I can remember the first time I saw
an RC turbine plane fly. It was about 8 years ago at the Sepulveda
Basin in California, at an RC helicopter fun-fly. It was the noontime
demo, and the pilot was flying a Comp-Arf Kangaroo. At the time,
it was the absolute coolest thing I had ever seen. I could not
believe how “real” it sounded. You could close your eyes and
just imagine a full-scale F-16 flying above. I knew then that
one-day, I would own an RC turbine fixed wing plane.
It would be another 5 years or so until
I had the pleasure. The first thing I learned about turbines is,
there’s a lot to learn about turbines. It wasn’t quite as
simple as the “Fill & Go” style of glow or gas engines.
There was a lot more to it, not to mention, to the layman, it was pretty
To digress for a minute, most people
that have been flying jets for a while, started with ducted-fan jets.
These were jets flying with over-stressed, over-revved gas engines that
were spinning ducted fans, instead of propellers, for that “scale”
jet appearance. The people that pioneered the way with ducted-fan
jets had to be some pretty good pilots, as the engines were not very
reliable, the plane’s had high wing loadings, and the thrust to weight
ratio was not in the pilot’s advantage.
Fortunately, real gas turbines would
eventually make their way in to the RC market. While initially
heavy, propane fueled, and not very powerful, today’s RC gas turbines
are kerosene or Jet A powered and can generate anywhere from 3-52 pounds
of thrust. Some production RC turbine aircraft even allow the
option of installing two turbine engines, such as the big Mibo A-10.
So, getting started, the first thing
a new jet pilot should do, is find a mentor already flying turbines
in their area. There are a couple of resources for this, including
both RC Universe (RCU) and the Academy of Model Aeronautics (AMA).
Using the RCU jet forums, you can find quite a few like-minded people
that love the thrill of flying RC turbines. The AMA also has a
published list of turbine pilots in your area. Find someone you
get along with and pick his or her brain.
After that, it’s time to pick out
a good stable airframe. Resist the temptation to buy that 1/7th
scale F-18 as your first turbine aircraft. While they look and sound
cool, they do not make a good first turbine aircraft. Most scale
fighter jets have the glide slope of a brick, and are not very forgiving.
They also have relatively high stall speeds, making them extremely unstable
at slow speeds. They also require a good command of using the
throttle, not the elevator, to control one’s decent for landing.
In the right hands, and after some practice, these planes can be a thrill
to fly, but it’s good advice to start with something a little more
forgiving. My first turbine aircraft was a Boomerang XL, and I
would highly recommend it to anyone wishing to learn about turbines.
Some other aircraft well suited for beginners are the Reaction 54, the
Bandit Arf, and the Boomerang Elan. All of the above mentioned
aircraft have retracts, flaps, and a speed range of 30mph to 150mph+,
for a true learning experience in to the world of more complicated aircraft.
They also have good slow-flight characteristics, allowing the new pilot
to learn about proper approaches and turbine spool-up time. Turbine
engines do not have the same throttle response as a nitro or gas engine,
as such, even throttling up a turbine will be a new learning experience.
The next order of business is picking
out your gas turbine engine. Just like any other product in the
market place, there are varying degrees of quality when it comes to
gas turbine engines. Suffice to say; that you will get what you
pay for, just like most anything else. If you’re trying to enter
on a budget, consider the RCU market place classified ads. There
are always some great deals on used, quality turbines for sale, many
of them are from people just like yourself that are moving up to the
next level in RC turbines. Do your research, read seller’s feedback,
and buy something that you can afford. Don’t over-extend yourself
when it comes to your hobby. Expect to pay anywhere from $1500
for a good used turbine, to potentially $5,000 for a new, big-block
turbine that you could launch a small child to the moon with.
Another thing to consider when purchasing
a turbine is; what type of starting mechanism do I want. There
are two main types currently in the market: propane- start and kerosene-start.
Both have their advantages and disadvantages. Propane- start is
the most common starting method. This method uses propane gas
injected in to the turbine, and ignited by a standard glow plug to begin
the starting process. The propane heats the turbine combustion
chamber and gets the compressor spinning to a pre-determined RPM.
