Engines
The Reaction 54 is designed for tubines in what is commonly known as the "12-lb. Class". The BTE prototype models
have been thoroughly tested with a RAM 500 which puts out 11+ pounds of thrust and a PST J600R which puts out 14
lbs. of thrust. Therefore, the R54 airframe is rated for a maximum thrust of 14 lbs. Through continued refinement, the
engines in this class are now putting out more power. If necessary, limit the thrust of your turbine by programming
your ECU to a new, lower maximum rpm (check with the manufacturer for the proper rpm setting). A list of suitable
turbines is presented on the next page.
Radio and Servos
You will need at least a six-channel radio for the R54. To comply with AMA Safety Regulations, all radios used in
turbine-powered models must be equipped with fail safe and ECUs shall be configured to shut down the engine within
two seconds of fail safe activation. You will also need some mixing functions, primarily to add a bit of down elevator
with flap deployment. Personally, I have settled on the Futaba 9C transmitter because it is easy to program, has lots
of mixing functions, and has slider switches for flaps, which I consider much easier to use than knobs.
Every turbine pilot has their own opinion on servos. This is an entry-level turbine model designed to fly at modest
speeds with an eye towards economy. The place to economize, however, is not with your servos! Digital servos are
mandatory for all of the flight control surfaces. Prices for digitals are coming down, and there is a wide selection from
all the radio manufacturers. Digital servos also offer an extra level of security against flutter thanks to their ability to
“lock in” around neutral. There have been no problems with the Hitec servos used in the prototypes, so I will use their
specifications as minimum requirements, as follows:
Ailerons (2 servos) and Rudder (1 servo)
Hitec HS-5625MG - 110 oz.in. @ 4.8V Dual BB, Metal Gears
Flaps (2 servos) and Elevator (1 servo)
Hitec HS-5645MG - 143 oz.in. @ 4.8V Dual BB, Metal Gears
Nosewheel Steering (1) and Retract Valve (1)
Hitec HS-225MG - 54 oz. in. @ 4.8V Top BB, Metal Gears
Retracts
The R54 was designed around the Robart 500-series retracts. The Retract Package from BTE uses Robart #530 units
for the main wheels and #563 for the nose wheel. The nose wheel unit was particularly attractive to me because it has
mounting holes for both firewall and belly mounting. It seemed natural to me to design the model to utilize both sets of
mounting flanges for maximum strength, and it has proven its strength in flight testing several times. (Translated: I've
made some really bad landings that should have torn the gear out, but both the Robart gear and the airframe took the
punishment with no damage beyond bent struts!). There are other retract units on the market that can be substituted,
but I haven't tried them and cannot recommend their use. If you want to try different retracts, it will be up to you to
engineer their installation.
Header Tank / Air Trap
In addition to the Du-Bro 60 ounce fuel tank, I recommend using a header tank for reliable fuel flow to the turbine. The
most popular header tank in use today is the BVM Ultimate Air Trap (UAT). It is what I used in the prototypes and is
shown on the plans. The UAT is a special header tank that incorporates a fibrous bag to trap air bubbles, preventing
them from getting to your turbine and possibly causing a flameout. It holds four ounces of fuel, bringing the total fuel
load to 64 oz. There are several less expensive alternatives on the market now and they should all work fine. Visit
www.dreamworksrc.com
for a wide selection of header tanks and lots of other turbine-related products.
Appendix A 35
Summary of Contents for Reaction 54
Page 1: ...INSTRUCTION BOOK...
