New Delhi [India], July 12 : Retired Captain and Aviation Expert Alok Singh on Saturday said that the preliminary "fact-finding" report by the Aircraft Accident Investigation Bureau (AAIB) on the Air India flight 171 crash has put some rumours to rest, asserting that the conversation between the two pilots confirms that they didn't turn off the fuel switches.
The Cockpit Voice Recorder (CVR) transcript establishes that pilots didn't turn off fuel switches intentionally, and it seems like there was a technical malfunction, he added.
"It is a fact-finding report, and it has put some rumours to rest. CVR recording has clearly established that the pilots did not turn off fuel switches. A technical malfunction seems more likely. We should congratulate the Civil Aviation Minister and the Indian government for deciding to conduct this investigation in and by India," Singh told ANI.
"A relief to the victims and their families is that a fair probe is being conducted. There was an advisory on the malfunction of these switches. That angle also needs to be probed," he added.
The AAIB's Preliminary Report, released on Friday, said that both the engines of the aircraft were moved from "run" to "cutoff" in quick succession, which resulted in the fuel supply being cut off. The report says that in the cockpit voice recording, one of the pilots is heard asking the other why he did the cutoff, which the other pilot denied ever doing so.
"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 preliminary report said.
"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 added.
As per the Enhanced Airborne Flight Recorder (EAFR) accessed by the AAIB, engine 1's fuel cut switch transitioned from 'cutoff' to 'run' at about 8:08:52 UTC (Coordinated Universal Time), and at 8:08:56 UTC, Engine 2's fuel switch also went from 'cutoff' to run'.
According to the report, just 13 seconds later, at 8:09:05 UTC, one of the pilots transmitted the Mayday call, which the Air Traffic Control Officer (ATCO) enquired about, but did not receive a reply. Shortly after, the aircraft was observed crashing outside the airport boundary, and the emergency response was activated.
The Airline Pilots' Association of India on Saturday also called for a "fair, fact-based inquiry," into the incident and rejected the "tone and direction of the investigation" which suggested a bias towards pilot error.
"The report was leaked to the media without any responsible official signature or attribution. There is a lack of transparency in investigations as investigations continue to be shrouded in secrecy, undermining credibility and public trust. Qualified, experienced personnel, especially line pilots, are still not being included in the investigation team," the association said in a statement.
Notably, Minister of State for Civil Aviation Murlidhar Mohol urged people not to draw conclusions based on the preliminary report. While speaking to mediapersons, the MoS said, "The AAIB has brought out a preliminary report. This is not the final report. Until the final report comes out, we should not arrive at any conclusion. AAIB is an autonomous authority, and the ministry does not interfere in their work."