I used to watch a lot of airplane landings and take-off. My favourite moment is when airplane tyres touch the ground. Friction produces a lot of heat and hence, smoke.
But i wonder, why not pilot start rotating wheels before landing and match the speed of wheels such that it doesn’t cause any friction.
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Wheels are not powered. Since this is a DAL A system, it would require a boatload of money and complex tech to make it powered, which would also increase weight.
Comparing the cost of development, implementation and maintenance vs the cost of replacing tyres a bit more often, it really is a not brainer to leave them unpowered.
There are no motors on airplane wheels. They have no way to rotate them prior to landing.
Also, the amount of friction and heat is well understood and accounted for in the wheel design and manufacturing. Doing anything more complicated would have a huge cost (weight and money) for functionally zero benefit.
* Planes use the friction of the wheels to help slow the plane down.
* Matching wheel speed to the ground speed of the airplane wouldn’t help at all.
* That’s why there are no motors in the wheels to allow them to move on their own.
Here are a couple of good videos on the topic.
1. [why not make plane tires spin on landing](https://youtu.be/AJRf1jDiaXw)
2. [use wind to spin aircraft tires before landing](https://youtu.be/3eE0GJ-7sdY)
It’s been a while since I watched these videos, but from what I recall it’s just not worth all the extra complexity for what ends up being a minimal gain.
The answer is the same as most business decisions: Cost.
They actually tried this many years back.
I was a simple ROI calculation that just didnt pan out……buying new tires is more simple and most importantly, cheaper.
Engineer here: less parts = less opportunity for failure. Less moving parts = less opportunity for failure. Also doesnt require they staff a mechanic who knows how to service motors required to spin the wheels.
Someone pointed out that airstream could be used to spin the tires……sure….but how to you control the speed?
I think we also forget about the operating conditions any solution would have to withstand. Youre not slapping a conventional motor on the wheels and expecting it to work (and last longer than a year) at those temps and speeds
Why not have an airfoil to direct the air to turn the wheels?
they want friction because it helps reduce speed and eventually stop the airplane completely, which is the #1 concern during landing.
Replacing tires periodically is a lot more acceptable to the industry than dealing with planes that run out of runway and crash.
Also, as others said, there is no way to spin the wheels. Airplane wheels have brakes, but no motor. When moving on the ground, they use the power of the engines. This is why airplanes cannot go backwards, and airports have special tug vehicles to move airplanes.
The friction helps to slow the plane down. There wouldn’t be any benefit in trying to reduce it. You’d spend more money and have to work harder in other places in order to slow the plane the same amount.
There are a couple that do, usually by directing pressurized air onto a ring of fins to spin. It’s not a popular design option because it’s one of those things that is a soloution looking for a problem.
Spin up motors would be far more expensive as a whole than replacing tires.
Airplane tires wear fast anyway
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