THE Aircraft Accident Investigation Bureau’s (AAIB)preliminary probe report on the fatal Air India plane accident has put the spotlight on the fuel switches of the crashed Boeing 787-8 and the confusion among the two pilots over the switches being cut off. Fuel switches regulate the flow of fuel into an aircraft’s engines. The switch has two positions -- ‘RUN’ and ‘CUT OFF’ -- and are used to start or shut down engines.

 

According to a veteran pilot, the position of a fuel switch cannot be changed accidentally and there is a procedure in place. The fuel switches are generally guarded with brackets so that there are no accidental movements. The switches have to be first pulled up before changing their position, the pilot said. In a Boeing 787 Dreamliner, the fuel switches are located under the thrust levers.

 

In the case of the ill-fated AI 171 flight, the fuel switches to the two engines of the aircraft were cut off within a gap of one second and later, they were switched on. “Thrust lever is like a car accelerator pedal, the more you open it the more power you get , the less you open it the less power you get. There are two extreme positions-- one is idle power and one is full power. Then there is a fuel control switch which has got two positions-- cut off and run. So when you shut down the engine or the engine is not running the fuel control switch is in cut off mode and fuel is being fed into the engine,” the pilot explained.