Skinny Scale North American T-28 Trojan - 2004/08

FOLLOWING WORLD War II, the Air Force needed a
trainer that would make it simple for the beginner pilots to
transition to the new jet fighters that were just then in
production. North American Aviation came up with the T-
28 design, and it proved to be such a good trainer that the
Navy decided it would use a version of the aircraft to train
its pilots.
The Air Force retired its T-28s from the trainer role in
the late 1950s, but the airplane saw service as a light attack
aircraft for many years thereafter. The T-28 lived on in the
Navy as a trainer until the early 1980s. Many are flown
today in civilian hands as an economical warbird.
The Model: While out at the flying field, my friend Mark
told me he was thinking about building a model of a T-28
using a profile fuselage. After talking it over with him, I
convinced Mark that I could design a T-28 model with a
fuselage that would be wide enough to fit the engine (and
hide it), and it would only be slightly more difficult to
build than the trainer with which he was learning to fly. To
further convince him, I told him it would even be able to
fit a set of retractable landing gear.
To make the model easy to build, I used flat sides on
18 MODEL AVIATION
The T-28 is highly visible in the air, thanks to the bright Navy paint scheme.
The retractable landing gear aids in achieving a scale effect.
by Gary Fuller
Famous Navy trainer re-created in
easy-to-build format
08sig1.QXD 5/24/04 10:37 am Page 18
the fuselage, as are used on a trainer. The top and bottom sheeting is
thick, and combined with the 1⁄4 balsa triangle stock in the corners, you
can almost sand the fuselage to an oval shape. The top sheeting of the
fuselage over the engine is cut away to allow easy access to the engine,
as in a trainer.
To make the T-28 easy to fly, I used a thick semisymmetrical airfoil
with a great deal of dihedral, as the full-scale T-28 has. To make the
model as economical as possible, I designed it with the .40-size engine
in mind, with which most trainers are equipped. Therefore, you should
be able to use the engine that was in your primary trainer.
The T-28 should appeal to a wide range of modelers, from those
who are moving up from a trainer to those who are more experienced
and looking for a nice-flying semiscale Sunday flier.
I generally believe that if a full-scale airplane has retractable
landing gear, a model of the aircraft won’t look right tooling around
with its gear hanging in the breeze; I designed my T-28 with this in
mind. But I do realize that the expense and trouble associated with
retracts don’t appeal to everyone, so the plans do show the provisions
for fixed gear.
I tried to design the T-28 with the novice builder in mind, but do get
some help from an experienced builder if you have never built a radiocontrolled
airplane.
CONSTRUCTION
Fuselage: The fuselage is fairly simple and straightforward. Lay both
fuselage sides on your worktable so that they are positioned top to top.
Doing this will keep you from building two left or two right sides.
Glue the 1⁄8 balsa fuselage doublers to the fuselage sides. Make sure
the shorter of the two doublers is glued to the inside of the right
fuselage side; this is so the engine will have 2° of right thrust.
Glue the 1⁄4 balsa triangle stock in place on the sides as shown on
the plans. Glue the 1⁄4 square balsa to the sides aft of the wing as shown
on the plans. Drill the holes in F1 for the engine mount, throttle cable,
and fuel lines. Glue bulkheads F2A, F2B, and F3 in place on the right
side only. Ensure that the bulkheads are 90° to the side.
Install the left side to the bulkheads. I did this by leaving the right
side on the workbench and placing the left side on the bulkheads. I
made sure the sides were aligned to each other by using a carpenter’s
square to check at various places on the top and bottom of the fuselage
sides.
Install the firewall F1. Glue in the 1⁄4 plywood nose-wheel retract
mount plate, the 1⁄16 plywood fuel-tank compartment floor, and the 1⁄4
plywood wing-mount plate. Glue the 1⁄4-inch balsa triangle to F1, F2B,
the nose-wheel retract mount plate, and the wing-mount plate as shown
on the plans.
If you don’t plan to use retractable landing gear, you can forego
installing the 1⁄4 plywood nose-gear mounting plate. Use a steerable
nose-gear mount attached directly to the firewall, or use an engine
mount that has provisions for mounting a nose-wheel assembly.
Flip the fuselage up on its bottom and join the sides at the tail. You
will need to trim the 1⁄4-inch balsa triangle to do this. Make sure the
fuselage is not twisted or crooked as you perform this step.
Glue on the 3⁄16 balsa top sheeting with the grain running side to
side. Flip the fuselage over and glue the 3⁄16 balsa bottom sheeting to the
fuselage, aft of the wing, with the grain running side to side. Don’t glue
on the bottom sheeting forward of the wing until later. Install the nosewheel
retract unit on its mounting plate.
Put the fuselage off to the side and out of the way, and start the
wing.
Wing: The wing is slightly more difficult to build than a trainer’s, but it
is a fairly straightforward design, and you should not have any
difficulties. Cut the 3⁄8 balsa LE from medium to hard balsa. Cut the LE
so that it is approximately 3⁄16-inch wider than each rib’s LE. This will
be approximately 1 inch at R3, tapering down to roughly 13⁄16 inch at
R12. The inboard LE will taper from approximately 11⁄16 inch to 1 inch
at R3. You may want to add a bit more to be on the safe side.
Cut the R1 and R2 rib template from the plans, and glue it to a piece
of cardboard or scrap balsa for later use. I used a 3⁄8-inch-diameter
sharpened brass tube to cut the holes in R2 and R3 for the retract air
lines.
Start constructing the wing by building one side first, pinning the
outer lower main spar in place over the plans. Pin the lower forward
inboard spar in place over the plans. Place the lower aft inboard spar on
the plans, but do not pin it; it will need to be lifted up into place after the
Tim used a clear canopy and installed a pilot in his version of the
T-28 to enhance its scale appearance.
Alternate wing-mounting method uses a single 1⁄4-20 nylon bolt.
Cutouts in the mount plate are for aileron torque rods.
Tim Neal’s Thunder Tiger .40-powered T-28 built from Gary’s
plans is covered with MonoKote in an alternate Navy scheme.
August 2004 19
Photos by the author
08sig1.QXD 5/24/04 10:38 am Page 19
20 MODEL AVIATION
Don’t pin lower aft spar to plans surface; it needs to be above surface when it is
glued to ribs. Install 1⁄4 x 1⁄2-inch plywood landing-gear mounts to ribs R4 and R5, and
make sure that R4 and R5 will set at 90° to work surface before you glue landing-gear
mounts to ribs and ribs to spars.
Rubber bands hold two full gallon cans to fuselage to hold it in place while the top is
sanded to shape. Use a strip of sandpaper and the “shoe-shine” method.
The Trojan’s fuselage sides are ready to
be joined. The right fuselage side has all
the formers glued to it.
Shown is the bottom of the fuselage
looking aft. “T” pins hold the bottom
sheeting in place as the glue dries.
The firewall is drilled for the engine
mount, the fuel tubing, and the throttle
linkage before it is installed.
ribs are in place and glued to the main spar
and the forward spar.
Glue all the ribs in place on the main spar
and the forward spar, keeping them at 90° to
the work surface. Do not glue in ribs R1 and
R2 at this time because they need to be glued
at an angle later.
Put the upper spars in place over the ribs,
and glue them to all the ribs except R1 and
R2. Pull the lower aft inboard spar up into the
slot cut for it in each rib and glue in place
except for ribs R1 and R2. Glue the 1⁄4 balsa
TE in place on all the ribs except R1 and R2.
Glue the outboard 3⁄8 balsa LE in place on all
the ribs, and sand it flush with R3.
Using the R1 and R2 angle template, glue
R2 in place on all the spars, and then do the
same for R1. Glue the inboard LE to R3 and
R2, and make sure R2 is still at the correct
angle using the R1 and R2 angle template.
For retractable landing gear, glue the 1⁄2 x
3⁄8-inch hardwood landing-gear mounts in
place in R4 and R5. If you plan to use fixed
landing gear, glue the 1 x 1⁄2-inch grooved
hardwood landing-gear block to R4 and R5.
At R4, glue an additional 1 x 1⁄2 x 1⁄2-inch
grooved hardwood block on top of the
landing-gear block with the groove running
vertical and against R4, and then drill a 5⁄32-
inch-diameter hole down through the landinggear
block using the groove in the top 1 x 1⁄2 x
1⁄2-inch block as a guide.
Glue the 1⁄16 balsa shear webbing in place
to the top and bottom spars, as shown on the
plans, with the grain running vertical. Sand
the 1⁄4 balsa TE flush with the top of the ribs,
and then glue the 3⁄32 x 1-inch balsa TE
sheeting in place.
Sand an angle in the LE top sheeting to
match the angle where the sheeting will meet
the 3⁄8 balsa LE. Glue the top LE sheeting to
the 3⁄8 balsa LE, and let the glue dry without
gluing the LE sheeting to the ribs.
After the glue has dried, adhere the top LE
sheeting to the ribs. Wetting the outer surface
08sig1.QXD 5/24/04 10:39 am Page 20
Main landing-gear retract mounts need to have some wood
removed so retract units will fit. Retracts are secured to mount
with 4-40 bolts with blind nuts.
The 1⁄16 balsa shear webbing has been installed on the spars.
Webbing is installed between the spars on the aft spars.
Left wing is ready for 1⁄16 balsa shear webbing to be installed on spars. Rib R2
needs to be mounted at an angle so that it will mate correctly with fuselage.
Forward part of wing is held to fuselage with 1⁄4-inch hardwood
dowels. Install dowels before bottom of wing is sheeted.
Before fully sheeting the bottom of the wing, install main
landing-gear retract units and the air lines to supply them.
Cut R1/R2 angle template from plans; glue to scrap
wood. Use it to glue R1/R2 to spars at correct angle for
dihedral.
August 2004 21
08sig1.QXD 5/24/04 10:40 am Page 21
Fuselage sides in engine-compartment area will need small
holes cut in them for such items as engine muffler and
needle-valve extension.
The engine area is a bit tight. Top
sheeting has been cut to clear rocker arm
cover and allow cooling for engine.
Additional Specifications:
Wing chord: 83⁄4 inches (average)
Wing area: 524 square inches
Wing location: Lower fuselage
Airfoil: Semisymmetrical
Wing planform: Double tapered
Dihedral (each tip): 3 inches
Fuselage length: 461⁄4 inches
Radio compartment size: 107⁄32 (L) x 21⁄2 (W) x 83⁄4 (H) inches
Stabilizer span: 2411⁄32 inches
Stabilizer chord: 51⁄4 inches (average)
Stabilizer area: 126 square inches
Stabilizer airfoil: Flat
Stabilizer location: Top of fuselage
Vertical fin height: 83⁄4 inches (includes rudder)
Vertical fin width: 7 inches (average)
Vertical fin area: 74 square inches (includes rudder)
Recommended engine size: .32-.50 two-stroke or 40-65 four-stroke
Fuel tank size: 8-10 ounces
Landing gear: tricycle/retractable
Recommended number of channels: Five
Control functions: Rudder, elevator, aileron, throttle, retractable gear
CG (from LE): 47⁄8 inches
Elevator throws: 5⁄8 inch up; 5⁄8 inch down
Aileron throws: 5⁄16 inch up; 5⁄16 inch down
Rudder throw: 1 inch left; 1 inch right
Downthrust: 0°
Side thrust: 2° right
22 MODEL AVIATION
Left: Before sheeting forward bottom of fuselage, fit nose-gear
retract unit to 1⁄4 plywood mount. Lower bolts for engine mount will
need to be cut flush with back of firewall to clear retract unit.
Above: Before covering wing, author likes to put blob of epoxy
from inside wing to hold aileron hinges in place where they are
accessible.
Type: RC “Skinny Scale”
(semiscale)
Wingspan: 60 inches
Engine: .32-.50 two-stroke or
40-65 four-stroke
Flying weight: 6.5 pounds
Construction: Balsa and
plywood
Covering/finish: MonoKote
08sig1.QXD 5/24/04 10:43 am Page 22
August 2004 23
of the sheeting with water will help it
conform to the ribs. Glue the rest of the top
sheeting in place. Glue the 1⁄4 x 3⁄32-inch balsa
rib caps in place.
Unpin this side from the plans, and prop
up the wingtip at R12 using a 6-inch-high
block that is longer than R12 and has sides
that are 6 inches parallel to each other so that
the wing will not have any twist at the
wingtip. Glue the 3⁄8-inch square hardwood
aileron servo mounts to R1 and R2. Build the
other wing half the same way you built the
first, but go ahead and glue R1 to the other R1
without using the R1 and R2 rib template.
Unpin the wing from the building board.
Glue the 1⁄4 plywood center wing mount to R1
and R2 as shown on the plans. Fit the wing to
the fuselage, and drill the holes in the 1⁄4
plywood F2B in the fuselage using the center
wing mount as a guide. Remove the wing
from the fuselage.
