section solved my problem. I replaced the monofilament with fine steel fishing leader line. It only cost a few dollars, and dozens of flights later the water rudders are perfectly centered.
Pilatus PC-6 Turbo Porter
New from Hitec Multiplex is the Pilatus PC-6 Turbo Porter. The full-scale Porter is built by Pilatus Aircraft and has been in service since May of 1959. The powerful engine and large flaps make the Porter a true STOL aircraft.
The Porter is a heavy hauler that can carry 2,500 pounds of payload or up to 10 passengers. Flexibility has allowed it to assume roles in civilian aviation, military flight operations, and law enforcement. It can take off and land almost anywhere and its STOL capabilities have made it a natural for getting in and out of unimproved fields in Indonesia and Papua, New Guinea, that would scare many sane pilots. One such landing was made on the Dhaulagiri glacier in Nepal at 18,865 feet above sea level, the current record for a landing by a fixed-wing aircraft.
The full-scale Porter had flown in a variety of roles, but I didn’t know if it had flown off water. The Cub and Beaver have a well-known history of water operations, but was surprised that a Web search turned up a number of hits of full-scale PC-6 Porters equipped with floats.
The Turbo Porter is constructed of Elapor foam and is available in two attractive color schemes with scalelike trim. Scale enthusiasts will be pleased with the details molded into the parts such as corrugated control surfaces and some amazing panel line and rivet details. Even the landing gear is a close approximation of the full-scale Porter with articulating spring action to smooth out landings.
Like the Rx-R Beaver, all of the servos, speed controller, and motor are preinstalled. Assembly consists of bolting the tail and landing gear in place, sliding the wings on, and connecting the servos. Bolt the propeller and spinner in place and the Porter is nearly ready to fly. I’ll be using AGA Power 2,200 mAh batteries and my Spektrum DX-18G2.
Converting to floats only requires removing a few screws and the landing gear will pop off. There were no instructions with the floats, but a look at the pictures showed where the struts went and there are only four screws holding them on. A water rudder is provided that attaches in place of the tail wheel. I decided to skip it based on experience and the fact that I didn’t like the way it looked on the airplane, but took it with me in case water handling turned out to be a problem.
Battery Access
When I review an electric aircraft, I always rate the accessibility to change the flight battery. Out of our three models the clear winner in this category is the Porter. A magnetic hatch is provided behind the cowl on the top of the airplane so you can change the battery without having to flip over the aircraft.
The Sport Cub has a large hatch with plenty of room, but the airplane needed to be upside down to remove the flight battery. This usually requires a cradle, a helper, or a third arm. The float struts also keep the battery door from swinging all the way open as it does when the model is on wheels.
Similarly, the Beaver has a foam hatch on the bottom. The battery sits in a molded slot that’s nearly vertical. The latch for the battery access is disguised as a small radio antenna, which is cool. The bottom-based hatch requires the airplane to be inverted to change the battery, but if you flip it over, the scale antennas on the top of the model will hit the ground, bend backward, and possibly break off. I made a cradle from scrap packing foam to support the airplane without touching the rudder or antennas while changing the battery.
Water Taxiing
With no wind, the three models are comparable, but the water-rudder-equipped Beaver (with the aforementioned fix) has an edge on handling in the water. Setting the rudders with a tiny bit of tow in allows for straight takeoff runs.
The Porter does a good job in the water even without the water rudder installed and blipping the throttle to blow some air over the rudder will make it turn well. I was pleasantly surprised that the Porter handled so well in the water without the extra rudder, even in mild wind.
The Cub is identical in this regard, although the smaller air rudder takes some technique to get it pointed where you want it. Chopping the throttle on the water will result in it weathervaning into the wind, setting up a perfect takeoff run.
Takeoff
Pointing the nose into the wind, lowering the flaps slightly, and smoothly advancing the power resulted in a respectable takeoff with all three of our test models. The Sport Cub has the most power-to-weight ratio and smooth float bottoms. It was off the water in a few feet.
The Beaver needed the longest takeoff run and on really smooth water it pays to taxi in a circle to create some wake so it will break free of the water.
The Porter took off quickly and easily and definitely exhibits the STOL characteristics of its full-scale counterpart.
