What Led To Air India Crash In Ahmedabad? Probe Officials Point To 'Contained Electrical Fire' In Tail Section: Report

The rear black box was severely damaged, hindering data retrieval. A prior flight reported a stabilizer sensor issue, raising questions about pre-flight malfunctions.

File image.

Source : PTI

Days after the June 12 Air India plane crash in Ahmedabad, the investigators are closely examining the tail section of the aircraft, which showed signs of a “contained electric fire” but was restricted to only a few components located in the rear, reports The Indian Express.

Air India’s Boeing 787-8 aircraft from Delhi to London crashed into a medical hostel last month, killing 240 persons out of the 241 onboard.

According to the report quoting officials, the officials aware of the probe said the wreckage of the empennage, or tail assembly, of the aircraft showed signs of a “contained electric fire” but restricted to only a few components located in the rear. The tail had disengaged and remained largely unaffected by the post-crash explosion and fuel fire, which had charred the rest of the aircraft body.

The officials also said that the components located in the tail have been identified and safely stored at a location in Ahmedabad. 

“They hold the key for a detailed analysis of a possible malfunction in the electric supply of the aircraft during liftoff,” an official told The Indian Express.

The officials cited in the report said that the aft Enhanced Airborne Flight Recorders (EAFR), or the rear black box, found from the rooftop, had suffered extensive internal thermal damage.

Earlier, a preliminary probe report released by the Aircraft Accident Investigation Bureau had pointed out that the data from the EAFR “could not be downloaded through conventional means” as the “damage was extensive”.

The initial report released by AAIB after a month said that both the engines lost power almost simultaneously when the fuel control switches — which regulate the flow of fuel to the engines—shifted from the "run" to "cutoff" position within the space of one second.

According to the officials cited by the newspaper, the aircraft’s tail suffered the expected crash impact when it made contact with the hostel mess building, but they added that this was not the rare kind of damage where the aft EAFR (rear black box) should have been damaged beyond salvage. The B787 model of the aircraft carries two black box sets—one under the cockpit and the other in the tail section.

“It needs to be probed if the electric fire in the tail was due to a fault that originated in one of the flight components when it began rolling for take-off, or was it purely a fire following the impact… The fire was contained in the tail section, which, despite being embedded in Building A (hostel mess), did not spread to the structure or its electrical framework,” the official said.

According to the report, this holds significance, as the crew of the previous flight, AI-423 from Delhi to Ahmedabad, had recorded a Pilot Defect Report in the technical log noting the status message “STAB POS XDCR” (Stabilizer Position Transducer – a sensor in the tail). This was troubleshooted by the Aircraft Maintenance Engineer in Ahmedabad before clearing the flight for AI-171 on June 12.