Deflating Tyres For Aeroplane Trip

General cycling advice ( NOT technical ! )
island girl
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Deflating Tyres For Aeroplane Trip

Postby island girl » 24 Jan 2010, 12:02am

All information from airlines says to deflate tyre for plane trip. CTC advises it is not necessary. I am confused - what should I do?

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hubgearfreak
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Re: Deflating Tyres For Aeroplane Trip

Postby hubgearfreak » 24 Jan 2010, 1:27am

you should do what the aeroplane company ask you to.

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meic
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Re: Deflating Tyres For Aeroplane Trip

Postby meic » 24 Jan 2010, 1:40am

If you let the tyres down by 1 atm (15psi) then you will have followed the spirit and the letter of the requirements. They didnt say fully deflated. 8)
If your tyres were inflated to almost the point of explosion then the reduced atmospheric pressure could cause the tyres or rims to blow. However the most that the air pressure in the airplane can be reduced is 1 atm or 15psi.
I dont know if the difference between being pumped up at 0 deg C in UK and landing at 35 deg C will make much difference either. However it wont get warm until you get down to the ground anyway.
Yma o Hyd

thirdcrank
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Re: Deflating Tyres For Aeroplane Trip

Postby thirdcrank » 24 Jan 2010, 8:33am

Speaking as a non-flying realist - do as they say. I've watched from the sidelines when this has come up from time-to-time and I suppose the most convincing argument that it's a load of twaddle is supplied by the fact that the plane's own tyres will not be deflated (fully or partially.)

On one occasion a very proud daddy wrote to the CTC mag to say that he had two sons, both senior captains with BA and they had absolute authority to decide what happened on their planes. Setting aside any concerns about putting your life in the hands of somebody with such a poor grasp of physics, I get the impression from seeing those 'up yours' telly programmes about the aggro of flying (or rather waiting to fly and even not flying) that decisions like this are made much further down a truculent hierarchy.

Comply or be messed about.

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Re: Deflating Tyres For Aeroplane Trip

Postby Gearoidmuar » 24 Jan 2010, 8:48am

As someone who has flown with his bike countless times on foreign cycling trips it's a giant irritation. Sometimes you will manage to get them to leave them alone.
Why is it an irritation? If you've ever pumped tyres in a hot airport abroad you will find out why. You will be roasted from the effort.

It's total blsht from start to finish.
Firstly an extra atmosphere will not burst tyres, but secondly the holds are not in a vacuum. They are pressurised too, as if they weren't there would be a lot of pressure on the structure of the aircraft, and thirdly, you don't go into outer space in a plane.
So from start to finish it's a most irritating nonsense.
This was discussed some time ago, several years to be precise in the CTC magazine and some fuddy duddy wrote about the potential damage caused by an exploding tyre. I wrote a sarcastic letter to the magazine suggesting that the said individual put a car inflation pump on a bike tyre and set the thing inflating and surround the wheel by all kind of objects and flee the garage and when the explosion came, to go back in and report to us on the resultant Hiroshima. He wrote a hurt letter to the following issue!

byegad
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Re: Deflating Tyres For Aeroplane Trip

Postby byegad » 24 Jan 2010, 9:39am

Since when do we expect anyone, even the Airlines to understand physics. As as has been well exercised above the chances of a tyre letting go even if the ambient pressure in the hold falls to a neat vacuum is zero. If you doubt this try over inflating your tyres by 14 psi and leaving the bike in the shed for 24 hours.

Even if a tyre lets go so what? we're talking about a very small volume of air in any case.
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Mick F
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Re: Deflating Tyres For Aeroplane Trip

Postby Mick F » 24 Jan 2010, 9:42am

Gearoidmuar wrote: If you've ever pumped tyres in a hot airport abroad you will find out why. You will be roasted from the effort.
I'm unlikely to take my bike on a plane, but bearing in mind your comment, I'm glad I don't carry a pump and use CO2. Simple, easy, absolutely zero effort!

