PPRuNe Forums - View Single Post - Wheel Spin-Up, pre-landing..?
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Old 14th Jul 2018, 03:30
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pattern_is_full
 
Join Date: Jan 2008
Location: Denver
Posts: 1,226
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1. Putting a spinup device on the aircraft landing gear will cost the operator money, which is OK, but why should an operator spend money to protect the "numbers and piano keys" - whose cost is the responsiblity of the airport authority? Maybe - if the airports give landing fee rebates to aircraft that use the device. (In our deams... )

2. Therefore the costs of adding such a device (certification per aircraft type, required inspections and maintenance (down time plus labor), weight penalty on payload (cash income, fuel expense) have to be less than simply replacing the tires as needed, to actually produce a benefit.

3. Possibly addressable - but spinning tires/wheels produce gyroscopic forces. May produce control surprises on short final with yaw or roll. Ever heard that "RUm-M-m-M-mblebleble" as the gear retracts on some planes, vibrating while changing plane of rotation, before the autobrakes stop them for stowing? Lot of gyro precession going on there.

Depends on how late and how fast the spinup can take place. 50 foot callout? 200 foot? Required complete as part of "landing configuration/stable" (500-1000 feet)? At "gear-down?"
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