I have always enjoyed watching model airplanes fly and spending time with the wonderful people who fly them. As a hobby shop owner, I got to know many modelers personally and found that they and their families are some of the best people I have ever met. After a while watching other people fly, I decided to join them in the air.

It took a while, the hobby shop made weekend flying with an instructor difficult to schedule, but I had advanced to the point that I could fly a trainer without everyone in the pits diving for cover each time I landed. After a few more landings even my trainer’s nose wheel stopped bending so far backwards that it needed to be straightened before the next flight.

A few years ago I “retired” and closed the Hobby Shop. Family responsibilities and a busy travel schedule kept my trainer securely grounded except for one or two flight sessions per year. This was not enough air time to keep up my piloting skills. Gradually, my flying skills diminished and I no longer felt comfortable flying solo.

I do not like losing skills and miss all the friends I had made during my flying years. So this year, things are going to be different. This year, I am going to fly, solo and become a better pilot than I ever was. With that decision made, I needed to find an airplane that will let me get into the air often and is easy to fly with the fewest hassles.

Electric power has advanced since I was active in the sport. I had no trouble fueling and starting the glow engine in my old trainer. Even setting the mixtures was not a real problem. But an airplane that starts almost by itself with just a switch, and doesn’t go “dead” in the air, will allow me a lot more air time.

Photo 1                  Photo 2

After talking to many pilots, reading Sport Aviator and Model Aviation, and checking around for electric-powered trainers, I settled on the new Black Horse Models “Liberty” Almost-Ready-to-Fly (ARF) trainer. This brand new airplane combines the power of an advanced “outrunner” electric motor with an easy-to-manage size and light weight. The wingspan is just under 58 inches and will be easy to see in the sky and to transport on the ground. Weighing around 2 1/2 pounds makes this airplane easy for me to handle at the field. It is supposed to have a very light wing loading around 12 oz. / sq. ft. so it should fly slowly and give me time to regain my skills.

Hobby Lobby offers the Liberty and all the support equipment to finish it at a good price. The airplane itself costs just $110 for the ARF kit. I chose the AXI motor, despite its $80 cost, on the advice of some of my flying “buddies”. They said this airplane would do best with a strong motor to handle climbs and winds. The Jeti Advance PLUS 30 Amp Brushless Controller cost $69 but can be adjusted to suit the airplane using the included programming card.

The HS-55 HiTEC and HS-85BB servos seemed the right size for the Liberty and cost less than $60 for the three of them. Power is supplied by the Poly-Quest 1800 mAh, 3-cell, Lithium-Polymer battery. This battery is called the “Twenty” because it can continuously put out 20 times its rated 1800 mAh capacity.

Translated into English (not always easy for a native Cuban like me to do) this means the battery can supply up to 36 amps of current for the entire time the airplane is flying. As it turned out, the AXI motor and APC 9 x 6 in. propeller required only 21 amps of power. Since the Speed controller was rated at 30 amps continuous power output, the battery was outperforming the rest of the power system. The battery costs $64.

The total cost form me was just under $400. This is about the price of most Ready-To-Fly (RTF) glow trainers that do not have the convenience of electric power. And I will not need to buy fuel and a lot of field equipment, just a charger. On that, one of my good flying friends, Joe Lachowski, had an extra Smart Charger 2500 that he was kind enough to give me. Thanks, Joe! Like glow equipment, all these new items can be transferred from one airplane to another so the cost is not really as much as it may first appear.

The Smart Charger senses when the battery is near full charge and also works with the Poly-Quests’ Protective Circuit Module / and PCM Guard to monitor each of the battery’s three cells during charging. Monitoring each cell is the safest way to charge a Li-Poly battery as no one cell can receive too much charge.

As you can tell, learning all this “electric stuff” took some time but my friends helped out and any remaining questions the people at Hobby Lobby were able to answer. I am not an electric power expert but I am learning. I love to learn new things and this is just one more good part about model aviation.

Building the ARF Liberty

Photo 3

Another new thing to learn was how to build an ARF. My other trainer was an RTF; I just screwed the tail on and rubber banded the wing halves together. There are few RTF aileron equipped electric-powered trainers available and I don’t think they would include the motor and battery selection the ARF Liberty allows me. So I had to build an ARF if I wanted a high-performance electric-powered airplane.

But the Liberty is easier to build than many ARF trainers. Some parts bolt on like an RTF. The wing spar is an aluminum tube just like my old RTF wing. The motor mount must be glued in place but then the motor is just bolted to it; no positioning or adjustments required. There is no fuel tank or throttle linkage to worry about. All the construction is strong but light and easy to align.

