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Journalism of Courage
THE TWO most crucial aspects of the Air India plane crash in Ahmedabad the preliminary report sheds light on are the movement of the fuel control switches that allow and cut fuel to the aircraft engines, and what the two pilots discussed in the final moments.
The aircraft has two fuel control switches, one for each of the two engines. Moments after lift-off, both the switches transitioned from ‘RUN’ to ‘CUTOFF’ position within a second of each other. The two switches were found in the wreckage, and both were in the RUN position, the report said.
After a few seconds in the CUTOFF position, the switches for both engines on the doomed aircraft transitioned from CUTOFF to RUN position — evidently an attempt by the pilots to recover thrust in the engines. But given the extremely low altitude of the aircraft, there wasn’t enough time for the engines to recover to a level that would have allowed them to climb to safety.
Further, the report paraphrases only a part of the discussion between the pilots, with the transcript of the recording in the cockpit voice recorder yet to be released. It says, one of the pilots can be heard asking the other why he cut off the fuel, to which the other pilot responds saying he did not.
The report does not say who said this to whom, and does not mention any other exchange between the pilots. It also does not mention whether the investigators have so far been able to ascertain if the switches were toggled by one of the pilots or not.
According to airline pilots and experts, accidental movements of the switches may not be possible since the spring-loaded switches have brackets on either side to protect them. Further, there is a stop lock mechanism that requires the pilots to lift the switch up before moving it from either of its two positions — RUN and CUTOFF — to the other.
These fuel switches are usually moved only when the aircraft is on ground — to start the engines before departure and to shut them down after the aircraft reaches the gate. Movement of either of the switches during the flight would be required only in the event of failing of the corresponding engine or suffering enough damage that would require shutting off its fuel supply to ensure flight safety.
The pilots may also switch off the fuel supply and then immediately switch it on if they believe that the affected engine could be restarted safely.
* Co-pilot Clive Kunder was flying the aircraft, while commander Sumeet Sabharwal was the ‘pilot monitoring’ for this flight. Both had an adequate rest period and just before the flight, they had a breathalyser test at the airport, the report said. Aircraft maintenance checks were on schedule. It was a normal take-off till the aircraft reached an altitude of around 400 feet.
* Incidentally, the preliminary report does mention that the US Federal Aviation Administration (FAA) had in 2018 issued a Special Airworthiness Information Bulletin (SAIB) regarding the “potential disengagement of the fuel control switch locking feature”. This was essentially for 737 fuel switches, which are the same design as the module housing the switches on the 787s. Air India, however, did not carry out the inspection as the SAIB was merely advisory and not mandatory.
* According to the report, the scrutiny of maintenance records revealed that the cockpit’s throttle control module — which houses the fuel control switches among others — was replaced in 2019 and 2023, but the reason for replacement was not linked to the fuel control switches. It said no defect was reported pertaining to the fuel control switch since 2023 on the aircraft. “All applicable Airworthiness Directives and Alert Service Bulletins were compiled on the aircraft as well as engines,” the report said.
* The report notes that the Ram Air Turbine was deployed immediately after engine shutdown while the Auxiliary Power Unit automatically started after the control switches were transitioned back to RUN. Both the APU and RAT are emergency power sources on the aircraft. The RAT is essentially a wind turbine located just behind the landing gear console that deploys into the airstream to generate power only when primary and secondary power sources fail. The APU is a smaller turbine engine, typically located in the tail section of the aircraft, that provides electrical and pneumatic power for various on-board systems. Their deployment signifies a complete engine shutdown or flameout.
* The report notes that there are no recommended actions to B787-8 and/or GE GEnx-1B engine operators and manufacturers. This is a clear indication that the investigators are sure there is no issue with either the aircraft or engine. Pilot action is thereby a focus of the investigations to follow. The final report is likely to come out in about a year’s time, or could be even earlier, given how detailed the initial report has been.
