The recent Air India crash, which tragically claimed 260 lives, has brought the function and design of the fuel control switch to the forefront of aviation safety discussions. A preliminary report by India's Aircraft Accident Investigation Bureau (AAIB) indicates that the fuel control switches for both engines were abruptly moved from the "run" to the "cutoff" position shortly after takeoff. This action starved the engines of fuel, leading to a loss of thrust and the subsequent crash of the Boeing 787 Dreamliner.
Fuel control switches regulate the flow of fuel to an aircraft's engines. Pilots use them to start and shut down engines on the ground and, in certain emergency situations, to manually shut down or restart engines during a flight. The switches are most often used to turn engines off once a plane has arrived at its airport gate and in certain emergency situations, such as an engine fire.
On a Boeing 787, the two fuel control switches are located below the thrust levers and are spring-loaded to remain in position. To move a switch from "run" to "cutoff," a pilot must first pull it up and then move it to the desired position. According to U.S. aviation safety expert John Cox, there are independent power systems and wiring for the fuel cutoff switches and the fuel valves controlled by those switches.
The AAIB's preliminary report reveals that the switches flipped from "run" to "cutoff" almost simultaneously shortly after liftoff. Cockpit voice recordings captured a moment of confusion between the pilots, with one asking why the other had cut off the fuel, to which the other responded that he had not. At the crash site, investigators found the fuel switches in the "run" position, suggesting that the engines had begun to relight automatically, but there was not enough time to recover from the rapid loss of thrust.
The report does not explain how the switches could have moved to the "cutoff" position during the flight. There was no indication of an onboard emergency that would have necessitated an engine cutoff. Switching to cutoff is typically done to shut down engines after a plane has reached the airport gate or in specific emergencies, such as an engine fire. Aviation experts find it "absolutely bizarre" for the engine cutoff switches to be switched off seconds after takeoff. U.S. aviation expert John Nance stated that a pilot would almost never turn the switches off mid-flight, especially during the initial climb.
The crash has raised renewed scrutiny over the design and placement of the fuel cutoff switches. In 2019, the U.S. Federal Aviation Administration (FAA) issued a Special Airworthiness Information Bulletin (SAIB) warning that some Boeing 737 fuel switches had been installed with their locking features disengaged. Additionally, the AAIB report noted that the throttle control module on the crashed aircraft had been replaced in 2019 and 2023, though the replacements were not linked to the fuel control switch.
The preliminary report lays out the facts of the case, but not the "why". The investigation is ongoing, and the focus of investigators may change as they delve deeper into the circumstances surrounding the crash.
