ParkZone RTF P-51D Mustang

MOVIE FILES

 

There, passing swiftly just under the nose, an enemy FW-190 speeds by. The Mustang’s canopy flashes sunlight as the nimble fighter rolls to vertical. With ailerons at full deflection, the speeding Mustang twists into the dive, roaring down after the fleeing FW-190. There is no escape this day for the FW. The Mustang is just too quick in the dive. As the lucky FW pilot bails out of his burning fighter, the P-51D streaks back up to its patrol altitude, nestling closely next to the bombers whose protection is its very reason for existence.

There are few model airplane pilots, or full-size pilots for that matter, who have not drifted into Walter Mitty land at least once while thinking about that scenario. Imagining yourself in a fighter cockpit during a desperate battle is the rightful heritage of all pilots. While only a skillful few live the reality, the rest of us can imagineer ourselves at their side. Movies like “Top Gun” and “Flying Tigers,” along with the passage of time, have removed the real horrors of air combat, leaving only the “romance” and excitement.

The P-51D is, by far, the most popular “scale” model pilots use to capture that excitement. A “scale” model is a miniature copy of a full-size aircraft that is built to a certain proportion, or “scale,” of the full-size airplane. Building a scale model from a wood kit will usually take months. Even P-51 ARF kits require weeks to complete and need some of the more advanced building skills. So most model pilots just stick to imagination and don’t ever get to enjoy flying their own P-51D.

Well, that isn’t the case anymore. ParkZone has just released their new P-51D Mustang. The new fighter is part of ParkZone’s “Charge and Fly” Series of aircraft. These new Ready-To-Fly (RTF) airplanes are the most “RTF” we have ever seen. Never mind requiring building skills, these aircraft kits don’t even require assembly skills. Having your own scale fighter is now as easy having one of the common high-wing, pusher electric park flyers. But the fighter looks a lot better and has far more performance.

Photo 1

Nestled inside that foam cradle is the most work-free scale model we have yet experienced. Everything required for flight is included, even the transmitter batteries. A lot of thought went into this “kit” and its components. As we will see, the equipment here is more advanced than the usual “basic” components supplied with this class of model.

 
Photo 2    Photo 3

Remove the fuselage and the horizontal stabilizer from the foam cradle. The horizontal stabilizer slides into the rear fuselage slot as shown in photos 2 and 3. Notice the “ridges” that are about 2 inches long on the top and bottom of the stabilizer. Slide the stabilizer into the fuselage until these ridges, there are two on the top and two more on the bottom, are aligned with the fuselage fillet as shown in photo 4 below.

Photo 4

Slide the stabilizer all the way forward. The ridges align the stabilizer inside the fuselage. Sliding the stab forward makes sure that the incidence, the angle of the stabilizer to the oncoming air, is correct. Enlarge the photos by clicking on them to see the details.

Photo 5

Photo 5 has been edited to try to show the next assembly step. At the end of the knife blade is a short piece of clear tape. The clear tape is supplied with the kit and is precut. Once the stabilizer is in position, apply the tape to the fuselage fillet and the stabilizer using a hobby knife blade as shown. Trying to apply the tape by hand just gets it wrinkled and full of fingerprints. Make sure the tape is about equally positioned on the fillet and the stabilizer. Apply the tape to each side, top and bottom.

Photo 6

After securing the stabilizer in place with the clear tape, attach the elevator control clevis to the outer-most hole in the elevator control horn as shown in photo 6. Be sure to position the silicone locking ring in place. The clevis itself does not have a locking mechanism so using the lock ring is important. If the ring is ever lost or broken, a small piece of silicone fuel tubing can be easily cut to size and substituted.

