With Bergen RC's cost friendly 44 Magnum, I finally had reason to contact Chris Bergen and fulfill a longtime dream to get into turbine powered flight. I did end up with the larger Bergen Intrepid RC turbine helicopter in the end, but it was the 44 Magnum that first grabbed my attention.
Like many of you, I have been dreaming of building and flying an RC turbine helicopter for several years now. Ever since I saw one fly several years ago, it has been in the back of my mind. Actually the flying had nothing to do with it; it was the wonderful sound and smell. Seeing the heat waves blowing out the exhaust nozzles is pretty special and with those three ingredients stimulating your senses, it really hits home that this is as close to the real deal as most of us RC'ers will get.
I've had my turbine powered Intrepid now (2015) for 6 years and have had hundreds of great flights with it. To this day, I still get just as excited firing it up and then taking to the sky as I did back in 2009 when I first got it!
My Intrepid Turbine In Action
Living fairly close to a Bell helicopter service center in BC. Canada, has certainly helped "fuel" my turbine helicopter fetish and as it turns out, has made it so convenient to access jet fuel and turbine oil. I should actually take the time to thank the folks at Yellowhead Helicopters LTD for my fuel and oil needs over the past several years now.
In fact, new regulations here in Canada require that samples of Jet fuel be tested on a regular basis. These 1L batches which only a small amount of fuel is used for testing purposes, are then usually disposed of. In other words, getting to know your local heli base is a huge bonus as they very well may give you this "sample fuel" for free, which is the exact arrangement I have worked out with Yellowhead.
RC turbine helicopters are actually not very different from gas or nitro RC helis with the exception of size (perhaps) and cost. They are not enormous, pretty much the same size as larger gas helicopters or 700/800 electrics with rotor diameters in the 2000-2500mm (80-100 inch) range.
Most will weigh in at 20 to 30 pounds when fully fueled so they are heavy buggers compared to equivalent 700 or 800 size electrics at roughly double the weight. You do notice that weight in flight and have to fly accordingly - thinking ahead in other words.
far as controls, mechanics, and how they are built, RC turbine helis
are pretty much exactly the same as gas or nitro RC helicopters. Some of
the larger helicopter kits on the market for example (90/700 size or larger) can be fit with turbine engines with somewhat minimal modifications. If you perform an internet search for "Trex 700 Turbine Conversion", there is lots of information out there on the process.
The main differences between turbine powered and gas or nitro lie around the systems required to keep a turbine engine running such as the turbine engine's FADEC , electric fuel pump and valves, larger fuel tank/s, UAT (universal air trap), auto start motor, and perhaps a dry sump oil system for gear box lubrication.
All these extra systems use quite a bit of electrical power and require a dedicated battery pack over and above the normal receiver battery that we are all used to. Speaking of receivers, the radio equipment, servos, gyro are the same you would use on any large nitro, gas, or electric radio controlled helicopter.
One of the biggest differences I found between a turbine powered RC helicopter over gas or nitro internal combustion engines is just how smooth and vibration free a turbine engine runs. They are very much like an electric motor in that respect and have that same "feel" while flying. No reciprocating mass of a piston going up and down and no exhaust pulse, only silky smooth power - and lots of it! :-) No tuning or starting hassles either as the FADEC controls engine management perfectly every time from start up to shut down! So yes, there are certainly some "tangible" performance benefits over the obvious ones that just stimulate the senses.
Now that you know a bit more about turbine RC helicopters, let’s spool our way into specifics.