Country of origin:

Australia

Description:

Agricultural monoplane

Power Plant:

One Textron Lycoming 298 kw (400 hp) IO-720-D1BD eight-cylinder horizontally-opposed air-cooled engine

Specifications:

History:

To meet customer requirement, Transavia continued with further development of the basic Airtruk, and this led to the Model T-320 Airtruk fitted with the Rolls Royce/Continental Tiara 6-320-2B engine producing 239 kw (320 hp).  Production of this model began in October 1976, and several were assembled in New Zealand by Flight Engineering Ltd but, after eighteen months, production of this engine ceased. The T-320 had an empty weight of 816 kg (1,800 lb) and a loaded weight of 1,855 kg (4,090 lb).

Transavia then selected the Lycoming IO-540 series engine of 224 kw (300 hp) as a replacement.  Fitted with the IO-540-K1A5 engine, the new model became known as the T-300 Skyfarmer.  This model was certified in Australia for a max take-off weight in the agricultural role of 1,925 kg (4,244 lb), lifting 953 kg (2,101 lb), but in some parts of the world lifting 1,179 kg (2,599 lb).  Max dry hopper load was 907 kg (2,000 lb) or 818 litres (180 Imp gals) of liquid.

The basic airframe was stressed to +3.8 and –2 G, and was built around a one-tonne capacity hopper.  It could spread up to a 30 metre (98 ft 5 in) swathe of liquid or solid payload, and could deliver up to 450 litres (90 Imp gal) per minute in the spraying role.  Transavia’s Powermist system only absorbed two percent of the power available.  The Skyfarmer had an empty weight of 907 kg (2,000 lb), a loaded weight of 1,855 kg (4,090 lb) and a maximum speed of 206 km/h (128 mph).  Computer studies by the CSIRO revealed the spraying swathe of the PL-12 series was twice as wide as that of a conventional aircraft adapted for agricultural work.

In June 1981 the improved Skyfarmer T-300A was flown to and displayed at the Paris Air Show.  Significant changes included an expansion of the cabin structure to provide a larger, roomier cockpit and hopper throat, new aerodynamically balanced ailerons, horn balanced elevators, and electro-mechanical flaps to reduce the workload of the pilot.

The T-400A SkyFarmer was developed by Transavia as a trainer for China, production of this model commencing in early 1986.  The first mock-up of this model was based on the prototype utility aircraft VH-TRM (c/n 1043).  Four were purchased by the Australian Government following Australian certification on 23 December 1985, a new certificate of airworthiness over the T-300 being required because of the marked alterations to the design.  These four aircraft were donated under the Australian Aid Programme to China and were used to train crews in agricultural operations, instructors being trained at Cudal, NSW.

The prototype T-400 was badly damaged during the pilot conversion course following a heavy landing and had to be rebuilt.  The mock-up of the two-seat trainer was built and went to the Heilongjiang Province in south-east China.  At that time plans were being considered to build the SkyFarmer in China.  The T-400 first flew in September 1984 with a 224 kw (300 hp) IO-540-K1A5 engine with a Hartzell three-blade propeller, the 298 kw (400 hp) Lycoming IO-720-DIBD unit being installed and flown a month later. The T-400 series had a 50% larger stub-wing, a new Hartzell propeller, a 76.2 cm (30 in) extension to the booms to improve effectiveness of the control surfaces, and carried an extra 299 kg (660 lb) load.  It also had electric flaps and trimmer, and a re-designed undercarriage.  US Certification was received in June 1987 in a ceremony at Sydney’s Randwick Racecourse.

Studies at one stage led to the design of the PL-12 MIL with a gross weight of 2,722 kg (6,000 lb) aimed at producing a COIN aircraft with provision for armament, this having four underwing hard-points capable of carrying 7.62 mm machine guns on each, or rocket launchers, or light bombs, the pod fuselage providing ample accommodation for a rear gunner.  This design could also be used as an aerial ambulance, freighter, medium-range patrol, or forward control aircraft.  In the ambulance role the PL-12/N300 could accommodate two stretchers and an attendant in addition to the pilot.  A mock-up of this variant was built, displayed at the Bicentennial Airshow at Richmond, NSW in 1988 and shown to a number of interested organisations.  A number of countries also indicated interest in this model for border-patrol work, but this variant did not enter production. The mock-up was retained and placed on display at the Australian Aviation Museum at Bankstown, NSW.  Its fate is not known following the closure of the museum in 2019.

A turboprop variant known as the PL-12-550T was also offered, powered by a 410 kw (550 shp) Pratt & Whitney Canada PT-6A or Allison 250-C30 (Soloy conversion) turboprop, with a larger propeller.  This variant, also referred to as the Scorpion in its military role, if built, would have had a wing area of 26.38 m² (284 sq ft), a length overall of 8.15 m (26 ft 9 in), a maximum take-off weight of 2,903 kg (6,400 lb), and a maximum level speed of 222 km/h (138 mph).  The turbine powered aircraft was expected to have a 1.98 m³ (70 cub ft) hopper and be capable of carrying 2,087 kg (4,600 lb) but was also not placed into production.

Accurate figures of production are not available but some 118 examples of all models are believed to have been completed, of which 80 were for export.