Place the 1⁄4-inch hardwood dowels in the
holes to hold the wing to the fuselage. Place
the 1⁄8 plywood dowel supports on the dowels,
and then glue the supports to the forward
inboard top and bottom spars so that the 1⁄4-
inch dowels are 90° to the 1⁄4-inch wingmount
block and parallel to each other. Glue
the 1⁄4-inch dowels to the 1⁄4 plywood wing
mount and to the 1⁄8 plywood dowel supports.
Begin sheeting the bottom of half of the
wing by gluing the LE sheeting to the 3⁄8-inch
LE, as you did for the top LE sheeting. When
the glue has dried, use slow-drying
cyanoacrylate to glue the sheeting to the ribs.
If you wet the sheeting, place the wing on the
building board and weight it down until the
sheeting has dried. Prop up the other half of
the wing with the 6-inch block while the
sheeting dries.
Glue the LE sheeting on the other wing
half using this same method. After the LE
sheeting has dried, remove the building tabs
from the bottom of the ribs, sand the 1⁄4-inch
TE flush with the ribs, and then glue the 1 x
3⁄32-inch balsa TE sheeting in place.
Before the rest of the bottom sheeting is
installed, fit the main landing-gear retracts in
place and run the air lines to the center of the
wing. Trim ribs R3 and R4 as necessary to fit
the retract units and wheels when the wheels
are in the up position. Glue the rest of the
bottom sheeting in place along with the 1⁄4 x
3⁄32-inch rib caps.
Cut the slots for the aileron hinges in the
wing’s TE. Install the hinges in the wing, and
then temporarily tack-glue the 1⁄4 x 1-inch
balsa TE to the wing. Sand the 1⁄4 x 1-inch TE
to match the wing airfoil’s contour.
Remove the TE from the wing, and cut the
aileron from the inboard section of the TE.
Cut a groove in the TE to accept the aileron
torque rods. Lubricate the torque rods’
bearings with Vaseline or such so that the
glue will not cause the rods to stick to the
bearing, and then glue the torque-rod bearings
to the TEs. Make sure they can rotate freely,
and then glue the TE to the wing.
Score the 1⁄16 plywood wing-mount plate
down its centerline so that it can be “cracked”
and bent so it will conform to the dihedral.
Glue the plate to the TE as shown on the
Full-Size Plans Available—see page 191
08sig1.QXD 5/24/04 10:43 am Page 23
24 MODEL AVIATION
plans. Glue the wingtip blocks to the wingtip,
and then sand them to shape. Sand the LE to
match the airfoil as shown on the plans.
Reinforce the center-section of the wing on
the top and bottom with 2-inch-wide, 6-ounce
fiberglass cloth. Cut the opening in the centersection
of the wing for the aileron servo, and
trim rib R1 to fit the servo. Cut a small
opening for the retract air lines.
Place the fuselage upside down on your
workbench, and secure it so it won’t move.
Install the wing on the fuselage. You may
need to trim the holes in the F2B plate for the
1⁄4-inch dowels so that the wing will fit to the
fuselage properly.
Once you are satisfied with the fit of the
wing to the fuselage, align the wing so that it
is square to the fuselage, and then drill the
wing-bolt holes in the wing and wing-mount
plate. To do this, place weights on the wing so
that it is held securely to the fuselage while
you measure from the center of the fuselage to
where the rudder mounts to the wing TE at the
tips. (I use the place where the tip blocks join
the wing at the TE.) Adjust the wing so that
these measurements are the same.
Once you are satisfied that the wing is
aligned correctly, drill a 13⁄64-inch hole
through the 1⁄16 plywood wing-bolt
reinforcement and the 1⁄4-inch wing-mount
plate in the fuselage. Remove the wing from
the fuselage, and then tap the wing-mount
plate in the fuselage with a 1⁄4-20 tap. You can
use some thin cyanoacrylate-type glue to
strengthen the threads in the plywood.
Use a 1⁄4-inch drill bit to enlarge the hole in
the wing plate so that a 1⁄4-20 nylon bolt will
fit through it. Bolt the wing to the fuselage,
recheck the alignment, and then drill the hole
for the other bolt the same way you drilled the
first hole.
Keep the wing mounted to the fuselage,
and cut the landing-gear struts to the correct
length. I did this using the following method
and utilizing adjustable axles. On the nosegear
retract unit I installed the strut for the
nose wheel. I cut the strut a little long for the
axle so that when the wheel is up, there is a
slight gap between the wheel and the forward
wing-mounting plate.
With the axle and wheel mounted to the
strut, I retracted the nose wheel into the
fuselage to check the clearance. I adjusted the
axle on the strut to the correct location for the
wheel clearance and tightened the axle on the
strut. I extended the wheel and removed it
from the axle. I cut the strut flush with the axle
and soldered the axle to the strut. After that, I
reinstalled the nose wheel so I could move on
to the main gear.
I installed the struts on the main landinggear
retract units and installed the axles and
wheels. I flipped the airplane over and set it on
the bench on the landing gear. (You may need
to put some weight on the front of the fuselage
so it won’t sit on the tail.)
I adjusted the position of the main gear
axles so that the fuselage sat in a level
position fore and aft and side to side, and I
tightened the axles on the struts. Make sure
the wheels are aligned so the model will
roll straight ahead. I removed the wheels
and cut the struts flush with the axles, and
08sig1.QXD 5/24/04 10:43 am Page 24
then I soldered the axles to the struts.
Now is a good time to glue the 1⁄8-inch
balsa belly pan sides to the wing along with
the F3A bulkhead and the 3⁄16-inch belly pan
bottom sheeting.
Remove the wing from the fuselage, and
cut the bottom sheeting for the main wheels
to retract into. You accomplish this by
mounting the wheels to the axle and then
actuating the retract unit by hand so that the
main wheel is lying against the sheeting.
Mark the sheeting around the wheel and
strut. Move the wheels to the down position,
and cut the sheeting where you marked it for
the wheels and strut. Move the wheel to the
up position, and trim the hole and ribs R3 and
R4 so the wheel and strut fits into the wing.
You need to trim the sheeting so that there
is roughly 1⁄4 inch of clearance around the
wheel and strut. This is necessary for those
not-so-pretty landings that may bend the
struts. If you want, you can line the openings
with 1⁄16 balsa now, but this is not shown on
the plans.
Sheet the bottom of the forward fuselage,
and cut the bottom sheeting for the nosewheel
opening as you did for the main
wheels.
Glue all the pieces together for the vertical
stabilizer. Hinge the rudder to the vertical
stabilizer, but don’t glue the hinges in place.
Hinge the elevators to the horizontal
stabilizer, but don’t glue those hinges either.
Glue the piece that separates the elevators
to the horizontal stabilizer. Cut a groove in
the bottom of the center of the horizontal
stabilizer for the music-wire elevator joiner.
Mark the elevators for the location on the
joiner, and drill the hole and cut a groove for
it in each elevator. Remove the elevators and
the rudder from the stabilizers. Set them
aside.
Refit the wing to the fuselage, and mount
the horizontal and vertical stabilizers. To do
this, place the fuselage on the workbench,
right side up, and secure it so it won’t move.
Adjust the fuselage position to get the wing
sitting level fore and aft by measuring at the
center of the LE of the wing and the TE of the
wing to the workbench, and then adjust the
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position of the fuselage so these are the same
distance from the workbench. You do this so
you can set the wing a stabilizer incidence.
Pin the horizontal stabilizer in place on the
back of the fuselage. Get a few feet out in front
of the fuselage and sight down along the
fuselage toward the horizontal stabilizer.
Compare the position of the stabilizer to the
wing, and look to see if it is tipped to one side
or the other. Sand the high side of the
horizontal stabilizer mounting area if necessary
so that the stabilizer is not tilted.
Measure the distance from the LE and the
TE of the stabilizer to the workbench surface.
These need to be the same so that the incidence
angle between the horizontal stabilizer and the
wing are 0° to each other. Sand the horizontal
stabilizer mounting area if necessary to achieve
this. Double-check the horizontal stabilizer to
make sure it is not tipped to the side compared
to the wing.
Measure from the wing TE at the tip to the
horizontal stabilizer TE at the tip on both sides
of the fuselage, and adjust the horizontal
stabilizer so these are the same. When you are
satisfied with the stabilizer’s alignment, glue it
in place on the fuselage. Make sure the elevator
joiner is installed in the horizontal stabilizer
center when the horizontal stabilizer is glued in
place.
Pin the vertical stabilizer in place while the
fuselage is still mounted on the bench. Sight
down the front of the fuselage toward the tail,
and align the stabilizer with the centerline of
the fuselage. When you are satisfied with this,
glue the vertical stabilizer to the fuselage,
making sure it is 90° to the horizontal stabilizer.
Finish: Most of the airplane is finished now,
and all it lacks are the finishing touches and the
radio installation. I haven’t discussed the
canopy yet because if you plan to use a plastic
type, it needs to be mounted after you cover the
fuselage. If you plan to carve and sand a balsablock
canopy, you could mount it before you
cover the fuselage. It is a good idea to hollow
out the balsa canopy; it makes an ideal place to
mount the retract air tank.
Finish-sand the T-28 to the cross-sections
shown on the plans. Bevel the hinged part of
the control surfaces while you are finishsanding.
The more time you spend here, the
better looking the finished model will be.
Temporarily mount the rudder, elevators,
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08sig1.QXD 5/24/04 10:44 am Page 26
and ailerons, and then mount the servos and
build up the pushrods. Do the same for the
engine. Run the nose-wheel steering cable to
the nose-wheel retract unit, hook it up, and
adjust it for smooth operation. I recommend
that you use pneumatic retracts for your T-28
and route the air lines for the main gear
through the wing before you cover it.
Decide where you want to mount the
retract air tank. If you don’t plan to use a clear
canopy with a little cockpit dressing, I
recommend that you mount the air tank under
the canopy. If you use a clear canopy and
dress up the cockpit, mount the air tank
behind the wing on the bottom sheeting inside
the fuselage. Glue the tank to the bottom
sheeting using RTV. Make sure the air tank
doesn’t interfere with the elevator and rudder
pushrods.
I covered my T-28 with MonoKote, but
use whatever brand you want. Once you have
your model covered, cut away the covering
where the canopy belongs and dress up the
cockpit to suit your fancy. Glue the canopy to
the fuselage using formula 560-type glue. If
you use a cyanoacrylate-type glue for this
operation, you run the risk of permanently
fogging the canopy.
Permanently mount the rudder, elevators,
and ailerons. Hook up the servos to the
control surfaces, and check to make sure they
all operate in the correct direction and have
the recommended throw.
Install the engine and fuel tank. Install the
retract air valve and retract servo in a
convenient location. Install the radio on/off
switch and the retract air fill valve on the side
opposite the engine exhaust. Install your
receiver, but hold off on installing the battery
so you can move it around to adjust the
balance point.
Assemble the wing to the fuselage, and
check the balance point. Figure out where you
need to place the battery to achieve the correct
balance point. I placed the battery as far
forward as I could, and I still ended up adding
a lot of nose weight to get the proper CG.
Remove the wing from the fuselage, and
install the battery in the location you
determined for the balance point. Reassemble
the wing to the fuselage, pressurize the retract
air system, and make sure the retracts work
the way they are supposed to. Check to make
sure they don’t leak air excessively. Check
your wing for warps, and correct any you
find.
Flying: My first flight with the T-28 was a
near disaster. The O.S. 40 four-stroke wasn’t
putting out anywhere near full power because
of a bad glow plug, but I didn’t realize that
until I rotated and my T-28 staggered into the
air. It was barely able to climb higher than
approximately 10 feet.
So after getting roughly 200 feet away
from the runway, I decided to chop the
throttle and land the airplane in the bean field
to the north of the runway. As I walked out to
retrieve it, I thought about the one good thing
to come out of this short flight: the airplane
seemed to have excellent low-speed handling.
When I retrieved my model, I found that it
had not sustained any damage. After
changing the glow plug and readjusting the
high-speed needle on the engine, the next
flight went off much better.
Once I got the airplane to a safe altitude, I
was able to confirm that the slow-speed
handling was very good. It will slow down
quite a bit before it starts to wallow around
and then stall and drop a wing. Despite the
small chord of the ailerons, the roll rate is
respectable and the ailerons feel solid.
Vertical performance with the O.S. 40
four-stoke is nothing to write home about, but
it is more than adequate for scalelike flight.
Landings with the T-28 are a breeze. As it
gets near the runway, hold the airplane off
with up-elevator as you bleed off the
airspeed, and you will be rewarded with a
beautiful touchdown on the mains. On
pavement you will be able to hold the nose
wheel off the runway until the T-28 is nearly
stopped.
This has turned out to be a thoroughly
enjoyable airplane. The simple construction
technique, pleasant flight characteristics, and
semiscale looks have given me many hours
of satisfaction.
