deflating tyres on planes



C

Clive George

Guest
Well, we all know that the ostensible reason, that the pressure in the hold
is lower so the tyre might pop is a crock of ****.

What about deflating them so if it's badly packed in the hold there's less
chance of something wearing through the tyre and making it go pop? (I
suppose the first question is which is more likely to suffer such wear - a
hard or soft tyre?)

cheers,
clive
 
J

JLB

Guest
Clive George wrote:
> Well, we all know that the ostensible reason, that the pressure in the hold
> is lower so the tyre might pop is a crock of ****.
>
> What about deflating them so if it's badly packed in the hold there's less
> chance of something wearing through the tyre and making it go pop? (I
> suppose the first question is which is more likely to suffer such wear - a
> hard or soft tyre?)


Soft or deflated tyres are more easily damaged, in particular by being
pinched against the rim, so it's still a crock of ****.


--
Joe * If I cannot be free I'll be cheap
 
J

James Annan

Guest
Clive George wrote:

> Well, we all know that the ostensible reason, that the pressure in the hold
> is lower so the tyre might pop is a crock of ****.
>
> What about deflating them so if it's badly packed in the hold there's less
> chance of something wearing through the tyre and making it go pop? (I
> suppose the first question is which is more likely to suffer such wear - a
> hard or soft tyre?)


Um...smells like it...looks like it...yes, it's a crock of ****.

James
--
If I have seen further than others, it is
by treading on the toes of giants.
http://www.ne.jp/asahi/julesandjames/home/
 
Z

Zog The Undeniable

Guest
Clive George wrote:

> Well, we all know that the ostensible reason, that the pressure in the hold
> is lower so the tyre might pop is a crock of ****.
>
> What about deflating them so if it's badly packed in the hold there's less
> chance of something wearing through the tyre and making it go pop? (I
> suppose the first question is which is more likely to suffer such wear - a
> hard or soft tyre?)
>
> cheers,
> clive
>
>

I think it's just that the airlines are wary of any compressed gas, so
tyres get lumped in with Sodastream cartridges, scuba tanks and whatever
else people might want to carry.

The main reason they're wrong is (a) the hold of a passenger plane is
pressurised if the cabin is; (b) even if it wasn't, reducing the outside
pressure by an absolute maximum of 14.7psi makes sod all difference,
unless your tyre is already overinflated by about 200% so it's on the
verge of blowing off the rim.
 
J

James Annan

Guest
Zog The Undeniable wrote:


> I think it's just that the airlines are wary of any compressed gas, so
> tyres get lumped in with Sodastream cartridges, scuba tanks and whatever
> else people might want to carry.


It's not even that they have thought about it particularly: it is simply
a Rule, and therefore has a life of its own independent from any
rational justification.

James
--
If I have seen further than others, it is
by treading on the toes of giants.
http://www.ne.jp/asahi/julesandjames/home/
 
T

Tony Raven

Guest
James Annan wrote:
> Zog The Undeniable wrote:
>
>
>> I think it's just that the airlines are wary of any compressed gas, so
>> tyres get lumped in with Sodastream cartridges, scuba tanks and
>> whatever else people might want to carry.

>
>
> It's not even that they have thought about it particularly: it is simply
> a Rule, and therefore has a life of its own independent from any
> rational justification.
>


As you say it is in the rules if your tyres are pumped up over 40psi.
The tyres are caught by the hazardous materials regulations which have a
fairly simple definition for a container of compressed gas which catches
bicycle tyres probably as an unintended consequence of using a fairly
simple definition to ensure catching all the really hazardous situations.

Compressed gases are defined as those exerting more than 40.6psi at 20C
on their container (Division 2.2 of FAA DOT49CFR173.115 and its
virtually identical ICAO equivalent). So if they are inflated to less
than 40psi you are fine under that regulation (unless you pump them full
of flammable or toxic gas)
http://frwebgate.access.gpo.gov/cgi...E=49&PART=173&SECTION=115&YEAR=1999&TYPE=TEXT

British Airways seem to have taken it on themselves to override that as
they now say:

"British Airways Safety Services have determined that it is not
necessary from a safety perspective to deflate typical tyres found on
bikes and wheelchairs for carriage in the hold."

In any case the actual hazard of an inflated bicycle tyre is virtually zero.

Tony
 
P

Pete Biggs

Guest
Clive George wrote:
> Well, we all know that the ostensible reason, that the pressure in
> the hold is lower so the tyre might pop is a crock of ****.
>
> What about deflating them so if it's badly packed in the hold there's
> less chance of something wearing through the tyre and making it go
> pop? (I suppose the first question is which is more likely to suffer
> such wear - a hard or soft tyre?)


