Design. Yes, it is quite recognizable DaVinci - modest, but of high quality, and in some places - even with some pretensions to originality. From the first glance it is clear that we do not see a reverent ultralight product, but rather a work horse - a heavyweight. The free ends are made of wide tape, with powerful iron in the form of connectors and trimmer buckles, tucked into a fairly thick neoprene. The slings are just like the ends - thick and, naturally, braided. The fender pleases the eye with bright colors of rather thick and durable skatex. The lines in the leading edge are not very long, but they are pretty stiff and interestingly configured: each line has about equal length on the upper and lower surface of the wing. Apparently, due to this the cunning Koreans managed to avoid any mylar reinforcements of air intakes (which is more typical for lighter equipment) - the front edge of the Duet is very rigid and well stretched even without it, promising quick filling and easy takeoff. The huge intakes are nicely rounded - similar to some of the Evans Bibets - but the Duet's wing shape is undoubtedly original. Surprised by a simple but unusual solution to remove debris from the last sections of the "ears" - ripstop-reinforced notches that are valves themselves.
Launch. Weakly depends on the flight weight (flew in the range of flight weights from about 160 to 220 kg). In a calm and weak wind the plane goes perfectly - easily, but not too sharply, it is very well fixed in the flight position. I was even able to lift the wing with my body only, without even touching the front rows with my hands. This is very cool for a tandem!
Controllability. This is probably my most positive impression of the wing. In my tandem rating for maneuverability this unit is now in second place with a very small margin over the Sup'Air Sora. The winglets are light, with flight weight of 160-180 kg it's no harder to control than a single-seat wing. No backlash, which is surprising for a tandem. Brake response starts from the first centimeters of travel. At the same time full brake travel is very big, as it usually is with tandems.
On turns the machine is not inclined to roll at once, it likes flat spirals, but at the same time it enters a turn surprisingly fast. The turning radius is adjustable with the brakes, you can always make it a little steeper if needed, and if you work sharply with your hands - the wing can even bend a little concerning the suspensions. Such behavior is more typical for single-seat wings, and maneuverable enough even by the standards of single-seat technique.
It is possible to roll the Duet if you want, but you have to do it purposefully, it won't roll on its own, because it is very well damped. But if you ask the machine properly, it can perform good vingovers. I like the wingovers most with a moderate weight in flight (up to about 180 kg) - the brake is not too heavy yet, but the reaction of the rig is very good. With a heavy passenger (flight weight 220 kg) the Duo goes into a roll more readily, but the load on the arms is not so pleasant.
Pitch damping was very impressive. The Duo seems to be one of the most damped tandems I know. It becomes noticeable already at the start, when the machine literally "hangs" overhead, not trying to either fall forward or fall backward. In flight, it is not so easy to pitch the Duo - it stands on your head almost like a fit, and both the pilot and the passengers are pleased with it. You can't say that the Duet can't feel the air around it, which has already started to wake up little by little from its winter hibernation. Changes in the brakes are very informative. When entering thermal "bubbles" the unit "swallows" them with its intakes, slightly crunching the fabric, barely moving in pitch and noticeably changing airspeed. There is also a fair amount of information coming to the hanger points, but not so much that the unit scares the passenger even when the weather is brisk.
Landing. Had no problems throughout the entire range of flight weights tested. "The cushion is very effective, even a heavy passenger can be "lapped" to the ground with almost zero speed in no wind (although I was not used to it, but it's a matter of getting used to the wing).
Conclusions. The general impression is that the DaVinci turned out an excellent tandem for commercial use. Great take off, great landing, very high pitch damping, all this is very much in demand especially for commercial flights. I really like the response of the wingtip, and again, I can hardly see any competition to the Duo in this respect. On the whole, the Duet does not look like an obscure product of an unknown company - on the contrary, it feels like a serious product, which was fine-tuned for a long time and very carefully. I can confidently recommend the Duo as a commercial tandem. That's not to say it's bad for any other use case - just that it's hard for me to evaluate all aspects of this wing's behavior so far. But on the whole I like it very much!
- Very good low wind takeoff, one of the best I've seen in tandems
- Very good landing behaviour
- Outstanding maneuverability
- Not found
Thanks to Rinat Sabitov and DaVinci Gliders for providing the glider for the tests.
Photo: I.Tarasova, A.Tarasov