Hobby Lobby Intl. PBY Catalina Flight performance

The instructions did not recommend a CG position or control throws. Because the Catalina is somewhat short-coupled, I placed the CG at 25 percent MAC, which comes out to 2 1/8 inches from the LE. I used my JR X783 radio to set the control throws as follows: elevator, /- 3/8 in.; aileron, 3/8 in; rudder 5/8 in. I then set the dual rates so that I'd be able to reduce these in flight if necessary.

Because of their low current draw, it's common to wire S400 twins in parallel, and the PBY uses this scheme. After talking with Jim Martin at Hobby Lobby, I decided to use eight cells instead of the suggested seven. Experience has shown that this is a better setup for the 7.2V motors, provided the current is kept below 10 amps. Another option is to wire the motors in series and use 16-600AE cells (provided you use a 16cell controller), and I also tested this setup. Both power schemes worked very well.

Takeoff and landing

As recommended, the flights were made by hand-launching the Cat and belly landing it in the grass. With its low wing loading, the PBY was easy to hand-launch, and it climbed away with power to spare. I'd recommend getting an assistant to handle the launches until it's trimmed out, but solo launches are not a problem.

Landings are made with a straight-in approach. Keep the speed up during the turn on to final and then cut power, making a slightly steeper approach than normal. Just fly it down and hold it a foot or two off the ground until it settles in, Landings are slow and predictable, and the props and motors are well protected high on the parasol wing.

I haven't yet been able to try the PBY off water. The kit includes clear butyrate plastic that you can use to make a set of side boards for the hull. These are supposed to help keep water spray out of the prop arcs and get the plane up on step more quickly. Jim Martin suggested flying the Cat without mounting the tip floats on extended struts, it seems the floats tend to catch on the waves and "water-loop" the plane. The best bet is to carefully balance the wing so that the plane sits level at rest. To take off, advance power slowly. As speed builds up. use the ailerons to hold the wing level. and avoid making excessive rudder inputs. The P-boat should pop up on the step and accelerate to takeoff speed.

High-speed performance

I once had the pleasure of talking with an old PBY driver, and he told me the plane pretty much cruised at 100mph, red-lined at 105 and landed at 95. He was. of course, exaggerating a little, but the PBY was one slow machine, This model is certainly faster than scale, with top speed around 40mph, but that's hardly the point of this type of model. At full power, it's crisp and responsive. and it penetrates wind better than I expected.

LOW-speed performance

Cruise is where the PBY shines. A 1/23-scale model isn't going to fly at true scale speeds, but it looks very nice at 2/3 throttle. Be forewarned: this is a small, shortcoupled model, and it will tip-stall. During a turn at low altitude, the PBY snapped without warning, and at that height, recovery was not possible. Damage to the airframe was moderate, and the plane was quickly repaired. The lesson learned is that while this model flies well and looks beautiful in the air, it will snap if a turn is attempted at low speed. I got my best results keeping the speed up (say 2/3 to 3/4 throttle) during turns. You can safely reduce power clear back to idle in level flight (I like to make gliding, power-off, strafing runs), but be sure to apply power before climbing out or turning. Aerobatics

I prefer to fly my planes in a scale-like fashion, and I restricted the PBY to steep turns and split-S's. I'd avoid high-G maneuvers, since the wing mount wasn't designed to take unlimited loads. Spin recovery is not automatic; you'll have to apply opposite rudder to stop the spin and ease it back to level flight; abrupt pullouts will pop it right back into a spin. The plane is responsive and will look great flying figure-8s low over the water. All in all, it's a very pretty model in flight.