Olmsted Model D4LP Pusher Propeller, fixed-pitch, two-blade, wood

Display Status:

This object is not on display at the National Air and Space Museum. It is either on loan or in storage.

Collection Item Summary:

Charles M. Olmsted, a European trained physicist from Upstate New York, had an interest in flight from his early years. His success with gliders in the 1890's led to the formation of the Buffalo-Pitts-Olmsted Syndicate in 1910 to develop aircraft. Following failure of the related agricultural equipment manufacturing company, Olmsted formed the CMO Physical Laboratory, continuing to manufacture and sell his ultra-efficient propellers. Olmsted designs differed from other propellers, having a large surface near the blade base and very little surface at the tip. Olmsted's propellers represented a fundamental difference in design philosophy that has not been duplicated by any other designer.

Loaned to the Sperry Gyroscope Co for testing in 1916, this left-turning pusher propeller is similar to those of the famous Curtiss-Wanamaker America flying boat, and those ordered by the British Admiralty for World War I service on other Curtiss aircraft based on the America design.