Hangar 9 extra 33OL ARF

Model Airplane News, Dec 2001 by Onorato, Jim

MODEL AIRPLANE NEWS FIELD & BENCH

REVIEW

Classic competition aerobat

When Walter Extra first introduced his full-scale Extra, chances are he had no idea that it would be among the most widely modeled aircraft in recent times.

The full-scale Extra debuted in 1987, but since then, it has gone through a number of changes to improve its aerobatic performance. The latest modifications include a larger rudder and elevators with added counterbalanced areas for improved control authority in yaw and pitch. These improvements resulted in the newest generation of Extra: the 330L.

Designed by world-class pilot Mike McConville, Hangar 9's 1/3-scale Extra 3301. is a fantastic-looking plane. It duplicates the full-scale tail modifications that give the model the same increased control authority.

WHAT'S IN THE BOX?

I was very impressed when I opened the boxes and saw what was inside. The Extra corner comes CoMpletely built up and beautifully covered w%ith pearl blue, red and white Goldberg Ultracote. Its craftsmanship is topnotch, and the overall appearance of the plane is outstanding.

The wings are built up and fully sheeted; the hinge pockets and servo pockets are already cut out. All of the control surfaces are dual-beveled at the hinge line, which allows for more than 45 degrees of throw for radical freestyle maneuvers.

The canopy and forward section form a one-piece hatch that permits easy access to the interior of the fuselage. The cowl, wheel pants and rugged, T-6 aluminum landing gear come already painted, and all of the painted parts perfectly match the Ultracote covering.

The fuselage is made of lite-ply and is extremely lightweight. The kit does not contain any of the necessary hardware, but a Hangar 9 hardware package is available separately; it includes just about everything you'll need to complete the Extra except a radio and an engine. All of the parts meet the high standards required for a plane of this size.

You can usually judge the quality of a kit by the quality of the instruction booklet, and that is certainly true in this case. The 40-page instruction book is full of photos and is very well written. It lists the equipment, parts, tools and adhesives needed for each step. It even includes some great setup and flying tips from Mike McConville.

ASSEMBLY

Before I started the assembly, I shrank out the wrinkles in the covering. Since there is very little overlap between the various colors of covering, I first sealed the edges with a heating iron; then I used a heat gun. If you don't do this first, bare wood may later be exposed where the colors overlap.

Begin the assembly with the installation of the aileron servos and control horns, then hinge and seal the control surfaces and install the aileron linkages. Hangar 9 recommends that you use servos with a minimum torque of 80 oz.-in. on all of the control surfaces. For the ailerons, I used JR 8411 servos, which have a torque of 155 oz.-in. Be sure to center the aileron servos in the cutouts; they are a little long, and you want to ensure that the mounting screws go into the wood mount.

I replaced the stock servo arms with the 1-inch, heavy-duty metal arms included in the optional hardware package. I also used the recommended Rocket City control horns, ball links and titanium Pro-links for the linkages and Robart Super Hinge points for the hinges. The Pro-links feature right-hand threads on one end and lefthand threads on the other, and this permits easy, accurate adjustments without disconnecting the linkages.

The instructions say you must seal the aileron and elevator hinge lines because failure to do so may cause control-surface flutter, which would result in a crash. I was surprised that the kit did not include the material necessary to seal the hinge lines. If you want to match the colors on the control surfaces, you'll need to buy two rolls of Ultracote to get the four strips required; you could also simply seal the hinge lines with clear plastic tape.

After I had replaced the stock servo arms with metal ones, I installed JR 8101 servos (two each) for the rudder and elevator. I used a Y-harness on the rudder servos and a reversing Y-harness on the elevator servos. I then added the elevator control horns and hinges.

The Extra has a removable two-piece stab/elevator that plugs into two aluminum tail tubes. Attach the stab to the longer of the two tail tubes with 4-40x-inch socket-- head screws; thread the screws through a hole in each stab half and then into the tube. Hangar 9 uses a shorter tube to prevent the stab from rotating.

I was sent one of the earliest production kits, and the internal stops in the stab halves that would have prevented the short tube from sliding all the way in were inadvertently left out of it and the other early models. I understand that Hangar 9 has since remedied the situation, but if you have an early production model, you can simply glue the short tube securely to the fuselage. After I installed the stab, I added the control horns to the rudder, hinged it and installed the Pro-links. I then added the tailwheel.