Design
Omitting rapturous epithets about the quality of tailoring and trendy this season colors, I will focus on the main thing. It is clearly seen that, creating Hook4, Niviuk took a course on simplicity and technology. The device does not shake hi-tech, but it is made well and accurately, as befits a wing of a famous manufacturer. However, close examination shows that everything is not so simple...
The loose ends let you know at a glance who the Hook4 is designed for. A wide, fairly thick powerband — but rather intricate kinematics of an acceleration system with two bearing blocks and a soft, slippery dyneema sling. At first glance, it looks simple and even brutal — but a closer look reveals details that point to a certain ambition inherent in the design. Almost a training wing, but not quite... The brake handles are standard for Niviuk, quite large and comfortable.
The sling develops and enhances the first impression. The lower tier slings are quite thick, braided — but there are surprisingly few (A2A'1B3C2). Three rows, and a rather ambitious one at that. The third A-row could have been eliminated, of course, but Niviuk seems to have left it in so novice pilots could work comfortably with the "ears". In the upper tiers, the sling begins to branch not only in breadth, but also in chord, so we see a pseudo-three-row. But there are still very few slings, and in the upper tiers, we use splinterless slings. Logically arising fears about entanglement and other difficulties with the start do not apply to Hook - the slings are short enough, so there are no problems with the prelaunch preparation and lifting of the wing.
The wing itself. Yes, baby, it's a Niviuk! The nicely branded shape of the wing nicely hints that our test subject is a blood relative of sporty Pikes and Icepicks. Hook's shape, however, doesn't look aggressive; it's more likely to create a sense of confidence in the wing in advance - which, by the way, will be confirmed in practice later. The lengthening of our prototype is quite reasonable for a modern "after school" wing - 5.4. There are quite a lot of sections (52), but the air intakes are quite large, interestingly shaped, with small roundings on the lower edge.
The rigid elements in the front edge are present, of course, but if they make something shark-noise-like, you can see it only under the microscope. But what are these elements made of! This is not some humble lawnmower line, like some pathetic Ozon, but real, hardcore nitinol. That is, an alloy of titanium and nickel. It looks pretty humble on the outside, a little wire and a little wire less than a millimeter thick. But Nitinol is one of the very few shape memory alloys. Nitinol parts can, under certain temperature influences, "remember" the shape they took before. That is, at least in theory it is possible to restore the shape of the nitinol rods if they inadvertently lose the shape given by the designer. High-tech is such that it cannot go any further!
The rest of the design is the same as all first tier manufacturers, give or take. There is a pronounced 3D cut, thanks to which the wing has a very smooth front chord. Another interesting detail is the abundance of internal longitudinal ties, unusual for an airplane with an elongation of less than 6. We managed to count as many as 6 ties on the centerplane! The back edge is generously stuffed with additional seminervous (however, Niviuk did not risk to stuff there also lines, as on sports craft) and riffles when you clamp the brakes. The reefing is really simple - just short horizontal braces, to the centers of which steering lines are attached. No eyelets, no rings. But the simpler solution in aviation is the better. The color design is typical Niviuk, it looks surprisingly good on any sized wing.
Lift, work with the wing on the ground
Naughty spring did not let me to make a test-drive, so my first acquaintance with Huk IV was limited to land flying in strong and very gusty wind. And the machine immediately showed his nature in all its completeness. Good-natured, a little slower in its reactions, but completely devoid of guile and unpredictability, somehow. Naturally, my perception of the wing was influenced by its large area, but I honestly tried to take a correction for the size of the subject. The Hook4 comes out very calm, smooth and even. It has no tendency to go forward, even in difficult weather and if the pilot makes a serious mistake, you should expect it to be under-endangered, rather than flying over the pilot's head. This does not mean you have to drag the wing with your hands to the flying position, it works fine but it does require the pilot to clearly indicate his intentions and encourage a small amount of A-racing up to the full overhead. If you fly the Hook4 with just the nose and not even touching the A-risers, it will still fly slowly and with a lot of fatigue, but it will reach its flight attitude. Hook4 doesn't require much attention, much less the use of overclockers when starting from the winch, it's easy and understandable, just a little less dynamic than some other EN B-labeled machines
The Hook4 plays games with climbing through the roll and touching the ground with its "ear" well and convincingly. A certain amount of wiggle room in the brakes and weights ensures that the pilot and the wing understand each other and do not get in each other's way. Even on the ground, the Hook4 is very docile and does exactly what the pilot asks of it. All in all, I liked it!