Photo 4           Photo 5

The wing looked like the simplest thing to build. So, after warning some of my best friends not to leave home without their cell phones so I could call for advice, (model people really are the best around), I opened the box and started my first major airplane project. I tried sliding the wing tube (spar) into one wing half. It fit but it looked like too much was left sticking out. I marked the wing tube where it met the center of the wing and then measured each “half”. The tube seemed a little too long on one side. I tried sliding the wing halves together just to check and they did not meet as planned (photo 5).

Photo 6               Photo 7

When the distance was measured, it turned out the tube was nearly 1/2 in. too long (photo 6). I marked slightly more than 1/2 inch on one side and used a pipe cutter to cut the tube (photo 7). The pipe cutter, a regular plumbing tool, cut the tube without bending it or deforming the ends. Use light pressure during the cut. Now everything fit together as it should so I went ahead and started wing construction.

(Ed. Note: We checked with Hobby Lobby, the exclusive Liberty distributor, about the wing tube spar problem Ms. Bueso experienced. Hobby Lobby checked the Liberty Kits in stock and found that every wing tube spar was the proper length. Obviously, Ms. Bueso's wing tube spar problem was strictly a one-of-a-kind incident that will not be repeated in any other Liberty kit. But it did happen so Sport Aviator included it in this review. At least we all now know that the kits we receive from Black Horse Models are just stock kits and not "hand picked" for reviews only. We also now know that Hobby Lobby cares enough about their quality to check every one of the hundreds of kits they have in stock just to be sure no defective products are shipped to their customers.)

Photo 8            Photo 9

Photo 7 has the items used to assemble the wing. One clap is an electrical connector and the other is a standard carpenter gluing clamp. I used 3M’s low tack masking tape to hold the wings together without hurting the plastic covering. Spread the 12-minute dry epoxy on one of the wing root ribs. Insert the wing tube into one half, then slide the other half onto the tube until both center ribs are together. Use the electrical clamp to hold the two front wing mount pieces together. Then apply the masking tape to both top and bottom.

Photo 10               Photo 11

Use a strong rubber band to hold the two aileron torque rods together at the rear of the wing. Finally, apply the carpenter’s clamp to the back edge of the wing to make sure both halves match (photo 11).

Photo 12         Photo 13

The directions did not provide it, but the correct amount of dihedral is two inches at the wingtip when the other side of the wing is against a flat surface. This is one inch under each wingtip. Just to be safe, I put a 2-inch high spacer under one wingtip while the epoxy was drying (photo 12). You probably wouldn’t be using a cake mix box (my grand daughters were coming to visit and they really like my brownies) but the box was a perfect fit. Whatever you use, make sure it is two inches high and flat enough to fit under the wing. With all the tape, clamps and dihedral spacer in place, hold one side of the wing flat against the building board until the epoxy cures.

Photo 14            Photo 15

Once everything is dry, remove the clamps and the tape. While the ailerons, elevator and rudder hinge slots are cut and the hinges mounted, the hinges are not glued. Remove the ailerons and drill a 3/16 in. hole in the center of each slot. Install the hinges half way into the wing. Normally a pin is put into the center of each hinge to position it halfway into the wing while the aileron is installed. Then the pin is removed. But the Liberty’s hinge slots were an exact half-hinge fit so no pins were needed. Apply 12-minute epoxy into the torque rod hole in the aileron. Then hold the aileron tightly against the wing and tilted up or down. Apply thin CAA adhesive to both the top and bottom of the hinges.

(Ed. Note: See the Sport Aviator Article “Installing Mylar Hinges” in the Flight-Tech section for complete hinging details.)

Photo 16          Photo 17

The Liberty’s aileron servo mount is designed for a micro servo like the HiTEC HS-55. This is my first electric airplane but I know that electrics do not need as much servo power as do glow airplanes. Servo demands are lower to do less vibration which also means the airplanes are lighter too. But still, I just was not sure that the 15 oz. in. output of the HS-55 was enough for two long ailerons. So I substituted an HS-85 BB servo which has a 42 oz. in. output.

But this required the servo mount hole to be made bigger as shown in photo 16. After cutting the larger opening, lay the mount on the wing and mark the area for the larger opening (photo 17).

Photo 18          Photo 19

After cutting out the larger opening, use a high speed rotary tool to remove enough of the center rib area to fit the larger, deeper servo (photo 18). Lay the mount centered on the larger opening and mark around it. Then remove the plastic covering where the mount will glue to the wing. Use epoxy to glue the mount to the wood in the center section.

Photo 20

Install the servo and screw in place. Assemble the provided aileron linkage and hook it up. The final result should look like photo 20 above. After test flying, the excess metal pushrods can be cut to final length. Center the servo and make sure the ailerons are centered as well when hooking up the final linkage.