BA, Aer Lingus and bicycle tires

[Dave]

Mal - yes really.  It amazed me at just how much pressure was in the bottle the first time I experienced it.  And it's a much much higher pressure change than anything I have experienced on-land.  No pressure build up at all in my water bottle when I got the cable car to the top of Mont Blanc (well, as high as you can get without walking).

I suspect that your Mont Blanc water bottle had less air in it.  Either that or it was less air-tight.  Mont Blanc is damn high, and the pressure far lower than on a commercial aircraft. Mrs MV was very short of breath up there.

Yep. The skiing areas of MB are well over 3000m, no modern (passenger) planes are (normally) pressurised that low.

The bottle 'collapsing' coming off the plane I can sort of understand. Plastic bottles are very flimsy and I can easily imagine a difference of 15 or so PSI making a difference. But we're talking about bike tyres and tubes designed to run at 120 PSI+, so not exactly comparable.

Edit: I'll add this - air pressure at sea level is about 15 PSI, at 30 000 feet it's about 4 PSI. So, if the cabin instantly depressurises, the tyres/rims will experience at most an instantaneous change of 11 PSI. If I run over a nail I can cause a much larger sudden depressurisation, but puncturing a tyre rarely takes out your rim as well...

[nuttycyclist]

Mrs MV wasn't the only one short of breath

<------   Mr very unfit.

[border-rider]

Here I have to confess to blowing up my Brommie tyres way over max pressure (as was my wont) on a sub-zero morning, commuting to London and putting it under my desk in an overheated open-plan government office.

Quite a startling effect at about 10:15

[Adam]

I can give a practical example here.  A long time ago,  I fly across from Shoreham to Deauville, taking my bike with me.  It was either at 5,000 or 6,000 feet, but I noticed the tyres were visibly bulging and straining and were rock hard, so I quickly let some air out.

I accept the science that it should only be a small pressure differential which shouldn't make much of a difference, but I wouldn't have liked to have flown longer or higher with the tyres looking the way they did.

[Mr Larrington]

Iz bollocks.

A Base Orztrylian of my acquaintance was once asked by an Airline Gribley to deflate the tyres of his bicycle prior to loading it aboard a hairyplane.  He gave them a withering look and asked them whether they required cats and dogs to be deflated prior to being carried in the hold.

[arry_b]

+1 to Greenbank and the airlines.

I'd rather not be on a plane that suddenly had a loud bang eminate from the hold, however unlikely that may be.

[mark]

Iz bollocks.

A Base Orztrylian of my acquaintance was once asked by an Airline Gribley to deflate the tyres of his bicycle prior to loading it aboard a hairyplane.  He gave them a withering look and asked them whether they required cats and dogs to be deflated prior to being carried in the hold.

Iz indeed bollocks, and I like your friend's response. Herr Brandt, that kind and gentle soul from rec.bicycles.tech., likes to ask if they are going to deflate the aircraft tires before taking off.

I'm usually a bit hesitant to get too confrontational with airline baggage people, if only because they're going to be handling my rather nice touring bicycle without me around to make sure they play nice with it. I did get the impression this time around that some of the airline baggage people I encountered were using the whole issue as an excuse to bully a few customers under the guise of "aviation safety". 

Note to "arry_b", how do you feel about the noise made by landing gear extending/retracting, the aircraft hitting rough air, etc.?

[arry_b]

That's a rather pointless comment from Jobst, an aeroplane tyre is designed to cope with rather different loads than a bicycle tyre. Being designed to cope with flying at altitude in a non-pressurised undercarriage bay and operating within those design parameters means they're far less likely to have a problem than a bicycle tyre.

As for the regular noises a plane makes on take-off, landing and in flight, well, they're just normal and air passengers expect that type of thing.

A sudden bang from the hold isn't a normal noise.

What would you do as an airline operator? Risk group hysteria on a plane or inconvenience a few cyclists who constitute a tiny percentage of their passengers?

[border-rider]

Being designed to cope with flying at altitude in a non-pressurised undercarriage bay and operating within those design parameters means they're far less likely to have a problem than a bicycle tyre

Given that the only design parameter that's relevant to a bike tyre in a hold is the ability to withstand a pressure change of 7 psi, I'm not sure that's so.

[arry_b]

Agreed MV, but given Valiant's report of an exploding tyre in a baggage hold, apparently not impossible.

[border-rider]

If it was within 7 psi, it could have gone bang as he rode up to the airport, in front of the police with big guns, or as he wheeled it across the concourse full of nervous passengers.

I would wholeheartedly agree that it is silly to put on a plane a bike with tyres that are on a hairspring, but it's the hairspring part of that that's the issue.  As I wrote upthread somewhere, if you really have tyres that are going to go pop, back them off by 10 psi. But that's generic advice; if  a front tyre goes when you are riding you'll be in a bad way anyway.  In fact I think I'd rather have it go in the hold than riding out of the airport.

The point is that putting a bike on a plane won't cause the tyres to exceed design parameters any more (and in fact likely rather less) than riding it up and down some hills, or leaving it in the sun.

