Mumbai: The Aircraft Accident Investigation Bureau (AAIB) released its preliminary findings into the tragic crash of Air India flight AI171 that occurred on June 12 in Ahmedabad. The accident claimed 270 lives, including 241 onboard the Boeing 787-8 Dreamliner. Only one passenger survived, making it one of India’s deadliest aviation disasters in recent memory.
Below are the key takeaways from the 15-page AAIB report:
- Engine Shutdown After Takeoff:
Both engines of the aircraft shut down within seconds of takeoff. Investigators found that the fuel cutoff switches were moved from 'RUN' to 'CUTOFF' just one second apart, leading to a complete loss of engine power.
- Cockpit Confusion:
Cockpit Voice Recorder (CVR) data revealed a startling exchange between the pilots. One asked, “Why did you cut off?” to which the other responded, “I didn’t,” indicating possible confusion or a technical anomaly in fuel switch operation.
- Emergency System Activation:
With both engines losing power, the Ram Air Turbine (RAT), a backup emergency power system, was automatically deployed to provide minimal hydraulic power. CCTV footage confirmed RAT activation during flight.
Ram Air Turbine (RAT) deployed shortly after takeoff | AAIB Preliminary Report
- Failed Engine Restart:
Pilots attempted to restart the engines mid-air. While Engine 1 showed partial recovery, Engine 2 failed to restart. The aircraft remained airborne for just 32 seconds before crashing into a hostel located 0.9 nautical miles from the runway.
- Throttle Inconsistency:
The thrust levers were found at idle during the crash, yet the flight data recorder indicated that takeoff thrust was still engaged, hinting at a possible disconnect or malfunction in the engine control system.
- No Bird Hit Incident
"No significant bird activity is observed in the vicinity of the flight path," revealed the AAIB report. It also stated that the aircraft started to lose altitude before crossing the airport perimeter wall.
- Fuel Quality Verified:
Fuel samples were tested and confirmed clean with no signs of contamination or improper refuelling.
- Normal Takeoff Configuration:
Flap settings were at 5 degrees, and landing gear was down, both standard for takeoff. Weather was not a factor: skies were clear, visibility was good and winds were light.
- Pilot Credentials & Fitness:
The report confirmed that both pilots were well-rested, medically fit and had valid credentials with sufficient experience on the aircraft type.
- Possible Technical Oversight:
While there was no evidence of sabotage, the report noted that an FAA advisory had previously warned of a potential flaw in the fuel switch system. However, Air India had not conducted the recommended inspections.
- Aircraft Compliance:
The aircraft was operating within its weight and balance limits and was not carrying any dangerous goods.
The final investigation report is expected to provide a more comprehensive picture of the causes behind this catastrophic crash.
