From markings on this artifact, it was identified as a Yamaha manufactured Model 2D60 propeller, of the "Hamilton Type." It was produced on February 23, 1941 for use on a Tachikawa "Ki-54" twin engine ...
The Hamilton Standard Hydromatic propeller introduced in the 1930s was a significant advance over the counterweight, controllable pitch propeller. Application of oil pressure to both sides of the ...