In December 2018, the United States Federal Aviation Administration issued a Special Airworthiness Information Bulletin issued, following reports from multiple Boeing 737 operators that fuel control switches were being installed with their locking features disengaged.
Published Jul 12, 2025 | 5:34 PM ⚊ Updated Jul 12, 2025 | 5:34 PM
A Boeing 787.
Synopsis: The AAIB’s preliminary report on the fatal crash of Air India flight AI171 has come under criticism for dismissing potential mechanical failure, despite clear parallels with a 2018 FAA bulletin warning of fuel switch defects. Former IAS officer Kannan Gopinathan and the Airline Pilots’ Association of India have questioned the investigation’s transparency and urgency, raising concerns over the disengagement of engine fuel control switch locks.
After the Airline Pilots’ Association of India (ALPA-India) raised concerns about ‘bias’ and mishandling of the preliminary investigation into the 12 June fatal crash of Air India flight AI171, engineer and former IAS officer Kannan Gopinathan has flagged several issues with the Aircraft Accident Investigation Bureau’s (AAIB) initial report, which was released to the public on Saturday, 12 July.
In a detailed post on X, Gopinathan referred to a December 2018 Special Airworthiness Information Bulletin (SAIB) – NM-18-33 – issued by the United States Federal Aviation Administration (FAA), following reports from multiple Boeing 737 operators that fuel control switches were being installed with their locking features disengaged.
“I171 Crash – Caused by a catastrophic & continuing oversight from FAA & DGCA? The preliminary investigation report points to glaring regulatory failures. Before jumping on to sabotage theories, a thread on the questions that demand answer,” Gopinathan wrote.
“When disengaged, switches can move from RUN to CUTOFF without pilot lifting action, leading to immediate in-flight engine shutdown.’
The attached copy of the bulletin read:
“If the locking feature is disengaged, the switch can be moved between the two positions without lifting the switch during transition, and the switch would be exposed to the potential of inadvertent operation. Inadvertent operation of the switch could result in an unintended consequence, such as an in-flight engine shutdown.”
AI171 Crash – Caused by a catastrophic & continuing oversight from FAA & DGCA?
The preliminary investigation report points to glaring regulatory failures.
Before jumping on to sabotage theories, a thread on the questions that demand answers: pic.twitter.com/Y2saPegpoy
— Kannan Gopinathan (@naukarshah) July 12, 2025
The bulletin listed several Boeing aircraft models, including the 737, 747, 757, 767, 787, and MD-series jets.
The FAA recommended a ground inspection of the locking mechanism and replacement of certain switch part numbers with improved designs. However, it made clear that the recommendations were not mandatory:
“This is information only. Recommendations aren’t mandatory.”
Gopinathan called this a “fatal flaw”, arguing the bulletin should have been issued as an Airworthiness Directive (AD), which would have made compliance mandatory.
Gopinathan also drew a direct connection between the 2018 SAIB and the sequence of events described in the AAIB’s preliminary report on the AI171 crash. According to the AAIB:
“The aircraft achieved the maximum recorded airspeed of 180 knots AS 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 second.”
The cockpit voice recorder reportedly captured one pilot asking, “Why did you cut off?” with the other responding, “I didn’t.”
The AAIB confirmed that both pilots were well-rested and that the fuel quality was satisfactory. The aircraft had reached maximum take-off speed and altitude before both engines shut down. Attempts to restart the engines were only partially successful before the aircraft crashed in Ahmedabad’s Meghani Nagar area, hitting the campus of BJ Medical College.
Gopinathan questioned the haste in ruling out mechanical failure and speculating on sabotage:
“Why rule out technical issues before sabotage theories? Technical defect means fleet-wide risk, requiring immediate action. Sabotage means one-off incident, convenient to close case and move on. Chasing sabotage while ignoring known switch defects leaves entire fleet at risk.”
He said the chance of disengagement of the locking mechanism was “low but non-zero”, and noted that during take-off – when vibration and acceleration peak – the consequences of fuel cutoff are catastrophic.
“When outcome is certain death, you don’t gamble with ‘advisories’,” he added. “FAA should’ve analysed worst-case scenario: What if the switch disengagement occurs during the most critical flight phase?”
Gopinathan also criticised the Directorate General of Civil Aviation (DGCA), stating that even after the 2018 FAA bulletin, no mandatory inspections were enforced.
“When there’s an SAIB warning about fuel switch locking disengagements and a fatal crash involving the exact same part showing fuel cutoff, the immediate response should be making inspections MANDATORY!” he wrote.
He further pointed out that despite this, the AAIB report concluded:
“At this stage of investigation, there are no recommended actions to B787-8 and/or GE GEnx-1B engine operators and manufacturers.”
The Airline Pilots’ Association of India has issued a strongly worded statement criticising how the preliminary investigation into the AI171 crash is being handled.
In a letter addressed to the Press Trust of India, ALPA-India President Capt Sam Thomas described the 12 July AAIB preliminary report as having been “shared with the media without any official signature or attribution.”
The association also expressed concern over a lack of transparency in the probe.
ALPA-India raised alarm over leaks of sensitive details to international media, which reported on the inadvertent movement of the fuel control switches – the key issue in the crash.
The association acknowledged the inclusion of a serviceability bulletin related to the aircraft’s fuel control switch gates, but said it wanted clarity on whether any corrective action was taken before the flight.
A central concern for the pilots’ body is what it sees as a built-in bias in the investigation – one that points towards pilot error without clear evidence.
According to the AAIB’s preliminary report, the aircraft reached its peak airspeed of 180 knots at 08:08:42 UTC. Moments later, fuel cutoff occurred on both engines after the switches were moved from “RUN” to “CUTOFF” in quick succession.
The cockpit voice recorder captured one pilot asking, “Why did you cut off?” with the other pilot denying doing so. The Enhanced Airborne Flight Recorder showed that both pilots made efforts to relight the engines, which were only partially successful before the aircraft went down.
The AAIB confirmed that both pilots were adequately rested and that there were no fuel quality issues.
