It just didn’t make sense. Ever since the tragic crash of the Air India Flight 171 seconds after takeoff from Ahmedabad Airport on June 12, aviation experts have been struggling to nail down a reason for the disaster. It was clearly a loss of thrust but why did it happen to one of the most sophisticated aircraft ever built, the Boeing 787 Dreamliner? Was it a mechanical, electrical, fuel or pilot error issue that caused the plane to lose lift and slam into several buildings on the ground? The families of 260 people killed on the plane and ground deserve answers.
Now that we have the Indian Aircraft Accident Investigation Bureau Preliminary Report it appears the Boeing was not the problem. On page 14 of the 15 page report you can find the most disturbing discovery the investigation team found so far from the Enhanced Airborne Flight Recorders (EAFR).
“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 report also 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 cut off.”
The switches were returned to the RUN position 10 seconds later. But by then it was too late to return the engines to takeoff power. At 08:09:05 UTC, one of the pilots transmitted “MAYDAY MAYDAY MAYDAY“. Soon after the 787 crashed.
08:08:42 FUEL CUTOFF – 08:08:52 FUEL RUN
This makes it clear why the Ram Air Turbine (RAT) was deployed. The RAT is a small propeller that drops from the fuselage into the airflow to generate power (electric and hydraulic) in the event of total engine failure. If the engine cutoff switches were selected then the RAT would automatically deploy. Videos have been doing the rounds on social media for weeks showing the RAT in operation.
SO WHAT NOW?
There is still much work to be done by investigators but clearly attention must turn to the pilots. How did the fuel switches move into the CUT and back into the RUN positions so quickly in such a critical period of the flight? The final report could take some time to complete so speculation will run wild over the coming months or years. For the sake of aviation safety we need a fearless investigation that will ask the hard questions and deliver the truth no matter how confronting that could be.