Once ignited and running on propane, the engine will then automatically
begin injecting kerosene in to the turbine. Once the start-up
process is complete, the engine will continue to run on kerosene until
you have exhausted your fuel tanks. While propane is the most
common starting method, this is also the most complicated and potentially
the most dangerous. As you (should) know, propane is very flammable.
Plugging, unplugging, and filling on-board propane canisters can be
dangerous. Caution should be used at all times with turbines anyway,
but especially when dealing with propane gas.
The other starting method is kerosene-start.
This method simply uses the same kerosene (or Jet A) fuel that powers
the turbine during flight, and a glow-plug element (similar to those
found in diesel engines) to start the turbine. On start-up, electricity
is applied to the glow plug, heating it up to a pre-determined level.
Once fully heated, kerosene is then slowly pumped in to the starting
chamber, where it is immediately heated and burned by the glow plug.
While this method consumes quite a bit more electricity from your Engine
Control Unit (ECU) battery, it is less complicated, and in some ways
a more safe method of starting your turbine. The downside to kerosene-start
turbines, is they are generally more expensive, and some of their glow
plugs are not user-serviceable, meaning they have to be sent to a service
center to be replaced. It is the author’s belief that all turbines
will eventually be kerosene-start, due mostly to the simplicity of the
So you’ve got your plane and you’ve
got your engine, what next? Well, there’s the small detail about
ground-support equipment. And the list can be as long or short
as your credit card can handle. Some “must have” items include
electric fuel cans (don’t even think about hand pumping), extra glow
plugs (or kero plugs), a 12V power source (for either charging or powering
ground equip), a plethora of tools (better to have a tool, than to need
one), propane cans, a knee pad, a turbine cooling fan (saves wear and
tear on your turbine starter motor), extra fuel cans, a fire extinguisher
(AMA requirement), and anything else your mentor tells you. Be prepared
(Seems like I’ve heard that before).
Another consideration should be your
transmitter. That 4-channel 72mhz radio that came with you RTF
trainer probably isn’t going to do the trick. The new 2.4ghz
radios seem to be the wave of the future. Having only experience
with JR radios, I can tell you they have some great 6, 7, 9 and even
12 channel radios. I have owned and used them all. Like
anything else in turbines, sky’s the limit, however a good computerized
radio with a decent set of mixes will last you for years to come.
Most beginning turbine aircraft are going to use 5-7 channels, depending
on how you have your control surfaces set-up. Some of the more
complicated, scale-competition birds can use all 12 channels when adding
speed brakes, bomb-drops, working canopies, etc.
Once you have your radio, plane, turbine,
and support equipment, it’s time to earn your waiver. WAIVER?!
No, it is not your God given right to fly turbine-powered aircraft anywhere
you wish, at least not while being insured. The AMA has set up
a turbine waiver system that allows all AMA members to earn a waiver
that will allow them to fly turbine-powered aircraft at an AMA approved
field. Details about this waiver system can be found on the AMA’s
website, but include both a good knowledge of turbine equipment, starting
procedures, flame-out procedures, landing procedures, and more complicated
flight maneuvers. Remember, these aircraft are capable of speed
exceeding 200 miles per hour. Striking any people or property
with these aircraft could be detrimental to them, you, and the hobby
as a whole. This leads me to the next topic, maintenance.
Take care of your equipment, and it
will take care of you. I have been to numerous jet rallies and
had a chance to view a lot of people’s aircraft. Some of them
are immaculate, while others look as though they were in some kind of
dust tornado. Interestingly enough, the pilots whose aircraft
that look like they were in a dust tornado seemed to experience more
problems (read as: crash more often). It may just be a coincidence,
it may not, but the point is, if you are not continuously performing
preventive maintenance, you may be doing crash repairs instead.
Doing a good pre-flight and post-flight inspection of your aircraft
may end up saving you thousands of dollars down the road.
This article was written to give you
just a sample of what is involved in getting in to RC turbines.
It should not be used as a complete guide. There are many different
aspects to RC turbines and no written guide could ever replace the first-hand
experience of a good, local mentor that can quickly address the “what
if” questions. Ask a lot of questions, practice on a simulator,
fly on a buddy box, (with a qualified, turbine waivered pilot) and most
importantly, BE SAFE. Anyone reading this article is always welcome
to contact me directly either through RCU (member name SinCityJets),
my website (www.sincityjets.com), or email (email@example.com)