The first Australian built Single Row Wasp was produced in January 1939, then 1 in April, 3 in May then production from July onwards. One reason for the choice was the Twin Wasp was is a simple step up as far as production was concerned. However through the Australian production run some parts needed to be imported (cylinder barrels?)
The decision to build the Pratt and Whitney R-1830 Twin Wasp in Australia by the Commonwealth Aircraft Corporation (CAC) was taken on 31 October 1939, first production was in November 1941, in the end 870 were built, versus the need for 1,650 new engines for local production Beauforts and Boomerangs. The idea of producing Twin Wasps was around as part of the March 1939 proposal to build Beauforts in Australia, initially it was assumed they would use imported Taurus engines, but continuing doubts about the Taurus resulted in the British proposing the Australians build the Twin Wasp, that was turned down, the British asked for a reconsideration, the Australians then decided to build the engines with the message agreeing to the production crossing one from Britain that said no need, Taurus production would be sufficient.
The decision to build Beauforts was made in late March 1939, but was delayed by inexperience, the 1940 crisis, the Taurus engine problems and Twin Wasp redesign, first Australian production in August 1941.
The Vengeance was the substitute for the Bermuda which had been scheduled to arrive in 1941, 5 Vengeance arrived in Australia in May 1942, 10 in July, then imports from February 1943.
Early P-40 imports that ended up in the RAAF were 162 March to September 1942, then further imports from January 1943.
The first 6 Spitfires arrived in August 1942, then imports from October 1942 onwards.
The first Beaufighters arrived in March 1942, local production was approved in January 1943, production began in March 1944 (the aircraft were costed at 40,000 pounds each, tooling at 700,000 pounds).
While 2 Boomerangs were flying by end July 1942 the usual teething problems meant official production began in September.
In 1941 Australia was producing 3 types of trainers, Wirraway using locally built engines, Tiger Moth with local engines and the Wackett trainer using imported engines. Trainer production was shut down by end August 1942, the Wirraway resumed production in November 1943 and a batch of 35 Tiger Moths were built 1943/44. Tiger Moths were exported to New Zealand and South Africa, the latter without engines.
The choice of the Wirraway design, and subsequent Beaufort, was to have in production an aircraft with all the latest features, including enclosed cockpit, retractable undercarriage and stressed skin construction, to create a modern industry, as things were changing fast. The P-51 kits North American put together for Australia were D-5 in March/April 1944, then add weeks to months to pack the kits, get them across the Pacific, unpacked and assembled, assuming everything is perfect. In June 1944 the P-51D-10 was in production, the D-15 in August, the D-20 in October, creating a real problem for Australia building up to date versions.
Note the Australian industry's limited capacity and lead times, also check out the stories of the CA-4 and 11 bombers, and the CA-15 fighter, even the supercharged Boomerang. If the RAAF is to have a modern fighter in local series production in early 1942 decisions on engine and airframe need to be taken in 1939 to early 1940 and would need to be a type in production so tooling could be more readily copied. The P-35A ended production in January 1941. Curtiss CW-21B built October to December 1940. P-66 production was October 1941 to April 1942, despite some British interest, most shipped to India for China, starting in February 1942. YP-43/P-43/P-43A production from September 1940 to April 1942, the RAAF did not like the P-43. F2A production ended in April 1942.
The R-1830 is really not powerful enough for a front line 1942 fighter unless some compromises are made on protection.
Wild card solution, NA-73 when the British ordered it, as part of a long term Australian Mustang production plan, first NA-73 produced in August 1941, added to Australian Merlin production which would also serve the local Mosquito program, the major hindsight picking the winners solution, Australia did built Merlin for its Lincoln bombers, but not until June 1947.
The 162 early RAAF P-40 were a mixture of P-40E-1 from the RAF order DA-3 (including 9 sent for the Netherlands East Indies but treated locally as USAAF) and P-40E from the USAAF orders. The RAAF were allocated 250 P-40 from DA-3 in January 1942, the RAAF thought it was going to receive 173 in early 1942, the allocation became a firm commitment for 143, of which 14 were subsequently lost at sea and not replaced. Upon arrival the P-40E and E-1 were assembled by whichever RAAF/USAAF unit had the capacity then allocated and even reallocated between the RAAF and USAAF, the RAAF ended up with 66 P-40E-1, another crashed on the delivery flight, hence 163 RAAF P-40E/E-1 serials. The difference of 162 P-40 to the RAAF versus 129 imported was partly repaid in 1944 when 20 RAAF lend lease P-40N were transferred to the USAAF. The first 78 RAAF P-40 serials were P-40E.
P-40 Order status as of 1 March 1943. A1196 1/501/466 part 5, page 162. First allocation was notified by the Secretary of State for Dominion Affairs, London in Cable No.138 dated 31st January 1942, for 250 aircraft, subsequently amended to a firm allotment of 143 machines. Australian War Cabinet Minute No.1845 Agendum 46/1942 authorised the acquisition.