Model Tech

It was only a matter of time, I suppose, before somebody hit the market with a proper electric powered 'traditional' trainer. Wilson Li at YT International has always had a bit of the visionary about him and his Model Tech range is well known for its high quality and low price. So it comes as no surprise that when the mainstream electric trainer did come along, YT International were behind it.

The Fledgling (not to be confused with Flair's Fledgling glider) is pretty good as trainers go. No EPP, Elapor or Gunther props in sight. Lightly built but using good quality materials it's presented in an ARTF package that's priced to suit the novice flier opting to avoid the i.c. route. It even has the look of a traditional trainer. Spanning 55" (1410mm) and 41" (1040mm) long with a high set wing and simple flat tail surfaces, it's around the size of some comparable 0.40 powered models.

WEIGHT WATCHERS
The Fledglings built up construction is achieved with significant weight reduction in mind, indicating that despite all the ground electric power has made up on i.c. flight just recently, it's just not quite there yet. In fact, the finished all-up weight of under 3 lbs strips no less than 2 lbs off similar glow-powered variants!

Packaged with its own direct drive Speed 600 brushed motor and intended for 7-cell NiCad or NiMH power packs, the kit is clearly designed to get novices into the air as quickly and as cheaply as possible. Is it good for beginners? Well, on the face of it I'd have to say yes. Although there is one niggle where I feel the model lets itself down and that is directly related to the dramatic weight reduction. It just doesn't feel very robust! Yes, the quality of the build is excellent but you can't ignore how light and fragile the individual parts feel. Even the covering film feels about half the thickness of the usual stuff and it's easily marked throughout the build process, no matter how careful you are. Up to a point, trainers are supposed to be chunky bricks capable of taking some serious abuse especially during learning to land, but I really don't think the Fledgling has that. Of course, less weight carries less inertia and less likelihood of damage in the first place. Anyway, fact is, a great deal of work has been put into the factory end of the building operation to achieve the substantial weight reduction, indeed the plethora of lightening holes removes even the smallest bit of balsa wood that looks as though it might not have a truly useful purpose. Just look at the ailerons for example.

It doesn't end here either, the obsession with weight loss continues right down to the choice of flimsy undercarriage wire and even the slight wire pushrods. It's fair to say that no corners have been cut to strip unnecessary grams from the basic airframe, and as a general concession to weight loss we find that the model is designed for standard radio gear. What's more, the supplied motor, despite being well up to the job, is heavy and somewhat bulky. It's cheap though, and there's no need to spend silly money on a brushless speed controller or tiny micro servos.

Now, although the model is supplied with the aforementioned heavy lump, plus its own prop and driver, YT International do offer an unbadged brushless outrunner upgrade that's suitable for 3s Li-Po packs. This, of course, brings the weight down even further and is the variant I used here. That said, some changes are needed in the installation to shift the balance point forwards with the lighter kit up front. I just about achieved the rearmost centre of gravity position with the FlightPower 3s1p 3700mAh battery pack stuffed right into the nose, instead of being housed in the purpose built battery bay. That's a thumping big battery pack though, capable of delivering up to 50C!

HICCUP
Battery location aside, a far more serious problem arises when fitting the brushless motor, one that would stall most novices when throwing a model together for the first time. In short, one has to fabricate a completely new plywood bulkhead from scratch in order to mount it.

There's no mention of this in the instructions which is a shame, since otherwise they rate as the best I'd ever experienced from any model I've put together. ARTF or otherwise. They truly are exemplary and many a bigger, more expensive kit manufacturer could learn a lot here. I would have thought YT might have supplied an alternative bulkhead with their upgrade package, which would seem to have been in keeping with the philosophy of the rest of the kit. Alas, in its absence, the photos will give you the gist of the modification.

QUICK AS A FLASH
With assembly underway the model fair rips together and follows a common build process of wings joined over a chunky dihedral brace, cyano' wick type hinges and flat plate tail feathers stuck into pre-cut slots. The use of a tail dragger undercarriage speeds the process but fitting the optional steerable tail wheel instead, slows it down again! Use the alternative fixed tail skid and you could have the whole thing together in an hour. No, really!

Since the captive nuts align perfectly with the pre-drilled wing bolt holes, and the tail fits straight as a die with no trimming required, the parts of the build which can often subliminally soak away the hours, take no time at all. I did have a little gripe about the cyano' affecting the coloured covering film adhesive in the locality of the hinges, as it seems to affect the coloured film adhesive. This wouldn't normally be a problem except that the Fledgling is covered in translucent film and you can see every little mark under the surface. You might spot it more noticeably on the Rudder hinge line.

Radio installation is quite quick but be aware that the wooden plate which cries out for the receiver to be mounted atop it, is in such a position that a decision to do so will certainly clash with the centrally mounted single wing servo.

At just 1.5mm the rather mediocre threaded pushrods dictate that you're pretty much tied to using the plastic clevices supplied. Be aware that the fit of these still feels very loose on the threads and when I was satisfied with the pushrod lengths I kicked a drop of cyano' over them to make sure they didn't easily part company.

