That reminds me of the story a couple months ago in Britain [1]:

"One passenger then identified himself as a qualified aircraft engineer and offered to try to remedy the fault. He was successful, and the plane landed in Glasgow only 35 minutes late...It was reassuring to know the person who had fixed it was still on the aeroplane."

Normally I'd be very worried that my plane was fixed by someone that didn't actually work for that company, but the fact that he trusted his own life to his fix would go a long way to reassuring me.

[1]http://www.dailymail.co.uk/news/article-1198058/Is-engineer-...

In the Canadian Army, the people who re-pack parachutes for soldiers (riggers) have a similar safe guard to ensure quality.

At any given time, a commander can select any particular chute that they've packed, and they have to jump using it. Needless to say the quality control is near perfect.

Once upon a time, the foreman on the shack that made a cannon would _sit_ on it when it was first fired (I don't think that included the cannonball, but still).

The reason was that if the inside wasn't smooth, the cannon might go off.

Well, you hope so anyway. There is always the chance that your pilot is in the process of getting a divorce or losing his/her house, going bankrupt, or something and decides to hell with it all. But your friend is right, either way, the people in the back have no choice but to follow.