A special NAV Canada Boeing 737 airplane is in Yellowknife testing runway and landing signalling equipment at the airport.
NAV Canada's flight inspection plane was in Yellowknife on Wednesday for routine maintenance of navigational aids to ensure they are functional and accurate, said Ron Singer, national manager for NAV Canada.
The company tests navigational aides every six months to ensure the instrument landing system is accurate to the centimetre.
The plane flies overhead but doesn't engage landing gear as it tests whether the navigational aids are giving correct signals.
The aides send signals to a pilot on board with the lateral, horizontal and vertical positions to assist planes in conditions where the runway is obscured, whether by fog or cloud.
“That has to be accurate,” said Singer. “You don't want to be off by a couple of feet.”
“It's what we do for safe operations. It's routine but very, very important,” said Singer.