Brian Cooper reviews the Graupner kit - 30/1/12
There can’t be many people who haven’t heard of the Harvard. Conceived in the 1930s, it was used extensively during W.W.II as an advanced trainer to prepare pilots for combat aircraft, and was considered ideal for the role because its flying characteristics required a light hand on the controls. If a pilot could handle a Harvard, it was said, he was ready for anything!
Graupner’s kit is based on #44, the Harvard II pylon racer which at one stage in its career laid claim to having won every national championship event held for its class at least once. #44’s R-1340 engine also hauled her to three speed records for closed-course pylon racing, clocking over 222mph around Reno’s five-mile course in 1981 - not bad for an aircraft with a Vne of 205mph! Unfortunately, the famous redhead is no more. She was destroyed during a low-level aerobatics display after rolling into the Niagra River. Which leaves us with Graupner’s kit - an eighth-scale ARTF (almost ready to fly) complete with retracts and racing livery.
The kit’s UK distributor, Motors and Rotors, has translated Graupner’s German instructions into English, and together with the accompanying diagrams these make the construction sequence very easy to follow. To make matters even easier, every last nut, bolt and linkage is included in the kit.
That’s not to say the building process was niggle-free, mind. However, solving the hitches encountered during construction wouldn’t be beyond the wit of anyone who already has a model or two under their belt. That’s not to say a number of areas required more attention than might have been expected. The hinges, for example, weren’t glued in securely (though to be fair, the instructions did suggest checking them carefully), but the joints themselves were glued-up. In the end, I scrapped the original hinges and fitted new ones from the vast selection in my accessories box.
Wing construction follows the traditional built-up route using sheeted leading edge, trailing edge, and centre-section with a substantial dihedral brace joining the two panels. The wings went together very well with both panels lining up nicely against their opposing root rib. That said, the retracts needed some additional fettling as wheels were coming into contact with the upper surface of the wheel well before the gear was locked. The answer was to shim the retracts at the mounting position, in order to alter the operating angles, so that the gear could go up, down, and lock.
The fuselage comes out of the box ready made, of course, and seems to be fairly well put together, making good use of lightweight plastic fairings - the neatly faired control pushrods are a particularly pleasing touch. But - and you knew there was going to be a ‘but’ - as with most ARTFs the tank bay needed a coat of fuel-proofer.
Marrying up wing and fuselage called for a little adjustment to the wing retaining former to close up the odd gap and get everything into line. By comparison, assembling the tail was relatively straightforward, requiring a small section of the covering to be trimmed back before gluing up, and bolting on the steerable tail wheel.
Graupner provides a two-piece engine mount, although I found that the retaining bolts were too long, and would have punctured the fuel tank if I’d used them as supplied. While I was shortening them, I made their receiving nuts captive on the tank bay side of the firewall, which keeps the whole installation neat and tidy. Attention to detail is the name of the game with this kit.
Although the model is designed for four-stroke engines of up to .56 cu. in., I elected to fit an O.S. 70 Surpass, mounted sidewinder style. Why? Well, a smaller and lighter engine would have put the C of G too far back resulting in a necessity to carry ballast up front. So, rather than hauling dead weight around, it made sense to use a bigger engine. The choice of the O.S. 70 was arrived at by installing the radio gear and then hanging ballast off the front end until the C of G came forward to the right spot. It was then simply a matter of finding an engine whose weight corresponded to the ballast, and the Surpass fitted the bill. Alright, so it’s a little over the top capacity-wise, but this is a racer!
With the engine in place, the fibreglass cowling can be trimmed to fit and screwed to its mountings. By the way, the latter also deserve a bit of close attention. On the review kit, I found it necessary to adopt a belt-and-braces approach by screwing as well as gluing them to the bulkhead. Moving on, the clear plastic canopy is well-made and only needs a very slight amount of trimming and painting (I used trim tape for ease and lightness) before being screwed in place. I decided not to use the pilot figure supplied with kit: the moulded halves don’t align terribly well, and besides, there are all those little pots of paint to buy. Instead, I simply bought a ready-painted figure and put that in.
TIME TO FLY
Being an old campaigner, the O.S. engine was already run in and set up, and with range and flying control checks completed there didn’t seem any reason not to get some daylight under old #44’s wheels.
As the Harvard taxied out, the wind was gusting 12 - 15mph - not too strong, but it was bumpy with it. Even so, it didn’t upset the aircraft as she accelerated down the runway and began her climb-out, raising her gear on the way. A definite retrim was needed to get the nose up and settle her on an even keel (maybe that O.S. was a little too much after all!), but otherwise the controls were smooth and well-balanced, with the model responding positively to the least input.
While setting up the aircraft, I had thought that the control throws looked pitifully tame. In practice, however, they proved to be perfect for a model of this type: the roll rate, elevator, and rudder response were all adequate, and she’ll even fly knife edge if you ask nicely! Initially, inverted flying required a lot of forward stick to counter-act that nose-heaviness, but shifting the C of G rearward cured this, and sharpened up the controls even more.
It was during these early flights that I discovered the problem with the engine cowling mountings: one broke away and severed the fuel line, which meant bringing the Harvard in on dead-stick. Now, this is no glider - the frontal area is pretty large, and speed bleeds off quite quickly. Remember too that although model has to be flying very slowly indeed before it stalls, when it does stall the left wing drops quite dramatically. So, don’t try stretching the glide on your approaches! That said, landing with the power on is very easy.
Just drop the wheels, line her up and drive her in with a touch of throttle until she’s about to touch down. As the wheels kiss the ground, throttle back to a slow idle and flair out for a greasy landing.
With her red and white racing livery, ol’ 44 looks fabulous beating up the field at low level, but does this Reno racer live up to her name? Well, yes and no. While she’s not over-powered, having the 70 up front certainly gives her purpose without provoking any outright misbehaviour. It’s obvious that the model’s enjoying it, too: she’ll do all the usual aerobatic manoeuvres without giving you any heart-stopping moments; stall turns look good; and she spins well in any direction. This is a scale aircraft with sports model handling - so much so that once she’s in the air it’s easy to forgive all those niggles in the construction phase. Great fun!
Wing area: 540 sq. in (3.76 sq. ft)
Wing loading: 23.5 oz / sq. ft
Fuselage length: 43''
All-up weight: 5.5 lbs
Rec’d engine range: .46 two-stroke or .56 four-stroke
Engine used: O.S. 70 Surpass
Prop used: 12 x 8 Master airscrew
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