If you’re a beginner or an advanced flier
who is looking for something that is simple to
build and doesn’t look like the ordinary
model, this may be the airplane for you. MA
Gary Fuller
7076 E. Heather Dr.
Claremore OK 74019
[email protected]
08sig1.QXD 5/24/04 10:44 am Page 28

FOLLOWING WORLD War II, the Air Force needed a
trainer that would make it simple for the beginner pilots to
transition to the new jet fighters that were just then in
production. North American Aviation came up with the T-
28 design, and it proved to be such a good trainer that the
Navy decided it would use a version of the aircraft to train
its pilots.
The Air Force retired its T-28s from the trainer role in
the late 1950s, but the airplane saw service as a light attack
aircraft for many years thereafter. The T-28 lived on in the
Navy as a trainer until the early 1980s. Many are flown
today in civilian hands as an economical warbird.
The Model: While out at the flying field, my friend Mark
told me he was thinking about building a model of a T-28
using a profile fuselage. After talking it over with him, I
convinced Mark that I could design a T-28 model with a
fuselage that would be wide enough to fit the engine (and
hide it), and it would only be slightly more difficult to
build than the trainer with which he was learning to fly. To
further convince him, I told him it would even be able to
fit a set of retractable landing gear.
To make the model easy to build, I used flat sides on
18 MODEL AVIATION
The T-28 is highly visible in the air, thanks to the bright Navy paint scheme.
The retractable landing gear aids in achieving a scale effect.
by Gary Fuller
Famous Navy trainer re-created in
easy-to-build format
08sig1.QXD 5/24/04 10:37 am Page 18
the fuselage, as are used on a trainer. The top and bottom sheeting is
thick, and combined with the 1⁄4 balsa triangle stock in the corners, you
can almost sand the fuselage to an oval shape. The top sheeting of the
fuselage over the engine is cut away to allow easy access to the engine,
as in a trainer.
To make the T-28 easy to fly, I used a thick semisymmetrical airfoil
with a great deal of dihedral, as the full-scale T-28 has. To make the
model as economical as possible, I designed it with the .40-size engine
in mind, with which most trainers are equipped. Therefore, you should
be able to use the engine that was in your primary trainer.
The T-28 should appeal to a wide range of modelers, from those
who are moving up from a trainer to those who are more experienced
and looking for a nice-flying semiscale Sunday flier.
I generally believe that if a full-scale airplane has retractable
landing gear, a model of the aircraft won’t look right tooling around
with its gear hanging in the breeze; I designed my T-28 with this in
mind. But I do realize that the expense and trouble associated with
retracts don’t appeal to everyone, so the plans do show the provisions
for fixed gear.
I tried to design the T-28 with the novice builder in mind, but do get
some help from an experienced builder if you have never built a radiocontrolled
airplane.
CONSTRUCTION
Fuselage: The fuselage is fairly simple and straightforward. Lay both
fuselage sides on your worktable so that they are positioned top to top.
Doing this will keep you from building two left or two right sides.
Glue the 1⁄8 balsa fuselage doublers to the fuselage sides. Make sure
the shorter of the two doublers is glued to the inside of the right
fuselage side; this is so the engine will have 2° of right thrust.
Glue the 1⁄4 balsa triangle stock in place on the sides as shown on
the plans. Glue the 1⁄4 square balsa to the sides aft of the wing as shown
on the plans. Drill the holes in F1 for the engine mount, throttle cable,
and fuel lines. Glue bulkheads F2A, F2B, and F3 in place on the right
side only. Ensure that the bulkheads are 90° to the side.
Install the left side to the bulkheads. I did this by leaving the right
side on the workbench and placing the left side on the bulkheads. I
made sure the sides were aligned to each other by using a carpenter’s
square to check at various places on the top and bottom of the fuselage
sides.
Install the firewall F1. Glue in the 1⁄4 plywood nose-wheel retract
mount plate, the 1⁄16 plywood fuel-tank compartment floor, and the 1⁄4
plywood wing-mount plate. Glue the 1⁄4-inch balsa triangle to F1, F2B,
the nose-wheel retract mount plate, and the wing-mount plate as shown
on the plans.
If you don’t plan to use retractable landing gear, you can forego
installing the 1⁄4 plywood nose-gear mounting plate. Use a steerable
nose-gear mount attached directly to the firewall, or use an engine
mount that has provisions for mounting a nose-wheel assembly.
Flip the fuselage up on its bottom and join the sides at the tail. You
will need to trim the 1⁄4-inch balsa triangle to do this. Make sure the
fuselage is not twisted or crooked as you perform this step.
Glue on the 3⁄16 balsa top sheeting with the grain running side to
side. Flip the fuselage over and glue the 3⁄16 balsa bottom sheeting to the
fuselage, aft of the wing, with the grain running side to side. Don’t glue
on the bottom sheeting forward of the wing until later. Install the nosewheel
retract unit on its mounting plate.
Put the fuselage off to the side and out of the way, and start the
wing.
Wing: The wing is slightly more difficult to build than a trainer’s, but it
is a fairly straightforward design, and you should not have any
difficulties. Cut the 3⁄8 balsa LE from medium to hard balsa. Cut the LE
so that it is approximately 3⁄16-inch wider than each rib’s LE. This will
be approximately 1 inch at R3, tapering down to roughly 13⁄16 inch at
R12. The inboard LE will taper from approximately 11⁄16 inch to 1 inch
at R3. You may want to add a bit more to be on the safe side.
Cut the R1 and R2 rib template from the plans, and glue it to a piece
of cardboard or scrap balsa for later use. I used a 3⁄8-inch-diameter
sharpened brass tube to cut the holes in R2 and R3 for the retract air
lines.
Start constructing the wing by building one side first, pinning the
outer lower main spar in place over the plans. Pin the lower forward
inboard spar in place over the plans. Place the lower aft inboard spar on
the plans, but do not pin it; it will need to be lifted up into place after the
Tim used a clear canopy and installed a pilot in his version of the
T-28 to enhance its scale appearance.
Alternate wing-mounting method uses a single 1⁄4-20 nylon bolt.
Cutouts in the mount plate are for aileron torque rods.
Tim Neal’s Thunder Tiger .40-powered T-28 built from Gary’s
plans is covered with MonoKote in an alternate Navy scheme.
August 2004 19
Photos by the author
08sig1.QXD 5/24/04 10:38 am Page 19
20 MODEL AVIATION
Don’t pin lower aft spar to plans surface; it needs to be above surface when it is
glued to ribs. Install 1⁄4 x 1⁄2-inch plywood landing-gear mounts to ribs R4 and R5, and
make sure that R4 and R5 will set at 90° to work surface before you glue landing-gear
mounts to ribs and ribs to spars.
Rubber bands hold two full gallon cans to fuselage to hold it in place while the top is
sanded to shape. Use a strip of sandpaper and the “shoe-shine” method.
The Trojan’s fuselage sides are ready to
be joined. The right fuselage side has all
the formers glued to it.
Shown is the bottom of the fuselage
looking aft. “T” pins hold the bottom
sheeting in place as the glue dries.
The firewall is drilled for the engine
mount, the fuel tubing, and the throttle
linkage before it is installed.
ribs are in place and glued to the main spar
and the forward spar.
Glue all the ribs in place on the main spar
and the forward spar, keeping them at 90° to
the work surface. Do not glue in ribs R1 and
R2 at this time because they need to be glued
at an angle later.
Put the upper spars in place over the ribs,
and glue them to all the ribs except R1 and
R2. Pull the lower aft inboard spar up into the
slot cut for it in each rib and glue in place
except for ribs R1 and R2. Glue the 1⁄4 balsa
TE in place on all the ribs except R1 and R2.
Glue the outboard 3⁄8 balsa LE in place on all
the ribs, and sand it flush with R3.
Using the R1 and R2 angle template, glue
R2 in place on all the spars, and then do the
same for R1. Glue the inboard LE to R3 and
R2, and make sure R2 is still at the correct
angle using the R1 and R2 angle template.
For retractable landing gear, glue the 1⁄2 x
3⁄8-inch hardwood landing-gear mounts in
place in R4 and R5. If you plan to use fixed
landing gear, glue the 1 x 1⁄2-inch grooved
hardwood landing-gear block to R4 and R5.
At R4, glue an additional 1 x 1⁄2 x 1⁄2-inch
grooved hardwood block on top of the
landing-gear block with the groove running
vertical and against R4, and then drill a 5⁄32-
inch-diameter hole down through the landinggear
block using the groove in the top 1 x 1⁄2 x
1⁄2-inch block as a guide.
Glue the 1⁄16 balsa shear webbing in place
to the top and bottom spars, as shown on the
plans, with the grain running vertical. Sand
the 1⁄4 balsa TE flush with the top of the ribs,
and then glue the 3⁄32 x 1-inch balsa TE
sheeting in place.
Sand an angle in the LE top sheeting to
match the angle where the sheeting will meet
the 3⁄8 balsa LE. Glue the top LE sheeting to
the 3⁄8 balsa LE, and let the glue dry without
gluing the LE sheeting to the ribs.
After the glue has dried, adhere the top LE
sheeting to the ribs. Wetting the outer surface
08sig1.QXD 5/24/04 10:39 am Page 20
Main landing-gear retract mounts need to have some wood
removed so retract units will fit. Retracts are secured to mount
with 4-40 bolts with blind nuts.
The 1⁄16 balsa shear webbing has been installed on the spars.
Webbing is installed between the spars on the aft spars.
Left wing is ready for 1⁄16 balsa shear webbing to be installed on spars. Rib R2
needs to be mounted at an angle so that it will mate correctly with fuselage.
Forward part of wing is held to fuselage with 1⁄4-inch hardwood
dowels. Install dowels before bottom of wing is sheeted.
Before fully sheeting the bottom of the wing, install main
landing-gear retract units and the air lines to supply them.
Cut R1/R2 angle template from plans; glue to scrap
wood. Use it to glue R1/R2 to spars at correct angle for
dihedral.
August 2004 21
08sig1.QXD 5/24/04 10:40 am Page 21
Fuselage sides in engine-compartment area will need small
holes cut in them for such items as engine muffler and
needle-valve extension.
The engine area is a bit tight. Top
sheeting has been cut to clear rocker arm
cover and allow cooling for engine.
Additional Specifications:
Wing chord: 83⁄4 inches (average)
Wing area: 524 square inches
Wing location: Lower fuselage
Airfoil: Semisymmetrical
Wing planform: Double tapered
Dihedral (each tip): 3 inches
Fuselage length: 461⁄4 inches
Radio compartment size: 107⁄32 (L) x 21⁄2 (W) x 83⁄4 (H) inches
Stabilizer span: 2411⁄32 inches
Stabilizer chord: 51⁄4 inches (average)
Stabilizer area: 126 square inches
Stabilizer airfoil: Flat
Stabilizer location: Top of fuselage
Vertical fin height: 83⁄4 inches (includes rudder)
Vertical fin width: 7 inches (average)
Vertical fin area: 74 square inches (includes rudder)
Recommended engine size: .32-.50 two-stroke or 40-65 four-stroke
Fuel tank size: 8-10 ounces
Landing gear: tricycle/retractable
Recommended number of channels: Five
Control functions: Rudder, elevator, aileron, throttle, retractable gear
CG (from LE): 47⁄8 inches
Elevator throws: 5⁄8 inch up; 5⁄8 inch down
Aileron throws: 5⁄16 inch up; 5⁄16 inch down
Rudder throw: 1 inch left; 1 inch right
Downthrust: 0°
Side thrust: 2° right
22 MODEL AVIATION
Left: Before sheeting forward bottom of fuselage, fit nose-gear
retract unit to 1⁄4 plywood mount. Lower bolts for engine mount will
need to be cut flush with back of firewall to clear retract unit.
Above: Before covering wing, author likes to put blob of epoxy
from inside wing to hold aileron hinges in place where they are
accessible.
Type: RC “Skinny Scale”
(semiscale)
Wingspan: 60 inches
Engine: .32-.50 two-stroke or
40-65 four-stroke
Flying weight: 6.5 pounds
Construction: Balsa and
plywood
Covering/finish: MonoKote
08sig1.QXD 5/24/04 10:43 am Page 22
August 2004 23
of the sheeting with water will help it
conform to the ribs. Glue the rest of the top
sheeting in place. Glue the 1⁄4 x 3⁄32-inch balsa
rib caps in place.
Unpin this side from the plans, and prop
up the wingtip at R12 using a 6-inch-high
block that is longer than R12 and has sides
that are 6 inches parallel to each other so that
the wing will not have any twist at the
wingtip. Glue the 3⁄8-inch square hardwood
aileron servo mounts to R1 and R2. Build the
other wing half the same way you built the
first, but go ahead and glue R1 to the other R1
without using the R1 and R2 rib template.
Unpin the wing from the building board.
Glue the 1⁄4 plywood center wing mount to R1
and R2 as shown on the plans. Fit the wing to
the fuselage, and drill the holes in the 1⁄4
plywood F2B in the fuselage using the center
wing mount as a guide. Remove the wing
from the fuselage.
