I must say that I disagree that a Project Manager must be a technical expert. That is like saying a formula 1 race car driver must be an expert mechanic. Far from it.

Like the formula 1 driver, a good PM will know the basics of how the technicalaspects relate to each other, and to be able to recognize some of the major components, but that is about it.

A good PM will deliver what the client wants (even though they might not know exactly what they want themselves!!!), on time, and under budget, all while keeping the technical team motivated and challenged.