The following is a text copy of the Scale R/C International kit review of the Aerotech Models, Inc. P51 Mustang
Kit built and article written by Jim Sandquist
Put 20 World War II aviation buffs in a room and ask
them to agree on the airplane that had the largest impact on the war and it will only take
a few minutes to agree on the P-51. This airplane above all others has left its mark on
aviation. As a fighter, bomber escort, ground attack and photo reconnaissance aircraft it
was far and away considered the best of the bunch by allies and enemies alike! The P-51D
is generally accepted as the definitive Mustang, with some 9,603 built, with the last one
rolling off the Dallas, Texas (USA) line in 1945. 52 years later they are once again
rolling off the line in Minneapolis, Minnesota (USA) This time as 1/5th scale Models.
Wayne Siewert of Aerotech Models has spent the better part of two years
creating what may be the definitive P-51D model aircraft. This 20% rendition is made with
state of the art technology that few have seen in model aircraft. Constructed of entirely
carbon fiber materials, the plane is strong and lightweight. Wayne has spent much time
researching the Mustang, making templates from the full sized P-51's as well as going over
numerous drawings. All of this has been done in an effort to have the most accurate
reproduction in a model today!
The Kit
When your kit arrives and you open the large box, be prepared for a big surprise! Surprise number one: The fuselage and wing are one piece, no halves to join! Surprise number two: The Detail! This kit comes with all panel lines, Dsuz(r) Fasteners, screws, and over 20,000 rivets molded into the airframe! Surprise number three! It is a complete kit with all hardware, retractable landing gear, wheels, fuel tanks, fuel filler valve, etc. This eliminates the need to chase endlessly back and forth to the hobby shop for screws and miscellaneous items! The kit comes complete except for the engine, muffler, glue, radio, and paint.
The instructions and plans are quite complete. The 12 (now 26) page instruction manual consists of illustrations where needed but is written a clear straight forward manner. Much of the needed instructions are printed on the three plan sheets. Full sized plans are not needed due to fuselage and wings being one piece. The plans are 24" X 36", which I found to be a convenient size to work with. On the plans you will find illustrations for assembly of the model as well as fuel tank installation, retractable gear and airline installation, radio, etc.
Construction/Assembly
Construction of this airplane will be a little different than typical wood kits, but no special tools will be required. The most exotic tools needed are a 'Zona' saw, hacksaw and Dremel Tool to facilitate the building of the model. As previously mentioned, this plane is built of carbon fiber, not fiberglass. Sharp edges tend to be almost needle like with carbon fiber, a few slivers can be anticipated, so keep some tweezers handy. Be sure to have a dust mask on hand, no need to inhale any of the carbon fiber dust while sanding!
Construction does not begin with the wing or the fuselage. Start by building a Stand! Included on the plans is the shape and dimensions for a stand for the fuselage. I can't stress enough how important this will be in building the aircraft. The shape of the P-51 fuselage makes it fairly awkward to handle on the bench. If you start construction without it, I guarantee you will build one shortly after you start. The other benefit of the stand is that it will work out great as a cradle for transporting your model to the field. Once the stand is constructed you can move on to the assembly of the fuselage.
The first step is to cut out the area in the fuselage that the horizontal stabilizer will fit into, and the gear doors for tail wheel assembly. This is best done with a Dremel tool and Zona Saw. The rudder is of built up construction and the elevators need to be shaped out of the supplied blocks of balsa. In the final finishing process these will need to be covered, fiber glassed and detailed to match the rest of the airframe.
The one piece wing attaches to the fuselage in a rather unique way. The trailing edge of the wing slides between the oil cooler scoop and the fuselage to lock it in place in the back and two bolts accessible through the wheel wells hold it down in the front. Once assembled it is hard to distinguish where the wing ends and the fuselage begins. All panel lines match up exactly! Earlier I mentioned the kit has a few surprises. The wing is certainly one of them. The next step in construction is to cut away the aileron and flap from the wing with a Zona saw. Once the cuts are made and you separate them from the wing you will find that all the hinges are already in place! Throughout this airplane you find 1/4 scale Robart Hinges and Hinge Pockets already in place. All you need to do is drill the small holes in the bottom of the wing that gives you access to the hinge pocket set screw.
Installation of the Century Jet Landing Gear is simple and straight forward. Aluminum plates are already installed to mount the landing gear to. This plate is attached to the aluminum spar running through the wing and the leading edge of the wing. In my early test flights I had a few hard landings. Hard enough to tear a wing apart with most normal airplanes. This set up was strong enough to take the bad landing and has continued to work well without any need for repair! All that is required for the retract installation is to drill 4 holes through the plates.
