Attempting to stop people or bombs in under carriage would EXACTLY BE SECURITY THEATER. That is an overreaction to insignificant but recently hyped/fear mongered threat that results in no statistically significant reduction in risk. But, writes up good in the papers.
People thinking like you are why security theater can exist.
However, I wasn't saying that we should be trying to stop this. I meant to show up, conversely, that a lot of the existing security is there merely for show.
How many planes have been bombed by someone sneaking something into the wheel well?
I can't imagine it would be too hard to place a bomb in the wheel well of a plane parked in Nairobi, for example. The biggest issue would be avoiding the pilot's pre-flight check.
That wouldn't be to hard to do if you are a member of a ground crew that has access to the aircraft after the pilot is on board.
BTW, we keep bombs out of the cargo area well because there was a time we didn't do this well at all. Then this happened: http://en.wikipedia.org/wiki/Air_India_Flight_182 along with this: http://en.wikipedia.org/wiki/Pan_Am_Flight_103
What might be better is having a camera or motion sensor in the wheel well that can look for surprise guests.
"In a lot of places around the world, the control of movement and airside control areas is not the same as what we have here."
"It's much easier in some locations to access the airside areas than it is in the UK. The only way it could be prevented is if the rest of the world tightened their procedures."
I would think the obvious solution would be to slap a big old multilingual warning sign on the wheel wells, clearly stating "flying in wheel wells WILL result in death by asphyxiation, hypothermia, and severe physical trauma".