It’s time for the third and final part of this Gas Bobcat 52 review; if you missed them, be sure to look back at Parts One and Two.
Whilst awaiting a decent slot in the awful winter weather, I supplemented the supplied decals with some stars and bars, my club name and a few other scraps of self-adhesive ‘bling’, created by those helpful chaps at rcgraphics.co.uk.
As the weekend approached, Friday evening saw more gales and rain over the entire country and I was none too optimistic when loading the car. Arriving to meet Andy Ellison at the Skunkworks early on Saturday morning, unbelievably, the sun had just peeked through a nasty black foreboding sky. Not wishing to miss the opportunity we loaded up and headed straight for Andy’s local flying field.
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On arrival I couldn’t lay my hands on an 11 x 7″ pusher prop, so an 11 x 6 was fitted and with the engine fired up and duly adjusted… the rain arrived with vengeance! Marvellous. Shoving the Bobcat unceremoniously beneath the club caravan we stepped inside and fired up the kettle instead. Fortunately, we only had to wait half an hour before we were able to wipe the moisture from the model and get the engine restarted.
With Bobcat poised on the runway I opened the tap and she shot down the strip, hit a lucky bump, and was off like a smelly sock, climbing out at 45 degrees in less than 30 metres. This, I hasten to add, took us both by surprise. No worries, I pushed the nose down and heeled her over, throttling back a shade to check trims. Nothing required! Not a click of anything was needed, in fact the model remained arrow straight and felt distinctly perky, although certainly not in the Magnum or turbine class as far as speed was concerned, but no slouch nonetheless; in truth we reckon it does about 100mph, or perhaps a little more.
Flipping her inverted I noted that little in the way of elevator compensation was necessary, although as the flight progressed and the tank emptied I decided that a sniff of ballast up front would do no harm on the next sortie. I like to feel my aeroplanes when downside up! Anyway, that aside the Bobcat flew perfectly and had a respectable vertical performance with four or five rolls easily achieved before the speed decayed. All this excitement was followed by a reversal, neatly converted into a four-pointer down the strip, and that into a further climb at the far end, another reversal, and so on for a good few minutes.
Eventually, of course, landing became a priority, at which point I put in a couple of dummy passes for the camera then dropped her in, mid strip, to end an excellent drama-free test flight.
Two more sorties were enjoyed that day, during which the Bobcat proved impeccable, showing no nasty traits whatsoever. Four ounces of lead were added up front and I also reduced both elevator and aileron throws from the initial (generous) settings. With this, rolls remained crisp and axial, requiring just a smidgen of down elevator during the inverted phase, with vertical performance arrow straight, always. Knife-edge flight needs very little rudder, large inputs having the effect of rolling the model upright if aileron compensation wasn’t invoked. Not a problem and indeed, something that a programmable mix could address. Four pointers are lovely and, all in all, this model looks the business in the air. One club member said how super the Bobcat looked as he drove up to the patch, but was just a little disappointed when he opened the car door and heard the howling two-stroke. Ah well, at least the flight pattern suggested ‘turbine’ and that’s the point – jet flight behaviour for a tenth of the cost, although I should say that folks are already bolting small Wrens to the back of these, albeit with a few mods to make the model suitable!
Although the Bobcat’s performance is perfectly adequate on a J’EN 56, proving reasonably quick if flown smoothly, the one big drawback of any pusher is the dearth of propellers. Choices are limited and props cost more, although the solution could be a reverse timed engine running the other way, which then puts all the tractor airscrews on the market at your disposal.
A quick call to Alan Greenfield at Weston UK produced one option, a Weston P55 based special with a mini pipe and a reverse timed crank. The J’EN pushes that 11 x 6 around at a respectable rate but the West 55 and pipe will provide twice the horsepower on a perfectly matched prop, giving the Bobcat the performance of a 90 without the weight penalty – nice!
So, the bottom line then: nice model; great paintwork; reasonable covering job; good structural integrity; average instructions and hardware. As far as the flying performance is concerned, put the centre of gravity smack on 10 inches from the leading edge of the wing with an empty tank and all will be well, then adjust to suit your flying style once airborne.
The Bobcat would be better with retracts (faster too!) and better still with a turbine for motive power. However, for simplicity and rough club field use it’s perfect as is and will give anyone an enjoyable fly. Aileron response is crisp without falling into the ‘strewth’ category and the whole thing looks posh and very shiny standing in the pits. This one is a definite attention grabber, either in the good old stars and bars livery of red white and blue (as here), or in the very pretty yellow option. Oh, and there’s talk of a grey and orange one too.