Great Planes Yak-54 1.60 ARF - GPMA1411 - Manual (Page 33)

Dependable, redundant and fail-safe battery systems
are recommended.
The use of anti-glitch devices for long leads is recommended.
There is no maximum engine displacement limit, as it is the
position of this body that an under powered aircraft presents a
greater danger than an over powered aircraft. However, the
selections of engine size relative to airframe strength and
power loading mandates good discretionary judgment by the
designer and builder. Current AMA maximums for engine
displacement are 6.0 cu in for two-stroke and 9.6 cu in for four-
stroke engines. These maximums apply only to AMA Sanction
competition events (such as 511, 512, 515 and 520). All non
competition events should be sanctioned as Class C events, in
which these engine size maximums do not apply.
Generally, it is recommended that no attempt should be made
to fly a radio controlled model aircraft with a gasoline engine in
which the model aircraft weight would exceed 12 pounds per
cubic inch of engine displacement (under powered), or be less
than 5 pounds per cubic inch of engine displacement
(overpowered). Example: Using a 3 cu in engine, a model
would likely be under powered at an aircraft weight greater
than 36 pounds. With the same engine, an aircraft weighing
less than 15 pounds would likely be overpowered.
Servo arms and control horns should be rated heavy-duty.
Glass-filled servo arms and control horns are
highly recommended.
Control surface linkages are listed in order of preference:
1. Cable system (pull-pull). A tiller bar is highly recommended
along with necessary bracing.
2. Arrow Shaft, fiberglass or aluminum, 1/4" or 5/16" OD.
Bracing every six (6) to ten (10) inches is
highly recommended.
3. Tube-in-tube (nyrod). Bracing every few inches is highly
recommended. Inner tube should be totally enclosed in
outer tube.
4. Hardwood dowel, 3/8" O.D. Bracing every six (6) to ten
(10) inches is highly recommended.
Hinges should be rated heavy-duty and manufactured
primarily for use in giant-scale aircraft. Homemade and
original design hinges are acceptable if determined to be
adequate for the intended use.
Clevis (steel, excluding heavy-duty ball links) and
attachment hardware should be heavy-duty 4-40 threaded
rod type. 2-56 threaded size rod is acceptable for some
applications (e.g. throttle). Clevises must have lock nuts and
sleeve (fuel tubing) or spring keepers.
Propeller tips should be painted or colored in a visible and
contrasting manner to increase the visibility of the propeller
tip arc.
❏
1. Fuelproof all areas exposed to fuel or exhaust
residue such as the cowl ring, cowl mounting blocks,
wing saddle area, etc.
❏
2. Check the C.G. according to the measurements
provided in the manual.
❏
3. Be certain the battery and receiver are securely
mounted in the fuse. Simply stuffing them into place
with foam rubber is not sufficient.
❏
4. Extend your receiver antenna and make sure it has a
strain relief inside the fuselage to keep tension off the
solder joint inside the receiver.
❏
5. Balance your model laterally as explained in
the instructions.
❏
6. Use thread-locking compound to secure critical
fasteners such as the set screws that hold the wheel
axles to the struts, screws that hold the carburetor arm
(if applicable), screw-lock pushrod connectors, etc.
❏
7. Add a drop of oil to the axles so the wheels will
turn freely.
❏
8. Make sure all hinges are securely glued in place.
❏
9. Reinforce holes for wood screws with thin CA where
appropriate (servo mounting screws, control horn
screws, etc.).
❏
10. Confirm that all controls operate in the correct direction
and the throws are set up according to the manual.
❏
11. Make sure there are silicone retainers on all the
clevises and that all servo arms are secured to the
servos with the screws included with your radio.
❏
12. Secure connections between servo wires and
Y-connectors or servo extensions, and the
connection between your battery pack and the on/off
switch with vinyl tape, heat-shrink tubing or special
clips suitable for that purpose.
❏
13. Make sure any servo extension cords you may have
used do not interfere with other systems (servo arms,
pushrods, etc.).
❏
14. Secure the pressure tap (if used) to the muffler with
high temp RTV silicone, thread-locking compound or
J.B. Weld.
❏
15. Make sure the fuel lines are connected and are
not kinked.
❏
16. Balance your propeller (and spare propellers).
❏
17. Tighten the propeller nut and spinner.
❏
18. Place your name, address, AMA number and
telephone number on or inside your model.
During the last few moments of preparation your mind may
be elsewhere anticipating the excitement of the first flight.
Because of this, you may be more likely to overlook certain
checks and procedures that should be performed before the
model is flown. To help avoid this, a check list is provided to
make sure these important areas are not overlooked. Many
are covered in the instruction manual, so where appropriate,
refer to the manual for complete instructions. Be sure to
check the items off as they are completed.
CHECK LIST
33