Crab
ER what R and D costs ? The US mil paid for all that in the 1960's The RR 300 and 500 engines are basically a c20B. Guess what a C20 B is a derivative of a C18 the original engine for the 206 and 500. Which came from the T63 the engine designed to go in the OH 6 and OH 58. Actually I am wrong not paid for by the US mil but the US taxpayer