This item is discontinued.

GREAT PLANES GIANT AEROMASTER
FIELD & BENCH REVIEW
by Vic Olivett

When I started in this hobby, my first plane was a high-wing trainer; my second was a low-wing beater; and the third, fourth, fifth and sixth were all Aeromaster kits designed by Lou Andrews. Over the years, all my Aeromasters met their demise in one way or another: a tree, a fence, another plane; and one time, the ground even jumped up 12 inches when I was coming out of a loop. When I saw that Great Planes was coming out with a Giant Aeromaster, I jumped at the chance to review it.

THE KIT

The kit comes in a rather small box, and I wondered how it could be giant scale. Well, I understood when I picked up the box. The kit is well packed with excellent materials, including full-size rolled plans and a photo-illustrated, 50-page instruction manual. The hardware package is full of all kinds of goodies, such as two-piece landing gear made of strong, good-quality aluminum and a heavy ABS cowl and wheel pants. This is not a run-of-the-mill kit; the Aeromaster is a well-thought-out, well-designed, rugged airplane that should give the builder many years of flying enjoyment.

TAIL SURFACES

The tail is large and strong. I usually like to add flying wires to support the stab, but the construction of the Aeromaster's tail is so well done that flying wires would be just for looks. The stab is built up using 3/8- and 1/2-inch stock. The trailing edge is doubled for support and to increase the gluing surface area for the hinges. The structure is cross-braced and then sheeted with 1/16-inch balsa. The elevators are built up, cross-braced and left open. The vertical fin is built up and then sheeted, as is the stab. The rudder follows the same construction as the elevators. Medium Zap works well on the entire structure.

One of the expert tips in the manual shows a simple way to mark and install the hinges. Be careful when cutting the slots for them, as the balsa used for the trailing edge is dense and hard (this adds to the strength of the stab). After the tail has been sanded (do not glue the hinges at this time), you can set it aside.

WINGS

Wing construction begins with some pre-assembly, including the four ribs that will be used for the strut tabs and the actual strut tabs. I used medium Zap on the ply rib doublers and the strut tabs. The strut tabs are made up of 16 die-cut plywood parts with the grain running in opposite directions on the two sets of eight. I used medium Zap to laminate, and then I wicked in some thin Zap at the punch marks before drilling the 1/16-inch holes for the struts.

There are several different types of wing ribs. Be very careful when gluing the ribs for the struts. Remember the strut tabs face downward on the top wing and upward on the bottom wing. The wings are built directly over the plans. I found that the backing from a roll of MonoKote will protect the plans much better than wax paper. Zap or another CA will not penetrate the plastic backing.

With the spars and ribs pinned down properly, you will construct a very straight, strong wing. I found that all the parts for the wing fit extremely well. The spars are webbed front and back with 3/32 balsa. The ailerons are built as part of the wing and then cut out later. This helps produce a straight wing.

Now is a good time to decide whether you want to use two or four servos in the wings. I decided to go with four because I find that slave struts just aren't worth the trouble. The instruction manual shows how to install the servos on removable plates that are then screwed into place. I first used this system in a Top Flite P-47, and it worked out very well. The ribs have large cutout through which the servo wires are pulled (using optional newspaper tubes or pull lines) during radio installation.

To provide some working time, I used thick Zap to sheet the wings. I found that all the sheeting in the kit was excellent. After the sheeting has been completed and sanded, the wing halves can be joined. The wing joiners and bolt plate will more than support this center section. The top wing is built in the same manner. There are a few more steps to building the top wing, due to its sweep and the mounting plates for the cabane struts. The ailerons can then be cut out to install the leading and trailing edges. They are shaped and sanded. Do not glue the hinges at this time.

THE FUSELAGE

The first step in the construction of the fuselage is very important. This is the installation of the 1/4-inch ply cabane doublers that are Z-poxied to the 1/8-inch ply top deck. The top side of the top deck has punch marks to ensure the proper alignment of the holes for the cabane struts. The strut bolts are anchored with 6-32 blind nuts, and a little medium Zap around each will hold them in place.

The Aeromaster was designed to use the U.S. Engines 41 cc engine. The instructions and plans show the proper installation of the engine. I also used the J'tec isolated engine mounts. The plywood space plates are provided in the kit if needed for other engines. All this makes for a very neat, clean and simple installation.