The tyres are the last thing I would worry about--flat tyres will stand
plenty of abuse while being not ridden. But it's a shame the wheel rims
won't have the ideal protective packaging of inflated tyres. Could use
some foam or cardboard instead.

~PB
 
M

mark

Guest
"Tony Raven" wrote
> British Airways seem to have taken it on themselves to override that as
> they now say:
>
> "British Airways Safety Services have determined that it is not
> necessary from a safety perspective to deflate typical tyres found on
> bikes and wheelchairs for carriage in the hold."
>
> In any case the actual hazard of an inflated bicycle tyre is virtually

zero.
>
> Tony

I read that statement on the BA website and left my bicycle's tires
completely inflated when I flew from Denver to Heathrow, no problem
When I returned from the UK to Denver on British Airways, the baggage staff
insisted that I had to deflate the tires on my bicycle for safety reasons.
When I quoted the above statement, I was told that BA management insisted
that all bicycle tires be deflated for safety reasons. I decided that it
might not be wise to argue with someone just as I was handing him a fairly
expensive touring bike, and let him deflate the tires.

Other than that little episode I thought BA ran a very good show, and took
very good care of my unboxed bicycle.
--
mark
 
M

Michael MacClancy

Guest
On Sat, 18 Dec 2004 16:21:20 GMT, mark wrote:

> "Tony Raven" wrote
>> British Airways seem to have taken it on themselves to override that as
>> they now say:
>>
>> "British Airways Safety Services have determined that it is not
>> necessary from a safety perspective to deflate typical tyres found on
>> bikes and wheelchairs for carriage in the hold."
>>
>> In any case the actual hazard of an inflated bicycle tyre is virtually

> zero.
>>
>> Tony

> I read that statement on the BA website and left my bicycle's tires
> completely inflated when I flew from Denver to Heathrow, no problem
> When I returned from the UK to Denver on British Airways, the baggage staff
> insisted that I had to deflate the tires on my bicycle for safety reasons.
> When I quoted the above statement, I was told that BA management insisted
> that all bicycle tires be deflated for safety reasons.


Your problem is that you had tires on your bike.

If you'd had tyres then the BA staff in the UK would have applied a
different set of rules. ;-)

--
Michael MacClancy
 
R

Robert Clark

Guest
mark wrote:
> "Tony Raven" wrote
>
>>British Airways seem to have taken it on themselves to override that as
>>they now say:
>>
>>"British Airways Safety Services have determined that it is not
>>necessary from a safety perspective to deflate typical tyres found on
>>bikes and wheelchairs for carriage in the hold."
>>
>>In any case the actual hazard of an inflated bicycle tyre is virtually

>
> zero.
>
>>Tony

>
> I read that statement on the BA website and left my bicycle's tires
> completely inflated when I flew from Denver to Heathrow, no problem
> When I returned from the UK to Denver on British Airways, the baggage staff
> insisted that I had to deflate the tires on my bicycle for safety reasons.
> When I quoted the above statement, I was told that BA management insisted
> that all bicycle tires be deflated for safety reasons. I decided that it
> might not be wise to argue with someone just as I was handing him a fairly
> expensive touring bike, and let him deflate the tires.
>
> Other than that little episode I thought BA ran a very good show, and took
> very good care of my unboxed bicycle.


I've found that it's a good idea, when travelling air with a bicycle, to
be armed with print-outs from the airline's own website, detailing
their bicycle policies. Too often the check-in staff are ill-trained or
have seldom eperienced a bicycle ... so being able to show them their
own policies helps!
 
M

mark

Guest
"Michael MacClancy" wrote...
> On Sat, 18 Dec 2004 16:21:20 GMT, mark wrote:
>
> > I read that statement on the BA website and left my bicycle's tires
> > completely inflated when I flew from Denver to Heathrow, no problem
> > When I returned from the UK to Denver on British Airways, the baggage

staff
> > insisted that I had to deflate the tires on my bicycle for safety

reasons.
> > When I quoted the above statement, I was told that BA management

insisted
> > that all bicycle tires be deflated for safety reasons.

>
> Your problem is that you had tires on your bike.
>
> If you'd had tyres then the BA staff in the UK would have applied a
> different set of rules. ;-)
>
> --
> Michael MacClancy


My LBS only sells tires, no tyres to be had where I live.
--
mark
 
J

JLB

Guest
Robert Clark wrote:
[snip]
> I've found that it's a good idea, when travelling air with a bicycle, to
> be armed with print-outs from the airline's own website, detailing
> their bicycle policies. Too often the check-in staff are ill-trained or
> have seldom eperienced a bicycle ... so being able to show them their
> own policies helps!


