Canadian Aircraft Requirement Designations


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Jul 25, 2007
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Canadian Aircraft Requirement Designations

The best-known Canadian aircraft requirements are the 'AIR' series associated with the Avro Canada fighters. That sequence dates back at least to 1944 (with Specification AIR-4-10, Iss 1 for an RCAF navigational trainer).

Prior to the 'AIR' requirements was the late-'30s 'AP' series. I assume that 'AP' stood for 'Aircraft Procurement' or some such. An example is AP/3/39 resulting in the DH.82C Tiger Moth - an improved version of the RCAF's DH.82A(CAN) trainer.

That DH.82A(CAN) was the result of the last example I can find of the earliest Canadian requirement listing system -- the 'C' series of specification designations. Below are 'C' series specs gleaned from Canadian Aircraft since 1909 (KM Molson and HA Taylor, Canada's Wings, Stittsville, 1982).

Does anyone have any other Canadian requirement designations?


C/5/25 -- Twin-engined transport/patrol 'hydro-plane'
- C/5/25 : Results in Canadian Vickers Varuna I prototype

C/3/26 -- Requested changes* to Canadian Vickers Varuna
- C/3/26 : Results in Canadian Vickers Varuna II
-- * Primarily Wright J-4 changed to RCAF std. AS Lynx IV

C/4/26 -- Single-seat, single-engined light flying boat
- C/4/26 : Req'd tractor engine, repl. by C/5/26 spec.

C/5/26 -- Single-seat, single-engined light flying boat
- C/5/26 : Pusher or tractor propeller now accepted
-- Resulted in Canadian Vickers Vista prototype

C/6/26 -- Aeroplane for Photographic Surveying
- C/6/26 : Results in Canadian Vickers Velos prototype

C/11/26 - Forest Fire Patrol Aeroplane (DH.4 replacement)
- C/11/26: Results in Canadian Vickers Vigil series

C/3/27 -- Requested changes* to Canadian Vickers Varuna II
- C/3/27 : Requirement for a metal-hulled Varuna II variant
-- June 1927 Varuna III concept eclipsed by C/5/27

C/5/27 -- Larger, more powerful flying boat than Varuna
- C/5/27 : Requirement replaced by C/12/18 (below)

C/12/28 - As per C/5/27 but with dual cockpit req't added
- C/12/28: Results in Canadian Vickers Vancouver I
-- Note: Vancouver I had twin, tandem pilot cockpits

C/18/29 - Vancouver I changes for prod'n, single cockpit
- C/18/29: Results in Canadian Vickers Vancouver II
-- 5 x Vancouver I (3 x AS Lynx IVC, 2 x Wright J-6)

C/17/30 - Vancouver I modified to Vancouver II standards
- C/17/30: Vancouver I with Vancouver II's AS Lynx IVC*
-- * Not considered practical to modify cockpits, etc.

C/12/33 - Photographic Aircraft Amphibian (Vancouver III)
- C/12/33: Vancouver III 2 x P&W Wasps, revised tailplane
-- Specification cancelled, no Vancouver IIIs built

C/18/36 - Requested changes* to De Havilland DH.82A
- C/18/36: Results in 25 x RCAF DH.82A(CAN) trainers
-- * Major changes: canopy, steel-tube struts, reinf.



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May 26, 2006
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OHG,very interested topic my dear Apophenia,

was there anther Requirements with unbuilt airplane Projects ?.


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Jul 25, 2007
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Thanks Hesham. There's a few requirements with unbuilt aircraft mentioned above.

For C/4/26, Canadian Vickers produced a wind tunnel model of a light flying boat with an air-cooled inline engine mounted on top of a parasol wing.

For C/6/26, Canadian Vickers prepared a biplane with twin pusher engines and individual cockpits arranged in a row. Construction actually began on that airframe but the RCAF demanded a huge number of changes. The resulting Velos was a cobbled-together, dog's-breakfast of an airplane ;p

C/3/27 resulted in the design of a metal-hulled Varuna III. The Varuna III remained unbuilt and C/3/27 was abandoned for the more ambitious C/5/27.

C/5/27, in turn, was abandoned in favour of C/12/28 and the larger Vancouver I (to C/18/29).

C/12/33 was for a photographic Vancouver III amphibian which remained unbuilt.

In the later sequence, AIR-4-10 was cancelled in 1945 in favour of a higher-powered (2 x 1,200 hp) navigational trainer. That requirement also fizzled out in 1946-47.

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