Bodies of the victims of a Ukrainian plane crash are collected by rescue team at the scene of the crash in Shahedshahr, southwest of the capital Tehran, Iran, Wednesday, Jan. 8, 2020. A Ukrainian passenger jet carrying 176 people crashed on Wednesday, just minutes after taking off from the Iranian capital's main airport, turning farmland on the outskirts of Tehran into fields of flaming debris and killing all on board. (AP Photo/Ebrahim Noroozi)

OTTAWA - The crash of an airplane, anywhere in the world, launches an investigative process with standards for what evidence needs to be collected and who can be involved. Here's how it might work after the crash of a Ukrainian airliner flying from Tehran to Kyiv, with many Canadians aboard.

Who is involved?

Under rules set out by the International Civil Aviation Organization (ICAO), the countries where the crash happened, where the plane is registered, where the plane's operator is located, and where its manufacturer is based are all brought in. In this case, the Aircraft Accident Investigation Board of the Civil Aviation Organization of the Islamic Republic of Iran is in charge. Ukraine assists because the operator is based there, and so should the United States because that's where Boeing, the manufacturer of the 737-800 aircraft, is located.

The lead country can call in other outside experts to look more closely at the engines, the pilots and maintenance, among other areas, said Barbara Dunn, president of the Canadian Society of Air Safety Investigators.

As well, the country suffering the most fatalities from the crash is usually invited to take part, said Daniel Adjekum, an assistant professor of aviation at the University of North Dakota.

Canada's Transportation Safety Board, in a statement, said it has an expert who will review factual information released by the Iranians and monitor progress on the investigation "by virtue of fatalities to Canadian citizens."

The host country can also turn to Interpol for assistance identifying victims, which could include help from the RCMP. In a statement Wednesday, the Mounties said they co-ordinate help coming from the military, forensic odontologists (experts on identifying people via teeth) and provincial pathologists. The RCMP said no such request for help has yet come in.

When a Malaysian Airlines plane crashed over Ukraine in 2014, flying from the Netherlands to Malaysia, the safety authorities from the Netherlands led the investigation; more than two-thirds of the passengers were Dutch.

What are the first steps in an investigation?

Investigators collect pieces of the plane, interview as many people as possible — including witnesses, air-traffic controllers and any survivors — and collect evidence, including any information from air-traffic control. They will also map the crash site to determine details about the impact.

Documents, too, are collected by other countries involved, including those related to pilot training and maintenance logs.

For instance, the U.S. Federal Aviation Administration issued a directive in October 2019 that airlines needed to inspect the 737-800, among other 737 models, for cracking. Adjekum said investigators would look for how Ukraine International Airlines responded to this issue to see if that provides clues.

But he cautions about jumping to conclusions about what downed the plane: "You don't want to speculate. You want to be guided by the evidence."

What about the "black boxes"?

The flight data and voice recorders, commonly known as "black boxes" (even though they are orange), record the sounds of the pilots' voices, alarms and engines that could give investigators clues about what happened. The recorders also keep track of external factors, such as the weather.

Dunn said it can take days to find the recorders depending on the wreckage field, though Iranian authorities said they'd found the ones from the Ukrainian plane quickly.

Dunn said the recorders are sent to an independent authority, such as the Transportation Safety Board in Canada, which Dunn said has among the best labs in the world to do the work. The idea of sharing the work is to "get as much information and as much causal factors as we possibly can because that's how we stop it from happening again," she said.

Others with noted reputations are the French and the Americans, but sending the recorders to the U.S. may be politically problematic with tensions high between Washington and Tehran; Iran says it won't do so. Likewise, having American crash investigators in Tehran could be difficult.

But Dunn and others said it's likely the Iranian investigators will turn to outsiders for help.

Is there a role for Canada here?

Transport Minister Marc Garneau has offered Canada's technical expertise, and this country may be asked to review the recorders as a third party, said Elaine Parker, vice-president of the Canadian Society of Air Safety Investigators. Such a setup would also allow Boeing to be involved in analyzing data, because investigators would want the company's expertise, she said.

Boeing is a major American defence contractor, which might complicate Iran's willingness to co-operate with it as the crashed plane's manufacturer.

What else might investigators do behind the scenes?

Parker said one thing investigators try to do is slow things down so no one gets hurt going to the scene of the crash and the scene is preserved. Slowing things down is critical because of the clamour from the public and politicians after a high-profile crash, she said.

"Everyone would like answers right away. I know they're not going to get them," Parker said, putting herself in the position of an investigator beginning work.

"The politicians are saying what they're saying because this isn't their area of expertise. I know they're going to say things that are not going to be accurate and so I'm going to set up briefings for them, I'm going to set up briefings for the media."

How long do investigations take?

It could be weeks, months or years before the details of what brought down the plane are learned, if they are learned at all. Normally, though, a final report is expected after two years.

"Aviation is a complex system and complex systems do not fail because of one thing," Parker said.

Adjekum noted that if the plane came down for nefarious reasons, such as sabotage or a bomb, then a criminal investigation would begin with prosecutors and other law enforcement involved.

The investigation of the Malaysian Airlines crash in Ukraine took about two months to produce a preliminary report and 15 months to reach a final conclusion that the plane had been shot down by a missile.

This report by The Canadian Press was first published Jan. 8, 2020.

News from © The Canadian Press, 2020