Which RK model is the fastest. And how fast does it go?

From : Don Stackhouse

Boy, that's a tough one. Some are definitely faster than others, but we've spent most of our efforts trying to make sure they can go slow enough to fly safely indoors in something the size of a basketball court. I don't really have good numbers on absolute top speeds, it just isn't a priority for most fliers of this type of model.

Typical "economy cruise" speeds of most of the RK models seem to be in the range of 10 to 15 mph in most cases. Top speeds of course can be much higher than that.

It also depends a lot on how cleanly you built it (no big, loose loops of wires hanging out in the breeze, etc.), whether you have the landing gear installed or removed, your flying style (just how much flight time are you willing to sacrifice with higher than necessary throttle settings?) and especially on motor and battery setups. The things we're seeing with the new Lithium-polymer batteries in particular are completely re-writing the book with regards to speed, maneuverability and flight times.

All that said, I'd have to say that the twins are the fastest, particularly the DC-3. The P-38 and Lockheed Model 10 Electra are almost as fast, and if you REALLY want to burn high-speed holes in the sky, try re-engining them with a pair of our new MPS-2a twin-motor power systems and a 3-cell 700 mah E-tec Li-poly battery. The MPS-2B (same as the MPS-2A, but with the smaller 5-4.3 prop instead of the 6-5 we use on the -2A) with a 3-cell 250 pack also performs extremely well in the single-engine models. With the twin-engined models I'd still recommend the 700 mah cells due to the high current required to feed two of the twin-motor units.

Others that are surprisingly fast if they need to be are the new Ryan ST (especially with the underside of the wing covered to make it flat-bottomed, which is also an option for more speed with the other models), the J-3 Cub, and most of the WW II warbirds, especially the Me 109, Mk I Spitfire, A6M5 Zero, F4U Corsair and the P-40. We should have our new FW-190A available soon, and with the MPS-2A and a two-cell 700 pack it really burns up the sky.

As far as how fast they are, probably the best real-world measure is how much wind they can handle. I don't have any really good numbers on top speed, but we've flown some of these in measured winds of well over 12 knots without problems. I've flown the P-38 with the stock pair of single-motor MPS-1 powerplants and a little 7-cell 110 mah NiMH battery in 12 knots with gusts to 20. With the new Li-poly batteries we're still learning what the upper limits are on all of the models. I've recently been testing the draggy little DR-1 Triplane with an MPS-2B and a 3-cell 250 mah E-tec battery in a frightening amount of wind. Anything will go fast if you put enough power in it. Even the very lightly loaded little Curtiss-Wright Junior flies OK in measured winds of 10-12 knots with gusts to 15, using the stock MPS-1A single motor system and a 2-cell 250 mah E-tec battery. It also has flown successfully indoors in spaces as small as 20 by 60 feet with a 10 foot ceiling.

The bottom line is "pretty fast", but we're still learning.

Don Stackhouse
DJ Aerotech