HANGAR 9: P-51 MUSTANG 1.50 ARF

Supersizing a sensational scale warbird

Every modeler knows that the P-51 Mustang is probably the most exciting U.S. fighter of the WW Il era. And there's plenty more to get excited about with this latest release, a 1.50-size P-51 Mustang ARF from Hangar 9! When I reviewed Hangar 9's 60-size Mustang in the April 2003 Issue, I raved about its great flying qualities. Therefore, I had great expectations of this new larger model. This larger version retains the retracts, as in the 60-size, but it uses a separate servo for each gear and adds flaps! Also, the elevator and rudder servos are in the fuselage rather than in the tail. Other subtle differences include an air-foil-shaped stab and fin and a tailwheel in the correct scale location, all of which give a more authentic scale appearance. all of this adds up to one impressive model, and I couldn't wait to get it into the air.

This model is very complete. It lacked only the radio, engine, scale pilot, spinner, canopy glue and CA. A universal aluminum engine mount is included, but my chosen engine, the Saito 200Ti, comes with its own custom mount.

Like the 60-size Mustang's, the instruction manual is very detailed and easy to follow and has many photos. It assumes little previous ARF experience, but there are a few specific areas of the assembly that I feel hold special interest.

ENGINE INSTALLATION

The firewall and the nose ring have the correct built-in right thrust and down-thrust offsets for the Saito 200, so I needed only to get the spinner to have a constant Vi 1/6- to 1/8-inch gap to the nose ring.

I went a step further with my installation; a major feature of the Saito twin is a small frontal area that allows it to fit better within cowls of aircraft with in-line engines. It would be a shame to have this engine protrude from the cowl on a P-Sl Mustang model, right? Right! After a bit of experimentation, I found that when I rotated the engine on the firewall (which required a cutout in the inner plywood frame for mount clearance and the removal of about 0.090 inch from two of the valve covers), it was possible to avoid the necessity of a cutout for the valve covers on one of the cylinders. I admit that this took some extra time and effort, but the aesthetic improvement was worth it for me.

I would have liked a slightly fuller cowl at the "chin" area to make it easier to conceal the Saito. A slightly larger cooling air-intake scoop would be nice, too, and it wouldn't detract from its scale appearance in my opinion.

The Saito 200 twin's manual calls for a baffle in a cowled application to allow more cooling airflow to the rear cylinder. However, it does not provide a diagram of such a baffle, but I figured that if it's a good idea for the rear cylinder, it's good for the front one also! I fashioned a 1/16-inch lite-ply plate on each side and glued them to the existing nose structure with ¼-InCh balsa triangle stock for support. I applied two coats of Sig clear dope for fuelproofing. These baffles are simply flat plates that help direct airflow within the cowl to travel close to the cylinders and through the engine's cooling fins as it moves aft toward the air exit. You can see my interpretation of this requirement in the photo.

For the exhaust, I used the optional Saito flex pipes, available from Horizon, because they can be totally concealed. I installed a McDaniel twin-type remote glow driver with its own Ni-Cd, a Tru-Turn 5-inch P-Sl aluminum spinner and Aerotrend Fireline colored fuel lines to identify the carb, muffler and crankcase vent lines.

RADIO INSTALLATION

As with the 60-size Mustang, much of the work is already done! The aileron servos are mounted to blocks that are glued to the wing hatches. You just drop the elevator, rudder and throttle servos into their trays. The weight of the engine that you use will determine where the batteries should be located to achieve the specified balance point. In my model, the receiver, glow driver and battery for the retracts went in front of the servos, while the receiver and glow batteries were placed aft. These items were secured with foam padding. I routed the receiver antenna through a nylon pushrod outer tube, which I placed inside the fuselage for concealment and positioned as far from the other control-system components as possible.

Plastic pushrod tubes for the fuselage controls come installed. Hardened-steel pushrods are slid into the tubes to connect the servos to the control surfaces. I had never seen this setup before, and at first, I was skeptical that it could give slop-free control. After it had been hooked up to the servos and control horns, there was virtually no play, and I was impressed!

This plane uses 10 (!) servos. Follow your radio's manual for installation and setup specifics. The plane requires at minimum a basic 6-channel; however, an 8- to 10-channel programmable makes it more fun. This was my first setup of a complex airplane with the JR 1OX outfit, and I found it very rewarding. This high-end radio provides numerous setup options and is a natural for this model! I used only one Y-harness (retracts). Every output socket was filled on the 10-channel receiver; almost every servo had its own channel, and there were also channels for the transmitter-adjustable onboard glow igniter, retracts and 3-position flaps!