A plane crash that killed two people in northern Quebec last year happened because the pilot was flying at a low altitude, according to the Transportation Safety Board of Canada.

In an incident report released Thursday, the TSB said the pilot of the small plane was flying between 40 and 100 feet above the ground when the crash occurred.

The agency's investigation found that a mix of "sensation seeking, mental fatigue, and an altered risk perception" led the pilot to fly so low.

Two pilots were on board the Piper PA-31 Navajo, operated by Exact Air Inc., when it crashed on April 30, 2017, near Schefferville Airport in Schefferville, Que., more than 500 kilometres north of Sept-Iles, Que., near the Labrador border.

Plane came into contact with power lines

The pilots, both of whom were killed in the incident, were conducting a survey flight when the plane came into contact with power lines.

"It is highly likely that the pilots were unaware that there were power wires 70 feet above the ground in their path. The pilot flying did not detect the power wires in time to avoid them," the TSB said.

The plane crashed on its way back to the Schefferville Airport in northern Quebec, near the border with Labrador. (CBC)

Exact Air Inc. didn't know the pilots in question had frequently flown at very low altitudes when going between the survey areas and the airport, the agency said.

The TSB said the company has since taken steps to prevent low-altitude flying, including an awareness campaign about the risks and meetings with company staff.

Equip planes with emergency tracking systems, TSB advises

The agency advised commercial and private airline companies, both in Canada and abroad, to adopt more rigorous standards to equip planes with flight recording systems.

These systems allow investigators to understand the sequence of events ahead of an incident, such as a crash, and allow companies to ensure their pilots are following safety regulations.

The TSB also advised Canadian and international flight companies to beef up their emergency tracking systems.

Immediately after the Schefferville crash, the plane's antenna and antenna cable were damaged, so responders could not detect its emergency locator transmitter signal.