Commonwealth Aircraft Corporation Boomerang Restoration

Heritage

The AT6 Texan, SNJ, P64, Harvard, Wirraway and Boomerang all owe their ancestory to the North American NA33 Trainer, which in turn owes itself to the earlier fixed undercarriage NA-16.

North American produced the NA-33 which went into production in the USA as the AT6 and SNJ (Marine Corps) and for the British Commonwealth as the Harvard. Noorduyn Canada were issued a license to construct the NA-33 which evolved into various models of the Harvard and later the Harvard Iv similar to the T6G.

Commonwealth Aircraft Corporation (CAC) Melbourne, Australia obtained a license to construct the NA-33 which evolved into the Wirraway, (Wirraway - aboriginal word for ‘challenge’), as CA-1, CA-3, CA-5, CA-7, CA-8, CA-9 and CA-16.

North American experimented with the building of the P64 fighter based of the AT6.

CAC used a clause in their license agreement to modify the Wirraway for local conditions, which saw them construct the Boomerang CA-12, CA-13, CA14, CA-14a, CA-19. Modifications employed saw a different aircraft to the Wirraway, but allowed the use of many jigs and parts of the Wirraway.

Design

All examples are based on the principal of a wing centre section featuring retractable undercarriage with outer wing panels butt joined to the centre section by attach angles top and bottom of the platforms. All models built on the American continent had a single centre section flap where CAC aircraft featured a fixed (up) section in the middle. All model had outer wing flaps extending to the Aileron.

Undercarriage assemblies are identical in style on all aircraft, with the methods of retracting on the AT6, SNJ, Harvard being identical, where as the Wirraway and Boomerang are identical to each other, but differ to the others in so far as the retracts ram does not connect to the fittings in the outer wing, but to a tubular stand off bracket attached to the wing centre section, allowing the outer wing to be removed without disturbing the hydraulics.

All examples carried two centre section fuel tanks. The Boomerang has a 70 IMP. Gal. tank behind the pilot in the rear fuselage. Total fuel 160 Imp. Gals. (504 lbs.)

ARMOURMENT

The AT6, SNJ, Harvard, Wirraway and P64 featured fuselage synchronised machine guns whilst the Boomerang featured only outer wing weapons, being one CAC 20mm Cannon and two Browning .303 machine guns in each wing. Cannons or machine guns could be fired separately or all together.

ARMOURMENT WEIGHTS – (GUNS AND AMMUNITION)
AT6/SNJ HARVARD WIRRAWAY P64 Boomerang
Max 126 lb Max 156 lb Max 188 lb Max 210 lb Max 720 lb
AIRCRAFT WEIGHTS – (ALL UP MILITARY)
AT6/SNJ HARVARD WIRRAWAY P64 Boomerang
5,300 lb 5,250 lb 6,595 lb 5,850 lb 7,600 lb
ENGINES – (PRATT AND WHITNEY RADIALS*) (WRIGHT CYCLONE RADIAL**)
*R1340-AN-1 *R1340-49 *R1340 S1-H1-G **R-1820-77 *R1830-90B
Single Row Single Row Single Row Single Row Twin Row
865 lb 865 lb 865 lb 1,100 lb 1,465 lb
600 HP 600 HP 600 HP 870 HP 1,200 HP

FUSELAGE CONSTRUCTION

COCKPIT
AT6/SNJ/Harvard/Wirraway/P64/Boomerang Tubular chrome-moly frame
REAR
AT6/SNJ/Harvard/P64 Metal monocoque
Wirraway Cloth over aluminium frame attached to chrome-moly tube main frame structure. Lower semi monocoque aluminium section below main frame.
Boomerang Cloth over Ply over wooden frame attached to chrome-moly tube main frame structure. Lower semi monocoque aluminium section below main frame.
PERFORMANCE
AT6/SNJ HARVARD WIRRAWAY P64 Boomerang CA12/13/19 Boomerang CA 14/14a *
Max. (MPH) 212 210 220 270 305 348**
Ceiling (ft) 21,500 22,000 23,000 26,000 34,000 38,000
Range (mls) 870 740 720 620 880 760
Wing Span (ft) 42 42 43 47.3 36 36
Wing Area (sq ft) 253.7 253.7 255.7 247.3 225 225
Climb Rate(FPM) 1,350 1,350 1,950 2,080 2,940 2,150

* CA14 featured a turbo charger (with intercooler unit) in the rear fuselage driven by the R1830 engine, increasing speed, height, and climb rates.
** CA14a production was to use a P&W R2000 engine (1425hp) increasing max speed to 372 MPH.

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Site last updated: June 2014 | site by creative curiosity