Pioneer aviation engineer (1889–1972) who developed the first four-engine airplane and the first modern helicopter to be put into widespread use. Personal check, 6.25 x 2.75, filled out in type and signed by Sikorsky, payable to the Frank Miller Lumber Co. for $93.37, December 15, 1948. In fine condition, with cancellation holes to upper portion, and stamps to reverse. RRAuction COA.
