Top Flite TOPA0500 - Manual (Page 4)

The flaps are not difficult to build, but they do require
good craftsmanship to fit and operate well. Flaps add
nicely to the model's flight characteristics and scale
appearance. Slight trim changes are needed when flaps
are extended. The trim corrections are discussed later in
the manual during radio setup and you will find more
information on the use of the flaps in the
Flying section.
For Flaps, you will need these additional items:
Two Standard servos
Y-connector
Servo extensions (if not part of the Y-connector)
SCALE RUDDER
You may build your DC-3 with either a standard in-line
hinged rudder or a scale appearing offset pinned hinge
rudder. The in-line hinged rudder is easier to build and is
hinged to the fin the same as any other model with
supplied CA hinges. But, the offset pinned hinge features
the offset hinge line characteristic of the DC-3. The scale
appearing offset hinged rudder does require more
craftsmanship to build than the standard rudder, so study
the plans carefully and think about it before you begin
that part of the model. All hardware required to build
either version is included with this kit.
PROPELLERS
Although there is no urgency at this point to decide
which propellers to use on your DC-3, we would like to
mention that we have had great success during our flight
testing using three-blade propellers. The nice thing about
using three-blade propellers with your DC-3 is first of all,
they provide more clearance between the propeller tip
and the fuselage, and second, they are scale! On the
O.S. .25 two-strokes we ran 10 x 4 three-blade
propellers. On the O.S. .52 four-strokes we ran 10 x 6
three-blade propellers. As with any model, you may
experiment with different propellers to find out what type
works best for you. We used Great Planes Aluminum
Spinner Hubs (GPMQ4630, 1/4-28 thread) which appear
scale as well.
COMPETITION-MINDED MODELERS
We designed our DC-3 from scale three-view drawings
supplied by Scale Model Research (address follows) and
photos taken of various DC-3's. The scale of your Gold
Edition DC-3 is 1:14, or one-fourteenth scale.
If you plan to enter your DC-3 in scale competition (it’s lots
of fun, and the runways are usually paved!), this kit qualifies
for Fun Scale and the
Sportsman and Expert classes in
Sport Scale. Fun Scale and Sport Scale have the same
flight requirements where you must perform ten maneuvers
of which five are mandatory. The other five are up to you—
easy stuff like cycling your landing gear, a slow, low
“inspection pass” with flaps extended, or maybe a touch-
and-go. If you have never competed in a scale contest, you
could start out in Fun Scale. In Fun Scale, the only
documentation you need for static judging is any proof that
a full size aircraft of this type, in the paint/markings scheme
on your model, did exist. A single photo, a kit box cover,
even a painting is sufficient proof! If you’re interested,
contact the AMA for a rule book which will tell you
everything you need to know. Look in the back of the AMA
magazine (
Model Aviation ) for a schedule of events.
The trim scheme we selected for our prototype on the kit
box cover is taken from Eastern Air Lines’ DC-3-201
NC18124. The last passenger flight of this subject took
place on October 12, 1952 after logging over 57,000 hours
in the air. It was then displayed at the Smithsonian but now
resides at the new National Air & Space Museum in
Washington D.C.
If you are not concerned with a scale trim scheme you can
make a variation of the one on the box, or design your own.
If you are going to compete in scale competition use the
photos in your documentation package as a guide for your
trim scheme.
DOCUMENTATION
Three view drawings and photo packs of full size
DC-3s are available from:
Scale Model Research
3114 Yukon Ave, Costa Mesa, CA 92626
(714) 979-8058
Fax: (714) 979-7279
Other sources of scale documentation include Squadron
Signal Publication’s book No. 1149 C-47 Skytrain in
Action, and various static display models such as
Monogram’s No. 5610 1:48 scale Eastern Air Lines DC-3.
DESIGNER NOTES
THIS SECTION
CONTAINS CRITICAL INFORMATION
CONCERNING YOUR DC-3 MODEL
The Top Flite DC-3 is a sport scale model of the Douglas
DC-3. The full size aircraft is gentle and forgiving, owing to
its excellent design and limited power. It is a classic aircraft
that has been flying for over sixty years. But, as an
overpowered model, it can be difficult to fly. Past models of
the DC-3, from other companies, have had a reputation for
unforgiving flight characteristics. Not so the Top Flight
DC-3. Built according to the instructions, you will be
rewarded with an aircraft every bit as good as the full size
DC-3. It is therefore essential that you build your model
according to the instructions in this manual.
SCALE ACCURACY
The Top Flite DC-3 is a faithful reproduction of the full
size aircraft, with a few exceptions. Flight testing of the
prototype models showed the need for some changes to
improve stability so that the average sport modeler could
handle this twin engine model.
1. The chord at the wing tips has been increased by 8%
to improve the stalling characteristics.
2. The scale airfoil blends into an S8037 at the tip to
improve the stalling characteristics.
3. The wing tips have washout of 2 degrees.
4. The engine nacelles have been lengthened by 1/2" to
allow room for retractable landing gear.
5. The engine nacelles have been moved 1/2" further
away from the fuselage to improve prop clearance.
6. The vertical fin/rudder area has been increased by
25% to improve single engine handling.
7. The horizontal stab/elevator area has been increased
by 23% to improve pitch control.
8. The engines incorporate 4 degrees of left/right thrust,
and 6 degrees of down thrust.
POWER
With two .40 2-stroke engines (or .52 4-stroke) the model
will fly very well, but not in a scale-like manner, as it will be
overpowered. It will take off in under ten feet and climb like
a typical overpowered model. Many modelers will like this,
but this is not my idea of a sport scale model of a DC-3. Of
course, one could control the throttles to fly the model in a
scale-like manner and save the reserve power for times
when it could be used effectively.
- 4 -