The Jonker dream became a reality on 12 December 2006 when Jonker Sailplanes first product, the JS1 Revelation with 18m wingspan, flew its maiden flight. The JS1, designed with incorporated aspects such as aerodynamics, structures and pilot comfort, has rapidly gained world recognition with its great performance and handling characteristics.

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 fin tanks.

The JS-21 not only displays good gliding ratio at moderate speeds but also at high speeds and maintains its outstanding climbing performance.

In 2014 the 18m “EVO” upgrade was introduced, improving the performance of the 18m version and also resulted in an increased roll rate with remarkable low speed behaviour.  The increased wing loading, combined with new tip aerofoils and 3rd generation winglets, gives the JS1C-18 EVO the edge at high speeds.  JS1C-18 EVO offers the serious competition pilot a performance advantage while remaining suitable for every pilot due to its handling qualities.

The JS1-18 has proven its performance by winning a national championship in each country it’s been sold.  During the 2016 and 2017 Sailplane Grand Prix Final the JS1-EVO took top honours, and during the 34th World Gliding Championship in Benalla, the JS1 18-EVO, flown by Killian Walbrou, won the 18m Class.

The JS1-21 has also proven its popularity during the 2017 WGC in Benalla with 23 out of 35 competitors flying JS1 in the Open Class.  Seven of the first 10 places were held by JS1 Pilots with Russell Cheetham and Andy Davis taking the gold and bronze medals respectively.


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.

JS1 Revelation with LX9000 and LX stick remote control

JS1 Revelation with ClearNav