Horizon Hobby Hangar 9 Mustang P51D

Written by Andrew Griffith This famous fighter comes in a friendly size Product Review As seen in the April 2019 issue of Model Aviation.

Bonus Video

At A Glance

Specifications Model type: Semiscale warbird Skill level: Intermediate Wingspan: 69.5 inches Wing area: 848 square inches Wing loading: 33.4 ounces per square foot Airfoil: Semisymmetrical Length: 60 inches Weight: 11.5 to 13 pounds Power system: 20cc gas or Power 60 electric Radio: Full-range, seven-channel minimum Construction: Built-up balsa and light plywood Covering/finish: Printed covering Price: $399.99 Test-Model Details Engine used: Evolution 20cc two-cycle gas Receiver battery: Spektrum 4,000 mAh 2S receiver; 2,000 mAh 2S ignition Propeller: 16 × 8 Evolution plastic Radio system: Spektrum DX-20; Spektrum AR9350 receiver; eight Spektrum A6380 HV Digital servos Ready-to-fly weight: 12 pounds, 5 ounces Flight duration: 15 minutes Pluses

• Exceptionally detailed printed covering includes rivet details, panel lines, and appropriate flat finish.
• Operational flaps and retractable landing gear.
• Supports fuel or electric-based power systems.
• Includes scalelike details such as a pilot figure, instrument panel, and wing tanks.

Product Review

I Was On Vacation in Washington, D.C., and had a chance to visit the World War II Memorial. It’s a stunning monument to the dedication and sacrifices the people of our nation and others made during the war. While I was taking in the experience, Model Aviation editor-in-chief, Jay Smith, called to ask if I was interested in reviewing the new Hangar 9 20cc P-51D Mustang. How appropriate! Why yes, I’d love to! The Mustang was born mainly from the requirement for a fighter with the legs to escort bombers from England into Germany and back. The large, internal fuel capacity, augmented by wing-mounted drop tanks, gave the Mustang the duration it needed for bomber-escort duty. The two-stage, supercharged Packard V-12 engine meant solid performance at high altitude where the bombers operated. The six .50-caliber Browning machine guns wreaked havoc on German fighters, and the Mustangs claimed nearly 5,000 aerial victories in WW II. The new Hangar 9 Mustang is interesting for several reasons. This one is built-up, with an accurate scale outline, and is extremely detailed, all in a package that will fit fully assembled in an average SUV and break down easily for storage. Throw in the fact that you can power it with gas or electric, and it comes equipped with flaps and optional retractable landing gear, and it’s easy to see how the 20cc Mustang will appeal to a variety of modelers. While unpacking the Mustang, the first thing that stood out was its printed covering. Gone are the days of spending hours with a fine-line drafting pen to create panel lines. All of the the panel lines, rivet details, and even nomenclature markings are applied at the factory with computer-aided design precision. The printed covering also brings a nice flat finish that is much closer to a painted finish than most film coverings can achieve.

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The P-51 is constructed of laser-cut balsa and light plywood. The previously mentioned covering is of the self-adhesive variety, so keep a hot covering iron away from it. Another point worth mentioning is that the wing and fuselage sheeting is hard and resists the hangar rash that often shows up on softer wood. Although fixed landing gear was provided, I couldn’t abide having a gas warbird with fixed gear, so I ordered the recommended E-flite electric landing gear. In addition to retracting landing gear, large wing flaps are provided, making the Mustang fully equipped. The pilot bust and a semiscale instrument panel interior are included and make up the battery or radio access hatch. Overall, the kit looks impressive.

