Extra 300S ARF (GPMA1240)
Tech Note

To all of you who are proud owners of the new Great Planes Extra 300S ARF...Congratulations on your purchase!

EXTRA 300S ARF ADDENDUM

THE STEPS IN THIS ADDENDUM REPLACE OR AMEND THE CORRESPONDING STEPS IN THE INSTRUCTION MANUAL. BEFORE YOU BEGIN CONSTRUCTION, MAKE NOTES IN YOUR MANUAL WHERE YOU ARE TO REFER TO THIS ADDENDUM.

Amend to the beginning of Page 7, Step 1: Before attaching the engine mount to the firewall, test the threads of the blind nuts by threading a 6-32 bolt into each blind nut. If this is difficult to accomplish, the threads are probably clogged with sealer. Clean the threads with a 6-32 tap.

Correct Page 7, Step 2: The measurement listed is in error. When adjusting the distance from the firewall to the spinner backplate, the correct measurement is 4-7/8" instead of 5-1/8" as listed in the manual.

Replace Page 15, Step 1 of "Install the Elevator Pushrod". Locate one of the two hardwood dowels. Cut the dowel to 15-1/2". This is the elevator pushrod dowel. Drill two 5/64" (or 3/32") holes near one end of the elevator pushrod dowel as shown in the sketch in the instruction manual.

Replace Page 15, Step 3: (Use the Elevator Pushrod Template shown here for this step.) Use two .074" x 12" threaded (one end) pushrod wires to make two elevator pushrod wires as shown in the sketch. Notice that the sketch shows two pushrod wires, one 1/4" shorter than the other. Save the longer cut-off piece of leftover pushrod wire to be used at the other end of the pushrod dowel.

PDF File (7 KB) of Elevator Pushrod
(if you do not have the reader, you can download it at: Adobe Reader Download Page.)

Replace Page 16, Step 7: Make a 90-degree "L" bend 1/4" from one end of the approximately 6" long piece of wire you saved from Step 3 in this addendum. Secure the wire to the front of the elevator pushrod dowel with a 1-1/2" long piece of heat shrink tube and thin CA. Cut the covering from the pushrod exit slots nearest the stab on both sides of the fuse. Route two flexible plastic inner pushrod tubes (from a Great Planes Accu-Glide Flexible Pushrod kit, GPMQ3710, not included) through the pushrod exit slots in the aft end of the fuselage until you can reach them in the radio compartment, then thread the plastic guide tubes onto the elevator pushrod wires.

Replace Page 16, Step 1: of "Install the Rudder Pushrod". Use the remaining hardwood dowel for the rudder pushrod dowel. Drill a 5/64" (or 3/32") hole 1 " from both ends of the dowel and make grooves for the pushrod wires.

PDF File (6 KB) of Rudder Pushrod
(if you do not have the reader, you can download it at: Adobe Download Page.)

Replace Page 16, Step 2: (Use the Rudder Pushrod Template shown here for this step.) Make a rudder pushrod wire as shown in the sketch from a .074" x 12" pushrod wire. Secure the rudder pushrod wire to the dowel with a 1-1/2" length of heat shrink tube and thin CA.

Replace Page 16, Step 3: Cut 3-1/2" from the threaded end of a .074" x 12" pushrod wire. Make an "L" bend 1/4" from one end of the longer wire and secure it to the front of the rudder pushrod dowel with a 1-1/2" length of heat shrink tube and thin CA. Install the rudder pushrod in the fuselage using an outer pushrod guide tube to pull it through the fuselage the same way you did with the elevator pushrods. Connect the pushrod to the rudder with a nylon clevis, a control horn, two 2-56 x 5/8" screws and the nylon backing plate. Slide a silicone retainer onto each clevis.

Replace Page 17, step 2: Glue the wing bolt plate to the wing, covering side away from the wing, over the location shown in the photo.


Note #1:

There is a small piece of wood (1.5"x4.5"x1/8"), which is covered in white MonoKote on one side in the kit. This is the wing bolt plate and needs to be secured to the wing prior to bolting the wing to the aircraft.

We apologize for any confusion this may have caused.

Great Planes Model Manufacturing