The Metric System #2

You know we all have to learn the metric system in school so why don't we just switch to it already??????

When we have important rockets blowing up because they parts were not made to the same scale there obviously is a problem!!!

I can understand that many Americans will complain that it would be to hard to learn a new system if they are unfamiliar with it. But the metric system is all based on multiples of tens, a second grader can count by tens!:) I'm sure in a game like football the distance of the field would still be 100 yards even if we are on the metric system because its just programmed in our heads that that is the distance.
Yet for important measurements such as train tract distances and medicine formulas a standard international system should be used.
The chances of a mistake being made when everybody is on the same system is far less than if they had to constantly convert measurements.

So when are we going to switch????