deflating tyres on planes



You could be right about the 220 psi, the space shuttle tyres are 340 psi.

http://aviation.webmichelin.com/about/space.html

"Surprisingly, a space shuttle tire is not much larger than a truck tire,
but a main landing gear tire can carry three times the load of a Boeing 747
tire or the entire starting line-up of a NASCAR race -- 40 race cars - "

I guess basically the bigger the tyres the lower the pressure.

Mind you the combinaation of the high rotational speed and high pressures
might be quite dangerous, as some concorde passangers found out.

I am not sure if it is the speed of rotation or the pressure which is most
to
blame, maybe a combination of both.

220 psi is some force.

http://216.239.59.104/search?q=cach....html+concorde+tire+pressure&hl=en&lr=lang_en

"The tire/wheel assembly exploded, tearing the hub into two pieces. One
piece bounced off a railing, hitting one helper in the head, killing him
instantly. His body was found 10 feet from the spot where he had been
standing. The other portion of the hub struck the crew chief with so much
force that he was thrown some 30 feet. His head and right arm were severed
from his body. All of the wheel bolts were found bent...and the threads on
five bolts were stripped. Only four of the wheel nuts were found."


Anyhow if aircraft tires were inflated to 27psi, (as I thought reasonable)
concorde might still be flying today!!

I guess there is no profit in transporting lots of tires though!!
 
half_pint wrote:
> You could be right about the 220 psi, the space shuttle tyres are 340 psi.
>
> Anyhow if aircraft tires were inflated to 27psi, (as I thought reasonable)
> concorde might still be flying today!!
>
> I guess there is no profit in transporting lots of tires though!!
>


Wheres the "could be right?" It is right.

David mis-calculated the number of tyres on a 757 there are only 10,
there are 18 on a 747 however, probably the cause of the confusion. Lets
use Concorde as the example it also has 10 tyres and slightly higher
pressures and well you seem particularly fascinated by its explosion. So
revisiting Davids calculations.

10 tyres on Concorde and a take off weight of 185,020Kg. 18.5 tons per
tyre (again rear are higher). ~232psi per tyre. 232psi = 105Kg/SqIn =
171SqIn contact patch or 17Inchx10Inch. With 27psi per tyre =
12.2Kg/SqIn = ~1500SqIn.

So youre right I guess, the question is where would you stow ~90 tyres
or 10 earth mover size tyres on a supersonic jet? I suspect there must
have been a design/safety compromise somewhere along the line.
 
"Vincent Wilcox" <[email protected]> wrote in message
news:[email protected]...
> half_pint wrote:
> > You could be right about the 220 psi, the space shuttle tyres are 340

psi.
> >
> > Anyhow if aircraft tires were inflated to 27psi, (as I thought

reasonable)
> > concorde might still be flying today!!
> >
> > I guess there is no profit in transporting lots of tires though!!
> >

>
> Wheres the "could be right?" It is right.


I didn't know the figure myself.

>
> David mis-calculated the number of tyres on a 757 there are only 10,
> there are 18 on a 747 however, probably the cause of the confusion. Lets
> use Concorde as the example it also has 10 tyres and slightly higher
> pressures and well you seem particularly fascinated by its explosion. So
> revisiting Davids calculations.
>
> 10 tyres on Concorde and a take off weight of 185,020Kg. 18.5 tons per
> tyre (again rear are higher). ~232psi per tyre. 232psi = 105Kg/SqIn =
> 171SqIn contact patch or 17Inchx10Inch. With 27psi per tyre =
> 12.2Kg/SqIn = ~1500SqIn.
>
> So youre right I guess, the question is where would you stow ~90 tyres
> or 10 earth mover size tyres on a supersonic jet? I suspect there must
> have been a design/safety compromise somewhere along the line.


Well I guess more tires means less passenger space
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