Survivals of undercarraige bay stowaways have been known. This was the one that prompted me to search Google for hard facts

http://findarticles.com/p/articles/mi_m0CWU/is_2000_August_7/ai_63918543

and this came up too

http://www.stormingmedia.co.uk/57/5737/A573713.html?PHPSESSID=ee042c6655b68bff81922d9f6db09b18

Still don’t fancy trying it, though.

William