Assembly

The Mustang arrived well protected and free of damage. After sitting down and familiarizing myself with the manual, I was excited to get started. I’ll assemble the Mustang using Zap thin and medium CA glue, Z-Poxy epoxy, and Z-42 threadlocker. All are available from Frank Tiano Enterprises. The following practices will be used wherever required while assembling the Mustang. All metal-to-metal fasteners will be secured using a drop of Z-42 threadlocker, except where using nyloc nuts. All wood screws, such as for servo mounting, will be installed by prethreading the hole, hardening the threads with a drop of thin Zap CA adhesive, and then installing the screw. Painter’s tape is used in several steps. Not knowing how well the printed details would hold up to tape, I used a technique that is used when masking painted foam surfaces. Take the tape and stick it to your shirt once or twice to tame down the adhesive. The control horns are painted, which looks great when finished, but you need to sand the paint from the gluing areas and clean them with isopropyl alcohol before installing them with Z-Poxy 30-minute epoxy. To avoid mixing several small batches of epoxy and waiting for them to cure as I went, I prepped and glued the control horns at the same time. Assembly begins by hinging the flaps and ailerons and installing the four wing servos. The flaps use point-style hinges that install on the bottom of the flap surface so that they move slightly back as well as down when deployed. A drop of oil on the hinge pivot prevents any glue from seizing up the hinge. The point hinges were installed using 30-minute Z-Poxy. The ailerons are hinged using CA hinges and thin Zap CA adhesive. The wing servos are all mounted to hatch covers then installed in their respective bays. Each servo mount and hatch cover was prepared as previously described. Strings are provided to facilitate pulling the servo extensions to the wing roots. With the wing servos installed, it’s time to turn your attention to the main landing gear. The Mustang comes equipped with fixed gear, but most buyers will surely equip theirs with retracting landing gear. Because retracts are optional, you must carefully remove the covering from the landing gear bays to expose the liners. I recommend using a fresh blade in your hobby knife. The E-flite landing gear drops right in and the servo extensions are routed to the wing root. With three connections at each wing root, I suggest marking them in some way to make connections easier. This might be the most tedious part of the build, but spending some time here getting the gear doors correctly rigged will pay dividends in a nice, tight fit.

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With the wings done, it’s time to turn your attention to the fuselage. The cockpit forms the hatch and there is plenty of room to install the radio gear and tank (or batteries if you go electric). The hatch offers above-average ease of access for changing flight batteries for electric installations. With the wing mounted, I checked the horizontal stabilizer’s alignment. Many installations require shimming the stabilizer or sanding the saddle, but I was pleased to see the stabilizer was correctly aligned. An old soldering iron was used to remove the covering from the gluing area on the stabilizer. With the covering removed, I glued the stabilizer in place with 30-minute Z-Poxy. The tail wheel assembly is hidden by a removable hatch, bolted into place, and hooked up to the steering servo. I was pleased to see that the tail wheel is in the scale location behind the oil cooler vice attached to the bottom of the rudder, like many models. An optional, retractable tail wheel is available, but I also appreciate that the fixed tail wheel reduces complexity, cost, and weight. I was supplied a 20cc Evolution engine to power the Mustang. Small gasoline engines are transforming the hobby. They are easy to operate and with glow fuel in the $30 per gallon range, the operational cost difference quickly shifts in favor of gas engines. Installing the Evolution 20, which is similar to a large glow engine, is accomplished using fiberglass-filled, rail-style motor mounts. A laser-etched drilling guide for the firewall is provided, which covers the recommended power options. When the blind nuts were installed and the rails temporarily mounted, the engine was clamped into place to give the proper backplate spacing. The rails were marked, removed, and drilled using a small drill press. Be sure to use threadlocker on the bolts mounting the rails to the firewall, and not on the nyloc nuts used to mount the motor to the motor mounts. The electronic ignition module and throttle pushrod were installed and set up. In addition to an electronic ignition kill, I like to ensure that the throttle servo will fully close the carburetor and shut down the engine. The fuel tank is assembled using a three-line system—one line to the carburetor, one line as a vent, and the third line as a fill. Because the top hatch is easy to remove, the fill line was routed to the rear of the tank and is accessible when the hatch is off. The entire fuel system was plumbed using Du-Bro medium Tygon fuel line. I mounted the receiver and ignition switches internally, making the outside of the fuselage clean of switches and fuel dots. The one exception to this was the indicator LED for the Evolution remote ignition kill, which was mounted externally. The cowling, spinner, and propeller were all tested on a magnetic propeller balancer and all three were close enough to not need any extra work. RTL Fasteners bonded washers were added to the screws that secure the cowling. These do a great job of protecting the fiberglass cowling and resisting vibration. A pilot bust was attached using clear silicon adhesive and taped down using low-tack painter’s tape while it cured. The canopy was then glued into place with Formula 560 canopy glue. While the glue was drying, I applied the remaining decals. I set up the Mustang on my Spektrum DX20 using a Spektrum AR9350 DSMX receiver. The throws were set according to the manual and the center of gravity was verified. Hangar 9 setups generally balance if you use the recommended equipment and install it as shown, and that was no different for the Mustang. All that I needed was some nice weather!

