The Boomerang is an interesting aircraft.
Before the war Australia decided to build up its airforce and develop an incipient modern aircraft production industry. To serve both purposes it licenced for production the NA33 "Yale" as an advanced trainer. After modification it was locally manufactured as the "Wirraway" and more than 750 were delivered. One has actually been credited with a kill on a Zeke. North American further developed the "Yale" for the US market and produced it as the "Harvard".
The rapid advances of the Japanese in 1942 caused a panic in Australia. Britain had sent about 100 Hurricanes to bolster the forces at Singapore and they were all lost in days. Fighter aircraft earmarked for Australian defence were "diverted" to the middle east by theatre commanders. Spitfires were promised and did eventually arrive but there was a long gap. The few Buffaloes that were operated by the Netherlands East Indies and the pitiful remnants of the US forces in the Philippines didn't offer much of a shield to the north.
American forces trying to reinforce the Philippines started assembling aircraft in Australia and flying them there through the archipelago. These were generally P-40E's (49th PG) with some P39/P400s and a few F35s showing up later. B17s started round trip bombing raids in support of MacArthur from Australian bases. The fighters were being uncrated, put together and pointed north west. US Pilots had little or no idea how to get to where they were being ordered. The "Brereton Route" was 3600 miles from Brisbane to Java.
A famous if apocryphal remark was a response to a US pilot who asked a refueller at Cloncurry how to get to Darwin.
"You won't have any trouble finding your way to Darwin. Just follow the trail of crashed Kittyhawks, you can't go wrong."
The problem was that even though American aircraft were arriving they were not "sharing" and they were crashing most of them anyway. They were focused on defending the Philippines, not Australia, in the early days.
It is worth mentioning that Australian entrepreneurs managed to gather together a force of P40s by repairing aircraft written off in accidents by the USAAC but it wasn't a great way to build an airforce.
A proposal to adopt the Wirraway as an interim fighter until something better came along was accepted. The licence for the NA33 allowed the local manufacturer, CAC, to modify it. The 1200 hp P&W R1830 (also licence produced) was plumbed in and the airframe heavily modified. 2 20mm cannon and 4 browning .303s armed it. A supercharged version was to be developed as soon as possible.
It was produced in 3 main versions CA-12 CA-13 and CA-19. It was used as a stop gap, but in the second line, for air defence (the spits arrived). It went on to become a useful army cooperation and ground attack aircraft. It was underpowered but well armed and manouverable.
Perhaps its impact would be similar to an FM2 with a couple of Hispanos.
For the first model CA-12 these figures are normally quoted:
# Dimensions
* Span : 10.97m (36'0ft)
* Length : 7.77m (25'6ft)
* Height : 2.92m (9'7ft)
# Weight
* empty : 2,437kg (5,373lb)
* max : 3,742kg (8,249lb)
# Power Plant : 1,200hp P&W R-1830-S3C4G
# Performance :
* max speed : 491km/h (305mph)
* max climb : 2,940ft/min (896m/min)
* ceiling : 29,000ft (8,845m)
* range : 1,490km (930miles)
