A rotor kite or gyroglider is an unpowered rotary-wing aircraft.

These are known as rotor kites.

Rotor kite, if untethered, known as a rotary glider, or gyroglider.

In October 1940, work began on design and construction of rotor systems and scale models of rotor kites.

The Bensen designs became so ubiquitous that the term "gyroglider" is sometimes used to refer to any rotor kite, regardless of manufacturer.

Also of great interest was the Fa 330 Bachstelze rotor kite, a towed one-man aerial observation platform.

In 1940, he proposed the use of a single-place strap-on rotor kite in place of a conventional parachute, to deliver a soldier accurately to a battlefield.

Rotor kites are unpowered autogyros, which are towed to give them forward speed or tethered to a static anchor in high-wind for kited flight.

The Hafner H.8 Rotachute was a British 1940s experimental one-man rotor kite designed by Raoul Hafner.

The Bensen B-6 was a small rotor kite developed by Igor Bensen in the United States in the early 1950s and marketed for home building.

It was a single-seat, open framework machine based on the B-5 rotor kite with small, gasoline- or fuel oil-burning ramjets mounted as tipjets on the rotor blades.

In this scheme, it was proposed to integrate combat aircraft ejection seats with a small autogyro or rotor kite to allow downed pilots more control over their post-ejection landing spot.

The Baumgärtl PB-60 was a 1940s experimental single-seat rotor kite designed and built by Austrian designer Paul Baumgartl for the Brazilian Air Ministry.

In World War II, Germany pioneered a very small gyroglider rotor kite, the Focke-Achgelis Fa 330 "Bachstelze" (Water-wagtail), towed by U-boats to provide aerial surveillance.

The U-boat successfully attacked the unescorted 4,195 ton Greek merchant ship Efthalia Mari east of Madagascar on 5 August, after spotting her using a Fa 330 Bachstelze rotor kite.

Similar in general configuration to Bensen's previous rotor kite and autogyro designs, it consisted of an open aluminum framework but substituted the autorotating main rotor for a coaxial, counter-rotating system of two, two-bladed rotors.

The fourth arm of the cross provided a mounting for a large, plywood fin and rudder, reminiscent of that of the Raoul Hafner's Rotachute that had shaped Bensen's thinking about rotor kite design.

At Ringway, one of the existing projects was the Hafner Rotachute, a rotor kite (unpowered autogiro) that was planned to deliver an armed soldier to a battlefield more accurately and reliably than conventional parachute methods.

Research into rotor kites began in earnest during World War II, and one type in particular, the Focke Achgelis Fa 330, reached active service, being towed behind German U-boats as an aerial observation platform.

During the 1950s, rotor kites were developed as recreational aircraft, largely due to the efforts of Dr. Igor Bensen in the United States, whose Bensen Aircraft Corporation produced a series of such aircraft, dubbed "gyrogliders" by Bensen.

The Hafner Rotabuggy (formally known as the Malcolm Rotaplane) and as the "M.L. 10/42 Flying Jeep" was a British experimental aircraft that was essentially a Willys MB combined with a rotor kite, developed with the intention of producing a way of air-dropping off-road vehicles.