Pioneer aviation engineer (1889–1972) who developed the first four-engine airplane and the first modern helicopter to be put into widespread use. Program celebrating the 40th Anniversary of Sikorsky Aircraft, March 5, 1963, 8.5 x 11, signed and inscribed on the first page in blue ballpoint, “With kindest personal regards of I. Sikorsky, March 28, 1963.” In fine condition. RR Auction COA.