Place the 1⁄4-inch hardwood dowels in the
holes to hold the wing to the fuselage. Place
the 1⁄8 plywood dowel supports on the dowels,
and then glue the supports to the forward
inboard top and bottom spars so that the 1⁄4-
inch dowels are 90° to the 1⁄4-inch wingmount
block and parallel to each other. Glue
the 1⁄4-inch dowels to the 1⁄4 plywood wing
mount and to the 1⁄8 plywood dowel supports.
Begin sheeting the bottom of half of the
wing by gluing the LE sheeting to the 3⁄8-inch
LE, as you did for the top LE sheeting. When
the glue has dried, use slow-drying
cyanoacrylate to glue the sheeting to the ribs.
If you wet the sheeting, place the wing on the
building board and weight it down until the
sheeting has dried. Prop up the other half of
the wing with the 6-inch block while the
sheeting dries.
Glue the LE sheeting on the other wing
half using this same method. After the LE
sheeting has dried, remove the building tabs
from the bottom of the ribs, sand the 1⁄4-inch
TE flush with the ribs, and then glue the 1 x
3⁄32-inch balsa TE sheeting in place.
Before the rest of the bottom sheeting is
installed, fit the main landing-gear retracts in
place and run the air lines to the center of the
wing. Trim ribs R3 and R4 as necessary to fit
the retract units and wheels when the wheels
are in the up position. Glue the rest of the
bottom sheeting in place along with the 1⁄4 x
3⁄32-inch rib caps.
Cut the slots for the aileron hinges in the
wing’s TE. Install the hinges in the wing, and
then temporarily tack-glue the 1⁄4 x 1-inch
balsa TE to the wing. Sand the 1⁄4 x 1-inch TE
to match the wing airfoil’s contour.
Remove the TE from the wing, and cut the
aileron from the inboard section of the TE.
Cut a groove in the TE to accept the aileron
torque rods. Lubricate the torque rods’
bearings with Vaseline or such so that the
glue will not cause the rods to stick to the
bearing, and then glue the torque-rod bearings
to the TEs. Make sure they can rotate freely,
and then glue the TE to the wing.
Score the 1⁄16 plywood wing-mount plate
down its centerline so that it can be “cracked”
and bent so it will conform to the dihedral.
Glue the plate to the TE as shown on the
Full-Size Plans Available—see page 191
08sig1.QXD 5/24/04 10:43 am Page 23
24 MODEL AVIATION
plans. Glue the wingtip blocks to the wingtip,
and then sand them to shape. Sand the LE to
match the airfoil as shown on the plans.
Reinforce the center-section of the wing on
the top and bottom with 2-inch-wide, 6-ounce
fiberglass cloth. Cut the opening in the centersection
of the wing for the aileron servo, and
trim rib R1 to fit the servo. Cut a small
opening for the retract air lines.
Place the fuselage upside down on your
workbench, and secure it so it won’t move.
Install the wing on the fuselage. You may
need to trim the holes in the F2B plate for the
1⁄4-inch dowels so that the wing will fit to the
fuselage properly.
Once you are satisfied with the fit of the
wing to the fuselage, align the wing so that it
is square to the fuselage, and then drill the
wing-bolt holes in the wing and wing-mount
plate. To do this, place weights on the wing so
that it is held securely to the fuselage while
you measure from the center of the fuselage to
where the rudder mounts to the wing TE at the
tips. (I use the place where the tip blocks join
the wing at the TE.) Adjust the wing so that
these measurements are the same.
Once you are satisfied that the wing is
aligned correctly, drill a 13⁄64-inch hole
through the 1⁄16 plywood wing-bolt
reinforcement and the 1⁄4-inch wing-mount
plate in the fuselage. Remove the wing from
the fuselage, and then tap the wing-mount
plate in the fuselage with a 1⁄4-20 tap. You can
use some thin cyanoacrylate-type glue to
strengthen the threads in the plywood.
Use a 1⁄4-inch drill bit to enlarge the hole in
the wing plate so that a 1⁄4-20 nylon bolt will
fit through it. Bolt the wing to the fuselage,
recheck the alignment, and then drill the hole
for the other bolt the same way you drilled the
first hole.
Keep the wing mounted to the fuselage,
and cut the landing-gear struts to the correct
length. I did this using the following method
and utilizing adjustable axles. On the nosegear
retract unit I installed the strut for the
nose wheel. I cut the strut a little long for the
axle so that when the wheel is up, there is a
slight gap between the wheel and the forward
wing-mounting plate.
With the axle and wheel mounted to the
strut, I retracted the nose wheel into the
fuselage to check the clearance. I adjusted the
axle on the strut to the correct location for the
wheel clearance and tightened the axle on the
strut. I extended the wheel and removed it
from the axle. I cut the strut flush with the axle
and soldered the axle to the strut. After that, I
reinstalled the nose wheel so I could move on
to the main gear.
I installed the struts on the main landinggear
retract units and installed the axles and
wheels. I flipped the airplane over and set it on
the bench on the landing gear. (You may need
to put some weight on the front of the fuselage
so it won’t sit on the tail.)
I adjusted the position of the main gear
axles so that the fuselage sat in a level
position fore and aft and side to side, and I
tightened the axles on the struts. Make sure
the wheels are aligned so the model will
roll straight ahead. I removed the wheels
and cut the struts flush with the axles, and
08sig1.QXD 5/24/04 10:43 am Page 24
then I soldered the axles to the struts.
Now is a good time to glue the 1⁄8-inch
balsa belly pan sides to the wing along with
the F3A bulkhead and the 3⁄16-inch belly pan
bottom sheeting.
Remove the wing from the fuselage, and
cut the bottom sheeting for the main wheels
to retract into. You accomplish this by
mounting the wheels to the axle and then
actuating the retract unit by hand so that the
main wheel is lying against the sheeting.
Mark the sheeting around the wheel and
strut. Move the wheels to the down position,
and cut the sheeting where you marked it for
the wheels and strut. Move the wheel to the
up position, and trim the hole and ribs R3 and
R4 so the wheel and strut fits into the wing.
You need to trim the sheeting so that there
is roughly 1⁄4 inch of clearance around the
wheel and strut. This is necessary for those
not-so-pretty landings that may bend the
struts. If you want, you can line the openings
with 1⁄16 balsa now, but this is not shown on
the plans.
Sheet the bottom of the forward fuselage,
and cut the bottom sheeting for the nosewheel
opening as you did for the main
wheels.
Glue all the pieces together for the vertical
stabilizer. Hinge the rudder to the vertical
stabilizer, but don’t glue the hinges in place.
Hinge the elevators to the horizontal
stabilizer, but don’t glue those hinges either.
Glue the piece that separates the elevators
to the horizontal stabilizer. Cut a groove in
the bottom of the center of the horizontal
stabilizer for the music-wire elevator joiner.
Mark the elevators for the location on the
joiner, and drill the hole and cut a groove for
it in each elevator. Remove the elevators and
the rudder from the stabilizers. Set them
aside.
Refit the wing to the fuselage, and mount
the horizontal and vertical stabilizers. To do
this, place the fuselage on the workbench,
right side up, and secure it so it won’t move.
Adjust the fuselage position to get the wing
sitting level fore and aft by measuring at the
center of the LE of the wing and the TE of the
wing to the workbench, and then adjust the
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position of the fuselage so these are the same
distance from the workbench. You do this so
you can set the wing a stabilizer incidence.
Pin the horizontal stabilizer in place on the
back of the fuselage. Get a few feet out in front
of the fuselage and sight down along the
fuselage toward the horizontal stabilizer.
Compare the position of the stabilizer to the
wing, and look to see if it is tipped to one side
or the other. Sand the high side of the
horizontal stabilizer mounting area if necessary
so that the stabilizer is not tilted.
Measure the distance from the LE and the
TE of the stabilizer to the workbench surface.
These need to be the same so that the incidence
angle between the horizontal stabilizer and the
wing are 0° to each other. Sand the horizontal
stabilizer mounting area if necessary to achieve
this. Double-check the horizontal stabilizer to
make sure it is not tipped to the side compared
to the wing.
Measure from the wing TE at the tip to the
horizontal stabilizer TE at the tip on both sides
of the fuselage, and adjust the horizontal
stabilizer so these are the same. When you are
satisfied with the stabilizer’s alignment, glue it
in place on the fuselage. Make sure the elevator
joiner is installed in the horizontal stabilizer
center when the horizontal stabilizer is glued in
place.
Pin the vertical stabilizer in place while the
fuselage is still mounted on the bench. Sight
down the front of the fuselage toward the tail,
and align the stabilizer with the centerline of
the fuselage. When you are satisfied with this,
glue the vertical stabilizer to the fuselage,
making sure it is 90° to the horizontal stabilizer.
Finish: Most of the airplane is finished now,
and all it lacks are the finishing touches and the
radio installation. I haven’t discussed the
canopy yet because if you plan to use a plastic
type, it needs to be mounted after you cover the
fuselage. If you plan to carve and sand a balsablock
canopy, you could mount it before you
cover the fuselage. It is a good idea to hollow
out the balsa canopy; it makes an ideal place to
mount the retract air tank.
Finish-sand the T-28 to the cross-sections
shown on the plans. Bevel the hinged part of
the control surfaces while you are finishsanding.
The more time you spend here, the
better looking the finished model will be.
Temporarily mount the rudder, elevators,
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08sig1.QXD 5/24/04 10:44 am Page 26
and ailerons, and then mount the servos and
build up the pushrods. Do the same for the
engine. Run the nose-wheel steering cable to
the nose-wheel retract unit, hook it up, and
adjust it for smooth operation. I recommend
that you use pneumatic retracts for your T-28
and route the air lines for the main gear
through the wing before you cover it.
Decide where you want to mount the
retract air tank. If you don’t plan to use a clear
canopy with a little cockpit dressing, I
recommend that you mount the air tank under
the canopy. If you use a clear canopy and
dress up the cockpit, mount the air tank
behind the wing on the bottom sheeting inside
the fuselage. Glue the tank to the bottom
sheeting using RTV. Make sure the air tank
doesn’t interfere with the elevator and rudder
pushrods.
I covered my T-28 with MonoKote, but
use whatever brand you want. Once you have
your model covered, cut away the covering
where the canopy belongs and dress up the
cockpit to suit your fancy. Glue the canopy to
the fuselage using formula 560-type glue. If
you use a cyanoacrylate-type glue for this
operation, you run the risk of permanently
fogging the canopy.
Permanently mount the rudder, elevators,
and ailerons. Hook up the servos to the
control surfaces, and check to make sure they
all operate in the correct direction and have
the recommended throw.
Install the engine and fuel tank. Install the
retract air valve and retract servo in a
convenient location. Install the radio on/off
switch and the retract air fill valve on the side
opposite the engine exhaust. Install your
receiver, but hold off on installing the battery
so you can move it around to adjust the
balance point.
Assemble the wing to the fuselage, and
check the balance point. Figure out where you
need to place the battery to achieve the correct
balance point. I placed the battery as far
forward as I could, and I still ended up adding
a lot of nose weight to get the proper CG.
Remove the wing from the fuselage, and
install the battery in the location you
determined for the balance point. Reassemble
the wing to the fuselage, pressurize the retract
air system, and make sure the retracts work
the way they are supposed to. Check to make
sure they don’t leak air excessively. Check
your wing for warps, and correct any you
find.
Flying: My first flight with the T-28 was a
near disaster. The O.S. 40 four-stroke wasn’t
putting out anywhere near full power because
of a bad glow plug, but I didn’t realize that
until I rotated and my T-28 staggered into the
air. It was barely able to climb higher than
approximately 10 feet.
So after getting roughly 200 feet away
from the runway, I decided to chop the
throttle and land the airplane in the bean field
to the north of the runway. As I walked out to
retrieve it, I thought about the one good thing
to come out of this short flight: the airplane
seemed to have excellent low-speed handling.
When I retrieved my model, I found that it
had not sustained any damage. After
changing the glow plug and readjusting the
high-speed needle on the engine, the next
flight went off much better.
Once I got the airplane to a safe altitude, I
was able to confirm that the slow-speed
handling was very good. It will slow down
quite a bit before it starts to wallow around
and then stall and drop a wing. Despite the
small chord of the ailerons, the roll rate is
respectable and the ailerons feel solid.
Vertical performance with the O.S. 40
four-stoke is nothing to write home about, but
it is more than adequate for scalelike flight.
Landings with the T-28 are a breeze. As it
gets near the runway, hold the airplane off
with up-elevator as you bleed off the
airspeed, and you will be rewarded with a
beautiful touchdown on the mains. On
pavement you will be able to hold the nose
wheel off the runway until the T-28 is nearly
stopped.
This has turned out to be a thoroughly
enjoyable airplane. The simple construction
technique, pleasant flight characteristics, and
semiscale looks have given me many hours
of satisfaction.
