Firth FH-1


Experimental helicopter built around the fuselage of an unusual fixed-wing aircraft, the 1948 Planet Satellite, with a light alloy semi-monocoque structure. It had a three-blade rigid rotor and tricycle landing gear. It was abandoned before flight testing due to financial and technical difficulties. The engine was a 146hp Gipsy Major.

G.Apostolo "The Illustrated Encyclopedia of Helicopters", 1984

In 1951 Firth Helicopters Ltd - the firm, which has now ceased to operate, started to build a prototype helicopter using a rotor system based on American patents held by Landgraf.


This helicopter was built round the fuselage of the unorthodox 1948 aircraft Planet Satellite. The latter was small, of monocoque construction in an extremely light magnesium-zirconium alloy, and fitted at the end of its tail with a pusher airscrew driven by an engine through an extension shaft.

The FH-1 had two three-bladed, non-articulated type rotors, mounted on outriggers and based on Landgraf patents. There was a tricycle landing gear.

This helicopter was abandoned before it ever flew because of financial and technical difficulties, the latter mainly connected with the forepart, which proved excessively heavy.