USAir Group and Piedmont Aviation Inc., which...

USAir Group and Piedmont Aviation Inc., which have agreed to merge, reported increased first-quarter earnings, citing strong traffic and lower costs. Washington-based USAir posted a $23.5-million profit, contrasted with a loss of $6.8 million in the first three months of 1986. Piedmont, which is headquartered in Winston-Salem, N.C., announced first-quarter earnings of $5.7 million, contrasted with a $6.9-million loss a year ago.