Photograph:
Jonker Sailplanes JS-3 Rapture VH-VJS4 (c/n 03-001) (Jonker Sailplanes)
Country of origin:
South Africa
Description:
High-performance 15 metre class glider with jet sustainer engine
Power Plant:
One M & D Flugzeugbau MD-TJ42 turbojet
Specifications:
Fuselage length: 6.86 m (22 ft 6 in)
Fuselage height: 1.22 m (4 ft)
Wing area: 8.75 m² (94.28 sq ft)
Wing loading min: 40 kg/m² (8.2 lb/sq ft)
Wing loading max: 60 kg/m² (12.3 lb/sq ft)
Empty weight without engine: 250 kg (579 lb)
Empty weight with engine: 280 kg (617 lb)
Max weight without ballast water: 415 kg (915 lb)
Max weight: 525 kg (1,157 lb)
History:
The JS-3 Rapture was one of a series of high performance gliders built in South Africa by Jonker Sailplanes, the first model being the JS-1, the prototype of which flew for the first time on 12 December 2006. The Company immediately became known as a builder of world-class sailplanes. Development of the series continued and subsequently ten years later the JS-3 with a jet sustainer engine was flown.
Jonker Sailplanes commenced with a team of three engineers and three technicians, and over the years this increased to 16 engineers and 110 employees, the Company facility being based at Potchefstroom in north-west South Africa, working in conjunction with M & D Flugzeugbau in Germany. More than 100 sailplanes have been delivered, with the JS-1 being available with 18 metre and 21 metre wings, and the JS-3 built for the 15 metre class, the latter being a completely new model with a new fuselage, cockpit and modified wing.
The glider was fitted with a retractable full FADEC MD-TJ42 jet engine for sustained flight, this being a single spool jet turbine with a two-stage axial-centrifugal stator-less compressor with a compression ratio of 1:3.8, and a cannular combustor with multiple fuel injectors and combustion zones contained within a single annulus casing. It had an idle speed of 30,000 rpm with a thrust of 3 daN, a maximum rotary speed of 97,000 rpm, a max thrust of 35 daN (42 kg) at sea level, and a max fuel consumption of 60 kg (132 lb) per hour. The engine weighed 3.3 kg (7.27 lb) and was 400 mm (15.7 in) long and 150 mm (5.9 in) in diameter
In early 2016 the Company decided to produce the JS-3 for the World Gliding Championships held at Benalla, VIC and the first aircraft was completed in December that year. The tailwheel was made retractable and the water tanks were placed forward and aft of the main spar, thus allowing the aircraft to meet the 525 kg (1,157 lb) weight stipulated for competition.
A number of examples of the JS-1 and JS-3 have been registered in Australasia, examples of the JS-3 including ZK-GXB (c/n 03-015) to JS Sailplanes Ltd of Tauranga on 6 April 2018; VH-VJS4 (c/n 03-001) registered on 22 December 2016; VH-XUJ (c/n 03-002) also registered on that date; and VH-XBE (c/n 03-017) registered in Armidale, NSW on 22 June 2018.