After that, there was no further communication with ATC.' The report added: 'The aircraft crashed in a field in Ucharpi village, triggering the Emergency Locator Transmitter (ELT). Villagers nearby saw the low-flying aircraft and rushed to the site. They rescued the unconscious pilot and took her to the hospital immediately.' Citing a report from Ahmedabad ATC, the AAIB report noted: 'At 12:58:52 UTC, VT-PBA contacted the APP (S&P) Controller. The trainee requested her position and vectors to Mehsana. She reported maintaining 3500 feet. The controller gave regular vectors and position updates. At 13:04:27 UTC, the aircraft lost contact, around 10 NM from Mehsana.' The AAIB team visited the crash site. It collected engine parts, fuel, oil, and hydraulic fluid samples. Investigators also interviewed the trainee pilot and the flight instructor.
