Spec.,and the Shorts Brother who was developed it. C.31 was a project of 1934 for a two-seat coupe autogyro with retractable landing gear and powered by one 385hp Napier Rapier IV engine. C.32 was similar to C.31 but powered by one 200 hp De Havilland DH Gipsy Six engine. C.33 (Avro-665) was an Avro project ,envisaged the combination of a four-seat Commodore biplane with a three-blade rotor,powered by one 240 hp Armstrong Siddeley Lynx IVC engine. C.37 was a twin-engined cabin autogyro,prposed by Avro as the Type-668. C.39 was a project for 2/3 seat fleet spotter autogyro to Spec. 22/38,this would have had a three-blade rotor and 600 hp Rolls- Royce kestrel engine.
I personally wouldn't call the Air Horse "little-known", although it remained a prototype. It is well documented and illustrated. Depending on generations and areas of interest, what is unknown to some may be very well known to others...
... I really do wonder if it wouldn't be best to have a "unbuilt projects" topic on one side and a "little-known rotorcraft" on the other. There is just too much stuff of different nature in this thread.
I have wondered the same thing myself, if they should be separate. I personally don't like to split categories up too much, it just makes certain aircraft harder to look up on the forum. Besides, I can't do any splitting or merging yet until ActiveBoard reads the user suggestions and adds that feature.
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lllllAs of 2019 I have transitioned; My name is now Rei. Please don't deadname or misgender me, thank you. <3 lllll
In 1928 the Cierva Autogyro Company contracted Parnall to design and build two machines to be designated C.10 and C.11 in the Cierva series, the C.11 being later called the Parnall Gyroplane. The airframes were designed by Harold Bolas. The C.10 was powered by an Armstrong Siddeley Genet while the C.11 used a 120 hp Airdisco. The C.10 turned over on take-off at the airfield in Yate and was taken to Hamble for repair at which time it was modified to incorporate an engine-driven rotor-starting device.
Is this really the Cierva W.10 as stated in these two articles. The first from The Aeroplane Spotter, 13th July 1946 and the second from Flight September 11th 1947?
Or is this information from the appendices of British Military Helicopters. John Everett-Heath, Arms & Armour Press 1986, nearer the truth.
"1946 Weir W.10, 510 h.p Armstrong-Siddeley Cheetah, Take off weight 2,222lbs, Rotor diameter 14.0m, 6 seats. Similar layout to W.9"
-- Edited by Ross on Tuesday 4th of October 2011 06:37:29 PM
Vince are you referring to the W.10 being discussed? If you are then I have to say you got the wrong aircraft. You're right about the C.10, but then a similar design with more powerful engine was developed shorly after called the C.11. The aircraft after the W.10 was the W.11 Air Horse, a large aircraft with 3 main rotors. My point is that you're mixing the W designations with the C designations, which were really different aircraft!1
That was almost a whole year ago, so of course I learned more about them through that period of time. Not enough to make a designation list like Stephane, but enough to make some helpful corrections.
It was as Stingray said a single-engined five-seater project, and it was definately a helicopter, not the usual autogyro. Apparently Cunliffe-Owen Aircraft built a prototype before Weir ceased investment in the Cierva company in 1948 due to the W.11 crash.
What happened with the design after that I'm not sure. Maybe it was known under a Saunders-Roe heading by then?
-- Edited by Pepper on Wednesday 5th of October 2011 01:21:49 AM
W.10 was abandoned in favor of developing the W.11.
Anthony, the first helicopter by Saunders-Roe was designated W.14 and it was AFAIK the one and only design post-Cierva/Weir with a W. After that they used P as their prefix, so it wouldn't make any sense at all that a "P.10" exist under their name.
And here is the real aircraft depicted in Ross' articles:
The "Spraying Mantis" (projected modification to W.11) designed by Pest Control Ltd. and the Cierva Autogiro Co., Ltd., and claimed to be exclusively for agricultural work.
I agree that the aircraft shown is the "Spraying Mantis". A mock-up built by Cunliffe-Owen for Cierva. It was never built as the real thing, during wind tunnel tests it was found that it was far better to have the single rotor at the front rather than the rear. The design was changed and Cierva also decided to capitalise on the potential load carrying capabilities for both military and civil applications by having an enclosed fuselage fitted, thus the W-11 Air Horse as we know it emerged. Pest-Control Ltd lost interest in the project when they found that crop spraying could be performed easier and more cheaply by smaller helicopters.
On a separate note the Cierva designation W.14 applied to the first two Skeeters built the Mks 1 & 2. When Saro took over responsibility for the design it became their P.501.
Thanks Ross for explaining the connection between the AIR HORSE and SPRAYING MANTIS, which was never too clear until now. I knew the Mantis came first, but didn't know how and why it had evolved.