Air India Crash: “Why did you cut off?” report finds fuel switches in cut-off

The preliminary report by India’s Air Accident Investigations Bureau (AAIB), shows that the fuel cut off switches of the Boeing 787 were in the off position when the London Gatwick bound plane crashed on take-off from Ahmedabad on the 19th of June killing 260 people.

The report shows the focus is currently on pilot error rather than a fault with the aircraft or its engines which will be a relief to North American OEM Boeing and GE, which makes the engines.

The fuel cut off switches sit behind he throttle levers on almost all aircraft and used to turn on the fuel supply when starting the engines and cut off the fuel supply to shut them down. If the report is correct and the switches were in the off position then the engines would have shutdown was soon as they were switched.

The switches are protected by metal guards either side of the switches which should prevent them being accidentally knocked by an inadvertent movement.

Both engines being shut down in the air would trigger the Ram Air Turbine (RAT) which we know was deployed as the aircraft descended towards the ground and this is further backed up with the mayday call during which the pilot said he had “no thrust”.

The report says “The aircraft achieved the maximum recorded airspeed of 180 Knots IAS 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 sec. 

“The Engine N1 and N2 began to decrease from their take-off values as the fuel supply to the engines was cutoff. 

“In the cockpit voice recording, one of the pilots is heard asking the other why did he cutoff. The other pilot responded that he did not do so.”

The question now turns to how and why the switches were set off, there is no mechanism for automatically doing so so it has to be some form of human interaction. There are no obvious switches nearby that could easily be mistaken, unlike the flaps/landing gear theory that many speculated on in the days after the accident.

The early indications though will be a relief for Boeing which has been plagued with faults and delays over the last few years with its 737 Max and 787 Dreamliner range and is in somewhat of a recovery mode after being overtaken by Airbus as the worlds biggest commercial plane maker.

It must be noted though that this is only a preliminarily report and there is still a long-way to go in the investigation before the formal cause is established.