Flight
Simplicity, comfort and tranquility. This is the first emotion that the Hook4 evokes from the pilot hovering underneath it, and this impression only gets stronger later on.
Futility. Clearly wasn't a top priority in the creation of this Hook, but overall everything is on a very decent level. The Hook's strength is its aerodynamic quality — and it's pleasing even on the first stage of the gas pedal. In terms of horizontal speed, the Hook doesn't shine, but it doesn't lag behind market demands, either. Speed increase on the first step of gas pedal is about 7-8 km/h, on the second one - about 10-12. With a sensible loading it corresponds to the maximum speed of about 50 km/h, quite decent figure. On the second stage of the gas pedal Hook quality noticeably - and quite expectedly - decreases, but the glide on the first stage is able to please even connoisseurs of more advanced equipment. Deceleration speed with moderate loading pleasantly pleases, allowing confidently flounder in the weak and torn evening streams. It's pleasant, too, that Hook is not inclined to "crumble" when narrowing the spiral, it floats quite convincingly in rolls up to 30-40 degrees. On aggregate merits we can give it a four-plus on a five-point scale.
Maneuverability. Perhaps the most tricky part of this test drive for me. Even with the ballast I couldn't load the machine more than halfway up the fork, which of course had an impact on the reaction of the wing. Perhaps it's best to call Hook's reactions balanced. There's no harshness, sharpness, or crispness, but there's no deliberate loading either, which is typical for many school gliders. Hook responds to the pilot calmly, a little slower, but very accurately. Just what you need for the after school pilot. The machine listens to the pilot quite well, but is still quite capable of forgiving piloting mistakes. Spiral behavior has no peculiarities in a wide range of roll angles and rotation speeds, when you give your hand and weight to the machine, it just smoothly speeds up the rotation, that's all. And the Hook smoothly flattens out the spiral as the control action decreases. Everything happens calmly, comfortably, transparently to the pilot. This is true of both vingovers and steep spirals. Sure, you can't put Hook "on the knife" with one brake and body move, but it's reasonable to pay for smooth and clear Hook's reactions.
Convenience and information value. Lots of comfort, plenty of information value. Perhaps, it is comfort that impresses Hook the most. Hook is very calm in roll and does not make any significant pitch or roll movements. It is interesting, that despite its relatively small elongation, Hook4, like its "big brothers" in the line, is inclined to "flap its ears" a little. A peculiarity, which is surprising considering the abundance of inner ties typical for Hook, but it does not create problems with safety and does not strain a pilot. Perhaps, such "waving of the ears" can even be recorded in aspects of informativeness. Hook's brakes are nicely loaded, and they don't tend to change much in flight. That is, there is some information value in the brakes, but it is rather sparing. Tip information is very much dependent on suspension, but Hook has more of it than brakes. In total, it's enough for relaxed and not too deep studying of the first route thermals. For a more accurate and bright dialogue with the air you will need a sharper and sharper tool. But it's comfortable!
Dynamics and power capacity. Unexpectedly good. However, this trick is familiar to me from some other wings, including Niviuk wings. The Hook4 can accumulate quite a lot of energy (you can tell from its good aerodynamic quality), but the speed to altitude transitions are comfortable and slow, typical of after-school wings. A couple of times I deliberately sent Hook into a "candle" with a vigorous exit from a wingover or spiral, and in response the unit only slightly subsided in the upper point of the trajectory, to then smoothly slide down, unhurriedly translating height into speed. Dashing swoop-style prelanding maneuvers on the Hook, if possible, are only possible with a very high load, which I could not provide during the test drive.
