Design
A good modern tandem. The design of the wing can be described as "neutral", a pleasant shape, no special features, elongation and number of sections are reasonable for a tandem. The coloring is a little bit aesthetical. Naturally there are lines, which became a de facto standard. The lines are thick, as it should be for tandem, because nobody chases volatility in this class of equipment, but durability and longevity are very important for tandem (especially for commercial one). Loose ends correspond to Joint's philosophy - no frills, but good quality, reliable and pleasant. Although the ends have their own zest: the minus-trimmers are equipped with huge plastic balls to make it easier to release and clamp.
Launch
Coupled with the landing is probably the main characteristic of any tandem. And the Joint did not let us down. But objectively we should notice, that this tandem's start is not without its own peculiarity. Personally I always want at the tandem start to work with the front rows as much as possible - in fact there can't be any confidence that the passenger will run in quality and load the wing. In the case of the winch start the situation is not much better, if at all. But it's surprisingly easy to pass the A-risers and break the leading edge of the Joint (this only applies to the start!). But if you believe in the machine, and moderately load A-risers, and calmly and without unnecessary efforts start moving forward, everything goes great. Climbing is unhurried, smooth, reliable, very predictable and controlled. No sinking or popping, just precise and smooth glider movement to the exact position over the pilot's head. Strong tandem pilots with inflated arms should be very careful about controlling efforts of their arms, but for less physically powerful tandem pilots (and tandem lady pilots ;) ) such launch will be just fine.
Flight
Flying. Is it so important? to "break through" against the wind and to hover in the thermals - that's what any tandem should be able to do. But tandems for cross-country flights are a different story. However, JDC flies very well, there's nothing to reproach it. And within the tandem test drive, the most interesting things are the rate of descent and the effectiveness of the minus-trimmers. The Joynt's thermal turn is quite effective, and it is quite capable of turning without a big increase in descent when the radius is narrowed. Of course, the speed of descent depends on the weight of the passenger, but in general the Joint is at least no worse than other tandems I know. Probably even better! The efficiency of the minus-trimmers is average: the plane certainly speeds up, but I wouldn't expect the Joint to do wonders in terms of maximum horizontal speed. Normal, period.
Maneuverability. That's where the Joint is interesting. You don't see any exceptional sharpness of reactions (and you don't need it), but you have a high precision of response to the work of your hands, which is a little unusual for a tandem. However, the Joint's turn is a very "skywalk" turn. It is easy to dose and smooth and comfortable increase in sensitivity of the wing to hand travel is maintained within the whole range of brake strokes available to the pilot. There are no complicated transitions - the glider just follows the hand, that's all. This unusual for tandem combination of quiet reactions and precision I understood not from the first flight, but when I understood it I understood at once why the tandem masters from Kamenka paradrome liked Joint so much. When flying in tandem it's very important to feel constant control over the situation - and the turn of Joint is exactly what gives this feeling. Unfortunately we didn't manage to soar in thermals, but this imitation of thermal spiral was no less exciting than usual turns. At a low speed the Joint retains its quiet precision and responsiveness to the brakes. I would venture to guess that as far as work in flows, Joint3 is one of the easiest and most understandable tandems I know. Quite calm reaction of the JDC to work with your arms should not confuse lovers of spirals and wing-overs, as JDC3 does them correctly if you ask it correctly. The calm nature of the Joint does not tolerate a too rough and abrupt control - it simply will not do anything. But if you feel the calm rhythm of Joint's movements and start to act in phase with him, the result will be great. The wingovers are perfectly controlled and you can get to a 90 degree roll, if not more, with just 3 or 4 strokes. However, a lot depends on passenger weight - a lightly loaded Joint has less loaded brakes, which makes piloting easier, but gives you less dynamic maneuvers. With a heavy passenger you can feel comfortable with an increased load on arms - and then a vigorous wing-over is achievable with only 2-3 moves. Moderate speed loss on the wingover leads to "warning" sag of leading edge - the case does not come to folding, wires in the leading edge save, and even inexperienced tandem pilot is able to understand his error by such "bell". The case with a steep spiral is about the same. You don't have to count on a fast entry mode, but you get superb control over the machine. The calm nature of the Joint allows for a brutal exit from the spiral in one turn - the resulting pecking does not lead to folding.
Comfort and information value. Joynt's comfort is first-rate. The machine reacts to chattering in the same way as it does to steering - calmly and therefore pleasantly. Smooth and lengthened movements of the wing are informative enough to find and center the airflow. Joynt's informativeness is more or less the same on all available channels - I mean pitch, airspeed changes and hand load. When entering the kernel, the unit gently "fluffs up", smoothly going back and losing speed slightly. The load on the brakes changes just as smoothly and delicately. Falling out of the kernel is accompanied by no less smooth accelerating roll of small amplitude. During the test drive we did not manage to catch any strong or even moderate turbulence in the air, so I can only assume that in strong conditions the Joint is likely to maintain a comfortable behavior.
Dynamics and power capacity. It's an old, tried-and-true approach: if the machine can store a lot of energy, it's better to let it happen smoothly. The power capacity of our test subject is obviously higher than average for tandems, but already mentioned quiet character allows "smearing" the changes of speed and altitude in time and space and smoothing them out. The most indicative in this respect are the vingovers and steep spirals. I have already written that everything is fine, you just have to act calmly, not to force the modes. It's perfect for jittery passengers: you can gently, carefully increase speeds and angles, carefully watching the passenger's reaction, and, if necessary, just as smoothly and gently return to normal flight.
Landing. The fact that the power capacity of the Joint is somewhat high leads you to expect that it may be difficult to bring your speed down to a minimum before touching the ground, but fortunately this is not a problem for the Joint. What helps is the high efficiency of the brakes near stall. I tried a couple of times to land with brakes applied at the height less than 2 meters - at these situations the machine will be able to stall at full throttle and ground speed is very low even at no wind. Approach with brakes tucked is very convincing - a good way to simplify prelanding maneuvering for limited landing sites - but the landing "cushion" will be less effective with this style of approach. With a slight overdrive near the ground and the following vigorous braking, the passenger is very likely to be able to stay on his or her feet - which is not the case with every tandem.
Conclusion
One should always consider tandems through the prism of their application. "Commercial" tandems must first of all start and land flawlessly. Tandems for occasional riding of friends and acquaintances should not make too strict demands to their piloting technique. "Sport-route" tandems - exotic, of course - should have flying ability sufficient for route flying. What's the best thing the Joint3 is good for? Launch is good plus. Landing is great. It's calm and undemanding to the pilot. And it flies quite well. In short, a kind of "universal soldier", a tandem of wide application without obvious weaknesses. Besides, it's very pleasant. No obvious disadvantages of our tandem were revealed, and advantages of our figurant are quite obvious even for a pilot, who is not experienced in tandem comparisons.
Advantages of
- Excellent positioning
- Relatively low dependence of behaviour on flight weight
Cons
- Not found
Features
- Easily breaks the leading edge on takeoff when overloading the A-risers
My thanks to Sergey Shelenkov for providing me with a glider for testing, as well as for his help in organizing the test drive.
Photo: A.Tarasov