My son and I are thinking of getting the P38 and we would like to know what you would recommend we purchase along with it?

I have flown gas rc before, but neither one of us has had any experiance with electric planes. Additionally, I did not build them... but I have built and flown U control planes.

From : Don Stackhouse

My first and most important bit of advice would be to try to find someone near you who is experienced with this class of models, to show you how to avoid the common pitfalls. There is no point in forcing yourself to repeat the same mistakes the rest of us have already made!

You don't mention what sort of "gas rc" it was or how much experience you had with it. Depending on specifically what sort of experience you and your son have, the P-38 may or may not be suitable for you. It is definitely not a trainer plane. Depending on your experience, you might do better with our Curtiss Junior or Piper J-3 Cub, both are somewhat easier to build, have more detailed instructions, are more durable and more forgiving in flight than the P-38.

For nearly all of the Roadkill Series models we recommend similar radio equipment. You'll need a radio with at least three channels, and the radio gear for the airplane needs to be what's referred to as "ultra-micro". You'll need a receiver in the 5-9 gram weight range, such as the GWS GWR-4P "Pico", or for flying around lots of other radios (such as with a club) or in an otherwise hostile RF environment (one with lots of radio interference), we've had excellent results with the FMA M-5 receiver.

You will need two servos in the 6-gram size class such as the GWS "Pico" or the Hitec HS-50.

You will need an electronic speed controller or "ESC" (it acts as a throttle for the motor, and also converts some of the electricity from the motor battery to power the radio). In our experience, by far the best choice in this size range is the Castle Creations Pixie 7-P.

You will need a battery. Until recently the dominant technology for these was Nickel-Metal Hydride ("NiMH"). We still sell these, and the appropriate chargers for them. For a single motor model like the Junior or the Cub we recommend a 7-cell pack of 110 milliamp-hour ("mah") cells to save weight. For outdoor flying, we recommend a 7-cell pack of 230 mah cells. This larger option is also the same pack we recommend for the P-38. The Sirius 200 charger is ideal for both of these batteries.

Recently some new Lithium-polymer cells have become available that are the right size and have the right electrical characteristics for our Roadkill Series models. These offer huge increases in capacity and/or substantial reductions in weight in comparison to NiMH cells. There are some safety concerns, particularly the possibility for fires if they are overcharged. The key here seems to be having a proper charger for them. From what we've heard, the folks who have had fires were either using the wrong type of charger (such as trying to charge them with a NiCad or a NiMH charger), or were charging with an older charger with the wrong settings (such as trying to charge a two-cell pack with a charger that was set for three cells). The new chargers have circuitry that checks to see what the characteristics of the battery are and whether they match the charger's settings before allowing the charge cycle to start. This error-checking isn't 100% perfect, but it seems to be close to that, and between that and a little diligence on your part (a good thing to have when doing ANYTHING involving flying machines of any kind!) the risks are minimal.

We've heard reports of some new Li-poly cells coming out soon from Kokam that sound promising. However, the very best Li-poly batteries for our models that we've actually tested to date are made by E-tec, and these are the ones we sell through our website. For the single-motor models like the Cub and Junior we recommend a 2-cell pack of 250 mah cells. This gives nearly the same power at full throttle as the 110 mah NiMH cells, weighs a full half an ounce less than the 110 mah NiMH cells (VERY significant on a model that light) and has more capacity than the 230 mah NiMH cells. Flight times are so long that there generally is no need to recharge during a flying session.

For twin-motor models such as the P-38, or our new Ryan ST with its MPS-2A (a two-motor gearbox driving a single prop), the best battery we've tested is the E-tec 2-cell 700 mah battery. This weighs a tenth of an ounce less than the 230 mah NiMH pack, puts out up to 55% more power at full throttle, and provides several times longer flying times per charge. For example, the 230 mah NiMH pack in the Ryan ST prototype gave scale-like performance for about 8-9 minute flights. The E-tec 700 mah pack gave about half-again more power, and flight times were something in excess of 35 minutes. How much in excess I don't know, I haven't been able to drain the entire contents of a pack yet in a properly controlled test. Extrapolating from the data I do have suggests very spirited performance for something approaching an hour.

The E-tec 700 pack would work in a Cub or a Junior although it would definitely be overkill.

We have some very economically priced chargers from E-tec for these cells. We've also had excellent results using a Plantraco LPC-400 charger. Both of these chargers are very easy to use, and have the appropriate safeguards and error-checking written into their software.

We don't presently sell transmittters, but we do have most of the other items described above available through our website.

Don Stackhouse
DJ Aerotech