 
Photo 7   Photo 8

Put the fuselage assembly aside for now. Unpack the transmitter and install the eight AA batteries supplied with the airplane. Center both trim tabs as shown in photo 7. MAKE SURE THE THROTTLE LEVER IS ALL THE DOWN AT LOW THROTTLE. Raise the fuselage off the bench and secure it. A foam cradle works well for this. Stay clear of the propeller and keep anything important out of its way. Then turn on the transmitter, making sure the throttle is set to low. Relocate the transmitter away from the work bench to prevent accidentally hitting the throttle lever.

The P-51 is meant for pilots already having some experience in electric flight. In order to save weight and to avoid current losses, there is no on/off switch. Once the battery is connected, the radio and motor are fully powered. There is no low-high-low throttle motor safety cutout either. Once the on-board battery is connected, the Mustang is ready to fly. So be careful of that motor for the final two assembly steps. Most electric models intended for pilots with some electric power experience, like the P-51, sacrifice some safety features to achieve maximum performance. So be careful.

Connect the battery to the connector located on the bottom front of the fuselage. The on-board radio system is now active. Check to make sure the elevator is exactly even with the stabilizer as shown in photo 8. Ours was perfect. If yours is not, unhook the clevis and rotate it until the elevator looks like the one in photo 8.

 
Photo 9    Photo 10

Move the wing close to the fuselage and connect the aileron servo lead to the extension in the open part of the fuselage where the wing will mount. Check that the ailerons are level with the wing. Ours were out of adjustment as shown in photo 9. ParkZone makes adjusting the ailerons very easy. Notice the silver locking wheel in photo 10. Just loosen the wheel, it is just finger tight, and move the ailerons level with the wing. Then just tighten the locking wheel and that’s it. Be sure that both ailerons are level with the wing as shown in photo 10.

Disconnect the on-board battery and then turn off the transmitter. No tools at all are needed. The entire assembly process took 7 minutes, counting photo time, and the aileron adjustments required another 5 minutes, again including the picture taking. Total building time was 12 minutes but it could have been done in about 8 minutes without doing the photos. There wasn’t even time to fast-charge the battery before the airplane was done. That is impressive.

While that battery is still fast charging, let’s do a check of the Mustang’s Center of Gravity (CG). Well, maybe not. First of all, everything is factory installed and even the clear tape is provided. There is no way the “builder” could possibly mess up the Mustang’s CG. It is factory set. In fact, the very complete instructions don’t even say where the CG is supposed to be. We will just have to skip checking it at this point and hope that ParkZone got it right. (They did but that is for later.)

 
Photo 11   Photo 12

The wing mounts on the fuselage bottom using two metal screws at the front (photo 11), and the plastic radiator scoop at the rear. If you are not going to be keeping the Mustang assembled, the forward screw mounts in the fuselage are good places to store the screws so they aren’t lost. Since the wingspan is about 40 inches and the weight about 28 oz., I prefer to keep the airplane assembled. But this is the pilot’s choice.

The wing must be carefully aligned, and exact, for the screws to go through the wing and mate with the fuselage sockets. Once assembled, it might be a good idea to mark the wing and fuselage as in photo 12. This makes re-installing the wing an easy and quick process if it has been removed.

Once everything is together, check the control surfaces for proper movement. Back on the transmitter stick and the elevator points upwards. Move the stick all the way right and the right aileron moves upwards while the left one goes downwards. Do not move the throttle stick unless someone is holding the Mustang in a safe position. Leave the motor run until the field and disconnect the battery.

 

The Unexpected, Quality Extras.

The ParkZone P-51D Mustang arrives with some unexpected extras, most of them welcome. The charger is a nice surprise. Unlike other RTF electrics that supply a time-based charging system, the Mustang’s charger uses the more advanced peak-detect charge system. This means that the charger senses when the battery is nearing a full charge and adjusts the charge current accordingly. The charger will not overcharge the battery even if the battery was not fully drained before charging.