The fuselage sides are designed for the servos to be installed in the tail or inside the fuse. This is accomplished by die-cutting the rear knockouts. If you are not going to install the servos in the tail, a few drops of thin Zap will keep the knockout permanently in place. The rest of the fuselage sides are constructed using 1/8-inch lite-ply reinforced with 1/4-inch balsa sheeting. This system will give you a very strong, straight fuselage. The rest of the fuselage is straightforward and easily constructed and is simplified by its interlocking construction.

ASSEMBLY AND ALIGNMENT

The final assembly of the fuselage, tail and wings is very important to ensure a good flying biplane. The bottom wing is installed first using four 1/4-20 bolts. This procedure is critical because this will be the reference point for the top wing and the tail, so take the extra time needed to get it right. After completing the final alignment and assembly, I sanded the entire airplane and prepared for finishing.

The wing struts are made of six pieces of airfoil stock that are drilled and tapped for 4-40 threaded rods and 4-40 clevises. One end of each strut has a 4-40 nut to lock the clevis in place and make it easy to adjust the wings. To help assembly at the field, I numbered the struts LI, -2, -3 and RI, -2,-3. The engine cowl and wheel pants are ABS plastic and have interlocking glue joints. That they interlock helps to strengthen the glue joints. For ABS plastic, the wheel pants are very strong.

A template for the cylinder head allows easy cowl installation. Although the Aeromaster's nose is rather small, the U.S. 41 fits in the cowl nicely. The instruction manual also shows you the proper wiring for the on/off ignition switch.

FINISHING

I finished the Giant Aeromaster with yellow MonoKote and burgundy trim. I like yellow because it's easy to see on sunny and cloudy days.

I then installed the Hitec HS-300 servos. The 300s have more than enough power to handle the control surfaces. I used four in the wings, one on each aileron and one on each elevator. I used 4-40 hardware on all the control surfaces. Powered by a 1700mAh battery pack, the always reliable Hitec Prism 7 was used for guidance.

FLIGHT PERFORMANCE

When I took the Giant Aeromaster to the field, it was like going back in time; this airplane brings back so many memories. I choked the engine, set the throttle at 1/4, turned back the spring starter and, to my surprise, the engine started the first time. As I pulled the stick back, the engine had a perfect idle. Transition to top end was excellent. The engine ran perfectly right out of the box.

After a few taxi and high-speed runs, I brought the Aeromaster back to the pits for one final check.

Takeoff and Landing

Back out on the runway and into the wind, I was finally ready to go. Once the power was applied, the Aeromaster became very responsive. The tail came up and it was off the ground with authority. The Aeromaster was as gentle as an advanced trainer and had a very smooth clean climb out. On the downwind leg, one click of up, and the Aeromaster was trimmed out perfectly. Turn to base and then final, and it was just a matter of keeping the wings level to a very nice 3-point touchdown. Then the surprise; during rollout, I neutralized the stick, and the Aeromaster wanted to lift off again. I found that this plane would fly at very slow speeds.

High-speed Performance

The Aeromaster cruises very nicely at a touch more than 1/2 throttle, and when full power is applied, the Aeromaster is ready for anything. It is very stable and responsive. This airplane settles into the groove and stays where you want it.

Low-speed Performance

Remember, I said that the Aeromaster would fly at very slow speeds. I had a great time just chugging around. The controls are still very effective even when the plane is flying at barely more than stall speed. The stalls are very clean and straightforward. Once the power is pulled back, just keep adding up-elevator and the nose will drop. You will be surprised how slowly the Giant Aeromaster will fly before it stalls. Recovery is accomplished by just adding power and it will resume level flight.

Aerobatics

The Giant Aeromaster makes you feel like a barnstorming pilot. It just wants to play and have a good time. Loops, rolls, split S's and stall turns are not a problem for the Aeromaster. This plane has many of the characteristics of a full-size aircraft. Keep the speed up, and your maneuvers are clean and impressive.

CONCLUSION

The Great Planes Giant Aeromaster will bring back memories for old-timers and will be a very enjoyable project for modelers who are thinking about their first giant-scale gas-engine project. Great Planes has done an excellent job on the design, instruction and quality of this kit. If you have any time on an advanced trainer, you will be able to fly the Giant Aeromaster very confidently.