Art-Tech Pitts – Part Two

In Part one of this review we looked at the build process for the Art-Tech Pitts, so let’s move on and examine how she flew. Although windy and miserable weather was awaiting, the Pitts was carefully loaded into the car and off I went. At the field and with my frequency clear, I powered up both Tx and model only to find the ailerons were quite a way from neutral; further than the trim could help out, so it was off with the wings to get at the servo. Five minutes later, and one servo output spline further around, the ailerons were as straight as could be. The rudder and elevator looked okay – although there didn’t seem to be all that much movement – and the ‘thrust’ didn’t inspire much confidence when the throttle was raised.

A quick check on the ‘E’ meter revealed a 10A draw at full throttle with a minimum voltage of 10.9V. This produced 110W of power, throwing the supplied prop around at 5,100rpm; not exactly 3D potential, but plenty for its intended use. And at only 10A current draw I wouldn’t be pushing the batteries hard at all.

When the rain finally gave in for a bit I ventured out with a helper to see if we could ROG the little model. A slight push at full chat and she was off, veering up and to the right at an alarming rate. She felt tail heavy and I had to hold in a lot of down elevator to stop the nose from pointing up, even with full down trim on the Tx. She then settled down nicely under low power, and the quickly-arranged landing proved a complete non-event.

Back in the pits (excuse the pun), I wound the elevator linkage in quite a few turns to where I thought I’d been holding the stick to keep her level. I also moved the linkage for the rudder to the innermost hole to see if any more reaction could be teased from the left stick.

Off she rolled down the runway again, but this time the lift-off was perfect in every way and she climbed out only when requested from the right stick. Now that the controls were sorted I began to explore the flight characteristics. Normal circuits were almost hands-off and inverted flight was pretty easy, although the roll rate was painfully slow. The rudder was now proving more helpful at the ‘quarter’ stages, keeping the nose from dropping.

Vertical performance soon ran out but loops could be made big enough, and general flying was great. The colour scheme is superb even in a dull sky, and the wind didn’t affect the model as much as I’d feared. The slow speed handling was excellent, and I would almost go as far as to say a complete beginner might even make a good show of it in the park. I’ll have to hand the box over to such a victim and see what he makes of it.

The next trip to the field was on a very windy day… 25mph+! Whilst walking the final few hundred yards to the patch I realised that I’d forgotten the Tx supplied with the model, but fortunately my JR PCM10X was by my side. No problem, thought I, I’ll just programme it into the memory. After all, it is 35MHz. Of course, nothings quite as easy as all that and, as it was, I had to switch channel one and three on the receiver to match JR’s configuration. Having done that I then had trouble getting positive communication between the Rx and Tx. With a synthesized module in the Tx I set it to the channel marked on the Rx Xtal (70 in this case) and selected PPM, but still nothing moved when the sticks were waggled. Rats. After this I tried SPCM, ZPCM, channels 69 and 71 but all to no avail.

With the channels unmatched there was severe glitching and nothing even remotely useful. I even tried some single and dual conversion Rx Xtals… still no joy. Eventually, I gave up on the supplied receiver and used a spare that I carry with me. All the control problems then disappeared but one of the aileron clevises had snapped, most likely due to the out-of-control glitching experienced earlier. With a spare suitably swiped from a model that was grounded for other reasons, we were ready to go.

Out to the runway for a photo shoot, where she was proving difficult to keep on the ground as it was so windy! Desperate to commit to any form of flight at this stage I raised the throttle and got her up where she belonged. Flying on the small amounts of travel I’d set up was interesting (to say the least!) but the Pitts was flying pretty well. Loops ended up very elongated and rolls were static, but great fun. Inverted went well for a while and the landing was a very pretty parachute, vertically down from about one hundred feet with a ground speed of zero! The excellent slow speed handling helped out again and the flight of just over ten minutes had only taken around half the juice out of the battery.

DIDN’T SHE DO WELL?
So, what’s the verdict? I reckon this little Pitts is a cracker. It really is a model you could pick up from the shop and have ready to fly before the battery was even charged! I do feel that the instructions should be a lot more idiot-proof than they are, considering the kind of market the model is aimed at. The radio has proved very reliable and I don’t recall suffering any glitching, but I wasn’t impressed to find that it was incompatible with the rest of my gear. The servos are on the budget side and produce even more noise than the motor! The clevises are pretty weak and one gave way after just one flight. That said, the battery is easily up to the job, although it can’t be removed from the fuselage to charge it, which goes against everything I know about Li-Po safety. And nowhere does the manual tell you to remove the battery from the model when charging it, either!

She’s a good size to just chuck in the car for a trip to the field, and she looks very pretty from all angles. This one will definitely see plenty of airtime! The flying characteristics made up for the gripes mentioned here, but I fear a lot of people might never get the chance to really enjoy the model if they don’t have the experience to overcome the difficulties I encountered.