The report of the investigation into the crash of Saras, the light transport aircraft, near here on March 6, 2009 that killed all three crew members on board, enumerates dozens of lapses, including an insufficient pre-flight debriefing, a poor telemetry system and “lack of crew coordination.”
The report, prepared by a board constituted by the Directorate-General of Civil Aviation (DGCA) and made public on the DGCA website on Thursday, said: “Incorrect relight [restart] procedure devised by the designer and adopted by the crew… [led to] abnormal behaviour of aircraft [and] resulted in the accident.”
The second prototype of the aircraft, built by the National Aerospace Laboratories (NAL), crashed and burst into flames near Bidadi, 30 km from here, less than an hour after it took off, killing Wing Commander K. Praveen, Wing Commander Dipesh Shah and test engineer Squadron Leader Ilayaraja, all in their mid-thirties.
The 75-page report says the pilots switched off one of the engines midair (as part of the programme requirement), but failed in their attempt to relight it. “Saras-specific intentional engine shutdown and relight procedure was not well planned and prepared,” it says. “Either wrong selection of mode switch or the [failure to press] engine start switch… during the first relight attempt is the most probable cause for the engine not to relight in the first attempt.”
Contributing to the tragedy was the lack of crew coordination; the failure to abort the flight by the crew in coordination with the flight test director after the failure of the first relight attempt; and the NAL's devising of the engine relight procedure without consulting the propeller manufacturer.
The cockpit voice recorder reveals that telemetry (communication between the aircraft and the ground station) was intermittent. Also, there appeared to be “no effective pre-flight briefing to the crew,” the report said, adding “there is no contingency plan for emergencies like accident, missing aircraft, loss of communication etc.”
The chilling transcript retrieved from the cockpit voice recorder in the past 38 minutes of the flight reflects concern over the loss of control on several occasions — on one occasion of laughter of relief when the aircraft appears to stabilise, and finally a distraught pilot calling “Going to ground.”