If you’re a beginner or an advanced flier
who is looking for something that is simple to
build and doesn’t look like the ordinary
model, this may be the airplane for you. MA
Gary Fuller
7076 E. Heather Dr.
Claremore OK 74019
[email protected]
08sig1.QXD 5/24/04 10:44 am Page 28

FOLLOWING WORLD War II, the Air Force needed a
trainer that would make it simple for the beginner pilots to
transition to the new jet fighters that were just then in
production. North American Aviation came up with the T-
28 design, and it proved to be such a good trainer that the
Navy decided it would use a version of the aircraft to train
its pilots.
The Air Force retired its T-28s from the trainer role in
the late 1950s, but the airplane saw service as a light attack
aircraft for many years thereafter. The T-28 lived on in the
Navy as a trainer until the early 1980s. Many are flown
today in civilian hands as an economical warbird.
The Model: While out at the flying field, my friend Mark
told me he was thinking about building a model of a T-28
using a profile fuselage. After talking it over with him, I
convinced Mark that I could design a T-28 model with a
fuselage that would be wide enough to fit the engine (and
hide it), and it would only be slightly more difficult to
build than the trainer with which he was learning to fly. To
further convince him, I told him it would even be able to
fit a set of retractable landing gear.
To make the model easy to build, I used flat sides on
18 MODEL AVIATION
The T-28 is highly visible in the air, thanks to the bright Navy paint scheme.
The retractable landing gear aids in achieving a scale effect.
by Gary Fuller
Famous Navy trainer re-created in
easy-to-build format
08sig1.QXD 5/24/04 10:37 am Page 18
the fuselage, as are used on a trainer. The top and bottom sheeting is
thick, and combined with the 1⁄4 balsa triangle stock in the corners, you
can almost sand the fuselage to an oval shape. The top sheeting of the
fuselage over the engine is cut away to allow easy access to the engine,
as in a trainer.
To make the T-28 easy to fly, I used a thick semisymmetrical airfoil
with a great deal of dihedral, as the full-scale T-28 has. To make the
model as economical as possible, I designed it with the .40-size engine
in mind, with which most trainers are equipped. Therefore, you should
be able to use the engine that was in your primary trainer.
The T-28 should appeal to a wide range of modelers, from those
who are moving up from a trainer to those who are more experienced
and looking for a nice-flying semiscale Sunday flier.
I generally believe that if a full-scale airplane has retractable
landing gear, a model of the aircraft won’t look right tooling around
with its gear hanging in the breeze; I designed my T-28 with this in
mind. But I do realize that the expense and trouble associated with
retracts don’t appeal to everyone, so the plans do show the provisions
for fixed gear.
I tried to design the T-28 with the novice builder in mind, but do get
some help from an experienced builder if you have never built a radiocontrolled
airplane.
CONSTRUCTION
Fuselage: The fuselage is fairly simple and straightforward. Lay both
fuselage sides on your worktable so that they are positioned top to top.
Doing this will keep you from building two left or two right sides.
Glue the 1⁄8 balsa fuselage doublers to the fuselage sides. Make sure
the shorter of the two doublers is glued to the inside of the right
fuselage side; this is so the engine will have 2° of right thrust.
Glue the 1⁄4 balsa triangle stock in place on the sides as shown on
the plans. Glue the 1⁄4 square balsa to the sides aft of the wing as shown
on the plans. Drill the holes in F1 for the engine mount, throttle cable,
and fuel lines. Glue bulkheads F2A, F2B, and F3 in place on the right
side only. Ensure that the bulkheads are 90° to the side.
Install the left side to the bulkheads. I did this by leaving the right
side on the workbench and placing the left side on the bulkheads. I
made sure the sides were aligned to each other by using a carpenter’s
square to check at various places on the top and bottom of the fuselage
sides.
Install the firewall F1. Glue in the 1⁄4 plywood nose-wheel retract
mount plate, the 1⁄16 plywood fuel-tank compartment floor, and the 1⁄4
plywood wing-mount plate. Glue the 1⁄4-inch balsa triangle to F1, F2B,
the nose-wheel retract mount plate, and the wing-mount plate as shown
on the plans.
If you don’t plan to use retractable landing gear, you can forego
installing the 1⁄4 plywood nose-gear mounting plate. Use a steerable
nose-gear mount attached directly to the firewall, or use an engine
mount that has provisions for mounting a nose-wheel assembly.
Flip the fuselage up on its bottom and join the sides at the tail. You
will need to trim the 1⁄4-inch balsa triangle to do this. Make sure the
fuselage is not twisted or crooked as you perform this step.
Glue on the 3⁄16 balsa top sheeting with the grain running side to
side. Flip the fuselage over and glue the 3⁄16 balsa bottom sheeting to the
fuselage, aft of the wing, with the grain running side to side. Don’t glue
on the bottom sheeting forward of the wing until later. Install the nosewheel
retract unit on its mounting plate.
Put the fuselage off to the side and out of the way, and start the
wing.
Wing: The wing is slightly more difficult to build than a trainer’s, but it
is a fairly straightforward design, and you should not have any
difficulties. Cut the 3⁄8 balsa LE from medium to hard balsa. Cut the LE
so that it is approximately 3⁄16-inch wider than each rib’s LE. This will
be approximately 1 inch at R3, tapering down to roughly 13⁄16 inch at
R12. The inboard LE will taper from approximately 11⁄16 inch to 1 inch
at R3. You may want to add a bit more to be on the safe side.
Cut the R1 and R2 rib template from the plans, and glue it to a piece
of cardboard or scrap balsa for later use. I used a 3⁄8-inch-diameter
sharpened brass tube to cut the holes in R2 and R3 for the retract air
lines.
Start constructing the wing by building one side first, pinning the
outer lower main spar in place over the plans. Pin the lower forward
inboard spar in place over the plans. Place the lower aft inboard spar on
the plans, but do not pin it; it will need to be lifted up into place after the
Tim used a clear canopy and installed a pilot in his version of the
T-28 to enhance its scale appearance.
Alternate wing-mounting method uses a single 1⁄4-20 nylon bolt.
Cutouts in the mount plate are for aileron torque rods.
Tim Neal’s Thunder Tiger .40-powered T-28 built from Gary’s
plans is covered with MonoKote in an alternate Navy scheme.
August 2004 19
Photos by the author
08sig1.QXD 5/24/04 10:38 am Page 19
20 MODEL AVIATION
Don’t pin lower aft spar to plans surface; it needs to be above surface when it is
glued to ribs. Install 1⁄4 x 1⁄2-inch plywood landing-gear mounts to ribs R4 and R5, and
make sure that R4 and R5 will set at 90° to work surface before you glue landing-gear
mounts to ribs and ribs to spars.
Rubber bands hold two full gallon cans to fuselage to hold it in place while the top is
sanded to shape. Use a strip of sandpaper and the “shoe-shine” method.
The Trojan’s fuselage sides are ready to
be joined. The right fuselage side has all
the formers glued to it.
Shown is the bottom of the fuselage
looking aft. “T” pins hold the bottom
sheeting in place as the glue dries.
The firewall is drilled for the engine
mount, the fuel tubing, and the throttle
linkage before it is installed.
ribs are in place and glued to the main spar
and the forward spar.
Glue all the ribs in place on the main spar
and the forward spar, keeping them at 90° to
the work surface. Do not glue in ribs R1 and
R2 at this time because they need to be glued
at an angle later.
Put the upper spars in place over the ribs,
and glue them to all the ribs except R1 and
R2. Pull the lower aft inboard spar up into the
slot cut for it in each rib and glue in place
except for ribs R1 and R2. Glue the 1⁄4 balsa
TE in place on all the ribs except R1 and R2.
Glue the outboard 3⁄8 balsa LE in place on all
the ribs, and sand it flush with R3.
Using the R1 and R2 angle template, glue
R2 in place on all the spars, and then do the
same for R1. Glue the inboard LE to R3 and
R2, and make sure R2 is still at the correct
angle using the R1 and R2 angle template.
For retractable landing gear, glue the 1⁄2 x
3⁄8-inch hardwood landing-gear mounts in
place in R4 and R5. If you plan to use fixed
landing gear, glue the 1 x 1⁄2-inch grooved
hardwood landing-gear block to R4 and R5.
At R4, glue an additional 1 x 1⁄2 x 1⁄2-inch
grooved hardwood block on top of the
landing-gear block with the groove running
vertical and against R4, and then drill a 5⁄32-
inch-diameter hole down through the landinggear
block using the groove in the top 1 x 1⁄2 x
1⁄2-inch block as a guide.
Glue the 1⁄16 balsa shear webbing in place
to the top and bottom spars, as shown on the
plans, with the grain running vertical. Sand
the 1⁄4 balsa TE flush with the top of the ribs,
and then glue the 3⁄32 x 1-inch balsa TE
sheeting in place.
Sand an angle in the LE top sheeting to
match the angle where the sheeting will meet
the 3⁄8 balsa LE. Glue the top LE sheeting to
the 3⁄8 balsa LE, and let the glue dry without
gluing the LE sheeting to the ribs.
After the glue has dried, adhere the top LE
sheeting to the ribs. Wetting the outer surface
08sig1.QXD 5/24/04 10:39 am Page 20
Main landing-gear retract mounts need to have some wood
removed so retract units will fit. Retracts are secured to mount
with 4-40 bolts with blind nuts.
The 1⁄16 balsa shear webbing has been installed on the spars.
Webbing is installed between the spars on the aft spars.
Left wing is ready for 1⁄16 balsa shear webbing to be installed on spars. Rib R2
needs to be mounted at an angle so that it will mate correctly with fuselage.
Forward part of wing is held to fuselage with 1⁄4-inch hardwood
dowels. Install dowels before bottom of wing is sheeted.
Before fully sheeting the bottom of the wing, install main
landing-gear retract units and the air lines to supply them.
Cut R1/R2 angle template from plans; glue to scrap
wood. Use it to glue R1/R2 to spars at correct angle for
dihedral.
August 2004 21
08sig1.QXD 5/24/04 10:40 am Page 21
Fuselage sides in engine-compartment area will need small
holes cut in them for such items as engine muffler and
needle-valve extension.
The engine area is a bit tight. Top
sheeting has been cut to clear rocker arm
cover and allow cooling for engine.
Additional Specifications:
Wing chord: 83⁄4 inches (average)
Wing area: 524 square inches
Wing location: Lower fuselage
Airfoil: Semisymmetrical
Wing planform: Double tapered
Dihedral (each tip): 3 inches
Fuselage length: 461⁄4 inches
Radio compartment size: 107⁄32 (L) x 21⁄2 (W) x 83⁄4 (H) inches
Stabilizer span: 2411⁄32 inches
Stabilizer chord: 51⁄4 inches (average)
Stabilizer area: 126 square inches
Stabilizer airfoil: Flat
Stabilizer location: Top of fuselage
Vertical fin height: 83⁄4 inches (includes rudder)
Vertical fin width: 7 inches (average)
Vertical fin area: 74 square inches (includes rudder)
Recommended engine size: .32-.50 two-stroke or 40-65 four-stroke
Fuel tank size: 8-10 ounces
Landing gear: tricycle/retractable
Recommended number of channels: Five
Control functions: Rudder, elevator, aileron, throttle, retractable gear
CG (from LE): 47⁄8 inches
Elevator throws: 5⁄8 inch up; 5⁄8 inch down
Aileron throws: 5⁄16 inch up; 5⁄16 inch down
Rudder throw: 1 inch left; 1 inch right
Downthrust: 0°
Side thrust: 2° right
22 MODEL AVIATION
Left: Before sheeting forward bottom of fuselage, fit nose-gear
retract unit to 1⁄4 plywood mount. Lower bolts for engine mount will
need to be cut flush with back of firewall to clear retract unit.
Above: Before covering wing, author likes to put blob of epoxy
from inside wing to hold aileron hinges in place where they are
accessible.
Type: RC “Skinny Scale”
(semiscale)
Wingspan: 60 inches
Engine: .32-.50 two-stroke or
40-65 four-stroke
Flying weight: 6.5 pounds
Construction: Balsa and
plywood
Covering/finish: MonoKote
08sig1.QXD 5/24/04 10:43 am Page 22
August 2004 23
of the sheeting with water will help it
conform to the ribs. Glue the rest of the top
sheeting in place. Glue the 1⁄4 x 3⁄32-inch balsa
rib caps in place.
Unpin this side from the plans, and prop
up the wingtip at R12 using a 6-inch-high
block that is longer than R12 and has sides
that are 6 inches parallel to each other so that
the wing will not have any twist at the
wingtip. Glue the 3⁄8-inch square hardwood
aileron servo mounts to R1 and R2. Build the
other wing half the same way you built the
first, but go ahead and glue R1 to the other R1
without using the R1 and R2 rib template.
Unpin the wing from the building board.
Glue the 1⁄4 plywood center wing mount to R1
and R2 as shown on the plans. Fit the wing to
the fuselage, and drill the holes in the 1⁄4
plywood F2B in the fuselage using the center
wing mount as a guide. Remove the wing
from the fuselage.
