The Extra 330S is Hangar 9’s newest plane in the 33% category. Designed by veteran Tournament of Champions pilot Mike McConville, it incorporates design features and enhancements that have been gleaned from his many years in competition. The Extra 330S will satisfy the needs of serious competitors, but it is also an excellent, stable-flying aircraft. It can be fine-tuned to perform precision aerobatics and tweaked to fly wild, 3D-style aerobatics as well.
WHAT’S IN THE BOX?
Detailed instructions explain how to install and hinge the ailerons; the same method is used for the elevators and rudder. The control surfaces are drilled out for Robart hinge points. I like to use Vaseline on the knuckles of the Robart hinges to prevent epoxy from seeping in during assembly. I also roughen up the hinge points with 100-grit sandpaper. It is important that the hinge pivot pins be parallel and flush with the aileron’s leading edge. Install the hinge points in the ailerons first, and allow them to dry. After the epoxy has fully cured, I work each hinge point back and forth until the hinge can move throughout its full travel without resistance. Attach the ailerons to the wings using this same method. Press the ailerons onto the wing so that there is a 1/64-inch gap between the aileron and wing’s hinge line. After the epoxy has cured, deflect the surface fully until there is full travel with little or no resistance.
The large hinge gaps on the control surfaces of the Extra 330S need to be sealed to prevent any flutter. Hangar 9 suggests that you use a strip of 3-inch-wide clear UltraCote that has been folded in half and ironed onto both sides of the hinge line (wing and aileron). This method is easy and works quite well. Sealing the aileron, elevator and rudder hinge lines is extremely important. If you fail to do this, the resulting surface flutter may very well cause a crash.
I centered the servos by connecting them to the receiver and turning on the transmitter. I then hooked up the aileron control rods to the control horns and servo arms. The wings were now finished and could be set aside; I attached them later when I was ready to adjust all the control surfaces.
Attach an elevator servo to the elevator control surface on each side of the plane. I used the new, heavy-duty control-horn system from Du-Bro for the rudder; this is essentially a pull-pull system that uses solid pushrods instead of wires. I used a JR MatchBox for the two elevators and another one for the two rudder servos. It made it simple to adjust the servos to synchronize with each other, so there won’t be any excess resistance caused by the servos working against each other. With the installation of the tail feathers complete, I moved on to the fuselage.
I found an appropriate spot on the side of the fuselage for the receiver switch and installed the receiver and battery pack inside the fuselage. I made 1/8-inch plywood receiver and battery trays and epoxied them in the fuselage at the recommended locations. I wrapped the battery, receiver and two JR MatchBoxes in foam and secured them with rubber bands. I also wrapped the fuel tank with foam, placed it on the floor of the tank compartment and secured it with rubber bands. I attached the rubber bands to small cup hooks screwed into the tank floor.
Attach the canopy to the hatch assembly; use four, 4-40 hex-head capscrews to secure it to the fuselage. I installed my custom-made 1/3-scale pilot figure using screws and Zap-a-Dap-a-Goo II. After that had dried completely, I sealed the canopy to the hatch assembly using RCZ56 canopy glue. Be sure to install the canopy while the hatch assembly is attached to the fuselage. I installed the canopy while the hatch was off the plane, and after everything had dried, I discovered that the hatch had warped somewhat.
ENGINE AND COWL INSTALLATION
To complete the engine installation, I used a rotary tool to make the necessary cutouts in the cowl to accommodate the engine. Following the instructions, I also cut a large air outlet into the aft end of the cowl. I mounted the cowl using five 4-40x3/4 hex-head screws. I balanced a 24x10 Pro Zinger prop and mounted it with a Tru-Turn spinner to complete the cowl installation.
Although a computer radio is not required for this plane, having one really makes the radio setup much simpler. This is especially true if you want to use any type of computer mixing such as flaperons, rudder-to-aileron and rudder-to-elevator which, of course, I did! I set the controls to the recommended throws for both standard and 3D maneuvers. I also included exponential settings that matched the prototype model setup outlined in the instructions.
The Zenoah GT-80 provides plenty of power for all but the most aggressive vertical maneuvers. The plane can pull itself out of a hover, but it requires a bit of patience. I’m sure if I had taken the time to properly tune the engine for my altitude and experimented with different props, I would have found its vertical performance to be even better. As it stands, I am very pleased with the power-to-weight ratio of this combination.
Landing this plane is simple because it’s a bit of a floater. My first approach was slightly high, so I decided to abort. I’m always careful to ease into the throttle with these big gassers, particularly when I’m low and slow. The second approach was much better, and I managed a pretty good 3-point landing. Subsequent landings proved to be equally easy. The key is to fly a shallow approach with a few clicks of throttle. When the Extra reaches the runway’s threshold, I chop the throttle to idle and carefully add up-elevator until the wheels touch down.
In 3D/High Alpha flight, the Extra maintains positive control throughout the entire flight envelope with proper use of high-rate throws and throttle management. The JR 8411 digital servos provide excellent response, and the limiting factor is definitely my own reaction time—not the servos’. Elevators are very stable, and harriers don’t even require full throw on high rates. High Alpha knife-edge, rolling harriers, waterfalls—quite simply, every 3D maneuver that I know how to do—are all easily within the capabilities of this plane. With the GT-80 and the Zinger prop, I was able to easily hover at a tick below 1/2 throttle. Torque rolls are slow and graceful, and once the sweet spot was found (for me, this was almost perfectly vertical with a hint of right rudder and a touch of up-elevator), only small corrections were required to keep going around and around. I have never professed to be a master of aerobatic or 3D flight, but this plane makes me look good!
The Zenoah GT-80 will definitely haul this plane around at a very high rate of speed, but I wouldn’t recommend flying it at full throttle unless it is in a vertical upline. As with any large plane, throttle management is critical. Never fly downlines with anything more than one or two clicks of throttle, if that. The Extra is an easy-to-fly aerobat, but you must pay constant attention to the throttle.