How Aircraft Tires Keep the Air Canada Fleet Rolling

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Groove‑treaded and nitrogen inflated jumbo tires are the unsung hero of every flight.

Burning rubber is probably still considered cool if you own a high‑performance automobile. But we pilots try to burn as little rubber as possible, even if we can’t avoid a small puff of blue smoke on landing.

Unseen by passengers on board, tires are a big deal in aviation: Each of the 12 tires on the main landing gear of the Boeing 777 (Air Canada’s largest aircraft) is more than 1.3 metres across and weighs in at 120 kilograms. And every tire in the fleet has its own history, tracked in its own file and monitored closely by the maintenance team. Main‑wheel tires have an average lifespan of 300 to 450 landings, while a nose wheel can withstand 200 to 350. (The nose wheel wears more when it pivots left and right to turn the airplane.) Depending on wear and tear, some tires might stay on much longer – up to 600 landings – while others will be replaced after 50.

Tires for the entire fleet are leased from Goodyear, Michelin and Bridgestone, who closely monitor each one via a serial number. Each aircraft model has a different baseline for tire maintenance: Length of service, number of retreadings, total landings and tire wear all factor into the supplier’s decisions on which tires to retread and which ones to replace.

Unlike those on a car, airplane tires are treaded with several long grooves allowing them to roll at faster speeds and also helping channel water, expelling it backward. (There are no such things as snow tires for airplanes.) All tires leave their mark on every landing, so from your window seat you may spot an accumulation of black scuffs near each end of the runway – part of runway maintenance is to remove the buildup of rubber.

January 15, 2021
A woman inspecting the tires of an Air Canada plane
   Photo: BrIan Losito

Nitrogen Boost

  • Aircraft tires are inflated with nitrogen gas instead of air, which contains moisture and would freeze at ‑57°C, the temperature at cruising altitude. Nitrogen doesn’t form a liquid until ‑173°C and contains little to no moisture.

  • Tires are subject to tremendous forces on landing and can heat up quickly; nitrogen gas does not support combustion.

  • Nitrogen is non‑reactive and thus also prolongs wheel life: Unlike oxygen, it does not promote rust on metal wheels or react with the rubber in tires.

 

Number

  • 230 — The optimal tire pressure, in pounds per square inch (PSI), for most wheels on the Boeing 787 aircraft. Car tires inflate to around 30 PSI.

 

Aviation Phrasebook

  • Square tires — Sometimes when an aircraft sits in prolonged cold temperatures, its tires take a while to warm up, so taxiing may be bumpier.

  • Kick the tires — Pilot talk for a walk around: an external inspection of the airplane.

  • Eau d’Aviation — If you watch airplanes land from near the airport fence, you will get whiffs of vaporized rubber. This distinctive fragrance, mixed with fuel exhaust, is one of the reasons people go tail spotting.

Ask the Captain

Send your aviation and operations queries to: douglas.morris@aircanada.ca

Portrait of Air Canada's Captain Doug Morris
Photo: Reynard Li

Doug Morris is an author, meteorologist, instructor and Air Canada captain on the Boeing 787.