'Super Boomer' - Part 10 - The Commonwealth Aircraft CA-19 Wirga trainer
CAC 's prototype CA-19 Wirga T.Mk.I first flew in late Jan 1946. Compared with the CA-14A Wallaby fighter, the CA-19 had a longer span wing. The CA-14A's wing panels had joined on the centre line. But the CA-19 featured a new centre section to which the outer wing panels were joined. This gave the Wirga a wing span of 36 ft 1 in versus 34 ft 5 in for the Wallaby.
Following the pattern of the Wallaby, the Wirga was assigned 'recycled' RAAF serials. The A69 sequence up to -150 had been for the Curtiss A-25 Shrike but these orders were cancelled. Thus, the serial sequence for the CA-19 Wirga trainers began with A69-151.
A69-151 flew with a hand-built prototype CAC R-1000 7-cylinder radial. The CA-19 flew much as expected but, as previously recounted, the RAAF had already cancelled its orders for the Wirga T.Mk.I series. As a result, A69-151 was re-engined with a CAC-built Pratt & Whitney R-1340 S3H1-G Wasp 9-cylinder radial to become the prototype CA-19 Wirga T.Mk.II. Using stockpiled stocks of these Wirrway engines, Wirga T.Mk.I components already begun at Fisherman's Bend were completed as Wirga T.Mk.II armaments trainers -- T.Mk.IIAs with 0.50" guns, T.Mk.IIBs with wing racks, and T.Mk.IICs with AC-20 cannons.
In the postwar environment, surplus AT-6 Texan components were available very cheaply. To take advantage of this windfall, Canberra ordered stocks of 600 hp P&W R-1340-AN1 (S1H1) Wasp radials from the US along with AT-6 engine bearers, cowlings, and two-blade Hamilton Standard propellers. These ex-USAAF components were incorporated into the next Wirga variant, the T.Mk.IIIA. All of these aircraft were gunnery trainers fitted with twin AC-20 cannons in their wings.
CAC had made several attempts to develop an improved canopy for the Wirga. Late model T.Mk.IIs and the T.Mk.III featured Wirraway-style canopies with reduced framing. But none of CAC's 'bubble' canopies had been acceptable to the RAAF -- mostly because of projected costs. In 1949, a new option became available -- adapting the canopy from North American's new T-28 Trojan trainer to the cockpit of the CA-19 Wirga. This concept was acceptable to the RAAF and CAC began delivering Wirga T.Mk.IVs fitted with North American-supplied canopies in 1951.
The final model of Wirga was the T.Mk.V, basically T.Mk.IIIs remanufactured to T.Mk.IV standard. As these aircraft entered RAAF service, they displaced earlier model Wirgas which, in turn, eclipsed the Wirraway in the target-towing role. Beginning in 1955, the more economical CAC CA-25 Winjeel began replacing the CA-19s. The Wirga T.Mk.IVs and T.Mk.Vs continued on as armaments trainers until 1959.
[Fin]