Despite a massive search over 37,000 square kilometres, military personnel and volunteers have been unable to find a missing Piper Warrior aircraft.

The Canadian Armed Forces says it has called off its search for the plane, which went missing more than two weeks ago.

The pilot, Alex Simons, was flying with his girlfriend Sydney Robillard.

The two 21-year-olds flew from Lethbridge to Cranbrook, where they refuelled before heading to their planned destination of Kamloops.

The couple never arrived.

"The families of the individuals have been informed and our thoughts are with them during this extremely difficult time," the Canadian Armed Forces said in a statement.