In addition, the charger has an adjustable charge rate. The 10.8-volt, 1000 mAh Nickel Metal Hydride (Ni-MH) battery takes about 30 minutes to charge at the recommended 1.4 amp charge rate. In order to insure that the battery reaches maximum capacity, I charged it the first few times at just 500 mAh. The charger is supplied with a cigarette lighter connector and works off the car’s 12-volt system. If the pilot desires, most electronic stores sell a connector for the charger’s plug that has clips at the other end so the charger can also be powered by a flight box’s 12-volt battery.

Since the charger determines the rate electronically, the Mustang can be charged while driving to the field. A fresh charge insures the longest possible flight time. The supplied charger is for Ni-MH batteries only and should never be used to charge a lithium polymer battery.

Why mention this? The Mustang has another welcome surprise. The speed controller and motor arrive almost ready to use a 3s, 1p lithium-polymer battery system. True, the airplane arrives set up for the included Ni-MH battery. But simply adding a jumper pin to the receiver converts the power system to Lithium Polymer specifications. The 3s lithium pack will fit into the airplane’s battery compartment without modifications.

The recommended Li-Poly battery has a 2100 mAh capacity, more than double the capacity of the supplied 1000 mAh Ni-MH battery. Instead of 10.8 volts, the 3s lithium pack should be nearer 11 .5 volts. While we do not yet have the lithium batteries to know for sure, I would expect that the Li-Poly system will weigh less as well. More power, double the flight time and less weight should provide a quantum performance leap. As soon as they arrive, we will test the lithium system and let Sport Aviator readers know for sure.

There is another jumper plug in the receiver. Adding this one mixes a little “up” elevator with aileron input. This helps the Mustang to maintain altitude in a turn. At least initially. The problem is that once the bank is established, the ailerons are returned to neutral while the aircraft continues the turn. As the ailerons return to neutral, the up elevator is released allowing the Mustang to descend, requiring more corrective action from the pilot than if the turn was initiated without any elevator input.

The mixed elevator input also makes for some strange rolls as the airplane rolls inverted and the up elevator is now “down.” Since the Mustang is really meant for pilots transitioning from an electric basic trainer anyway, a good suggestion would be to leave the jumper in place and investigate this option at some later date. If your previous airplane did not have elevator control, such as the excellent basic trainer the Firebird Commander reviewed elsewhere is Sport Aviator, then using this option could be helpful. Just remember to disable it before trying anything but gentle turns and upright flight.

The final surprise, very much welcome, is that the transmitter has dual rates. Yes, dual rates. That hardly ever happens with these aircraft. A transmitter switch determines whether the control surfaces move a lot, (very aerobatic but harder to fly), or a lot less, (very easy to fly but not very exciting), for a given transmitter stick movement. The switch is right on top of the transmitter and can be used during the flight. The amount of dual rate is fixed and appears to be about a 30% reduction in control surface movement at low rate.

For less than $180, getting a dual rate transmitter, a peak-detecting charger, a Li-Poly ready power system and a truly RTF scale airplane is just not normal. Buying the Mustang for this price feels a little like stealing, Just don’t tell ParkZone they are under-pricing this complete airplane system, OK?

 

Flight Performance

Photo 13

OK, so the airplane and equipment are better quality than expected. But I can’t experience the Walter Mitty Dream if the airplane does not perform. A quick look at photo 13 shows that performance is not a problem. The power system and aircraft weight are a good balance and the semi-symmetrical wing provides excellent inverted performance. ParkZone did a smart thing using ailerons instead of rudder for bank control. The ailerons really let the Mustang perform better than expected.

 
Photo 14   Photo 15

The Mustang, “Ferocious Frankie” (no I didn’t pick the name to match mine) is well done in yellow over olive drab with silver undersides. The actual yellow-nosed “Ferocious Frankie” P-51D flew as part of the Eighth Air Force’s 374th Fighter Squardron, serving in the 361st Fighter Group. Tail number 413704 flew bomber escort missions over Germany and covered the Normandy skies on D-Day. The full-size aircraft is credited with five victories and this is reflected in the canopy markings. Strangely, the 361st Fighter Group also had a P-51C model Mustang with the B7-H registration. It is possible the same pilot flew both; the C model before receiving the newer D model that ParkZone picked.

