Augmenting Helicopter Take‐off Power by Ram‐jets: An Account of Progress in the U.S.A. with Blade‐tip Ram‐jets of Compact Design Available to Purchase

The problem of supplying additional power to a helicopter rotor for take‐off or hovering under overload, hot‐day or altitude conditions is discussed briefly, and the boost system requirements are defined qualitatively. The Mirquardt Aircraft Co. is in process of developing a novel ram‐jet engine to meet these requirements under the sponsorship of the United States Air Force. The progress to date is reviewed, and the eventual application of this engine is discussed.