Langley Aerodrome A Pusher Propeller, fixed-pitch, two-blade, wood

Type: Two-blade, fixed pitch, wood, metal and fabric

Diameter: 250.2 cm (98.5 in.)

Chord: 67.3 cm (26.5 in.)

Engine Application: 39 kw (52-hp), five cylinder, radial, gasoline, water-cooled, geared transmission

Samuel P. Langley's successful 1896 flights of model Aerodromes Numbers 5 and 6 led to plans to build a larger, human-carrying airplane. However, his simple scaling of these earlier small aircraft to the required larger size proved unsuccessful. Despite an excellent engine, the larger Aerodrome A met with disastrous results, crashing twice on takeoff in late-1903. This ended Langley's aeronautical work, and he died in 1906.

Tests showed Langley that helical propellers made from solid wood were more efficient than blades constructed with a frame over which cloth was tightly drawn. However, it was found that cost and ease of repair made the latter type more practical. Furthermore, at the size required for Langley's Aerodrome A, solid wood propellers were too heavy. The design of this propeller, having a unit pitch ratio and 30-degree blade, was arrived at following tests both in a closed room and open air, and with various wood and steel frames.