[Cudzoziemiec]

Here I have to confess to blowing up my Brommie tyres way over max pressure (as was my wont) on a sub-zero morning, commuting to London and putting it under my desk in an overheated open-plan government office.

Quite a startling effect at about 10:15

I'm sure you're not the only cyclist who likes to overinflate their tyres. Baggage handlers needn't know much about tyres, so they have to treat each bike as a potential explosion. What startles a government office could be more startling at 30,000 ft. As for the potential damage, as others have pointed out, the airline's not bothered about your tyres destroying your rims, they're worried about it damaging other baggage. We also have to consider that air cabin pressurising systems could, I suppose, fail, and in that circumstance the priority must be to maintain pressure to the passengers and crew, not the hold.

So in all probability there is no technical need to deflate tyres by more than 15 psi, but airlines by their nature are going to err on the side of caution. Bike tyres are probably treated the same as motor vehicle tyres, which contain far more air so could make a bigger band... As with security, where in all probability any individual's luggage does not contain a bomb, nor their shoes a weapon, but if an exception were made for you they'd have to let everyone through.

So... everyone's right here, in a way!

[mark]

I'm sure you're not the only cyclist who likes to overinflate their tyres. Baggage handlers needn't know much about tyres, so they have to treat each bike as a potential explosion. What startles a government office could be more startling at 30,000 ft. As for the potential damage, as others have pointed out, the airline's not bothered about your tyres destroying your rims, they're worried about it damaging other baggage. We also have to consider that air cabin pressurising systems could, I suppose, fail, and in that circumstance the priority must be to maintain pressure to the passengers and crew, not the hold.

So in all probability there is no technical need to deflate tyres by more than 15 psi, but airlines by their nature are going to err on the side of caution. Bike tyres are probably treated the same as motor vehicle tyres, which contain far more air so could make a bigger band... As with security, where in all probability any individual's luggage does not contain a bomb, nor their shoes a weapon, but if an exception were made for you they'd have to let everyone through.

So... everyone's right here, in a way!

Baggage handlers don't need to know much about tyres, but airline management should get the facts and set policy accordingly, and instruct baggage handlers properly.

How much sound will travel from the cargo hold to the passenger area/cockpit while the plane is in flight? How much damage did MV's Brompton tire do to the surroundings? How much damage did Valiant's friend's bike tire do to the surroundings?

AIUI, the entire aircraft is pressurized. A pressurized passenger area and an unpressurized cargo hold would put enormous strain on the floor of the passenger area/ceiling of the cargo hold. Building this bulkhead to take such a strain would add a great deal of weight and cost to the aircraft, as would having separate pressurizing systems to the cargo hold and passenger/crew areas. Pressurizing systems don't fail too often, but if they do then the surest way to maintain pressure in the aircraft would be to descend to a lower altitude.

[mark]

Just a quick followup: I received a very nice e-mail this morning from BA customer relations, apologising for the episode and saying:

 "I have forwarded your comments to our management team at Gatwick airport for them to look into, and to take steps to insure this not happen again".

So if Tourist Tony spots any extra grumpy baggage handlers around Terminal North, this might be the reason why!

Points to BA for taking the time to address the issue.

[Regulator]

Just a quick followup: I received a very nice e-mail this morning from BA customer relations, apologising for the episode and saying:

 "I have forwarded your comments to our management team at Gatwick airport for them to look into, and to take steps to insure this not happen again".

So if Tourist Tony spots any extra grumpy baggage handlers around Terminal North, this might be the reason why!

Points to BA for taking the time to address the issue.

Glad to see BA are employing the illiterate to match the incompetent... 


 I'd much rather they 'ensure' it doesn't happen again.

[mark]

Glad to see BA are employing the illiterate to match the incompetent... 


 I'd much rather they 'ensure' it doesn't happen again.

If they're willing to apologize for the mistake and take steps to correct it, then I'm happy to leave a few trivial spelling errors to the pedants.

[Charlotte]

I'm taking my Brompton through LHR on BA this afternoon.  The tyres are at 80psi and I have printed off the relevant page from the BA website:

You may wish to deflate the tyres to reduce risk of damage.

_{(my italics)}

What's the betting that an Airline Gribley tells me to let them down anyway?  I've never used the little pump that comes attached to the Brommie - is it any good?

[mike]

you'll have plenty of time to find out in US immigration hell tomorrow morning  

have a wonderful time!!

[iakobski]

I'm taking my Brompton through LHR on BA this afternoon.  The tyres are at 80psi and I have printed off the relevant page from the BA website:

You may wish to deflate the tyres to reduce risk of damage.

_{(my italics)}

What's the betting that an Airline Gribley tells me to let them down anyway?  I've never used the little pump that comes attached to the Brommie - is it any good?

You certainly won't get 80 psi out of it, or anywhere near!

[andrew_s]

With Valiant's friend's wheel, it was almost certainly the rim that failed (due to brake wear), not the tyre. They will occasionally just blow even when not being ridden at the time.
Better on the plane than at speed on a downhill.

[LittleWheelsandBig]

You certainly won't get 80 psi out of it, or anywhere near!

Mine does but it takes a little while, reasonable for a little pump.