Photograph:
The prototype PL-7 at Bankstown, NSW in 1962 after being damaged in a hangar fire (David C Eyre)
Country of origin:
Australia
Description:
Single-seat agricultural biplane
Power Plant:
One 306 kw (410 hp) Armstrong Siddeley Cheetah X seven-cylinder radial air-cooled engine
Specifications:
- Wingspan [upper]: 12.46 m (40 ft 9½ in)
- Wingspa [lower]: 9.14 m (30 ft)
- Length: 7.46 m (24 ft 6 in)
- Height: 3.65 m (12 ft)
- Wing area: 37.62 m² (405 sq ft)
- Max speed at sea level: 204 km/h (127 mph)
- Cruising speed: 180 km/h (112 mph)
- Operating speed: 113 km/h (70 mph)
- Landing speed: 56 km/h (35 mph)
- Rate of climb: 226 m/min (740 ft/min)
- Service ceiling: 3,901 m (12,800 ft)
- Cruising range: 547 km (340 miles)
- Empty weight: 1,007 kg (2,220 lb)
- Payload: 992 kg (2,186 lb)
- Loaded weight: 2,268 kg (5,000 lb)
History:
In 1954 the need was seen by Kingsford Smith Aviation Services Pty Ltd of Bankstown, NSW for a large, high powered, agricultural aircraft of simple construction to replace the de Havilland Tiger Moth then in widespread use. The Italian born designer, Luigi Pellarini, who also designed the Fawcett 120, Victa R.2, Transavia Airtruk etc, designed the PL-2 Tanker, this being a large biplane of unequal span, of un-conventional design, fitted with a tricycle undercarriage and powered by an Armstrong Siddeley Cheetah 10 engine, this engine being available in some numbers following the retirement of the Avro Anson from military service. Construction of the prototype (the only aircraft built) began in March 1955 at Bankstown and it was completed 18-months later.
The prototype, for which no registration appears to have been allotted, was rolled out in September 1956 and taxiing trials commenced on the 19th of that month, the aircraft becoming airborne for about 274 m (900 ft) at that time. First official flight was made on 20 September and was to be a short hop but the pilot stated, when the aircraft was in the air, it handled so well he continued and made a circuit of Bankstown at 183 m (600 ft).
The forward section of the fuselage consisted of a 1.27 m³ (45 cub ft) mild steel tank forming a hopper and carrying all main loads. The exit chute was under the lower wing section. The lower mainplanes had full-span copper spray-booms built into the trailing edges with provision for a number of standard spray nozzles. The upper wings, which were supported by a single lift strut, were attached to a gulled centre-section supported by streamline struts. The fabric covered steel tube tail unit was carried in two tubular steel booms projecting rearwards from the upper wing section and were braced to the fuselage. Twin-fins and rudders, on which were carried the tailplane, were attached at their midpoints to the boom. All control cables from the cockpit to the tail were carried externally along the booms and supports.
The aircraft carried out a test flight programme. Visibility in level flight ahead and below was said to be poor but good in other directions. Controls were heavy but well balanced and the Tanker was regularly looped and spun during the program. A stall resulted in no more than a gently dropped starboard wing. When first flown it had an enclosed cockpit but the canopy was discarded after some little time.
However, it would seem due to lack of interest by local agricultural operators, the lack of appeal of the design to some, the limited market for an agricultural aircraft at the time, and the availability of overseas designs, Kingsford Smith Aviation Services did not proceed any further with development and testing, and the aircraft was stored at Bankstown until damaged by a hangar fire. In 1962 it was removed from the hangar and was later scrapped. It never received a Certificate of Airworthiness and at no time carried a registration. During its brief career it was painted overall yellow with black trim, with the words “Experimental” and “P.L.7 TANKER” painted on the side of the fuselage.