The inner and outer gear door panels attach to the plane in a similar fashion to the full sized aircraft. The gear doors come complete with vacuum formed inside door moldings so that you can scale your plane right down to the wheel wells!
A scale options package is available for complete scale detailing of the airframe. This includes scale exhaust stacks, gas caps, bomb drop hard points, machine guns, IFF lights, navigation lights, etc. This combined with the optional scale cockpit interior kit allows you to complete the plane as a real competitor!
Engine
Many manufacturers design an airplane kit with little thought to the engine until after the airframe is designed. All to often a nice scale kit has been manufactured only to have the engine cylinder or muffler hanging outside the fuselage. When this plane was originally conceived, the first consideration was the engine, the plane was then designed to fit around it. This approach developed a scale Mustang with no unsightly engine parts exposed!
The Moki 1.8 (Now using the new DA 50 Gas Engine) Glow engine was the engine of choice for this project. The power to weight ratio is really unsurpassed by any comparable engine on the market. After the engine break in period, I was getting approximately 21 pounds of thrust with a 18x10 propeller turning about 9000 rpm. On this airplane of 26 lbs., this gives very good aerial performance.! The power package is completed with a custom matched tuned pipe assembly. The pipe is enclosed inside of the fuselage and exits out the rear oil cooler door. The interior of the fuselage has a ducting not unlike the ducted fan aircraft. This draws air through the fuselage and insulates the pipe from the components in the air frame. Prior to the introduction of the kit, Aerotech did temperature readings at all critical points in the fuselage in insure that this system would work reliably After some 18 flights, I have seen no sign of any engine overheating or damage to other components of the aircraft. A bi-product of the pipe being installed inside the fuselage is the sound! I measured about 98db for my model, with a fairly low frequency sound output. The engine is mounted inverted and runs very well this way, even at idle! Aerotech offers the Moki 1.8 (2.1) and tuned pipe as an option with the kit.
Radio and Servo installation
This airplane is a minimum of 6 channels, aileron, elevator, rudder, flaps, throttle and landing gear. With the 7th channel you can also carry drop tanks or bombs and release them in flight. I utilized the Futaba 9 ZHP radio system with a S134 1/4 scale servo for the elevator. A standard servo was used for the throttle, flaps and retracts. 9302 high torque servos were used on the ailerons. Provisions for mounting of the radio gear and servos is more than adequate. All control linkages are connected to the control surfaces by pushrods with the exception of the rudder and tail wheel assembly which is controlled by a pull/pull system. One notable difference in the radio installation is the antenna. Carbon fiber has been known to create problems with the radio signal being received. For this reason the kit uses a Hayes vertical whip antenna to eliminate any potential problems. Don't worry about the scale look in flight, the antenna unscrews from the airframe when not in flight.
Finishing
The leading edges of the flaps and ailerons as well as the elevators need to by fiber glassed. The rudder will be covered with cloth if you want to duplicate the look of the full sized plane. The rest of the structure has a gel coat that makes it a very smooth finish right out of the box. To prepare my surface, I wet sanded the entire structure with 400 grit paper followed by 800 grit wet or dry. Most all of the rivet detail is in the kit right out of the box, but some rivets could not be put into areas close to seams. The modeler can add these himself with minimal effort.
My plane was painted with acrylic lacquer. This type of paint covers very quickly and is a bit lighter than many other paints.
Conclusion
Although it is not an inexpensive kit, I think that if you look at everything that is included in the kit, you will agree that is a good value for a very special aircraft. Aerotech models really did their homework when creating this fine scale flying model. I would recommend it to any discriminating modeler. Expect to have this plane completed and flying in about 100 hours.
Flying this bird was much like a full sized Mustang. Right rudder was required for the take-off roll and through the climb out. The plane has an actual flight speed of about 105 MPH. It performs loops and rolls as expected, crisp and clean. The plane simply goes exactly where it is pointed. Landing was pretty typical. Start from a high altitude, deploy the gear, then the flaps to about 20 degrees and reduce the throttle to about 80% for your final. Hold on about 50% power to touch down. At an altitude of about 5 feet pull off all power and the plane will settle in quickly, with minimal roll out.
I was so pleased with my model that I took it to the 'Top Gun Invitational' in West Palm Beach Florida in 1996. There it scored a 96.25 Static score and finished in the top 20 in the expert division. Whether you are looking for a Sunday flier or a competition aircraft, this kit could well be what you are looking for.
Jim Sandquist
02/20/08