New Delhi: A preliminary investigation into last month’s fatal Air India crash has brought a critical, and previously overlooked, mechanical issue to the forefront: a potential flaw in the Boeing aircraft’s fuel control switch locking system, a problem the U.S. Federal Aviation Administration (FAA) had issued a bulletin about nearly seven years ago.
The Indian Ministry of Civil Aviation, in a report released Saturday, stopped short of declaring a definitive cause for the tragedy. However, its findings, drawn from the Aircraft Accident Investigation Bureau (AAIB), have intensified scrutiny on the cockpit components and whether an unintentional fuel shutoff led to the catastrophic loss of engine power moments after takeoff.
A Warning Unheeded
The core of the issue dates back to December 2018. The FAA issued a Special Airworthiness Information Bulletin (SAIB) warning that some Boeing 737 aircraft had fuel control switches installed with their locking feature disengaged. This lock is a crucial safety mechanism designed to prevent the levers, which control fuel flow to the engines, from being moved from the ‘RUN’ to the ‘CUTOFF’ position accidentally.
While the bulletin was specific to the 737 model, the government’s report grimly notes that the design of the fuel control switch and its locking mechanism in the London-bound Boeing 787 Dreamliner was identical.
In a significant disclosure, the report states that Air India confirmed to investigators it had never conducted the recommended inspections of the locking system on its fleet. The carrier’s rationale was that the FAA bulletin was an advisory “bulletin” and not a mandatory “airworthiness directive.”
The Final Moments in the Cockpit
The AAIB report paints a tense picture of the aircraft’s final seconds. Flight data revealed that shortly after takeoff, both engine fuel switches were moved to ‘CUTOFF’ sequentially, with a gap of just one second.
The cockpit voice recorder captured the pilots’ confusion: “Why did you cut off the fuel?” one pilot asked. “I didn’t do so,” the other responded.
Although the switches were flipped back to the ‘RUN’ position seconds later, the sequence was enough to starve the engines, which had already begun to lose power irreversibly.
Experts Weigh In on Culpability
The aviation community is now carefully analyzing the implications of a disengaged locking feature. “If that’s the case, it’s a really serious issue,” Shawn Pruchnicki, an aviation expert at Ohio State University and a former accident investigator, told the BBC, questioning if the switch could “just flip itself to off.”
Other veterans are more circumspect. “I haven’t heard of this, which appears to be a low-profile FAA issuance,” said Peter Goelz, a former managing director of the U.S. National Transportation Safety Board (NTSB). “It’s worth examining since it’s mentioned, but it may just be a distraction.”
The ergonomics of the action are also under review. An investigator noted it would be “almost impossible to pull both switches with a single movement of one hand,” making an accidental deployment highly unlikely and deepening the mystery of how they were moved.
While the aircraft’s maintenance records show the entire throttle control module was replaced twice since 2019, neither action was linked to a known defect in the switches. Investigators say the final report, pending a full analysis, will provide more clarity on whether this overlooked FAA warning played a definitive role in the tragedy, raising critical questions about maintenance oversight and the implementation of non-mandatory safety advisories across the industry.