Abrams, who led the test-flight division of Lockheed's top-secret ''Skunk Works'' as it developed the YF-22 fighter plane, died Thursday in a Washington, D.C., hospital. He was 56. The cause of death was not given. Abrams joined Lockheed's Advanced Development Co., otherwise known as the ''Skunk Works,'' as a senior engineer in 1980. He was named flight-test manager for the YF-22 program in 1989 and flight-test director in 1991. In April, Abrams was honored by the American Institute of Aeronautics and Astronomy for his work on the YF-22A advanced tactical fighter and the F-117 stealth fighter.