Now you're going to tell me that I can't take CO2 cylinders on a plane!
Mick F. Cornwall

phil parker
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Re: Deflating Tyres For Aeroplane Trip

Postby phil parker » 24 Jan 2010, 9:47am

It doesn't really matter what the likelihood is of a cycle tyre exploding, or not, those who make the risk assessments try to eliminate any potential risk even the 1:1 million chances. It then becomes a regulation that must be complied with rather than debated upon and for that reason individual cases will not be considered. Whether or not one atmosphere of pressure makes any difference is also subject to there being no defects in the inner tube, which will also be an unknown quantity.

It may be an inconvenience, but so are many things like the carriage of hand luggage items and fluids etc. Unfortunately, it doesn't really matter what CTC deem necessary - and there is no need for you to be confused.

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andrew_s
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Re: Deflating Tyres For Aeroplane Trip

Postby andrew_s » 24 Jan 2010, 9:52am

British Airways advice is "you may wish to deflate the tyres to reduce risk of damage"
If you print it off beforehand and wave it at the check in, you may possibly get away with leaving the tyres pumped up.

Edwards
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Re: Deflating Tyres For Aeroplane Trip

Postby Edwards » 24 Jan 2010, 10:13am

A few thoughts on this.
Can you give an absolute total guarantee that all tyres will not go bang when in the hold.
Just imagine the panic and pandemonium of the passengers sitting above if they hear it.
Would you like the be at baggage reclaim when the other passengers find out the reason for the emergency landing, fighter escort armed police etc.
So is even the slightest outside possibility of the risk really worth letting a few pounds pressure out of the tyre.
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phil parker
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Re: Deflating Tyres For Aeroplane Trip

Postby phil parker » 24 Jan 2010, 10:54am

andrew_s wrote:British Airways advice is "you may wish to deflate the tyres to reduce risk of damage"
If you print it off beforehand and wave it at the check in, you may possibly get away with leaving the tyres pumped up.


That's also a good point - in today's era of litigation anyone who is unlucky to have damage done would probably find a solicitor or company willing to sue the airline for not preventing them from deflating the tyres!!

I've flown a number of times with a bicycle in the last 10 years and whilst I've been asked 'have I removed the pedals and deflated the tyres' etc. I've never had the bike checked! Of course, I have always complied because I don't want the embarrassment of retrospective action...or having told a lie!

irc
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Re: Deflating Tyres For Aeroplane Trip

Postby irc » 24 Jan 2010, 11:10am

I don't run my run my tyres at max pressures. So if before I fly I inflate them to max for 24 hrs then reduce pressure by more than 15psithen as far as I'm concerned I have deflated them and the chance of them blowing out in the cabin is as close to zero as it needs to be. I note for example that Virgin use the phrase "Tyres are partially deflated to reduce the risk of damage.".

I'd say a tyre deflated by 15psi from the max pressure complies fully with this. No lies required.

http://www.virgin-atlantic.com/en/gb/pa ... ycling.jsp
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s1965c
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Re: Deflating Tyres For Aeroplane Trip

Postby s1965c » 24 Jan 2010, 11:42am

Edwards wrote:A few thoughts on this.
Can you give an absolute total guarantee that all tyres will not go bang when in the hold.
Just imagine the panic and pandemonium of the passengers sitting above if they hear it.


And there's the reason they ask you to deflate your tyres. However unlikely you think it that your tyres will go off bang, the airlines would rather inconvenience a few cyclists than risk a mass panic on a plane in flight.

I agree with them.
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mw3230
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Re: Deflating Tyres For Aeroplane Trip

Postby mw3230 » 24 Jan 2010, 12:26pm

I agree with Thirdcrank - above ...

Why is it that when airline advice states that tyres should be deflated we proceed to question it. Do we ignore their advice about wearing safety belts?, or ignore their directions as to where to sit?

The airline might be wrong in terms of physics, but it is their plane and they have a casting vote!

I would always take the view that they are not people to be upset but then I'm just a silly old conformist!
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hubgearfreak
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Re: Deflating Tyres For Aeroplane Trip

Postby hubgearfreak » 24 Jan 2010, 1:01pm

those of you who say there's no need, the chances of an accident are so slim & etc. are of the exact same mentality of those who think speed cameras are a pointless interferance into people who know best's decisions.