Spin Wheels Before Landing
Spin Wheels Before Landing
(OP)
Everytime you see an airplane land, a large puff of smoke comes off the wheels as they skid before spinning up to speed. I imagine this wear is the major factor in short tire life. Some planes need new tires after just a few dozen landings.
Why not use an electric/hydraulic motor to spin the wheels up to speed. Better yet - could a small series of vanes be formed on the tire itself - that when exposed to the rushing air would cause the wheel to spin up. Might not be exact but might get it close enough.
Just a thought..
Why not use an electric/hydraulic motor to spin the wheels up to speed. Better yet - could a small series of vanes be formed on the tire itself - that when exposed to the rushing air would cause the wheel to spin up. Might not be exact but might get it close enough.
Just a thought..
RE: Spin Wheels Before Landing
RE: Spin Wheels Before Landing
RE: Spin Wheels Before Landing
Speaking for all lazy mechanics out there, I can say this is a royal PITA to work on.
There's also a bunch of Armour scabbed on the antenna's & flaps to deflect what rocks are thrown up anyway.
RE: Spin Wheels Before Landing
I dont see these around any more. Apparently the spinning mass of the tire caused more problems than it solved.
Here is a related article: http://
B.E.
RE: Spin Wheels Before Landing
Haven't head squat about it since then, so there must have been technical difficulties
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RE: Spin Wheels Before Landing
RE: Spin Wheels Before Landing
SAE AIR5800 Tire Prerotation at Landing
Intro paragraph...
RATIONALE
The idea of tire prerotation at landing to reduce tire wear and spin-up loads has been proposed many times in the past,
and continues to be proposed for new airplane projects. Yet, this practice has not been adopted in the aircraft industry.
This report explains why this is generally not a feasible idea, and also discusses situations where it may be beneficial.
This report is a compilation of all of the information available to SAE A-5, and comprises the general consensus from the
aircraft and landing gear industry on this subject.
There are a LOT of factors... intuitave and non-intuative... involved [for or against - depends].
Regards, Wil Taylor
Trust - But Verify!
We believe to be true what we prefer to be true.
For those who believe, no proof is required; for those who cannot believe, no proof is possible.
RE: Spin Wheels Before Landing
As an airline Engineer back in the 80's, we received many letters from passengers that had ideas on how airlines could save money which we had to address - windows in the cabin floor to see the ground inflight (they didn't know the baggage was stored under the cabin), runways that sloped upwards to help slow down the aircraft, and of course the multitude of ideas on spinning the wheels just before landing.
Airlines are very concerned with two critical areas - reliability and weight. Adding motors, vanes, or molded tires will increase aircraft weight (reducing revenue) and can increase flight delays and cancellations due to equipment malfunctions and normal maintenance (increasing costs).
The life of a bias ply tire is 350-500 landings and these could be retreaded multiple times to reduce costs. Radial tires, while lighter in weight, have a life less than bias ply tires. Additionally, they are for the most part not yet approved to be retreaded. Yes, costs are higher with radial tires but a value analysis of adding 'devices' to spin the wheels to only increase the tire life by 10% is not economcal.
Another interesting Air Force study. Brake wear can be different between the LH and RH landing gear not only due to which direction the aircaft turns a majority of the time but also due to the dominate leg effect of the pilot. The study showed that right handed pilots tended to add more force from their right foot to the brake pedal than their left foot and they compensated with rudder input to balance the difference in braking force. The opposite is true for left handed pilots. For an aircraft that is flown mainly by the same pilot, the brake wear difference was measureable.
Regards,
ERAU82
RE: Spin Wheels Before Landing
RE: Spin Wheels Before Landing
RE: Spin Wheels Before Landing
RE: Spin Wheels Before Landing