A little device with a big role on planes

Published 1:53 pm Wednesday, October 29, 2014

The R-2800 engines seen in the Flying Heritage Collection’s Hellcat and P-47 have a particularly noticeable device perched on the top of their nose case. The complex little component is a propeller governor.

Governor is an apt term as this piece of hardware is always working to mediate the forces of oil, engine, propeller, and the physics of flight to offer up a constant speed (rpm) for the fighter’s massive engine. The governor is controlled by the pilot, who uses the propeller control lever to move an arm that rolls a pulley that puts more or less pressure on a “speeder spring” inside the governor head that actuates flyweights that … well, um, you get the basics …

The pilot’s action, through a long series of mechanical workings, admits engine oil into the propeller dome for the propeller blade pitch changes necessary to maintain that constant engine speed.