Country of origin:

Australia

Description:

Single-seat agricultural monoplane

Power Plant:

One 448 kw (600 hp) Pratt & Whitney R1340-S3H1-G Wasp nine-cylinder air-cooled radial engine

Specifications:

History:

The CAC CA-28 Ceres (the God of Fertility) was developed from the CAC Wirraway trainer of World War II, which had been built at the Commonwealth Aircraft Corporation’s (CAC) plant at Fishermens Bend, VIC, between 1939 and 1945. In the mid 1950s CAC was looking for further work, at that time being involved in the production of the Australian variant of the North American F-86 Sabre. Consideration was being given to the construction of a feeder-line aircraft known as the ‘Wallaby’, which was never built, and an order was expected in due course for the construction of the Lockheed F-104 Starfighter for the RAAF, CAC to be the prime contractor.

However, the order for the Lockheed F-104 was not forthcoming and, pending the decision to licence-build the GAMD Mirage III, the Australian Government ordered a further 21 CAC CA-27 Sabres to keep the production line open. In the meantime, de Havilland DH.82 Tiger Moths were the backbone of the agricultural industry and, as the de Havilland DHC-2 Beaver and Fletcher FU-24 were a little way off, CAC decided to convert some examples of the RAAF’s multi-purpose trainer, the Wirraway, for agricultural use to meet a need foreseen at the time.

Construction of the Ceres was basically similar to the Wirraway but incorporated a number of new features. These included a completely re-designed centre-section, modified outer wing panels fitted with extended ailerons, fixed leading-edge slats, and slotted flaps. The undercarriage was fixed and the flaps were mechanically-operated. The fuselage incorporated a new section making it 71.12 cm (28 in) longer than the Wirraway, and its new structure consisted of a tubular steel frame over which was mounted sheet metal or fabric-covered fairings.

The stainless steel hopper had a capacity of 3.43 m³ (40 cub ft) and was located in front of the pilot directly above the wings. The hopper could accommodate both solid and liquid loads, and alteration of role from top-dresser to liquid sprayer was only a minor operation to change the appropriate fittings. The aircraft was initially known as the Wirraway Agricultural Conversion. The CAC Board gave approval to build two prototypes and proceed with the project in February 1957.

The aim of the designers was to produce an aircraft capable of carrying a payload of one ton (1,016 kg – 2,240 lb) of superphosphate or an equivalent volume of liquid material. CAC acquired two Wirraways in August 1957, serials A20-680 and A20-697, and these became the prototypes, the Company later obtaining a further 55 Wirraways in the expectation that the new design would be popular with agricultural operators. Most of these Wirraways were late production machines but early aircraft included A20-13, A20-16, A20-22, A20-24 and A20-29, all from the first production batch.

The prototype of the Ceres VH-CEA (c/n CA28-1), which was based on the airframe of Wirraway A20-680, flew for the first time on 18 February 1958 powered by a modified direct drive variant of the Wasp engine known as the S3H1-GMD. Basically an S3H1-G without the reduction gears, this engine gave a 30 percent increase in static thrust, but during early development flying it was found to be excessively noisy, and all production aircraft were fitted with the standard geared S1H1-G Wasp. The second prototype VH-CEB (c/n CA28-2), which was based on the airframe of Wirraway A20-697, completed type testing and these two aircraft were delivered to Airfarm Associates Pty Ltd of Tamworth, NSW and Proctors Rural Services of Alexandria, VIC in 1959.

The first production machine VH-CEC (c/n CA28-3) was followed by 18 production aircraft, a total of 20 being built. Although 21 construction numbers were allotted, the prototype (c/n CA28-1), after crashing at Seymour, VIC in March 1961 and being rebuilt as a new aircraft VH-CEX (c/n CA28-18), received a new construction or airframe number.

Six Ceres were exported to New Zealand and most of these were operated by Aerial Farming Ltd and Cookson’s Airspread Ltd. The main problem with the short production number was that potential customers were under-capitalised and could not raise the necessary funds to purchase new aircraft at the time, the production line being closed in July 1963.

Three variants were produced: the Ceres A with the direct drive engine; the Ceres B with the geared engine and a de Havilland-built Hamilton propeller; and the Ceres C with a ‘high solidity’ propeller and an enlarged cockpit to allow the carriage of a plant operator. The type was successful in its intended role and a few survived in operational service up to the 1970s when they were replaced by new purpose-built designs.

One ZK-BPU (c/n CA28-4) has been placed on display in the collection of the Museum of Transport and Technology at Auckland (MOTAT); and ZK-BZO (c/n CA28-9) has been held in the collection of the Silverstream Aeronautical Society in the Hutt Valley.

Two have survived in Australia, VH-SSF (c/n CA28-13), which was flown occasionally at Blayney, NSW, being part of the collection of historic aircraft at Historic Aircraft Restoration Society (HARS) at Albion Park, NSW. VH-SSY (c/n CA28-10) was on display at Airworld at Wangaratta, VIC for some time until that museum closed and the aircraft was sold to a private collector. A few others have been used in the restoration of Wirraways to airworthiness. VH-WOT has been rebuilt to display standard by the Australian National Aviation Museum at Moorabbin, VIC.

Operators of the type in Australia have included Super Spread Aviation of Moorabbin; Coondair Pty Ltd of Tintinara, SA; Airland Pty Ltd of Cootamundra, NSW which operated three (VH-WOT, VH-WAX and VH-WHY); Airfarm Associates of Tamworth, NSW; Blayney Air Farmers of Blayney, NSW; Marshalls Spreading Service Pty Ltd of Albury, NSW; and Doggett Aviation & Engineering of Jandakot, WA.

Ceres built have included: VH-CED (c/n CA28-4) which became ZK-BPU in December 1959; VH-CEF (c/n CA28-5) which registration was not taken up, the aircraft becoming VH-SSZ in 1959 and VH-CDO in 1964; VH-CEG (c/n CA28-6) which continued in service until 1985, despite hitting trees and crashing at Glen Innes, NSW on 6 April 1974; VH-CEH (c/n CA28-28-7) which became ZK-BXW in August 1960; VH-CEI (c/n CA28-8) which became ZK-BXY in September 1960; VH-CEK (c/n CA28-10) which became VH-SSY in December 1960; VH-CEL (c/n CA28-9) which became ZK-BZO in February 1961 and which crashed near Pahiatua Track on 17 January 1972; VH-CEM (c/n CA28-11) which became ZK-BSQ in March 1961; and VH-CEN (c/n CA28-12) which became ZK-BVS in March 1961.

VH-CEO (c/n CA28-13), which became VH-SSF in April 1963, remained in service until 31 January 1978 when it crashed at Carcoar, NSW; being rebuilt and, as noted above, being part of the HARS collection at Albion Park. VH-CEP (c/n CA28-14), which became VH-DAT in November 1961, ended up at TVW-7 television station in Perth, WA. VH-CEQ (c/n CA28-15), which became VH-WAX in March 1961, was badly damaged on 18 April 1966 during agricultural operations.

VH-CER (c/n CA28-16) crashed at Weule, NSW on 2 March 1967; VH-CET (c/n CA28-17), which became VH-WHY in March 1963, crashed at Cootamundra on 17 February 1970; VH-CEU (c/n CA28-19), which registration was not taken up and became VH-WOT, crashed near Mittagong, NSW on 28 May 1974; VH-CEV (c/n CA28-20) hit power lines and crashed at Inverell, NSW on 10 January 1975; VH-WEX (c/n CA28-18) which in February 1963 became VH-SSV; and VH-CEW (c/n 21) operated through to March 1978 when it was withdrawn from service.