Flying

The Mustang will transport in many SUVs fully assembled, but for those needing to break it down, the wing mounts with two easily accessible wing bolts and six servo connections. My RC Fueling Systems gas can was filled with 20:1 Red Line oil mixed with zero-ethanol regular gas (after 1 gallon you can switch to 32:1, but I maintain 20:1 on my smaller engines). With the engine running smoothly, taxi tests were done on both the paved and grass taxiways. A few tweaks to the tail wheel steering had the Mustang going nice and straight. Holding some slight up-elevator to keep the tail wheel down until it was moving, I smoothly added power and relaxed the elevator as the speed picked up. After approximately 50 feet, the Mustang made a nice takeoff and was climbing briskly as I brought up the landing gear. With a few clicks of up-elevator trim and some right aileron, the Mustang was flying hands off. After several laps around the field to get comfortable, I took the Mustang up high to test the stall. Into the wind, the Mustang slows extremely well, and although it will drop a wing in a full stall, the thick airfoil means that stall speed is quite low. Recovery consisted of relaxing the elevator and adding power.

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After a few tanks of fuel, the engine was starting to produce good power. Large loops from level flight are no problem. The aileron response is excellent, and the rudder has good authority. Speaking of the rudder, coordinated turns appear much more scalelike than "bank and yank." The Mustang looks best doing what warbirds do—flying down low and making lots of noise doing show passes and strafing runs. Although it’s a relatively small airplane, the Mustang is extremely locked in, even without using the AS3X capability of the Spektrum AR9350 receiver. It truly is an airplane that flies larger than its actual size. My estimate for speed with the 20cc engine is approximately 85 mph—slightly more if you remove the wing tanks. The landing setup consisted of deploying the flaps and gear and flying the approach with a little power to overcome the extra drag. The Mustang will settle onto the main gear and slow down nicely. A three-point landing can be done, but you must execute it perfectly or it sets up an ugly bounce and you need to apply power and go around to get out of it. The flaps are very effective, and landings are slower than I expected.

Conclusion

The Hangar 9 P-51 is a striking model in the air or just sitting on the flightline. Any time it came out of my truck, it attracted a curious crowd. The Evolution 20cc engine is a perfect match for the Mustang. It is economical to operate, and the wraparound muffler produces a nice, throaty sound. The included tank will provide more than enough fuel for more than 10-minute flights. Even at 12 minutes I had plenty of fuel remaining. The fit and finish is outstanding, and the fun factor in the air makes this Hangar 9 P-51 one of the most exciting new models to hit hobby shop shelves in a while.
Manufacturer/Distributor Horizon Hobby/Hangar 9 (800) 338-4639 www.hangar-9.com

Sources:

Spektrum (800) 338-4639 www.spektrumrc.com Du-Bro (800) 848-9411 www.dubro.com RC Fueling Systems (866) 450-0017 www.rcfuelingsystems.com RTL Fasteners (800) 239-6010 www.rtlfasteners.com Zap/Frank Tiano Enterprises (863) 607-6611 www.franktiano.com