True, but on at least one occasion when I tried that the jobsworth took
my bike with its inflated tyres after some grumbling, and at the other
end I found the tyres were completely flat. Whether that was done by the
first jobsworth or one who came along later I have no idea.

--
Joe * If I cannot be free I'll be cheap
 
H

half_pint

Guest
Its not clear whether you are saying that the pressure in the hold is lower
is untrue
or that that they would pop under lower pressure.


If the pressure is lower and you have inflted then to the max recommended
pressure then they are more likely to pop.

It is also unclear whether you are worried about the just the tire/tupe
popping and requireing replacement(s) and possible insureance claims.

Or whether the tire popping might damage the plane and cause it to
crash, destroying the bike and your own life.

Why not sneak into the luggage hold and inflate your tires to twice the
maximum pressure just to prove how clever you are?

If the plane does nose dive you can rest assured your were not responsible!

I cannot recall a type bursting ever bringing down concord for instance as
it says
in the manufactures data that that cannnot happen.

And of course a planes type is almost certainly inflated to a lower pressure
than a bikes tyre, as car tyres (which are bigger) are.






"Clive George" <[email protected]> wrote in message
news:[email protected]
> Well, we all know that the ostensible reason, that the pressure in the

hold
> is lower so the tyre might pop is a crock of ****.
>
> What about deflating them so if it's badly packed in the hold there's less
> chance of something wearing through the tyre and making it go pop? (I
> suppose the first question is which is more likely to suffer such wear - a
> hard or soft tyre?)
>
> cheers,
> clive
>
>
 
H

half_pint

Guest
They might be working on the assumption that cyclists have smaller,
lighter brains.
The extra ******** might be a factor though.

<[email protected]> wrote in message
news:[email protected]
> You are all missing the point.
>
> The airlines just don't want to carry all that extra weight in those
> tires ..:)
>
 
V

Vincent Wilcox

Guest
half_pint wrote:
>
> And of course a planes type is almost certainly inflated to a lower pressure
> than a bikes tyre, as car tyres (which are bigger) are.
>


Around 180-220psi for airliners so not really a job for a mini-pump.
 
V

Vincent Wilcox

Guest
half_pint wrote:
>
> And of course a planes type is almost certainly inflated to a lower pressure
> than a bikes tyre, as car tyres (which are bigger) are.
>


Around 180-220psi for airliners so not really a job for a mini-pump.
 
H

half_pint

Guest
That seems high they must be rock solid


"Vincent Wilcox" <[email protected]> wrote in message
news:[email protected]
> half_pint wrote:
> >
> > And of course a planes type is almost certainly inflated to a lower

pressure
> > than a bikes tyre, as car tyres (which are bigger) are.
> >

>
> Around 180-220psi for airliners so not really a job for a mini-pump.
 
D

David Martin

Guest
half_pint wrote:
> That seems high they must be rock solid


Do the math.

How big is the contact patch. How heavy is an airliner?

A quick google gives a maximum all up take off weight for a 757 at 122 tons

That weight is spread over 18 tyres. Each tyre therefore supports approx
6 tons on average [1].

At 220 psi (or 100kg/sq in) that would give a contact patch on each tyre
of 60 sq. in or a patch 6 inches long by ten inches wide. Seems about
right to me.

...d


[1] this is not th ecase. The weight would be spread over the 16 rear
tyres more than the front two.

>
>
> "Vincent Wilcox" <[email protected]> wrote in message
> news:[email protected]
>
>>half_pint wrote:
>>
>>>And of course a planes type is almost certainly inflated to a lower

>
> pressure
>
>>>than a bikes tyre, as car tyres (which are bigger) are.
>>>

>>
>>Around 180-220psi for airliners so not really a job for a mini-pump.

>
>
>
 
H

half_pint

Guest
"David Martin" <[email protected]> wrote in message
news:[email protected]
> half_pint wrote:
> > That seems high they must be rock solid

>
> Do the math.
>
> How big is the contact patch. How heavy is an airliner?
>
> A quick google gives a maximum all up take off weight for a 757 at 122

tons
>
> That weight is spread over 18 tyres. Each tyre therefore supports approx
> 6 tons on average [1].
>
> At 220 psi (or 100kg/sq in) that would give a contact patch on each tyre
> of 60 sq. in or a patch 6 inches long by ten inches wide. Seems about
> right to me.
>


You could say the same about cars, they are very heavy compared to bikes.
Depends on the size of the tyres I guess.
I cant say I am familiar with the size of big aircraft tyres. if the
dimensions were twice
you estimates that would but the pressure down to a uater of 220 psi or
55psi.
I am not sure what the design considerations are on such tyres are but I
guess
small tyres take up less space.
All i know is that the ride on my mountain bike at 60psi is pretty 'rough'
At 220psi the wheels might as well be made of concrete.