Jonker Sailplanes Celebrates Maiden Flight of JS2 Revenant
Updated: May 2
In March 2021, Jonker Sailplanes in South Africa unveiled their new self-launching airframe, the JS2 Revenant, during a livestream event. This was the first known livestreamed maiden flight ever.
The Revenant is billed as “a high-performance, versatile, easy-to-fly self-launcher! The name Revenant was inspired from the French verb Revenir, meaning “to return.” The JS1-C (a previous airframe) is now making a return with an amazing powerful self-launching system!”
Some Notable Features
1. The energy probes are placed on the T-tail-design horizontal stabilizer to avoid being in the prop wash when the engine is running in flight.
2. It has a steerable tail wheel, something that should prove quite useful on landing and during ground operations.
3.Retractable landing gear
“It took a long time to develop this aircraft. The focus of this project was a bit sidetracked when we decided to enter the competition market; first with the JS1, the JS1C Open Class, and the JS3." And now, Uys Jonker says, "finally we come back and we launch the self-launching JS2, which we expect to be a very, very good performing open class machine with self-launching capabilities.”
“What is amazing about this aircraft is it weighs less than 400kg without fuel. So you can even have a min wing loading of 41kg/m2 and a max wing loading of 58.8 kg/m2," reports Jonker.
One of the cockpit features are the spring-loaded pins that raise the canopy a small amount to allow for ground cooling – once the cockpit cools, the springs will retract and allow for a very flush fit of the canopy against the fuselage. Another utilitarian feature is a new flexible conduit underneath the instrument panel that keeps wiring protected and out of the way of the pilot's legs. The engine pylon controls are quite simple with an “extend/retract“ rocker switch, an override switch, and a “run” switch. The throttle control is on the left-hand side near the flap and spoiler handle. All of the best of Jonker technology - and it comes with a gray and red interior.
The first test flight took place later in the day with the planned release altitude of 2500 above ground level (agl). The flight performance tests included slow flight and handling maneuvers – avoiding stalls until a later date. During launch and throughout much of the flight, some formation flying was accomplished in order to take some photos and video to commemorate the achievement. At that time of day, “we basically have the skies to ourselves,” said Uys.
Final checks: canopy locked, belts fastened, ready, all out!
Takeoff was a three-ship formation with the tow plane leading and the photo ship flying off the left wing of the glider. During the climb, Uys set up the glider for 120km/h and showed that it was trimmed for hands-off flying. “It feels brilliant! The controls are unbelievably soft,” he exclaimed." He also noted the rudder control forces are so light compared to the JS3. Once the landing gear is retracted, the noise level is reduced dramatically – even while on tow. Uys put the glider through a series of turns - testing the roll rate and control feel. “It feels so light [the controls]. You think and then it happens.”
“We are extremely excited and we are extremely happy.” Uys Jonker CBO and Chief Test Pilot.
In a YouTube reaction video, competition sailplane pilot, Stefan Langer, swooned over the new design. “That’s so cool to have a livestream for the first test flight. I love it.”
The maiden self-launch test flight was accomplished several days later, during the first week of April 2021; again, with Uys Jonker at the controls. The start procedure was pretty simple: engine master on, extend the engine, clear prop, hit start button. The Revenent climbed skyward as though it was in its natural habitat.
The team at Stick and Glider wish to congratulate the Jonker Sailplane Team on a beautiful glider and a series of safe first flights!