Another
robunos rip-off ... this time, based on the de Havilland Australia
Sun Moth:
http://beyondthesprues.com/Forum/index.php?topic=9672.0The de Havilland Australia
Sun Moth II name is all but forgotten today. A major improvement over the original, more cramped
Sun Moth I, the prototype
Sun Moth II was let down by its underpowered de Havilland
Gipsy Six engine. [1] And that might have been the end of the story had the RAAF not experienced some overheating problems with the Armstrong Siddeley
Cheetah in their Avro 643
Cadet biplane trainers.
In anticipation of new RAAF Avro
Anson patrol aircraft, Canberra funded an improved version of the British engine. The result was the Commonwealth CAC-7
Cricket [2] 7-cylinder radial - with the same displacement as the British
Cheetah but with enlarged cooling fins on the cylinder barrels. [3] The
Cricket did all that was hoped for it but, before the first
Anson entered RAAF service, a pre-production CAC-7 was used to re-engine the prototype DHA-2
Sun Moth II. The intended market, once again, was the Australian Aerial Medical Service. But the 'Flying Doctors' lost out to the RAAF.
In service, the DHA-2M became the de Havilland Australia
Dingo - famed for its low-level air drops to jungle-fighting troops in New Zealand. The 375 hp CAC-7
Cricket provided enough power for the
Dingo to hang over the Diggers' position on its Handley Page slats while dropping urgent supplies through its belly hatch. (Such mad aerial antics probably being responsible for the DHA-2M's '
Drongo' nickname.)
Illustrated is the prototype '
Panacea II after its conversion to DHA-2M standards.
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[1] That original, inline layout being immortalized in the de Havilland Australia logo.
[2] The CAC
Cricket was named for the buzzing Black field cricket (
Teleogryllus commodus).
[3] Minor changes to better-suit Australian manufacturing practices and a switch from Claudel-Hobson to US Stromberg NA-R7A carburettors were other modifications. The parallel CAC
Cicada - a 420 hp, 1,072 cid (17.57 L) 9-cylinder radial - was not proceeded with (Commonwealth ultimately license-building the Pratt and Whitney
Wasp instead).