Place the 1⁄4-inch hardwood dowels in the
holes to hold the wing to the fuselage. Place
the 1⁄8 plywood dowel supports on the dowels,
and then glue the supports to the forward
inboard top and bottom spars so that the 1⁄4-
inch dowels are 90° to the 1⁄4-inch wingmount
block and parallel to each other. Glue
the 1⁄4-inch dowels to the 1⁄4 plywood wing
mount and to the 1⁄8 plywood dowel supports.
Begin sheeting the bottom of half of the
wing by gluing the LE sheeting to the 3⁄8-inch
LE, as you did for the top LE sheeting. When
the glue has dried, use slow-drying
cyanoacrylate to glue the sheeting to the ribs.
If you wet the sheeting, place the wing on the
building board and weight it down until the
sheeting has dried. Prop up the other half of
the wing with the 6-inch block while the
sheeting dries.
Glue the LE sheeting on the other wing
half using this same method. After the LE
sheeting has dried, remove the building tabs
from the bottom of the ribs, sand the 1⁄4-inch
TE flush with the ribs, and then glue the 1 x
3⁄32-inch balsa TE sheeting in place.
Before the rest of the bottom sheeting is
installed, fit the main landing-gear retracts in
place and run the air lines to the center of the
wing. Trim ribs R3 and R4 as necessary to fit
the retract units and wheels when the wheels
are in the up position. Glue the rest of the
bottom sheeting in place along with the 1⁄4 x
3⁄32-inch rib caps.
Cut the slots for the aileron hinges in the
wing’s TE. Install the hinges in the wing, and
then temporarily tack-glue the 1⁄4 x 1-inch
balsa TE to the wing. Sand the 1⁄4 x 1-inch TE
to match the wing airfoil’s contour.
Remove the TE from the wing, and cut the
aileron from the inboard section of the TE.
Cut a groove in the TE to accept the aileron
torque rods. Lubricate the torque rods’
bearings with Vaseline or such so that the
glue will not cause the rods to stick to the
bearing, and then glue the torque-rod bearings
to the TEs. Make sure they can rotate freely,
and then glue the TE to the wing.
Score the 1⁄16 plywood wing-mount plate
down its centerline so that it can be “cracked”
and bent so it will conform to the dihedral.
Glue the plate to the TE as shown on the
Full-Size Plans Available—see page 191
08sig1.QXD 5/24/04 10:43 am Page 23
24 MODEL AVIATION
plans. Glue the wingtip blocks to the wingtip,
and then sand them to shape. Sand the LE to
match the airfoil as shown on the plans.
Reinforce the center-section of the wing on
the top and bottom with 2-inch-wide, 6-ounce
fiberglass cloth. Cut the opening in the centersection
of the wing for the aileron servo, and
trim rib R1 to fit the servo. Cut a small
opening for the retract air lines.
Place the fuselage upside down on your
workbench, and secure it so it won’t move.
Install the wing on the fuselage. You may
need to trim the holes in the F2B plate for the
1⁄4-inch dowels so that the wing will fit to the
fuselage properly.
Once you are satisfied with the fit of the
wing to the fuselage, align the wing so that it
is square to the fuselage, and then drill the
wing-bolt holes in the wing and wing-mount
plate. To do this, place weights on the wing so
that it is held securely to the fuselage while
you measure from the center of the fuselage to
where the rudder mounts to the wing TE at the
tips. (I use the place where the tip blocks join
the wing at the TE.) Adjust the wing so that
these measurements are the same.
Once you are satisfied that the wing is
aligned correctly, drill a 13⁄64-inch hole
through the 1⁄16 plywood wing-bolt
reinforcement and the 1⁄4-inch wing-mount
plate in the fuselage. Remove the wing from
the fuselage, and then tap the wing-mount
plate in the fuselage with a 1⁄4-20 tap. You can
use some thin cyanoacrylate-type glue to
strengthen the threads in the plywood.
Use a 1⁄4-inch drill bit to enlarge the hole in
the wing plate so that a 1⁄4-20 nylon bolt will
fit through it. Bolt the wing to the fuselage,
recheck the alignment, and then drill the hole
for the other bolt the same way you drilled the
first hole.
Keep the wing mounted to the fuselage,
and cut the landing-gear struts to the correct
length. I did this using the following method
and utilizing adjustable axles. On the nosegear
retract unit I installed the strut for the
nose wheel. I cut the strut a little long for the
axle so that when the wheel is up, there is a
slight gap between the wheel and the forward
wing-mounting plate.
With the axle and wheel mounted to the
strut, I retracted the nose wheel into the
fuselage to check the clearance. I adjusted the
axle on the strut to the correct location for the
wheel clearance and tightened the axle on the
strut. I extended the wheel and removed it
from the axle. I cut the strut flush with the axle
and soldered the axle to the strut. After that, I
reinstalled the nose wheel so I could move on
to the main gear.
I installed the struts on the main landinggear
retract units and installed the axles and
wheels. I flipped the airplane over and set it on
the bench on the landing gear. (You may need
to put some weight on the front of the fuselage
so it won’t sit on the tail.)
I adjusted the position of the main gear
axles so that the fuselage sat in a level
position fore and aft and side to side, and I
tightened the axles on the struts. Make sure
the wheels are aligned so the model will
roll straight ahead. I removed the wheels
and cut the struts flush with the axles, and
08sig1.QXD 5/24/04 10:43 am Page 24
then I soldered the axles to the struts.
Now is a good time to glue the 1⁄8-inch
balsa belly pan sides to the wing along with
the F3A bulkhead and the 3⁄16-inch belly pan
bottom sheeting.
Remove the wing from the fuselage, and
cut the bottom sheeting for the main wheels
to retract into. You accomplish this by
mounting the wheels to the axle and then
actuating the retract unit by hand so that the
main wheel is lying against the sheeting.
Mark the sheeting around the wheel and
strut. Move the wheels to the down position,
and cut the sheeting where you marked it for
the wheels and strut. Move the wheel to the
up position, and trim the hole and ribs R3 and
R4 so the wheel and strut fits into the wing.
You need to trim the sheeting so that there
is roughly 1⁄4 inch of clearance around the
wheel and strut. This is necessary for those
not-so-pretty landings that may bend the
struts. If you want, you can line the openings
with 1⁄16 balsa now, but this is not shown on
the plans.
Sheet the bottom of the forward fuselage,
and cut the bottom sheeting for the nosewheel
opening as you did for the main
wheels.
Glue all the pieces together for the vertical
stabilizer. Hinge the rudder to the vertical
stabilizer, but don’t glue the hinges in place.
Hinge the elevators to the horizontal
stabilizer, but don’t glue those hinges either.
Glue the piece that separates the elevators
to the horizontal stabilizer. Cut a groove in
the bottom of the center of the horizontal
stabilizer for the music-wire elevator joiner.
Mark the elevators for the location on the
joiner, and drill the hole and cut a groove for
it in each elevator. Remove the elevators and
the rudder from the stabilizers. Set them
aside.
Refit the wing to the fuselage, and mount
the horizontal and vertical stabilizers. To do
this, place the fuselage on the workbench,
right side up, and secure it so it won’t move.
Adjust the fuselage position to get the wing
sitting level fore and aft by measuring at the
center of the LE of the wing and the TE of the
wing to the workbench, and then adjust the
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position of the fuselage so these are the same
distance from the workbench. You do this so
you can set the wing a stabilizer incidence.
Pin the horizontal stabilizer in place on the
back of the fuselage. Get a few feet out in front
of the fuselage and sight down along the
fuselage toward the horizontal stabilizer.
Compare the position of the stabilizer to the
wing, and look to see if it is tipped to one side
or the other. Sand the high side of the
horizontal stabilizer mounting area if necessary
so that the stabilizer is not tilted.
Measure the distance from the LE and the
TE of the stabilizer to the workbench surface.
These need to be the same so that the incidence
angle between the horizontal stabilizer and the
wing are 0° to each other. Sand the horizontal
stabilizer mounting area if necessary to achieve
this. Double-check the horizontal stabilizer to
make sure it is not tipped to the side compared
to the wing.
Measure from the wing TE at the tip to the
horizontal stabilizer TE at the tip on both sides
of the fuselage, and adjust the horizontal
stabilizer so these are the same. When you are
satisfied with the stabilizer’s alignment, glue it
in place on the fuselage. Make sure the elevator
joiner is installed in the horizontal stabilizer
center when the horizontal stabilizer is glued in
place.
Pin the vertical stabilizer in place while the
fuselage is still mounted on the bench. Sight
down the front of the fuselage toward the tail,
and align the stabilizer with the centerline of
the fuselage. When you are satisfied with this,
glue the vertical stabilizer to the fuselage,
making sure it is 90° to the horizontal stabilizer.
Finish: Most of the airplane is finished now,
and all it lacks are the finishing touches and the
radio installation. I haven’t discussed the
canopy yet because if you plan to use a plastic
type, it needs to be mounted after you cover the
fuselage. If you plan to carve and sand a balsablock
canopy, you could mount it before you
cover the fuselage. It is a good idea to hollow
out the balsa canopy; it makes an ideal place to
mount the retract air tank.
Finish-sand the T-28 to the cross-sections
shown on the plans. Bevel the hinged part of
the control surfaces while you are finishsanding.
The more time you spend here, the
better looking the finished model will be.
Temporarily mount the rudder, elevators,
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08sig1.QXD 5/24/04 10:44 am Page 26
and ailerons, and then mount the servos and
build up the pushrods. Do the same for the
engine. Run the nose-wheel steering cable to
the nose-wheel retract unit, hook it up, and
adjust it for smooth operation. I recommend
that you use pneumatic retracts for your T-28
and route the air lines for the main gear
through the wing before you cover it.
Decide where you want to mount the
retract air tank. If you don’t plan to use a clear
canopy with a little cockpit dressing, I
recommend that you mount the air tank under
the canopy. If you use a clear canopy and
dress up the cockpit, mount the air tank
behind the wing on the bottom sheeting inside
the fuselage. Glue the tank to the bottom
sheeting using RTV. Make sure the air tank
doesn’t interfere with the elevator and rudder
pushrods.
I covered my T-28 with MonoKote, but
use whatever brand you want. Once you have
your model covered, cut away the covering
where the canopy belongs and dress up the
cockpit to suit your fancy. Glue the canopy to
the fuselage using formula 560-type glue. If
you use a cyanoacrylate-type glue for this
operation, you run the risk of permanently
fogging the canopy.
Permanently mount the rudder, elevators,
and ailerons. Hook up the servos to the
control surfaces, and check to make sure they
all operate in the correct direction and have
the recommended throw.
Install the engine and fuel tank. Install the
retract air valve and retract servo in a
convenient location. Install the radio on/off
switch and the retract air fill valve on the side
opposite the engine exhaust. Install your
receiver, but hold off on installing the battery
so you can move it around to adjust the
balance point.
Assemble the wing to the fuselage, and
check the balance point. Figure out where you
need to place the battery to achieve the correct
balance point. I placed the battery as far
forward as I could, and I still ended up adding
a lot of nose weight to get the proper CG.
Remove the wing from the fuselage, and
install the battery in the location you
determined for the balance point. Reassemble
the wing to the fuselage, pressurize the retract
air system, and make sure the retracts work
the way they are supposed to. Check to make
sure they don’t leak air excessively. Check
your wing for warps, and correct any you
find.
Flying: My first flight with the T-28 was a
near disaster. The O.S. 40 four-stroke wasn’t
putting out anywhere near full power because
of a bad glow plug, but I didn’t realize that
until I rotated and my T-28 staggered into the
air. It was barely able to climb higher than
approximately 10 feet.
So after getting roughly 200 feet away
from the runway, I decided to chop the
throttle and land the airplane in the bean field
to the north of the runway. As I walked out to
retrieve it, I thought about the one good thing
to come out of this short flight: the airplane
seemed to have excellent low-speed handling.
When I retrieved my model, I found that it
had not sustained any damage. After
changing the glow plug and readjusting the
high-speed needle on the engine, the next
flight went off much better.
Once I got the airplane to a safe altitude, I
was able to confirm that the slow-speed
handling was very good. It will slow down
quite a bit before it starts to wallow around
and then stall and drop a wing. Despite the
small chord of the ailerons, the roll rate is
respectable and the ailerons feel solid.
Vertical performance with the O.S. 40
four-stoke is nothing to write home about, but
it is more than adequate for scalelike flight.
Landings with the T-28 are a breeze. As it
gets near the runway, hold the airplane off
with up-elevator as you bleed off the
airspeed, and you will be rewarded with a
beautiful touchdown on the mains. On
pavement you will be able to hold the nose
wheel off the runway until the T-28 is nearly
stopped.
This has turned out to be a thoroughly
enjoyable airplane. The simple construction
technique, pleasant flight characteristics, and
semiscale looks have given me many hours
of satisfaction.
