Fuel cut in 1 sec? AI-171’s final minutes flag mechanical failure, not pilot error

Time-motion studies from cockpit simulations indicate that, even under non-emergency conditions, operating such switches typically takes 2–3 seconds per switch


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A 2018 FAA bulletin that warned of possible failure modes in Boeing’s fuel shutoff switches is now under renewed scrutiny. Air India never conducted any specific inspections on these switches prior to the crash, because it wasn’t required to. Representational image: iStock
When Air India flight AI-171 fell from the sky on June 12 just seconds after takeoff from Ahmedabad, much of the Western media was quick to suggest pilot error as the cause.
These lines from the cockpit voice recorder, released by an Aircraft Accident Investigation Bureau (AAIB) report, were interpreted as confirmation of a fatal oversight:

"Why did you cut off the fuel?"

"I did not do so."

But aviation experts say the timeline tells a different and far more disturbing story:

13:38:39 IST — Aircraft lifts off
13:38:42 IST — Engine 1 fuel switch flips from RUN to CUTOFF
13:38:43 IST — Engine 2 fuel switch follows suit just one second later
13:38:47 IST — Engines drop below idle; ram air turbine (RAT) deploys
13:38:52 IST & 13:38:56 IST — Recovery switches return to RUN, four seconds apart

Physical impossibility

The US Federal Aviation Administration (FAA), custodian of global safety standards for US-built aircraft like the Boeing 787, provides essential context.
FAA human-factors research shows that pilots typically require at least 1 to 1.5 seconds just to recognise an unexpected event. Additional seconds are needed to operate a guarded, spring-loaded switch — such as the fuel cutoff levers on the 787’s throttle quadrant.

These timings are supported by NASA Ames Research Center studies, which emphasise that guarded cockpit switches are specifically engineered to prevent quick or accidental activation or deactivation.

Also read | What India, and the world, can learn from AI-171 Dreamliner crash report

According to NASA’s Human Integration Design Handbook, switches with safety covers and high-consequence functions must require more than one deliberate step (e.g., lift cover ➝ locate ➝ actuate). Time-motion studies from cockpit simulations indicate that, even under non-emergency conditions, operating such switches typically takes 2–3 seconds per switch.

How fuel switches work

To grasp the significance of that 1-second gap between the shutdowns, one must understand how fuel switches work. These are not casual toggle switches.
Capt Saurabh Bhatnagar, an aviation expert and Boeing 787 instructor, explained it in a conversation with The Federal.
“They’re spring-loaded, gated, and manually protected against accidental operation. You must lift, hold, and shift them with intent. It’s not like brushing your hand across a light switch. You’d have to reach below the thrust levers on the central pedestal and deliberately move them," he said.
Another pilot, currently in service said: "The pilot flying (PF) has both hands on the yoke and throttles. The pilot monitoring (PM) is running callouts and watching instruments. And in this case we know the PM was the captain and his co-pilot was flying the plane at takeoff. Neither would or could have shut both switches off in one second.”

Too quickly, too precisely

That impossibility is now central to the case that the engine cutoffs were not manually triggered. It looks like they happened too quickly; and too precisely to be human.
“This points clearly to an internal mechanical or electronic fault,” said Air Marshal (Retd) M Matheswaran. “There is no possibility of inadvertent tampering of the fuel shut-off switches by the pilots. By design, these are critical switches and are located such that it will need deliberate and clear action to operate these switches. This is clearly a mechanical and electronic system failure," he told The Federal in a recent interaction.
The only lines publicly released from the cockpit voice recorder so far are chilling in their ambiguity:

“Did you cut off the fuel switch?”

“No, I didn’t.”

That’s not the language of a mistake, it’s the language of disbelief, say experts. Investigators have yet to clarify which pilot spoke what, even though each cockpit microphone is recorded on separate audio tracks.
“The report doesn’t tell us who said what. That’s frustrating, because the CVR (cockpit voice recorder) can distinguish voices easily,” Bhatnagar said. “The captain was on the left, the co-pilot on the right. This level of vagueness only creates space for speculation.”

FAA didn't mandate fixes

A 2018 FAA bulletin that warned of possible failure modes in Boeing’s fuel shutoff switches is now under renewed scrutiny. Called Special Airworthiness Information Bulletin (SAIB) NM-18-33, the advisory warned that the switches could become dislodged or move inadvertently if their guards failed or were improperly latched.

NASA Ames Research Center studies emphasise that guarded cockpit switches are specifically engineered to prevent quick or accidental activation or deactivation.

But the advisory did not mandate any action. And Air India never conducted any specific inspections on these switches prior to the crash, because it wasn’t required to.
“This wasn’t just a known issue. It was a known hazard,” said a Lufthansa engineer, who handles Airbus maintenance. Airbus planes use the same fly-by-wire technology as the Boeing Dreamliner in question. “The FAA left it up to the airlines and Boeing to decide whether to act," the engineer told The Federal.

What happened after switch off?

When the fuel was switched off in the AI-171, the engines shut down mid-climb. The aircraft would have lost thrust. Although aircrafts are equipped with an emergency ram air turbine (RAT), it takes time to deploy and provides only minimal backup power.
The slats and landing gear never retracted, and there’s no indication the auxiliary power unit (APU) was successfully engaged. That alone confirms how little time the pilots had before the aircraft descended uncontrollably.
“When both engines stop due to lack of fuel supply, there is nothing you can do,” said the Lufthansa engineer. “The RAT will try to keep you flying, but not from that low. You’re in free fall.”

The AAIB’s preliminary report outlines what happened but not why. What it does do is question the theory that one pilot was actively engaged in flipping both fuel switches within one second of each other during one of the most critical phases of flight.

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