The wing is retained by two small steel bolts and whilst this is not the best idea on a trainer it is very clean. The small heads won't offer much resistance to ripping through the wings though, and the bolts are barely long enough to reach the captive nuts on the retaining plate within the fuselage.

BUSINESS END
Up at the business end the standard can motor supplied is retained by a number of metal straps and fits nicely into the front of the fuselage with the wires exiting to the rear into a large bay which will easily accommodate a variety of speed controller sizes. With this particular motor fitted the batteries would be housed underneath the wing, fastened to the underside of what I earlier described as the receiver mounting plate. Incidentally, there is a removable floor to this bay to facilitate battery changes, i.e. without removing the wing each and every time.

Go the lighter, brushless outrunner route however and once you're over the hurdle of the bulkhead fabrication, you'll find that the battery bay is useless to you and your pack will need shoving right into the nose to balance the model.

Incidentally, my chosen (rather sizeable) Li-Po pack could still be removed via the battery bay, but only just. Opting for a Castle Creations 35A speed controller this was mounted in the receiver bay where I attached it to the side of the fuselage. Now, you might suspect that cooling could become an issue here, but with the YT set up a good 10 minutes of full power thrashing about puts barely any heat into the set up. On the 10 x 5" propeller, current draw at full power is just 23.14 amps peak (240 watts) so it's hardly a hot-liner and at this low draw that big FlightPower battery should last forever! Flight times are certainly adequately long for two or three on one charge.

Model Tech Fledgling
FLIGHT OF THE FLEDGLING
Arriving at the field I was rather disappointed to find that the grass was a little too wet to cut, so it seemed highly likely that we might have to give her a chuck if she wasn't up to an ROG (roll off ground). As expected, those spindly legs tried their best but just couldn't stop the big motor from pulling her nose into the dirt. Accordingly it would have to be a hand-launch for the first attempt, whilst making a mental note to rake the legs forwards a bit.

Being trainer an' all I decided to perform the launch myself and was genuinely taken aback by the performance - she shot skywards like a homesick angel. No shortage of power here then!

Now, I could bleat on for a few hundred words about how she flies nice left and right hand circuits, but to be honest it would be pointless. Look, she flies very well. In fact I was surprised at just how well. The Fledgling is supposed to be a trainer though and if you've got this far you either work for YT and you want to know if I've slated your baby, or you're genuinely interested in how it goes.

On the whole the model goes where you point it. The small amount of dihedral is not going to allow it to roll back to upright if you get her out of sorts but she's stable enough through the turns to help heavy thumbed novices.

The elevator is very crisp and at the recommended throws, arguably a little sharp for a beginner. The light weight of the model with the powerhouse in front made it easy to fly consecutive square loops with very sharp corners. It's not twitchy in pitch with the CG at the back end of the range but the elevator control feels 'snappy', if you know what I mean. Conversely, the ailerons feel sluggish, which on a trainer is often a good thing. They aren't dead by any means but do feel unbalanced compared to the relative sensitivity of the back end. Look at them though. They're small. The result is that a typical full aileron roll might take anything up to 3 seconds, dependant on airspeed. Rudder control is fairly benign and quite soft. Whilst there's ample to steer the little Fledgeling around on the deck she's still quite tricky to get into a spin. You can do it if you keep some power on but back this off and straight away the model drops into a spiral dive. Inverted spins stay put for longer but the Fledgling does fall out eventually. Stall turns test your timing as there's little or no bite from the rudder over the top. A blip of power helps but you're not going to be blasting this one around in knife-edge I can tell you!

As I've established, the outrunner motor has plenty of grunt and the power is delivered smoothly throughout the throttle range. The model has the feel of being powered by a decent 0.32 glow motor yet it's not unnecessarily overpowered. Since the airframe is fairly slippery I found it much better to turn off the ESC brake as the stationary prop does nothing to slow her down on finals. A windmilling disc makes the model much easier to bring and she'll alight easily despite her bendy knees.

Of supreme importance for beginners, orientation has not been a problem despite the similarities between the colour scheme on the top and underside. Positioning the large decal over the red portion of the wing helps and in the sunshine the colours are quite vibrant, the yellow leading edge yelling 'THIS WAY UP' even at distance. The white tips are also subliminally conspicuous and that aspect of the scheme is well thought out.

TOP NOTCH TRAINER
All in all the model is more than capable of taking a pilot through the BMFA 'A' certificate and it's just as capable of taking them through the 'B' certificate, too! When you have an aeroplane that can do rolling loops and bunt for Britain you have to question whether or not it would be suitable for a novice, but I find myself thinking that it is. Not, perhaps, if you want to learn in the field at the back of your house on your own, but certainly under the infrastructure of a club or on a buddy box system with your mate. The only test for the model would be in its long time hardiness. Itís light and considerably more flimsy than an i.c. powered trainer and I think this might ultimately be its undoing. Thereís enough power in reserve to permit the model a bit of additional weight in certain areas, and simple band-on wings would doubtless prevent much of the damage usually demonstrated at the hands of novice fliers.