JS1C - 21

In 2012 Jonker Sailplanes penetrated the Open Class market with the introduction of the 21m version of the JS1. The outboard wing and wing-wingtip junction was redesigned to accommodate the higher wing loads and a higher maximum take-off mass of 720kg [1587 lb] (increased from 600kg). The 21m wingtips have integral water ballast tanks with a capacity of 17 litres [4.5 gallons US ] each with cockpit control allowing the pilot to jettison the wingtip water ballast separately to the main wing and tail fin tanks.
The JS1C-21 not only displays an excellent glide ratio at moderate speeds, but also at high speeds and maintains its outstanding climbing performance.
It has proven its popularity during the 2017 WGC in Benalla with 23 out of 35 competitors flying the JS1C in the Open Class. Seven of the first 10 places were claimed by JS1 pilots with Russell Cheetham and Andy Davis taking the gold and bronze medals respectively.

Wing Area 12.25 m² / 131.86 ft2
Aspect Ratio 35.9
Fuselage Length 7.052 m / 23.14 ft
Fuselage Height 1.32 m / 4.33 ft
Empty Weight without Engine 330 kg / 728 lbs
Maximum Weight 720 kg / 1587 lbs
Wing Loading (min) (70kg pilot) 32.6 kg/m² / 6.68 lb/ft2
Wing Loading (max) 58.7 kg/m² / 12.02 lb/ft2


Jonker Sailplanes aims to provide competitive market pricing selling at the OEM’s recommended sales price. Instrument & avionics installation is included in the standard specification (excluding installation of transponder and ELT, or customer supplied instruments).

A 15% handling fee will be added for instruments supplied by customers. This fee is based on the OEM or equivalent recommended list prices.

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