Canadian investigators are probing the loss of a main landing-gear wheel from an Air Canada Airbus A319, confirmed during a tower fly-by as the aircraft prepared for arrival at Toronto.

The aircraft (C-GAQL) had been operating the AC715 service from New York LaGuardia on 18 February.

Its crew had advised LaGuardia’s departure control, shortly after take-off, that they needed to maintain 220kt for a while because the brakes had “just got hot a little bit” and they had left the landing-gear deployed for cooling.

“It’s no big deal,” the pilot told the departure controller.

But as the aircraft approached Toronto, its crew requested an observational fly-by to check the landing-gear. The A319 was subsequently established on the ILS for runway 24L.

Toronto tower controllers, having received the fly-by request, told the crew to continue the approach visually but to “come as close to the southbound of the control tower as you can, give us a good look”.

Although the crew was asked to climb away – after passing the tower – on a right-turn heading of 290° to 5,000ft they requested to stay at 3,000ft to keep below cloud and out of any icing conditions.

As the aircraft broke off its descent the controller contacted the crew to inform them that the outside right-hand main-gear wheel “appears to be completely missing”.

“We do have one, though, for sure there?” the pilot replied.

“There’s one there, but can’t tell whether it’s inflated or not,” the controller said. “But the other one is definitely not in situ.”

“Interesting. OK. You guys must have some pretty good binoculars,” the pilot stated, to which the controller responded: “It’s pretty easy to see, believe me.”

After providing further information, indicating that the remaining wheel seemed inflated and intact, with no other damage apparent, the controller said: “I’m surprised they haven’t found the wheel at LaGuardia yet. Unless you dropped it into the bay.”

The A319 carried out a circuit and was subsequently cleared to land on runway 23, the crew being assisted by periodic wind checks in the gusting conditions, according to air-ground communications archived by LiveATC.

Cirium fleets data lists the aircraft involved as 1997 airframe, powered by CFM International CFM56 engines, delivered new to the airline.