<<In addition to what Michael says below, I don't believe the Piedmont of USAir is any relation to the real Piedmont that USAir took over. This Piedmont is a renamed Allegheny Commuter. Ditto for PSA and Allegheny (also owned by USAir)>> In fact, these are the old airlines, at least their certificates are. The reason USair still uses the names is so they can use the old certificates, take a look at the year founded for PSA airlines and it corresponds to the old US