Why has someone not designed a landing wheel with a fin or fins on it so that the air will start the wheels turning before the wheels touch the ground? Wouldn't that preserve the tires longer from wear? Or would it make the control of the aircraft more dangerous in some circumstances, such as rain or snow, to have the wheels already turning when landing? If so, perhaps the fins could be manually or computer controlled for various weather conditions.

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    $\begingroup$ You'd need to match speed exactly which is very hard. plus there is the weight issue, anything superfluous that is heavy will not get on board $\endgroup$ – ratchet freak May 3 '14 at 23:08
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    $\begingroup$ @ratchetfreak You wouldn't need to match it exactly at all! You'd just need to get closer to the actual ground speed than a stationary wheel is. Don't fall into the trap of failing to do anything just because a perfect solution isn't possible. (But I agree that the reason it's not been done will be that the advantages don't outweigh the costs.) $\endgroup$ – David Richerby May 4 '14 at 7:26
  • $\begingroup$ How do you spin the wheels in a way that does not affect their friction upon contact? I mean, if you use any kind of clutched drive, how do you ensure the clutch does not still contact the axle upon landing; any contact of the clutch would cause it to potentially burn out. If you use fins and airflow, would there possibly be enough airflow to overcome the inertial weight of the total tire/hub/etc. $\endgroup$ – CGCampbell Oct 15 '14 at 12:47
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    $\begingroup$ This guy claims to have designed some hubcaps with fins in then that catch the wind and supposedly spin the wheels up after the landing gear is deployed $\endgroup$ – Matt Hill Mar 5 '15 at 14:44
  • $\begingroup$ possible duplicate of How long do airliner tires last? Can this be improved? $\endgroup$ – Danny Beckett Apr 1 '15 at 5:48

This has been researched over the years, but it seems that the solutions did not find wide application. The oldest I could find is from 1941 (see page 112 in the September 1941 issue of Popular Science), and there have been several attempts to implement a spin-up turbine. See “Wheels with wings” on NewScientist Blogs or “Spin Wheels Before Landing”, a discussion thread on Eng-Tips forums, for more. The biggest problem seems to be the inertia of the spinning wheel because it makes the aircraft react in funny ways if the pilot wants to correct his approach.

The rough field package on the Cessna Citation 500 uses this technique (for the nose wheel only) to protect the fuselage from debris which could be kicked up by the wheel spinup.

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    $\begingroup$ Control issues make sense! Gyroscopic precession is weird. $\endgroup$ – egid May 5 '14 at 0:43
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    $\begingroup$ So if gyroscopic precession is an issue, does it have the same effect during take off? $\endgroup$ – MK Yung May 5 '14 at 1:05
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    $\begingroup$ @MKYung that's why people tap the brakes on takeoff $\endgroup$ – ratchet freak May 5 '14 at 10:09
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    $\begingroup$ Also, after take-off you mind less when the aircraft rolls a little when you yaw and vice versa. This is quite different to trying to line up with the runway during an approach in gusty air. $\endgroup$ – Peter Kämpf May 5 '14 at 18:26
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    $\begingroup$ And that's why Concorde had a disk brake on the nose wheel that was activated during gear retraction. $\endgroup$ – Marco Sanfilippo Sep 4 '15 at 10:21

It's just not cost-efficient. Any weight-add produces more fuel consumption, any systems produces more maintenance costs. It's just easier to change the tires if they're worn out. source: Aerospace engineering

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    $\begingroup$ could you expand your answer a bit? the content is fine, but expanding the reasoning would help. $\endgroup$ – Federico May 5 '14 at 9:03
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    $\begingroup$ I thing Hubschr is correct. In general the more things you add or make complex, the more things break and drive up the cost of maintenance. Also when a tire goes the mechanic knows how to change it. When some fancy electric motor or its controller, or it's power supply , or ... it's a much bigger deal to troubleshoot and fix. This can result in more down time. Planes only make money when they are working, so keep it simple and get back in the air making money. $\endgroup$ – JerryKur Oct 15 '14 at 20:24
  • $\begingroup$ Well, this is a generalization and in this case I do not agree. ^^ Progress is most of the time not the effect of simplification. Systems are getting more complicated. (As an example: If you would build a special rim (when you have retractions wheels) which use the airflow for generating the spin it does not have to make the maintenance costs higher and it maybe also not produce more weight. And (maybe) the over-all cost is better, because fewer tires worn out.) Source: My two cents as an engineer $\endgroup$ – TimK Mar 16 at 18:16

protected by Community Feb 7 '16 at 5:37

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