VANCOUVER - Federal investigators have an especially challenging mystery on their hands piecing together what caused a small jet to crash last Thursday shortly after taking off from a British Columbia airport, sending out no distress call.
The Cessna Citation carrying former Alberta premier Jim Prentice crashed outside Kelowna killing all four people on board. The aircraft wasn't carrying an in-flight data or cockpit voice recorder, which are commonly referred to collectively as a black box.
The absence of recording devices has put aviation analysts at a disadvantage when it comes to explaining what was behind the incident, said Bill Yearwood, a spokesman for the Transportation Safety Board.
"It's going to be very difficult," Yearwood said.
There is no legislation requiring smaller planes to carry black boxes, despite recommendations from the safety board dating back to 1991 that the devices be made mandatory.
The federal agency renewed its calls for legislative changes in the wake of Thursday's crash, calling on the federal government to expand the law, which orders only medium and large commercial planes to carry the recorders.
Transport Minister Marc Garneau said he has instructed his staff to look into possible regulatory changes.
"Over the past 20 years, there have been significant developments in technology that are more cost-effective and these options will be explored," Garneau said in a statement, explaining that the price tag was a major factor behind the lack of regulation.
Aviation experts say the absence of a black box may make an investigation more challenging but it doesn't alter the procedure analysts follow when examining a crash.
"It's more difficult but certainly it's been done many, many, many times," said retired aviation analyst Larry Vance, who spent 25 years with the Transportation Safety Board.
"It was the standard way of doing it before black boxes were invented."
Even with access to information from a flight recorder, Vance emphasized the importance of conducting a thorough investigation and not ruling out any possibility prematurely.
"You don't set out to say, 'OK, I think it might be this. Let's see what evidence there is.' If you do that then you'll miss other evidence," he said. "Anything is on the table."
Nothing can be left undone, Vance added. "You don't just go shooting in the dark on this stuff. You have to confirm everything."
Standard policies include analysing the wreckage, studying pilots' logs and flight records, listening to tapes of radio communication and taking the weather into account.
Brendan Kapuscinski of Beyond Risk Management, a Calgary-based safety education and accident investigation company, said the examination of any aviation incident is a long and complicated process.
The safety board uses what is called the SHELL model of investigation, which stands for software, hardware, environment and liveware, said Kapuscinski, also a former investigator with the Calgary Police Service.
Software includes not only computer programs but also the policies and procedures of both the aircraft's operator and the industry regulator, while hardware looks both at the plane and any machinery associated with it before the crash, he explained. Environment encompasses any factors surrounding the flight, including weather, and liveware refers to any human involvement, from the ground crew to the pilot.
"It's not a quick, 'He blew the red light and hit the other car,' " Kapuscinski said.
Also killed in the Kelowna crash were Ken Gellatley, the father-in-law of one of Prentice's daughters, and former RCMP officer Jim Kruk, who was piloting the aircraft. Media reports have identified the fourth victim as Calgary businessman Sheldon Reid.
The investigation is expected to take at least a year.
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