If you’re a beginner or an advanced flier
who is looking for something that is simple to
build and doesn’t look like the ordinary
model, this may be the airplane for you. MA
Gary Fuller
7076 E. Heather Dr.
Claremore OK 74019
[email protected]
08sig1.QXD 5/24/04 10:44 am Page 28

FOLLOWING WORLD War II, the Air Force needed a
trainer that would make it simple for the beginner pilots to
transition to the new jet fighters that were just then in
production. North American Aviation came up with the T-
28 design, and it proved to be such a good trainer that the
Navy decided it would use a version of the aircraft to train
its pilots.
The Air Force retired its T-28s from the trainer role in
the late 1950s, but the airplane saw service as a light attack
aircraft for many years thereafter. The T-28 lived on in the
Navy as a trainer until the early 1980s. Many are flown
today in civilian hands as an economical warbird.
The Model: While out at the flying field, my friend Mark
told me he was thinking about building a model of a T-28
using a profile fuselage. After talking it over with him, I
convinced Mark that I could design a T-28 model with a
fuselage that would be wide enough to fit the engine (and
hide it), and it would only be slightly more difficult to
build than the trainer with which he was learning to fly. To
further convince him, I told him it would even be able to
fit a set of retractable landing gear.
To make the model easy to build, I used flat sides on
18 MODEL AVIATION
The T-28 is highly visible in the air, thanks to the bright Navy paint scheme.
The retractable landing gear aids in achieving a scale effect.
by Gary Fuller
Famous Navy trainer re-created in
easy-to-build format
08sig1.QXD 5/24/04 10:37 am Page 18
the fuselage, as are used on a trainer. The top and bottom sheeting is
thick, and combined with the 1⁄4 balsa triangle stock in the corners, you
can almost sand the fuselage to an oval shape. The top sheeting of the
fuselage over the engine is cut away to allow easy access to the engine,
as in a trainer.
To make the T-28 easy to fly, I used a thick semisymmetrical airfoil
with a great deal of dihedral, as the full-scale T-28 has. To make the
model as economical as possible, I designed it with the .40-size engine
in mind, with which most trainers are equipped. Therefore, you should
be able to use the engine that was in your primary trainer.
The T-28 should appeal to a wide range of modelers, from those
who are moving up from a trainer to those who are more experienced
and looking for a nice-flying semiscale Sunday flier.
I generally believe that if a full-scale airplane has retractable
landing gear, a model of the aircraft won’t look right tooling around
with its gear hanging in the breeze; I designed my T-28 with this in
mind. But I do realize that the expense and trouble associated with
retracts don’t appeal to everyone, so the plans do show the provisions
for fixed gear.
I tried to design the T-28 with the novice builder in mind, but do get
some help from an experienced builder if you have never built a radiocontrolled
airplane.
CONSTRUCTION
Fuselage: The fuselage is fairly simple and straightforward. Lay both
fuselage sides on your worktable so that they are positioned top to top.
Doing this will keep you from building two left or two right sides.
Glue the 1⁄8 balsa fuselage doublers to the fuselage sides. Make sure
the shorter of the two doublers is glued to the inside of the right
fuselage side; this is so the engine will have 2° of right thrust.
Glue the 1⁄4 balsa triangle stock in place on the sides as shown on
the plans. Glue the 1⁄4 square balsa to the sides aft of the wing as shown
on the plans. Drill the holes in F1 for the engine mount, throttle cable,
and fuel lines. Glue bulkheads F2A, F2B, and F3 in place on the right
side only. Ensure that the bulkheads are 90° to the side.
Install the left side to the bulkheads. I did this by leaving the right
side on the workbench and placing the left side on the bulkheads. I
made sure the sides were aligned to each other by using a carpenter’s
square to check at various places on the top and bottom of the fuselage
sides.
Install the firewall F1. Glue in the 1⁄4 plywood nose-wheel retract
mount plate, the 1⁄16 plywood fuel-tank compartment floor, and the 1⁄4
plywood wing-mount plate. Glue the 1⁄4-inch balsa triangle to F1, F2B,
the nose-wheel retract mount plate, and the wing-mount plate as shown
on the plans.
If you don’t plan to use retractable landing gear, you can forego
installing the 1⁄4 plywood nose-gear mounting plate. Use a steerable
nose-gear mount attached directly to the firewall, or use an engine
mount that has provisions for mounting a nose-wheel assembly.
Flip the fuselage up on its bottom and join the sides at the tail. You
will need to trim the 1⁄4-inch balsa triangle to do this. Make sure the
fuselage is not twisted or crooked as you perform this step.
Glue on the 3⁄16 balsa top sheeting with the grain running side to
side. Flip the fuselage over and glue the 3⁄16 balsa bottom sheeting to the
fuselage, aft of the wing, with the grain running side to side. Don’t glue
on the bottom sheeting forward of the wing until later. Install the nosewheel
retract unit on its mounting plate.
Put the fuselage off to the side and out of the way, and start the
wing.
Wing: The wing is slightly more difficult to build than a trainer’s, but it
is a fairly straightforward design, and you should not have any
difficulties. Cut the 3⁄8 balsa LE from medium to hard balsa. Cut the LE
so that it is approximately 3⁄16-inch wider than each rib’s LE. This will
be approximately 1 inch at R3, tapering down to roughly 13⁄16 inch at
R12. The inboard LE will taper from approximately 11⁄16 inch to 1 inch
at R3. You may want to add a bit more to be on the safe side.
Cut the R1 and R2 rib template from the plans, and glue it to a piece
of cardboard or scrap balsa for later use. I used a 3⁄8-inch-diameter
sharpened brass tube to cut the holes in R2 and R3 for the retract air
lines.
Start constructing the wing by building one side first, pinning the
outer lower main spar in place over the plans. Pin the lower forward
inboard spar in place over the plans. Place the lower aft inboard spar on
the plans, but do not pin it; it will need to be lifted up into place after the
Tim used a clear canopy and installed a pilot in his version of the
T-28 to enhance its scale appearance.
Alternate wing-mounting method uses a single 1⁄4-20 nylon bolt.
Cutouts in the mount plate are for aileron torque rods.
Tim Neal’s Thunder Tiger .40-powered T-28 built from Gary’s
plans is covered with MonoKote in an alternate Navy scheme.
August 2004 19
Photos by the author
08sig1.QXD 5/24/04 10:38 am Page 19
20 MODEL AVIATION
Don’t pin lower aft spar to plans surface; it needs to be above surface when it is
glued to ribs. Install 1⁄4 x 1⁄2-inch plywood landing-gear mounts to ribs R4 and R5, and
make sure that R4 and R5 will set at 90° to work surface before you glue landing-gear
mounts to ribs and ribs to spars.
Rubber bands hold two full gallon cans to fuselage to hold it in place while the top is
sanded to shape. Use a strip of sandpaper and the “shoe-shine” method.
The Trojan’s fuselage sides are ready to
be joined. The right fuselage side has all
the formers glued to it.
Shown is the bottom of the fuselage
looking aft. “T” pins hold the bottom
sheeting in place as the glue dries.
The firewall is drilled for the engine
mount, the fuel tubing, and the throttle
linkage before it is installed.
ribs are in place and glued to the main spar
and the forward spar.
Glue all the ribs in place on the main spar
and the forward spar, keeping them at 90° to
the work surface. Do not glue in ribs R1 and
R2 at this time because they need to be glued
at an angle later.
Put the upper spars in place over the ribs,
and glue them to all the ribs except R1 and
R2. Pull the lower aft inboard spar up into the
slot cut for it in each rib and glue in place
except for ribs R1 and R2. Glue the 1⁄4 balsa
TE in place on all the ribs except R1 and R2.
Glue the outboard 3⁄8 balsa LE in place on all
the ribs, and sand it flush with R3.
Using the R1 and R2 angle template, glue
R2 in place on all the spars, and then do the
same for R1. Glue the inboard LE to R3 and
R2, and make sure R2 is still at the correct
angle using the R1 and R2 angle template.
For retractable landing gear, glue the 1⁄2 x
3⁄8-inch hardwood landing-gear mounts in
place in R4 and R5. If you plan to use fixed
landing gear, glue the 1 x 1⁄2-inch grooved
hardwood landing-gear block to R4 and R5.
At R4, glue an additional 1 x 1⁄2 x 1⁄2-inch
grooved hardwood block on top of the
landing-gear block with the groove running
vertical and against R4, and then drill a 5⁄32-
inch-diameter hole down through the landinggear
block using the groove in the top 1 x 1⁄2 x
1⁄2-inch block as a guide.
Glue the 1⁄16 balsa shear webbing in place
to the top and bottom spars, as shown on the
plans, with the grain running vertical. Sand
the 1⁄4 balsa TE flush with the top of the ribs,
and then glue the 3⁄32 x 1-inch balsa TE
sheeting in place.
Sand an angle in the LE top sheeting to
match the angle where the sheeting will meet
the 3⁄8 balsa LE. Glue the top LE sheeting to
the 3⁄8 balsa LE, and let the glue dry without
gluing the LE sheeting to the ribs.
After the glue has dried, adhere the top LE
sheeting to the ribs. Wetting the outer surface
08sig1.QXD 5/24/04 10:39 am Page 20
Main landing-gear retract mounts need to have some wood
removed so retract units will fit. Retracts are secured to mount
with 4-40 bolts with blind nuts.
The 1⁄16 balsa shear webbing has been installed on the spars.
Webbing is installed between the spars on the aft spars.
Left wing is ready for 1⁄16 balsa shear webbing to be installed on spars. Rib R2
needs to be mounted at an angle so that it will mate correctly with fuselage.
Forward part of wing is held to fuselage with 1⁄4-inch hardwood
dowels. Install dowels before bottom of wing is sheeted.
Before fully sheeting the bottom of the wing, install main
landing-gear retract units and the air lines to supply them.
Cut R1/R2 angle template from plans; glue to scrap
wood. Use it to glue R1/R2 to spars at correct angle for
dihedral.
August 2004 21
08sig1.QXD 5/24/04 10:40 am Page 21
Fuselage sides in engine-compartment area will need small
holes cut in them for such items as engine muffler and
needle-valve extension.
The engine area is a bit tight. Top
sheeting has been cut to clear rocker arm
cover and allow cooling for engine.
Additional Specifications:
Wing chord: 83⁄4 inches (average)
Wing area: 524 square inches
Wing location: Lower fuselage
Airfoil: Semisymmetrical
Wing planform: Double tapered
Dihedral (each tip): 3 inches
Fuselage length: 461⁄4 inches
Radio compartment size: 107⁄32 (L) x 21⁄2 (W) x 83⁄4 (H) inches
Stabilizer span: 2411⁄32 inches
Stabilizer chord: 51⁄4 inches (average)
Stabilizer area: 126 square inches
Stabilizer airfoil: Flat
Stabilizer location: Top of fuselage
Vertical fin height: 83⁄4 inches (includes rudder)
Vertical fin width: 7 inches (average)
Vertical fin area: 74 square inches (includes rudder)
Recommended engine size: .32-.50 two-stroke or 40-65 four-stroke
Fuel tank size: 8-10 ounces
Landing gear: tricycle/retractable
Recommended number of channels: Five
Control functions: Rudder, elevator, aileron, throttle, retractable gear
CG (from LE): 47⁄8 inches
Elevator throws: 5⁄8 inch up; 5⁄8 inch down
Aileron throws: 5⁄16 inch up; 5⁄16 inch down
Rudder throw: 1 inch left; 1 inch right
Downthrust: 0°
Side thrust: 2° right
22 MODEL AVIATION
Left: Before sheeting forward bottom of fuselage, fit nose-gear
retract unit to 1⁄4 plywood mount. Lower bolts for engine mount will
need to be cut flush with back of firewall to clear retract unit.
Above: Before covering wing, author likes to put blob of epoxy
from inside wing to hold aileron hinges in place where they are
accessible.
Type: RC “Skinny Scale”
(semiscale)
Wingspan: 60 inches
Engine: .32-.50 two-stroke or
40-65 four-stroke
Flying weight: 6.5 pounds
Construction: Balsa and
plywood
Covering/finish: MonoKote
08sig1.QXD 5/24/04 10:43 am Page 22
August 2004 23
of the sheeting with water will help it
conform to the ribs. Glue the rest of the top
sheeting in place. Glue the 1⁄4 x 3⁄32-inch balsa
rib caps in place.
Unpin this side from the plans, and prop
up the wingtip at R12 using a 6-inch-high
block that is longer than R12 and has sides
that are 6 inches parallel to each other so that
the wing will not have any twist at the
wingtip. Glue the 3⁄8-inch square hardwood
aileron servo mounts to R1 and R2. Build the
other wing half the same way you built the
first, but go ahead and glue R1 to the other R1
without using the R1 and R2 rib template.
Unpin the wing from the building board.
Glue the 1⁄4 plywood center wing mount to R1
and R2 as shown on the plans. Fit the wing to
the fuselage, and drill the holes in the 1⁄4
plywood F2B in the fuselage using the center
wing mount as a guide. Remove the wing
from the fuselage.
