A preliminary report by Indian aviation accident investigators said on Saturday the fatal Air India crash that killed 260 people in Ahmedabad last month showed the plane engines fuel cutoff switches shifting from cutoff to run within seconds of each other.
“At this stage of investigation, there are no recommended actions to Boeing 787-8 and/or GE GEnx-1B engine operators and manufacturers” India’s Aircraft Accident Investigation Bureau said.
The agency, an office under India’s civil aviation ministry, is leading the probe into the world’s deadliest aviation accident in a decade.
The Aircraft Accident Investigation Bureau (AAIB) has released a 15-page preliminary report into the Air India aircraft crash that took place in Ahmedabad on June 12.
The report offers early insights into the sequence of events and technical parameters leading up to the crash involving a Boeing 787-8 aircraft.
The AAIB has not issued any safety recommendations at this stage of the investigation for Boeing 787-8 aircraft or GE GEnx-1B engine operators and manufacturers.
According to the findings, Engine 1’s core deceleration initially halted, then reversed, and began progressing toward recovery. Engine 2, meanwhile, managed to relight but failed to arrest the core speed deceleration and continued to reintroduce fuel in repeated attempts to stabilise.
The report states that at approximately 13:38:42 IST (08:08:42 UTC), the aircraft reached a maximum speed of 180 knots indicated airspeed (IAS). Immediately afterward, both Engine 1 and Engine 2 fuel cutoff switches transitioned from ‘Run’ to ‘Cutoff’.
Shortly thereafter, Engine 1’s fuel cutoff switch moved back from ‘Cutoff’ to ‘Run’ at 13:38:52 IST (08:08:52 UTC), followed by Engine 2’s switch transitioning to ‘Run’ at 13:38:56 IST (08:08:56 UTC). Rising Exhaust Gas Temperatures (EGT) were observed in both engines, indicating relight activity.
Cockpit voice recordings captured a moment of confusion between the pilots. One pilot was heard asking, “Why did you cut off?” The other responded, “I did not do so.”
The AAIB report also revealed that both engines’ N2 values had dropped below the minimum idle speed, according to data retrieved from the Engine and Flight Recorder (EAFR).
However, the aft EAFR was found to be substantially damaged in the incident and could not be downloaded using conventional methods, the agency said.
