Suddenly there’s a red-hot competition under way to develop rotorcraft capable of flying at sustained speeds well above the theoretical limits of conventional helicopters. To meet the challenge, ...

The speed limiter in question here is called retreating blade stall. You can think of a helicopter's top rotor blades as wings – wings capable of varying their pitch to generate more or less lift as ...

A team of US Army, Navy and NASA researchers has successfully tested a helicopter rotor blade with a variable-droop leading edge (VDLE) that could dramatically expand the operational envelope of ...

IIIF provides researchers rich metadata and media viewing options for comparison of works across cultural heritage collections. Visit the IIIF page to learn more. Early helicopter engineers soon ...