Spencer-Larsen Aircraft Corp
Spencer and Vincent A. Larsen design the single engine SL-12C amphibian.
Spencer leaves Spencer-Larsen in September 1940 and starts the work on his own S-12 Air Car amphibian design.
The Spencer S-12 Amphibian Air Car, NX29098, takes to the air for the first time on 8 August 1941, from sea on Belmore, Great South Bay, Long Island.
Spence accepts a job offer from The Mills Novelty Company, Chicago, IL, in 1943. In April the Air Car is flown from Long Island to Chicago, Illinois.