In the U.K., a well known company, Short Brothers & Harland, developed the Skyspy, a vertical take off UAV (VTUAV) fitted with a piston engine that drove a shrouded rotor. Hovering and forward flying test began no later than the spring of 1975. Development apparently came to a stop around 1977, when a rival design won a development contract.
The rival design in question, the Wisp, had been developed by Westland Helicopters, an equally well known company. The story of this VTUAV program actually began around 1967. A small team was set up at that time to see what a future battlefield surveillance / surveillance / observation vehicle might look like. It soon concluded that a small VTUAV was the way to go; piloted helicopters, however small and agile, were just too vulnerable. The Ministry of Defence (MoD) was quite intrigued by the idea. It issued a preliminary specification in 1971. Unwilling to wait until the purpose-built TV camera was ready, Westland Helicopters designed and built a proof of concept prototype fitted with a pair of contra-rotating rotors powered by two piston engines. This Westland WR.05 Mote made its first flights (tethered and free) in June 1975. The MoD was so impressed that it put up money to develop a larger design that would be closer to an operational VTUAV it might use in Northern Ireland. The first of three WR.06 Wisps made its first flight in December 1976. Within a year, the British military concluded that the payload of the new VTUAV was too small.
Westland Helicopters kept at it though and developed a larger design, the WR.07 Wideye, to fulfil a new British Army programme. A prototype flew for the first time in August 1978. Westland Helicopters received a contract to build three or four more Wideyes but control of the VTUAV was still problematic when the programme was cancelled, in December 1979. The company later developed a stealthy VTUAV based on its earlier work. This WR.09 Sharpeye was abandoned, in the early to mid ’80s, before an actual prototype was built. Mind you, Westland Helicopters also took part in a MoD UAV competition around that time. Its thoroughly re-redesigned WR.10 proposal was successful during the first round of the competition but was not chosen to take part in flight trials. No prototype was actually built. In 1990, an American firm, Martin Marietta, approached the company see if it was interested in jointly developing a new VTUAV. A Wideye was duly assembled using spare parts and shipped to California. It was test flown in 1991 but no further development ensued.
In early 1980, Westland Helicopters’ chief project engineer for UAVs joined a small British company, M.L. Aviation. The MoD remained interested in acquiring a VTUAV similar to the Wideye but did not wish to help the new project team too much. Design of a VTUAV with a pair of contra-rotating rotors powered by two piston engines began in early 1981. The first Sprite (Surveillance Patrol Reconnaissance Intelligence Target designation Electronic warfare) was flight tested in 1983.
In 1988, a Sprite was tested on a rolling platform used to simulate the deck of a ship in heavy seas. The U.S. Navy was sufficiently intrigued to organise sea trials. A Sprite thus flew off the aft deck of a U.S. Coast Guard cutter / patrol vessel, in the spring of 1989. Better yet, M.L. Aviation received a seemingly firm order from the Swedish army for 130 Sprites. Sadly, the company went into liquidation after delivering a couple of VTUAVs. Even though interest seemingly remained high within the MoD and in foreign countries, no further production took place. All in all, a dozen or so Sprites were built.
With its numerous ups and downs, the quarter century story of the Westland Helicopters and M.L. Aviation VTUAVs oddly resembles the 35-year saga of the Canadair and Bombardier projects (CL-227 and CL-327).
