First impressions are important! Here are some pics of the Reaction ARF straight out of the box
along with some of my comments. Overall, this is a magnificent product. The glass work is immaculate, the
finish is smooth and glossy, the glue joints are sound and strong. I am proud of my simple, all-wood Reaction 54
design, but PST has taken the Reaction concept to a new level. The engineering is impressive and the workmanship
is first-rate. I can't wait to fly this beautiful jet!
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THE ARRIVAL!
I'm not normally an ARF builder, but have to admit it was pretty exciting when the FedEx truck
arrived with these two big boxes from Thailand. The contents were packaged beautifully and protected
well with all sorts of bubble wrap, newspaper, and foam. There was no damage to the boxes or the model.
Let's dig in!
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FIN AND RUDDER
Light and accurate. The rudder is the only control surface that the builder has to hinge. Three
point-style hinges are included in the kit. The stabilizer and fin unit are designed to be glued in place
on the fuselage - there is no provision for a removeable tail unit.
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LIVE HINGES
Here's a view of the stabilizer bottom, with the elevator flexed open to show the live hinge. The
hinge is actually the molded fiberglass top skin, which is incredibly strong and aerodynamically clean.
Live hinges are also used for the ailerons and flaps. Note the small slot in the bottom of the elevator
for the machined elevator horn which must be glued in by the builder.
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WING BOTTOM
An overhead shot of the wing bottom surface clearly shows the cutouts for the aileron and flap servos.
Thick fiberglass plates are provided as hatch covers/servo mounts. Threaded steel pushrods with Sullivan
clevises are provided for linkages.
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WING JOINER TUBES
The shiny, smooth finish on this model resulted in reflections from my overhead lights in most of the
photos, sorry. The two-piece wing is joined using two aluminum tubes, then attached to the fuselage
with dowels and bolts. For the technically-minded, it should be noted that the Reaction 54 wood kit uses
a semi-symetrical airfoil with a flat spot on the bottom to make building easier. The ARF uses a pure
symmetrical airfoil.
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WHEEL WELL
The main landing gear are bolted to heavy plywood beams built into the wing. Of course, the PST units
are a drop in fit, but Robart and Spring Air units should fit as well.
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REAR FUSELAGE VIEWED THROUGH WING OPENING
You can see the excellent fiberglass work here. Carbon fiber strips are used for extra strength over
the wing opening. The supplied fuel tank (2.5 liter, not shown) is custom molded to fit just in front of
the forward-most bulkhead shown in this photo. PST offers an optional one-liter tank to expand the fuel
capacity, but I suspect it would work well as a smoke fluid tank.
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ENGINE MOUNT AND ELEVATOR SERVO MOUNT
The two bulheads shown here take the thrust loads. The actual turbine mounting rails are laser-cut from
plywood and supplied in the kit, but they must be glued in by the builder. PST did this so that the rails can
be trimmed before installation to fit a variety of powerplants. As supplied, the rails fit the PST J800R. Cut
lines are etched in for the larger PST J1300R. There is lots of room for cool airflow into and around the
turbine. You can also see the metal elevator servo mount, installed just aft of the turbine.
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CANOPY PARTS
The Reaction ARF comes with a clear canopy, fiberglass canopy frame/hatch, and a
molded plastic cockpit. Guess I'm in the market for a jet pilot bust! The printed instrument panel is a
nice touch, but creative builders will go far beyond that and add lots of details.
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FRONT FUSELAGE
The fuselage is molded in two pieces to keep the shipping box a reasonable size. In most cases, the front
and rear sections will be bolted permanently. But if you need to squeeze your jet
into a small vehicle, you could possibly break it down for transport and assemble at the field. A rugged
plywood box in the nose serves for mounting the nose wheel retract, the retract and brake servos, and their
respective valves. Batteries can be installed in front of the plywood assembly, to help with balance.
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MOLDED LEAD NOSE WEIGHT
Here is something you don't see every day. This 1-1/4 pound (400 gram) chunk of lead is molded to fit precisely in the
nose. It's a nifty little part, but the actual amount of nose weight that you will need depends on your choice
of turbine, batteries, and equipment layout.
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FIRST FLIGHT REPORT - JULY 2, 2008
Well, I finally tore myself away from the shop for a little fun. Just days before, I found out about a
nearby airport that is R/C friendly, so a small group of us loaded up and went to check it out. The Reaction
is known for its small-field ability, but it's still nice to have a long runway available for test flights.
Allow me to step back a bit and tell you about my setup. The airplane shown here is the same one used for
all of the assembly instruction photos. It has a PST J800R for power, and the original 2.5L main tank with
a 4 oz. header/air trap. The retracts and brakes are from PST. I balanced the model close to the "novice"
position of 14.5 cm aft of the LE. Incidentally, the molded lead nose weight was exactly perfect for balancing
at this point, but I used an equivalent amount of lead shot in baggies for the test flights. I wanted to be able
to remove some of the nose weight later, if necessary. My final, ready-to-fly dry weight was 24 lbs. Still
no graphics, but I'm working on it...
After range testing with and without the turbine running, there were no more excuses! Taxiing out to the runway
gave me a chance to test the brakes, which seemed to work just fine. The takeoff was smooth, the retracts
snapped up quickly, and I started a procedure turn to bring it back down the runway. It was during that
turn and first low pass that my mind said, "I've flown this airplane before. I know this airplane!"
Having flown my wood Reaction 54 for many years, this ARF was instantly comfortable and familiar. During
the rest of my flight, it became very clear that it flies just like the R54, but maybe a little smoother if
that's possible. I love it!
Aerobatics are smooth and easy. Full-throttle passes are plenty hot for me -
I'm not a speed freak. In fact, I like to throttle back, put the flaps down about halfway and watch it
doodle around through lazy figure eights. Then throttle up into a split-S and roar by doing a slow barrel roll.
Heaven! Even with its small rudder, it does knife edge easily. My control throws were set as shown in the
instructions, with expo set at 25 percent for the ailerons and elevator. They controls felt a little light for
my taste during the first flight, so I bumped the expo up to 40 percent on the ailerons and elevator and liked it
much better. Inverted flight needed just a hint of down elevator, and the landing approaches were solid and smooth.
At this point, I will probably leave the CG right where it is now.
Speaking of landings, this is the only flight regime where I noticed any difference with my wood R54. The ARF has
a higher wing loading and seems to land a bit faster. BUT, the overall handling during the approach is actually an
improvement! The R54 has a reputation of being a floater, and we have learned over the years that the lighter ones
(18-20 lbs.) are actually more difficult to land accurately than the heavier ones (over 20 lbs.). This ARF has the
same wing area, but builds out heavier, putting it closer to the "normal" jet wing loading range. It was dead calm
during my test flights, but it was still obvious that the ARF has a heavier, more solid feel during landing that I
liked very much.
Oh, a quick note on the PST brakes. This is the first time I've used pneumatic brakes on a model (my R54s use an
electric brake on the nose wheel), so that was something I was a little worried about. I've seen a lot of jets at
rallies swerve from side to side because the brakes were too strong and/or uneven. The PST brakes worked perfectly
- not a hint of wiggling or swerving. They did not seem overly powerful, which is a good thing in my book, but
they certainly did their job.
The J800R with 18 lbs. of thrust is a fantastic
combination with this airframe, particularly if you are new to jets. It won't push this model straight up out of
sight, but it's no slug either. Many builders are putting larger turbines in theirs, and they will no doubt be
spectacular.
All in all, it was a great day!
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