On the ground, The Mustang looks great. But flight is what this sport is all about. Hand launching is required but the Mustang has so much extra power that getting airborne is easy. For the first flight, I set the elevator trim at 3 clicks “up” to allow me time to get my launching hand back to the stick. The Mustang jumped out of my hand with hardly a push. The geared 480 motor has a lot of pulling power.

 
Photo 16   Photo 17

The Mustang climbed quickly to about 200 ft (photo 16). The silver bottom with its black and white invasion stripes made seeing the airplane easy (photo 17). There is no problem telling right side up from down as the silver bottom is very different from the olive drab topside. Being able to easily discern right side up from inverted is important because most “Ferocious Frankies” will be spending a lot of time inverted.

Once at altitude, I reduced the throttle for cruise flight and found another welcome surprise. The transmitter’s throttle control has an indent at about the 60% throttle level. This throttle indent is actually the “cruise” power setting. At this throttle setting, The P-51 can not only comfortably maintain altitude but will also climb with a little up elevator. Leaving the throttle at this setting insures flights over ten minutes, sometimes even past 12 minutes.

 
Photo 18  Photo 19

But who can just cruise a Mustang around? Not me. Photo 18 shows the Mustang in the middle of three consecutive rolls. Photo 19 is coming over the top in a loop. The best loop diameter is about 30 feet and the Mustang has no trouble performing it even 5 minutes or more into the flight. Immelman turns, a half loop with a half roll on the top, are fun since the Mustang flies so well inverted that not much altitude is lost at the top.

While we don’t have a photo of it, they came out a little blurry, the Mustang even flew respectable outside loops, (flying inverted and pushing down to make a loop with the airplane’s top facing away from the center). Inverted passes were stable without drama.

Steeply-banked, inverted turns used almost all the available “down” elevator on low rate. High rates were used for all the other aerobatic maneuvers. Performing slow rolls requires the nose to be raised about 30 degrees since there is no rudder to maintain altitude when the aircraft is on its sides.

 
Photo 20     Photo 21

Is there a Walter Mitty among us who could resist flying those low passes and strafing runs so popular in all the old war movies? Probably not, so I didn’t try. The Mustang was firm on both high and low-speed passes. At slow airspeeds, a little throttle in the steep approach turn helped to maintain altitude without sacrificing airspeed.

Photo 22

Stalls are possible but are not violent. Recovery is quick and the aircraft showed no tendency to fall off on a wing. Spins were tried but just would not happen without rudder control. The Mustang exhibited excellent handling habits in every flight régime. There was never a tendency to “tip stall”, drop a wing in a tight turn, and even flight right above the stall speed (photo 22) had some reserve elevator authority remaining.;

Photo 23

Landings were especially rewarding. Just a little power would keep the Mustang aloft in ground effect at a very slow speed. I would guess the landing speed to be around 15 mph. Cutting the power gently lowers the Mustang to the ground while still in full control, despite the extremely slow flying speed.

The ParkZone Mustang is not really meant to serve as a first airplane. New pilots should transition to the Mustang from a basic trainer like the Commander. But this airplane makes a great second electric sport model. Even pilots just out of their trainers will have no problem flying this airplane. More experienced pilots can safely push it to its limits and beyond, grinning all the way.

I can’t wait to get the Li-Poly batteries and then try flinging the Mustang through even more advanced maneuvers. If there is a weight savings of at least an once or more, I might try adding a small servo for rudder control. As soon as the batteries are available, I will report on the improved Mustang.

For more information on this fine airplane, please go to: http://www.masportaviator.com/activedit/redirect.asp?website=ArticleLink_Hobbico_P51Mustang

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