Scale Looks
This is purely subjective, but I like the Beaver for its scale looks. The lighting system, although not enough for true night flying, looks awesome at dusk and lets you keep flying for a while after the other two have to be put away.
The Cub is a Cub and everyone loves them. The Porter strikes a unique look in the air and has a distinctive, pleasing appearance on floats.
Flying
Floatplanes are generally less nimble than their wheel-equipped counterparts. Floats present more mass hanging below the model and actually enhance the model’s stability. The floats and struts create drag so the top speed on all three models was slightly slower with floats attached.
That said, the Sport Cub has more power than the others and the AS3X system gives it the feel of a much larger model. The AS3X only widens the gap as the wind picks up. Loops, rolls, and inverted flight are all possible and fun, even with the floats hanging off the bottom. Minimal elevator correction is required to fly inverted because of the stabilizer system.
The flaps are effective and the Sport Cub can be slowed to walking speed as it settles into the water. A slight elevator flare keeps the front of the floats from digging in and the drag from the floats will slow the Cub to a stop almost immediately.
The Porter flew really nicely. It gets off the water quickly and with full flaps and full power, will practically jump out of the water like the bluegill that were jumping around the dock while we were filming. (I think they were showing off, knowing we didn’t have fishing poles!)
Aerobatics are possible and the Porter has plenty of power to do loops from level flight. Rolls, especially with the floats installed, are more barrel rolls than axial rolls. Inverted flight requires down-elevator because of the semisymmetrical airfoil and the floats. The rudder is effective and allows for graceful stall turns and good-looking coordinated turns.
Setting up into the wind with the flaps fully extended requires some power to overcome the drag of the flaps and floats. After you figure out the power needed, the Porter will settle into a level approach and kiss the water and settle in.
The Beaver takes a nice scale takeoff run to build up some speed and break free of the water. The large round cowl creates drag, but the Beaver looks good calmly taking off after a smooth takeoff run. I nearly had to launch the rescue boat because I was applying up-elevator too soon and the Beaver bounced from float to float before finally coming to rest upright. Letting it build up speed before easing it out of the water solved that issue. I knew immediately that it was my fault because I was trying to make it take off like the other two did.
In the air, the best description of the Beaver I can think of is stately or majestic. It is capable of loops and rolls, but it doesn’t have the zip of the other two—especially the Sport Cub.
What the Beaver does well though is touch-and-go water landings. I flew entire packs doing splash-and-go landing after splash-and-go landing, while concentrating on perfecting my technique to make them look scalelike. When you’re done, the water rudder equipped floats will get you back to the dock on the first try.
Wrap-Up
So back to the question, “Which is best?” Assembly is a draw: they all are easy to assemble and can go from box to pond (river in my case) in the time it takes to charge a flight battery. They all use 3S LiPo batteries between 1,300 and 2,200 mAh capacity, so having several batteries is cost effective.
The Sport Cub has the most power and the AS3X system will keep it flying in the wind. This might seem like a big advantage, but when the wind really picks up the swells increase and the AS3X can’t make the Cub any bigger than it is when the water gets rough.
If I want to do aerobatics even with floats on, the Cub’s power and maneuverability make it stand out. The floats will remain ding free longer than either of the foam floats, no matter how careful you are. Conversion between wheels and floats is also quick.
The Turbo Porter is an interesting model. It isn’t as aerobatic as the Sport Cub but it’s a distinctive, interesting-looking airplane. You can change its batteries while it’s sitting on its floats without flipping it over. Like the Cub, the Porter can quickly be converted to conventional landing gear.
The Beaver looks great and the lights add a nice touch when flying near sunrise or sunset. Although not as spirted as either of the others, the Beaver is relaxing to fly and its scale detail is amazing. Conversion to wheels takes slightly longer, but that is because of the complex, scalelike float struts rather than the Cub’s basic bolt-on wire struts or the Porter’s flat aluminum struts. Of the three models, the Beaver would probably be the best for preparing one to fly larger float-equipped models.
For aerobatics, my choice would be the Sport Cub. If scale looks and flying are the most important, then it’s the Beaver. The best combination of scale looks and aerobatics goes to the Turbo Porter.
