Jonker sails to a century

It all started with a boyhood dream to build the world’s best glider – now brothers, Attie and Uys Jonker of Jonker Sailplanes, celebrate a century of engineering and aerodynamic excellence.
When these Potchefstroomers, together with Johan Bosman, realised their dream of building their first JS1 racing sailplane 10 years ago, they never would’ve thought they would reach another historic landmark so quickly.
On 4 February 2015, Jonker Sailplanes celebrated the launch of their 100th sailplane with a glamorous and glitzy function at the Roots Lifestyle Centre in Potchefstroom, which attracted a host of media, local and national dignitaries and sailplane owners, to name just a few.
The JS1 is one of the world’s most sought-after sailplanes, which has produced numerous world champion results through its high-tech design and groundbreaking aerodynamics.
The JS1 started as a glider in the 18-metre class and then made a successful jump to the open class with a 21-metre wingspan.
This marvelous machine could be seen firsthand through a spectacular airshow, where the sailplanes glided and swerved in the air like a majestic bird taking flight in its natural habitat – breathtaking is a word that comes to mind.
The detailed and progressive journey of the JS1 was then told from start to finish as well as the unveiling of further developments for the groundbreaking team of Jonker Sailplanes.
“It is absolutely unbelievable. It is almost unreal to be sitting in the 100th JS1. My personal highlight was when we test-flew the first JS1 in 2006. As far as international competitions go, the JS1 also achieved 4 out of 6 podium positions during the World Championships in 2014,” said Uys.
10-times world gliding champion, Sebastian Kawa of Poland was also at the event and expressed his gratitude to the Jonker brothers for their impeccable work ethic and innovation in racing aircraft. “In the near future, we plan to extend our product lines to approximately 50 aircraft a year. The next model will be an upgrade on the JS1 with pilots having the ability to take off on their own power,” added Uys.
“I believe that the JS1 has the certain edge, not only to compete but to beat the best in the world for years to come,” said Attie.
Technical data JS1:
Wing Area: 12,25 m
Aspect ratio: 36
Max Weight: 720 kg
Best glide speed: 120 km/h
Rough air speed: 203 km/h
Jet engine fully fueled: 40 kg
R.P.M.: 75 000