Originally Posted by
Station_Calling
...so if those tyres would freeze solid at the reported -47, How do they go on underneath a B737 at FL390 - i.e. about -56?
Not having seen the television program, I can't really comment on what was said, but I do have a little experience in extreme cold temps. A tire (Airplane or car) which has been sitting overnight in really cold conditions will have a flat spot. the low temps makes the rubber less flexible, so the part of the tire which was in contact wit the ground will stay a bit flat. As it starts rolling, this flat spot is noticeable. As you roll along, the tire will start to warm up from the flexing (the tire is not completely rigid) and eventually the "flat spot" will diminish and go away. This isn't a concern for tires which have become cold at cruise altitude, because they aren't bearing any weight, so no flat spot.