Altair Airlines yesterday began nonstop air service from Dulles International Airport to both Pittsburgh and Richmond.

The Philadelphia-based airline is beginning its Dulles service with two roundtrips daily to each city during weekdays and one roundtrip on Sunday. Service to Richmond connects with flights to Raleigh/Durham, N.C.

On April 1, the carrier plans to expand its Dulles service by instituting flights to both Philadelphia and Newark.

Service from Washington National to the cities Altair plans to serve varies -- ranging from eight nonstops a day to both Richmond and Pittsburgh on various airlines to a whopping 21 roundtrips a day to Philadelphia on Ransome Airlines -- but service from Dulles is sparse, nonexistent in some cases.

Altair's service to Pittsburgh is the first available from Dulles, for instance. Altair hopes to fill this void.

"We hope to transform Dulles from an airport that has been used exclusively for international flights and those west of the Mississippi to an airport that can be used by people who live around the airport for day trips," Altair President Michael L. Lehrman said in an interview.

Lehrman who became president of Altair in January after serving as a consultant to the airline in his capacity with Avmark Inc., a aviation management service, has an ambitious program for the airline, expecting to carry about 260,000 passengers this year, up from 196,000 last year.

"The focus of my strategy for growth is up and down the eastern seaboard because big carriers can't efficiently operate in these short haul, high density markets," he said.

Altair now serves a total of 16 airports in New York, Delaware, Pennsylvania, Maryland, Virginia and North Carolina; it added service to Elmira and Binghamton, New York this week from Philadelphia although it soon plans to drop service from hectic JFK International Airport in New York altogether.

The Dulles service utilizes 27-passenger French-built Nord planes operating out of the airport's convenient center finger so mobile lounges are not needed. Southern Airways is handling Altair's flights and ticketing at the airport. Lehrman is currently looking to move to larger planes in the future.

Under the terms of the recently-enacted Airline Deregulation Act, Altair dropped its commuter status to become a fully-certificated airline, which allows it to participate in jointfare and interline airline activities and get its schedules listed with the larger airlines in the Official Airline Guide.

Fares from Dulles may be somewhat higher -- 10 percent to 20 percent -- than the equivalent flights from National to cover increased costs, Lehrman said, but he thinks people will pay a little more for the convenience of flying from Dulles if they live nearby.

This isn't the first time the 46-year-old Lehrman has run an airline. As a graduate student at Harvard Business School in the early 1960s, he established the first helicopter airline in New England, operating from Boston's Logan Airport to heliports surrounding Boston.

A pilot with a pilot-wife, Lehrman island-hopped in a small plane to Europe from the U.S. on his honeymoon.