William Lee Howard Jr., 72, an aviation lawyer who was a major force in turning USAir into one of the world's largest airlines, died March 21 at Shady Grove Adventist Hospital after a heart attack.

Mr. Howard represented the USAir forerunner, Allegheny Airlines, before the Civil Aeronautics Board as the company grew from mergers and acquisitions in the 1960s and 1970s.

He was a former senior trial lawyer for the federal agency that regulated air transportation and worked for Allegheny for 13 years until 1979, when the airline changed its name to USAir, about a year after the adoption of the Airline Deregulation Act.

He ran a private practice in Washington from 1980 to 1988 and worked in sales and marketing for AEC Design Group, a software company in Gaithersburg.

Mr. Howard, a Potomac resident, was born in Salem, Mass., was raised in Washington and graduated from Gilman School for Boys in Baltimore. He graduated from Brown University in 1952 and Georgetown University law school in 1955.

From 1956 to 1959, he was a Marine Corps captain and was assigned to the office of the judge advocate general in El Toro, Calif.

He worked in the office of the general counsel at the Civil Aeronautics Board from 1959 to 1966.

He was an active member of Alcoholics Anonymous and a member of the Del Ray Club in Bethesda.

Survivors include his wife of 47 years, Jude McCarthy Howard of Potomac; two children, Matthew Charles Howard of McLean and Jessica Ann Mocarski of Damascus, Va.; a brother, Mark Howard of Springfield; and five grandchildren.