Low visibility: AAIB report on Air India crash needs technical clarity

Last week’s preliminary report by the Aircraft Accident Investigation Bureau (AAIB) on the crash of Air India Dreamliner Flight 171 to London on June 12, killing 260 people, has raised more questions than answers. The probe by the AAIB, which was set up in 2012 to comply with the International Civil Aviation Organization’s (ICAO’s) recommendations, is significant because it comes a little over three years after the Tata group acquired Air India. But the report appears to raise a raft of speculative conclusions, which will neither bring closure to the victims’ families nor offer clarity on safety protocols for the aviation industry. The report’s lack of clarity on the role of the pilots is also troubling. 

The plane crashed 30 seconds after takeoff from Ahmedabad, ploughing into a doctors’ hostel in a crowded locality. One of the pilots had submitted a Mayday call just before the crash. The AAIB’s preliminary report said the fuel supply to the engines stopped moments after takeoff because the fuel-control switch had shifted from “run” to “cut-off” position. Recordings from the cockpit voice recorder (CVR) report one of the pilots asking the other why he had switched off the fuel switch, to which the reply was that he hadn’t. The report does not identify the voices. It also cites a 2018 Special Airworthiness Information Bulletin of the United States (US) Federal Aviation Administration, which flagged a disengagement issue with the fuel switch-locking mechanism. Because the bulletin was advisory and the issue was not deemed an unsafe condition requiring a legally enforceable airworthiness directive, Air India had not conducted inspections on its fleet. Adding to the ambiguity is the statement in the report that there was no recommended action for Boeing or manufacturers of the GEnx-1B engine.   

The problem with the AAIB’s 15-page report is that it has sparked damaging speculation about “pilot error” or, worse, pilot suicide. Neither finding has a bearing on compensation payouts to the families of victims. But experts have sharply criticised the report, pointing out that the issue of whether the fuel “cut-off” was a result of human error or a technical flaw requires more comprehensive information. It has been suggested that the order of events presented in the report is confused. The report states that the fuel-control switches moved to cut-off position some seconds after the liftoff. But the report also notes that the Ram Air Turbine, or the backup power source that activates only after both engines fail, was deployed immediately after takeoff, suggesting that the engine ceased functioning before liftoff or the moment the aircraft’s wheels left the ground. Without an analysis of the full transcript of the CVR and other technical data, it is impossible to gain clarity on the cause of the crash. 

Civil Aviation Minister K Ram Mohan Naidu has rightly urged the media and the public not to jump to conclusions since, as he has pointed out, these preliminary findings are just the beginning of a complex investigation, which will take at least a year. The question is why it was issued with such obvious gaps. The AAIB’s investigation team is not lacking in expertise. It is led by the director general, who is a former Indian Air Force aeronautical engineer, and includes members from the US National Transportation Safety Board, an air traffic control officer, and an aviation-medicine specialist. India had also granted a request for observer status for an ICAO expert. Given this collective expertise, a report with clear findings would have been in order.