WASHINGTON (AP) _ Charles L. Woods, whose career in the U.S. airline industry spans more than 40 years, was sworn in Thursday as a member of the National Mediation Board.

The board, which handles railroad and airline labor disputes, will now have its full complement of three members for the first time since August 1984.

Woods, 70, has lived in Manhattan Beach, Calif., a suburb of Los Angeles, for 37 years. He was a captain with United Airlines from 1947 to 1975. For the last dec ade, he was the West Coast airline representative to the Teamsters airline division, with offices in Los Angeles.

During his career as a pilot, Mr. Woods played a significant role in labor negotiations between the Air Line Pilots Association and United Airlines.

Kay McMurray, director of the Federal Mediation and Conciliation Service and a former chairman of the National Mediation Board, administered the oath at ceremonies attended by government officials, airline and railroad management and labor representatives, mediators and members of the Woods family.