MONTREAL — An aviation expert says the mid-air crash in Washington, D.C., Wednesday night is likely the result of unique air traffic patterns in the area and shouldn’t cause wider fears over air safety.

John Gradek, who teaches aviation management at McGill University, says the Ronald Reagan Washington National Airport has possibly the busiest runway in the country while military aircraft also frequently fly in the area to make it a higher-risk airspace.

The collision between an American Airlines jet carrying 64 people and an Army helicopter carrying three soldiers is believed to have killed everyone on board both aircraft.

There was no immediate word on the cause of the collision, but officials say the jet was making a routine landing when the helicopter flew into its path.

Gradek says air traffic controllers told the helicopter about the plane and it would have been the responsibility of the helicopter pilot to avoid the jet.

He says that while there are concerns about air traffic controller shortages in Canada, flight volumes are managed so they’re never overstretched.