Originally Posted by Retro Grouch
Bologna! This is just another one of those bicycling myths that get repeated so often that many people believe them.
Air pressure at sea level is only around 15psi. So a tire that contained 110psi at sea level would contain 125psi in a pure vacuum. At 36,000 feet the internal tire pressure would still only be around 122psi. assuming the cargo compartment was unpressurized. But, since airlines routinely ship pets in cargo compartments, I assume the cargo compartments are both pressurized and heated just like the cabin.
I agree with with the sentiment. The 10psi pressure increase with in the tire is probably an insignificant amount to blow it off the rim, due to the decreased atmospheric pressure at high altitude. I was only stating it for what I think the concerns are of the Airlines if they ask/recommend you to deflate the tires. Either that or they don't want the slight chance that if the tube/tire blows for what ever reason, that it's bursting could be mistaken for a bomb
I guess it's also possible, it may happen if the tire was already inflated to some crazy pressure that is near blowing it off the rim at sea level. That additional 10 psi could be the amount to push it over the limit
Such as 2manybike's example.