It's easy to see how searchers missed the remains of Chuck McAvoy's plane. The 39-year-old wreckage was found earlier this week, hidden among a jumble of rocks on the barrenlands.

On Sunday, a helicopter pilot discovered the crash site near Lupin Lake on the Northwest Territories/Nunavut border. Curtis Constable was flying a crew of geologists back to a nearby camp when he passed 200 feet above the site. He says he wouldn't have seen it if he wasn't directly overhead.

"It's camouflaged in the rocks pretty well," Constable says. "You've got to be pretty close to see it. If you're off by a couple hundred feet you wouldn't really be able to tell what was there – you would just think it was rocks, it's blended in so well."

Constable landed nearby to get a closer look at the wreckage. He says the plane was largely intact, and he speculated that McAvoy might have been attempting to land when he caught a skid and rolled.

McAvoy and two passengers are believed to have died in the crash.

Daryl Browne, the pilot who was working with McAvoy the night he went missing, still remembers the ensuing search.

The two pilots had been ferrying a team of geologists between two lakes. When McAvoy didn't land on schedule, Browne set out in his single Otter to look for him.

"That's the longest I've ever spent in my life without putting my head in a pillow," Browne says. "It was 50 hours. I stayed awake to search for him. You know you've got to find him now, or the airplane would go through the ice if he landed on a lake."

The hunt for McAvoy would last for months. Since then, McAvoy's fate has been one of Canada's most famous aviation mysteries.

Authorities are now studying the crash site to see if they can figure out what went wrong four decades ago.