Somebody actually said that once. But in aerospace, the best you can hope for is that the unanticipated problems won't be too serious.

From Jerry Pournelle's website:

Subject: Testing F-16s

This story was told by people from Motorola and is supposedly included in every microcontroller training course Motorola gives.

Test flights of F-16's were being conducted in Israel. The F-16's were doing low height rounds. On approach to the Dead Sea, the whole navigation system suddenly reset itself. The daring pilot landed the bird. HQ called up Motorola and ordered a team on the spot ASAP. The ground tests went perfectly, but every time the bird went airborn, it rebooted.

The pilots were getting restless. Flying on the border of hostile territory without navcom, with the Arabs pointing their earth-to-air missiles at anything that moves, wasn't that pleasant. Neither was debugging the whole navcom in-flight. Then someone figured it out.

The height of the Dead Sea relative to world sea level is -50 meters. As soon as the F-16 reached sea level, the navcom did a divide by zero, crashed, and rebooted.

Mike

So, how many engineers would design flight control systems to operate below sea level? But you never know...