Dangerous Flight Modes
Asymmetric folding
Simple and comfortable, but with features that do not affect safety. It's physically very hard to induce folding — it looks like 80 percent of the Hook's entire load "hangs" on the front rows. It's even tougher to fold more than 50% of his wingspan and 15-20% of his chord. Hook with all its might resists strange actions of the pilot, but unlike other machines with a very loaded front chord, is not prone to "explosive" deployment, dangerous by its unpredictability. The hook makes very small movements with a big flat part of the wing, which is totally atypical for intermediates, but very normal for competitors! Each swing is a few open sections. The result is that in some of these strokes the whole wing unfolds, and it is quite smooth and clear, without any tricky jerks. Roll angle in this mode does not exceed 45 degrees, pitch deflection - up to 90 degrees, no more. The loss of altitude is, however, slightly above average, due to the leisurely nature of the opening, up to 10 meters.
Asymmetric folding at full speed
Occurs more dynamically, that is all. The angles of rolls and deviations do not change noticeably, but it takes less time to get out of the mode than without the gas pedal.
Frontal folding
Even more difficult to produce than "asymmetry". It opens quickly, with a pronounced roll of small amplitude, without "wiggling of the ears". It takes quite a long time to gain speed after the flip.
Breakout from a thermal spiral
This develops very smoothly and unhurriedly, but involves a very large proportion of the cantilevered arm span. There is no "ear" undercutting, the arm goes to the breakdown almost entirely. The fall of the load on the inner arm is somewhat below average. The device warns you about the beginning of the disruption mainly by the increase in the angular velocity of rotation. The release of the inner arm is momentary with a short, unexpectedly energetic splash and a very quick climb rate.
Rapid Descent Modes
"Ears."
Classic! Folds over the highlighted A'-rows without much effort, prone to slight "sticking". Very stable, no tendency for the wing to open randomly, no tendency for the ears to bump up as a result of turbulence. Unless the pilot wants to, the ears will not unfold. A couple of small weight movements or one short movement of both brakes is enough to open them. The rate of descent in the mode is low, less than 3 m/s.
"Ears" Accelerator
Differs from "ears" without a gas pedal only by a slightly higher rate of descent (-3...-3.5 m/s).
Steep Helix
I didn't bring it down to more than -10 m/s (for it is hardly necessary for typical Hook owner). The -10m/sec reduction spiral is simple and comfortable, the unit does not tend to accelerate sharply or increase sensitivity to pilot's actions abnormally. The exit occurs very smoothly, attempts to force it are not too effective, it is better to give the apparatus one or two more turns of the spiral.
Conclusions
Low specific load made the test drive a little bit more difficult, but it hardly distorted the true character of our test piece. I have no doubt, that in the whole range of the manufacturer recommended flight weights Hook4 is a simple and calm wing, created for comfortable and safe teaching its owner how to soar and make routes. You shouldn't expect great flyability from Hook, but it's more than enough for all the aforementioned training and sport tasks, plus there's a nice bonus in the form of high quality on the first stage of gas pedal. At low specific load, the Hook is very good on a flat terrain - it soars convincingly, perfectly filters chatter, and it's not a problem that its steering response is not great. If somebody needs "same Hook, but sharper" - I can recommend overloading at the top of the fork or even slight overloading. Safety margin of Hook allows it, and I think that high loading could make Hook very interesting for mountain flying, where sharper wing reactions to pilot's actions are desirable. What is the minimum flight time required? Approximately 5 hours, but no more. And you have to be clear, the Hook4 was not designed as a training machine. Nivic has an even simpler wing, the Koyot3, for basic training.
Pros of
- A calm, comfortable feel
- Relatively high quality on the first stage of the gas pedal
Cons
- Not found
Features
- Specific nature of the disclosure of asymmetrical folds
I express my gratitude to Niviuk dealers in Russia Tatyana Noskova and Vitaly Miroshnik for providing the wing for the tests.
Photo: I. Tarasova