The Kamov Ka-26 is a Soviet light utility helicopter with co-axial rotors.
The Lockheed XH-51 is an American single-engine experimental helicopter designed by Lockheed Aircraft, utilizing a rigid rotor and retractable skid landing gear. The XH-51 was selected as the test vehicle for a joint research program conducted by the United States Army and United States Navy to explore rigid rotor technology.
The Aerotécnica AC-14 was a Spanish five-seat light helicopter of the 1950s, designed by Jean Cantinieau, based on enlarging his Nord Norelfe design.
The Agusta A.115 was a prototype helicopter flown in 1961 in Italy. It was essentially a Bell 47J-3 with an unclad, tubular tail boom, and powered by a Turbomeca Astazou II turboshaft engine. No production ensued.
The Agusta A.101 was a large prototype transport helicopter developed in Italy during the 1960s. Despite prospective orders from the Italian armed forces, no buyers emerged and the project was abandoned in 1971.
The Agusta A.103 was an Italian prototype single-seat light helicopter flown in October 1959. The pilot was enclosed by a perspex bubble with the engine at the rear and the tail rotor carried on an enclosed boom.
The Agusta A.106 was a single-seat light helicopter designed to provide an anti-submarine warfare (ASW) platform for the Impavido-class destroyers of the Italian Navy. The aircraft was provided with a sophisticated electronics suite by Ferranti for autostabilisation and contact identification. Two torpedoes could be slung under the fuselage. The tail and two-bladed main rotor could be folded for shipboard stowage, and the skid undercarriage had fittings for flotation bags.
The Agusta AB.102 was an Italian helicopter produced in small numbers in the early 1960s. The aircraft was based on the mechanical components of a Bell 48 that Agusta incorporated into an all-new, streamlined fuselage. The first flight was on 3 February 1959 and the prototype was exhibited at that year's Paris Air Show in faux military colours. Only two production examples were built, operated by Elivie in a regular air service between Turin and Milan from 1961. However, the advent of turbine-powered helicopters in the 1960s soon rendered the AB.102 obsolete.
The AISA GN was a prototype four-seat autogyro developed in Spain between 1971 and 1982. it featured an extensively-glazed cabin fitted with a pusher engine and tricycle undercarriage. A separate tail fin was carried at the end of two booms mounted to stub wings. The prototype was developed with a 200 hp engine. The aircraft suffered from an extremely prolonged development, but finally took to the air on 20 July 1982. In September that year, however, it was damaged in an accident, and development was finally abandoned.
The RotorWay Scorpion is a family of helicopters manufactured by RotorWay International.
The Cierva C.17 was a British experimental autogyro built by Cierva Autogiro Company in England in 1928, in association with Avro. It was an attempt to build upon the successful Cierva C.8 design using the smaller, more streamlined fuselage of an Avro Avian IIIA as a starting point. The type was found to be underpowered, and when the first attempt at fitting a more powerful engine still did not result in acceptable performance, the design was abandoned.
The Cierva CR Twin was a five-seat utility helicopter that first flew in the UK in 1969. It was a joint development between Cierva Autogiro Company and Rotorcraft now a subsidiary of Cierva, based on the dynamic systems of the latter company's Grasshopper design. A new, highly streamlined pod-and-boom fuselage was married to the Grasshopper's coaxial rotor system, and the new aircraft registered G-AWRP first flew on 18 August 1969.
The Kellett XR-10 was a military transport helicopter developed in the United States in the 1940s that only flew in prototype form. It was designed in response to a USAAF Technical Instruction issued for the development of a helicopter to transport passengers, cargo, or wounded personnel within an enclosed fuselage. Kellett's proposal followed the general layout that the company was developing in the XR-8, with twin intermeshing rotors, and was accepted by the Air Force on 16 October over proposals by Sikorsky, Bell, and Platt-LePage.
The Agusta A.105 was an Italian rotorcraft designed by Agusta. It was never developed beyond the prototype stage.
The Dornier Do 32E was a simple, collapsible one-man helicopter, designed for military use in Germany in the 1960s. Despite initial hopes of large orders and some proposed civilian roles, only three flew.
The I.P.D BF-1 Beija-Flôr was a two-seat light helicopter designed by Henrich Focke.
The Ekin WHE Airbuggy is a British single-seat autogyro designed and built by the W. H. Ekin (Engineering) Company in Northern Ireland.
The Airmaster H2-B1 is a British two-seat ultralight helicopter built by Airmaster Helicopters of Camberley, Surrey.
The American Air Jet American is an American homebuilt tip jet helicopter designed and built by American Air Jet of Woodland Park, Colorado for amateur construction from kits.
The VTOL Aircraft Phillicopter is a 1970s Australian light utility helicopter designed and built by VTOL Aircraft of Newcastle West, New South Wales.
