Sam I. Aldock, 63, founder and president of the Systems Analysis and Research Corp. in Washington and a former Civil Aeronautics Board official, died of cancer Saturday at Georgetown University Hospital.

Mr. Aldock came to this area in 1936. After joining the CAB in 1941, he became chief economist and assistant chief of the commercial rates section. He was named special assistant to the director of the Bureau of Air Operations in 1955, a position he held until 1959.

While at the CAB, Mr. Aldock initiated the "class rate" concept, which develped into the government's aircraft guarantee loan program. The program, which was credited with helping small air carriers avert bankruptcy, allowed for the purchase by small carriers of post-war turbinepowered aircraft, which resulted in jet aircraft service to small towns in the U.S.

Mr. Aldock also was a consultant to a Hoover Commission study on military air transportation.

In 1959, he became a vice president and manager of the Washington office of United Research Inc., where he directed transportation studies and was coauthor of a Commerce Department study on the domestic air transport industry.

In 1961, he established his corporation, which represented members of the Association of Local Transport Airlines.

Mr. Aldock, who lived in Washington, was born in New York City. A certified public accountant, he graduated from the City College of the City University of New York.

Survivors include his wife, Myrtle, of the home; a son, John, of Bethesda; two sisters, Gertrude Vigoda, of Tamarac, Fla., and Nettie Waters, of Avenel, N.J., and two granddaughters.