USAir ordered 20 Fokker F-100 passenger planes.

The value of the contract, the biggest in the Dutch aircraft manufacturer’s history, is $350 million, the company said, adding that the Washington-based airline took options on 20 more aircraft of the same type. The order is a major breakthrough for Fokker, which introduced the F-100 medium-range plane earlier this year. So far, 38 firm orders have been placed for the aircraft, which seats 105.