Place the 1⁄4-inch hardwood dowels in the
holes to hold the wing to the fuselage. Place
the 1⁄8 plywood dowel supports on the dowels,
and then glue the supports to the forward
inboard top and bottom spars so that the 1⁄4-
inch dowels are 90° to the 1⁄4-inch wingmount
block and parallel to each other. Glue
the 1⁄4-inch dowels to the 1⁄4 plywood wing
mount and to the 1⁄8 plywood dowel supports.
Begin sheeting the bottom of half of the
wing by gluing the LE sheeting to the 3⁄8-inch
LE, as you did for the top LE sheeting. When
the glue has dried, use slow-drying
cyanoacrylate to glue the sheeting to the ribs.
If you wet the sheeting, place the wing on the
building board and weight it down until the
sheeting has dried. Prop up the other half of
the wing with the 6-inch block while the
sheeting dries.
Glue the LE sheeting on the other wing
half using this same method. After the LE
sheeting has dried, remove the building tabs
from the bottom of the ribs, sand the 1⁄4-inch
TE flush with the ribs, and then glue the 1 x
3⁄32-inch balsa TE sheeting in place.
Before the rest of the bottom sheeting is
installed, fit the main landing-gear retracts in
place and run the air lines to the center of the
wing. Trim ribs R3 and R4 as necessary to fit
the retract units and wheels when the wheels
are in the up position. Glue the rest of the
bottom sheeting in place along with the 1⁄4 x
3⁄32-inch rib caps.
Cut the slots for the aileron hinges in the
wing’s TE. Install the hinges in the wing, and
then temporarily tack-glue the 1⁄4 x 1-inch
balsa TE to the wing. Sand the 1⁄4 x 1-inch TE
to match the wing airfoil’s contour.
Remove the TE from the wing, and cut the
aileron from the inboard section of the TE.
Cut a groove in the TE to accept the aileron
torque rods. Lubricate the torque rods’
bearings with Vaseline or such so that the
glue will not cause the rods to stick to the
bearing, and then glue the torque-rod bearings
to the TEs. Make sure they can rotate freely,
and then glue the TE to the wing.
Score the 1⁄16 plywood wing-mount plate
down its centerline so that it can be “cracked”
and bent so it will conform to the dihedral.
Glue the plate to the TE as shown on the
Full-Size Plans Available—see page 191
08sig1.QXD 5/24/04 10:43 am Page 23
24 MODEL AVIATION
plans. Glue the wingtip blocks to the wingtip,
and then sand them to shape. Sand the LE to
match the airfoil as shown on the plans.
Reinforce the center-section of the wing on
the top and bottom with 2-inch-wide, 6-ounce
fiberglass cloth. Cut the opening in the centersection
of the wing for the aileron servo, and
trim rib R1 to fit the servo. Cut a small
opening for the retract air lines.
Place the fuselage upside down on your
workbench, and secure it so it won’t move.
Install the wing on the fuselage. You may
need to trim the holes in the F2B plate for the
1⁄4-inch dowels so that the wing will fit to the
fuselage properly.
Once you are satisfied with the fit of the
wing to the fuselage, align the wing so that it
is square to the fuselage, and then drill the
wing-bolt holes in the wing and wing-mount
plate. To do this, place weights on the wing so
that it is held securely to the fuselage while
you measure from the center of the fuselage to
where the rudder mounts to the wing TE at the
tips. (I use the place where the tip blocks join
the wing at the TE.) Adjust the wing so that
these measurements are the same.
Once you are satisfied that the wing is
aligned correctly, drill a 13⁄64-inch hole
through the 1⁄16 plywood wing-bolt
reinforcement and the 1⁄4-inch wing-mount
plate in the fuselage. Remove the wing from
the fuselage, and then tap the wing-mount
plate in the fuselage with a 1⁄4-20 tap. You can
use some thin cyanoacrylate-type glue to
strengthen the threads in the plywood.
Use a 1⁄4-inch drill bit to enlarge the hole in
the wing plate so that a 1⁄4-20 nylon bolt will
fit through it. Bolt the wing to the fuselage,
recheck the alignment, and then drill the hole
for the other bolt the same way you drilled the
first hole.
Keep the wing mounted to the fuselage,
and cut the landing-gear struts to the correct
length. I did this using the following method
and utilizing adjustable axles. On the nosegear
retract unit I installed the strut for the
nose wheel. I cut the strut a little long for the
axle so that when the wheel is up, there is a
slight gap between the wheel and the forward
wing-mounting plate.
With the axle and wheel mounted to the
strut, I retracted the nose wheel into the
fuselage to check the clearance. I adjusted the
axle on the strut to the correct location for the
wheel clearance and tightened the axle on the
strut. I extended the wheel and removed it
from the axle. I cut the strut flush with the axle
and soldered the axle to the strut. After that, I
reinstalled the nose wheel so I could move on
to the main gear.
I installed the struts on the main landinggear
retract units and installed the axles and
wheels. I flipped the airplane over and set it on
the bench on the landing gear. (You may need
to put some weight on the front of the fuselage
so it won’t sit on the tail.)
I adjusted the position of the main gear
axles so that the fuselage sat in a level
position fore and aft and side to side, and I
tightened the axles on the struts. Make sure
the wheels are aligned so the model will
roll straight ahead. I removed the wheels
and cut the struts flush with the axles, and
08sig1.QXD 5/24/04 10:43 am Page 24
then I soldered the axles to the struts.
Now is a good time to glue the 1⁄8-inch
balsa belly pan sides to the wing along with
the F3A bulkhead and the 3⁄16-inch belly pan
bottom sheeting.
Remove the wing from the fuselage, and
cut the bottom sheeting for the main wheels
to retract into. You accomplish this by
mounting the wheels to the axle and then
actuating the retract unit by hand so that the
main wheel is lying against the sheeting.
Mark the sheeting around the wheel and
strut. Move the wheels to the down position,
and cut the sheeting where you marked it for
the wheels and strut. Move the wheel to the
up position, and trim the hole and ribs R3 and
R4 so the wheel and strut fits into the wing.
You need to trim the sheeting so that there
is roughly 1⁄4 inch of clearance around the
wheel and strut. This is necessary for those
not-so-pretty landings that may bend the
struts. If you want, you can line the openings
with 1⁄16 balsa now, but this is not shown on
the plans.
Sheet the bottom of the forward fuselage,
and cut the bottom sheeting for the nosewheel
opening as you did for the main
wheels.
Glue all the pieces together for the vertical
stabilizer. Hinge the rudder to the vertical
stabilizer, but don’t glue the hinges in place.
Hinge the elevators to the horizontal
stabilizer, but don’t glue those hinges either.
Glue the piece that separates the elevators
to the horizontal stabilizer. Cut a groove in
the bottom of the center of the horizontal
stabilizer for the music-wire elevator joiner.
Mark the elevators for the location on the
joiner, and drill the hole and cut a groove for
it in each elevator. Remove the elevators and
the rudder from the stabilizers. Set them
aside.
Refit the wing to the fuselage, and mount
the horizontal and vertical stabilizers. To do
this, place the fuselage on the workbench,
right side up, and secure it so it won’t move.
Adjust the fuselage position to get the wing
sitting level fore and aft by measuring at the
center of the LE of the wing and the TE of the
wing to the workbench, and then adjust the
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position of the fuselage so these are the same
distance from the workbench. You do this so
you can set the wing a stabilizer incidence.
Pin the horizontal stabilizer in place on the
back of the fuselage. Get a few feet out in front
of the fuselage and sight down along the
fuselage toward the horizontal stabilizer.
Compare the position of the stabilizer to the
wing, and look to see if it is tipped to one side
or the other. Sand the high side of the
horizontal stabilizer mounting area if necessary
so that the stabilizer is not tilted.
Measure the distance from the LE and the
TE of the stabilizer to the workbench surface.
These need to be the same so that the incidence
angle between the horizontal stabilizer and the
wing are 0° to each other. Sand the horizontal
stabilizer mounting area if necessary to achieve
this. Double-check the horizontal stabilizer to
make sure it is not tipped to the side compared
to the wing.
Measure from the wing TE at the tip to the
horizontal stabilizer TE at the tip on both sides
of the fuselage, and adjust the horizontal
stabilizer so these are the same. When you are
satisfied with the stabilizer’s alignment, glue it
in place on the fuselage. Make sure the elevator
joiner is installed in the horizontal stabilizer
center when the horizontal stabilizer is glued in
place.
Pin the vertical stabilizer in place while the
fuselage is still mounted on the bench. Sight
down the front of the fuselage toward the tail,
and align the stabilizer with the centerline of
the fuselage. When you are satisfied with this,
glue the vertical stabilizer to the fuselage,
making sure it is 90° to the horizontal stabilizer.
Finish: Most of the airplane is finished now,
and all it lacks are the finishing touches and the
radio installation. I haven’t discussed the
canopy yet because if you plan to use a plastic
type, it needs to be mounted after you cover the
fuselage. If you plan to carve and sand a balsablock
canopy, you could mount it before you
cover the fuselage. It is a good idea to hollow
out the balsa canopy; it makes an ideal place to
mount the retract air tank.
Finish-sand the T-28 to the cross-sections
shown on the plans. Bevel the hinged part of
the control surfaces while you are finishsanding.
The more time you spend here, the
better looking the finished model will be.
Temporarily mount the rudder, elevators,
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08sig1.QXD 5/24/04 10:44 am Page 26
and ailerons, and then mount the servos and
build up the pushrods. Do the same for the
engine. Run the nose-wheel steering cable to
the nose-wheel retract unit, hook it up, and
adjust it for smooth operation. I recommend
that you use pneumatic retracts for your T-28
and route the air lines for the main gear
through the wing before you cover it.
Decide where you want to mount the
retract air tank. If you don’t plan to use a clear
canopy with a little cockpit dressing, I
recommend that you mount the air tank under
the canopy. If you use a clear canopy and
dress up the cockpit, mount the air tank
behind the wing on the bottom sheeting inside
the fuselage. Glue the tank to the bottom
sheeting using RTV. Make sure the air tank
doesn’t interfere with the elevator and rudder
pushrods.
I covered my T-28 with MonoKote, but
use whatever brand you want. Once you have
your model covered, cut away the covering
where the canopy belongs and dress up the
cockpit to suit your fancy. Glue the canopy to
the fuselage using formula 560-type glue. If
you use a cyanoacrylate-type glue for this
operation, you run the risk of permanently
fogging the canopy.
Permanently mount the rudder, elevators,
and ailerons. Hook up the servos to the
control surfaces, and check to make sure they
all operate in the correct direction and have
the recommended throw.
Install the engine and fuel tank. Install the
retract air valve and retract servo in a
convenient location. Install the radio on/off
switch and the retract air fill valve on the side
opposite the engine exhaust. Install your
receiver, but hold off on installing the battery
so you can move it around to adjust the
balance point.
Assemble the wing to the fuselage, and
check the balance point. Figure out where you
need to place the battery to achieve the correct
balance point. I placed the battery as far
forward as I could, and I still ended up adding
a lot of nose weight to get the proper CG.
Remove the wing from the fuselage, and
install the battery in the location you
determined for the balance point. Reassemble
the wing to the fuselage, pressurize the retract
air system, and make sure the retracts work
the way they are supposed to. Check to make
sure they don’t leak air excessively. Check
your wing for warps, and correct any you
find.
Flying: My first flight with the T-28 was a
near disaster. The O.S. 40 four-stroke wasn’t
putting out anywhere near full power because
of a bad glow plug, but I didn’t realize that
until I rotated and my T-28 staggered into the
air. It was barely able to climb higher than
approximately 10 feet.
So after getting roughly 200 feet away
from the runway, I decided to chop the
throttle and land the airplane in the bean field
to the north of the runway. As I walked out to
retrieve it, I thought about the one good thing
to come out of this short flight: the airplane
seemed to have excellent low-speed handling.
When I retrieved my model, I found that it
had not sustained any damage. After
changing the glow plug and readjusting the
high-speed needle on the engine, the next
flight went off much better.
Once I got the airplane to a safe altitude, I
was able to confirm that the slow-speed
handling was very good. It will slow down
quite a bit before it starts to wallow around
and then stall and drop a wing. Despite the
small chord of the ailerons, the roll rate is
respectable and the ailerons feel solid.
Vertical performance with the O.S. 40
four-stoke is nothing to write home about, but
it is more than adequate for scalelike flight.
Landings with the T-28 are a breeze. As it
gets near the runway, hold the airplane off
with up-elevator as you bleed off the
airspeed, and you will be rewarded with a
beautiful touchdown on the mains. On
pavement you will be able to hold the nose
wheel off the runway until the T-28 is nearly
stopped.
This has turned out to be a thoroughly
enjoyable airplane. The simple construction
technique, pleasant flight characteristics, and
semiscale looks have given me many hours
of satisfaction.
If you’re a beginner or an advanced flier
who is looking for something that is simple to
build and doesn’t look like the ordinary
model, this may be the airplane for you. MA
Gary Fuller
7076 E. Heather Dr.
Claremore OK 74019
[email protected]
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