Frequently Asked Questions About the Reaction 54
Answers by Bruce Tharpe
Q: How fast does it go?
A: Ah, the most frequent question by far! Well, it's never been measured with a radar gun,
but it appears to top out around 130, maybe 140 mph at full throttle. That's on the pokey
side for a turbine model, but that's exactly what it was designed to do. Sure, it's fun to do
a high-speed pass now and then, but the R54 is much happier cruising around at 2/3 throttle
and doing maybe 80 or 90 mph. Sucks less fuel that way, too.
Q: How long do your flights last?
A: Turbines are thirsty beasts, so jet models tend to have relatively short flight times.
With the RAM 500 on the prototype and 54 ounces of fuel, I set my timer for eight minutes.
The model typically lands with 1/4 tank fuel load, so there is
plenty of cushion for a missed approach or a touch and go if I feel like it.
Q: Touch and goes with a jet?
A: Yeah! The R54 isn't your typical heavy jet. It's more like a Sunday flyer. Like many pilots,
I love to do touch and goes, and don't want to give that up just because my model is powered by
a turbine. The Robart retracts will cycle up and down about twenty times, so there's no worry about
running out of air.
Q: Don't you need a special license or something to fly turbines?
A: If you want to be covered by AMA insurance, you must obtain a turbine waiver from the AMA. They
have a qualifying process to make sure that pilots flying under their insurance are somewhat competent.
You can actually take your check-out flight with the R54, but any previous flights must be made with
a turbine waiver holder on a buddy box. Not a bad way to get your feet wet!
Click here for more details.
Q: Don't you have to fly ducted fan models before going to turbines?
A: Nope! Many pilots used to go that route, but models like the Reaction 54 make it easy to move
straight into turbine models. Turbines are more expensive, but in many ways they are actually easier to
operate and more reliable than ducted fans.
Q: Can I use my JetCat P80 (or RAM 750 or KJ-66 based turbine)?
A: No, at least not as designed. There is only so much physical space between the top of the wing and the
fuselage, and that space is just right for 54-class engines. That's why I was careful to incorporate the
number 54 into the model's name. The bigger turbines are simply too big, too heavy, and too powerful for
the R54. The higher residual thrust at idle presents problems as well.
Q: Okay, how about the JetCat P70?
A: First of all, the P70 is no longer made by JetCat, but there are still a lot of them on the used market.
The P70 is an "in-between" turbine; it's bigger than the 54-class turbines but still narrow enough to
fit on the model. It isn't my first choice due to it's size, weight, and excess thrust, but it can be used.
The ideal engine from JetCat is their P60, which is slightly smaller and lighter than the typical 54-class
turbine, but still puts out 13+ pounds of thrust.
Q: What kind of radio and servos do I need?
A: You will need at least a six-channel radio for the R54. AMA requires fail safe in all turbine models.
Digital servos are recommended for all the flight control surfaces because they provide an extra level of
security against flutter. I use Hitec HS-5625MG servos (110 oz.in.) on the ailerons and rudder, and Hitec
HS-5645MG servos (143 oz.in.) on the flaps and elevator.
Q: How big of a runway do I need?
A: One of the major goals with this design was to be able to fly at my local field, which is a paved 400-foot
strip. The R54 can get in and out of that field with no problem. If you are new to turbines, I highly recommend
doing your test flights from a longer runway, not only to get used to the model, but to familiarize yourself
with the slow throttle response typical of all turbine engines. This throttle lag takes some getting used to.
Q: All right, bottom line, how much is it going to cost me to get my R54 in the air?
A: You're looking at around $4000. The turbine engine itself accounts for at least half of that. Compared to most
other turbine models on the market, that's a bargain! If you're the adventurous type, you can probably save some
money buying a used turbine, but you might be buying some headaches along with it. Many of my customers are
spreading out the expense by buying the kit, then the retracts a month or so later, all the time saving their
pennies for a new turbine. Works for me!
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