Re: Tire burn-out during landings

From:         megazone@obsidian.WPI.EDU (MegaZone23)
Organization: WPI USAF -- United Society of Animation Fans
Date:         28 Dec 92 22:47:43 PST
References:   1 2
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In article <airliners.1992.191@royko.Chicago.COM> Geoff.Miller@Corp.Sun.COM writes:
>megazone@obsidian.WPI.EDU (MegaZone23) writes:
>>When you spin a tire it acts as a gyroscope and will resists having it's 
>>course altered. This can make handling tricky as you would have 10 or more 
>>wheels all spinning on most airliners.
>First, I'd think that the mass of the spinning wheels, and therefore the
>magnitude of their gyroscopic effect on handling, would be insignificant
>compared to the mass of the rest of the airframe and payload and the 
>power of the control surfaces.

That's probably correct, although I don't have the weight of an average wheel
and tire on hand to compare it seems so. Though a 26" 12-speed tire is enough
to affect my 300lb body, I uspect the ratio of the gear to the aircraft weight
is MUCH less...

I too feel the major reason is cost, both for the hardware and lifetime costs.

>Second, assuming that the effect *was* significant, wouldn't it simply be 
>a stabilizing influence, i.e., a resistance to changes in attitude about 
>the longitudinal (roll) axis?  That doesn't sound all that hazardous.

Arg,old physics comes back to haunt me...

Making the large assumption that the mass is significant and the effect is as
stated; I can see a few problems in that course correction includes rolling
for turns, although I realize the angles used by airliners are a bit less than
what I use in a C-172....

But that is just speculation, thinking about it now I would agree that the 
mass difference makes the gyroscopic effects negligible.

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