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Alfa P-47 Thunderbolt ARF

Foam planes have definitely been improving in quality and finish over the past few years, and the P-47 represents the latest and most advanced generation of this lineage. It is almost fully built, with the main wing attached and only a few items left to assemble, and has nice details that make it stand out, whether in "the hanger" or in flight.

Splash



Wingspan 32 3/4" (83.19 cm)
Length 28" (71.12 cm)
Wing Area 192 sq.in. (1239 cm.)
Flying Weight 15 oz. (425.2 g)
Wing Loading 11.25 oz/sq.ft. (34.32 g/sq.dm.)
Controls aileron, elevator and throttle
ESC Jeti 110
Battery 8x720 mAh NiMH
Motor Graupner Speed 300 6v
Gearbox MPJet 300 BB (5:1)
Prop APC 9x6 Slowflyer
Manufacturer Alfa Model
Available from Hobby Lobby International Inc.
The planes of the Second World War were designed for a deadly purpose, but even so, they had a beauty of their own. Many of these sleek machines had striking lines and graceful curves. Ironically, the P-47, which was designed around a massive 2000 horsepower radial engine, gave up a slender cowl and some of those graceful curves for raw brute power.
If you would like to see some original training videos for the P-47, check out "Zenos Warbird Videos".
While there are many sites with loads of information about the P-47, the site, "Cradle of Aviation", had one of the most extensive records of the P-47 that I found during my searches.
I have long been fascinated with planes of that era, and the P-47 has always been one of my favorites. When I first saw a picture of the P-47 from Alfa Models, I knew that I had to have this plane. Having owned and flown several ARF foam planes, I thought I knew what to expect from the Alfa P-47, but my expectations fell far short.
As soon as I received the kit, I knew that this plane was going to be different from any foam plane I had owned to that point. It arrives in a custom protective box that can later be used to store and transport the plane, and it is almost fully built, with the main wing attached and only a few items left to assemble. Foam planes have definitely been improving in quality and finish over the past few years, and the P-47 represents the latest generation of this lineage. The plane is well designed, and it came with many features that I have not seen in a foam plane before now.


The plane comes with detailed panel lines and rivets molded in the surface of the foam. Furthermore, the P-47 is very nicely painted, and this top-notch paint job even includes the cowl and canopy, areas that aren't usually much fun to paint.
With few exceptions, I have rarely seen a plane that deserved the title ARF as much as the Alfa P-47. When I took the plane out of its box and counted the parts yet to be assembled, I briefly wondered if a parts bag or two were missing. As I quickly discovered, nothing was missing. The plane was so complete that Alfa just didn't leave much for the builder to do.
Note: This review includes videos in the Windows Media Format (WMV). If you would like to view these videos, you may need to install the Window's Media Player.

Getting ready to "build" a plane

When I opened the parts bag, I was shocked to see that there were a handful of parts. There was a light plywood plate that had two pieces to punch out, an ABS plastic pilot (the only un-paint part of the plane), a spinner, a spinner-retaining plate, three pushrod connectors, some plastic tube, and a piece of Velcro. The plane had three major parts, which consisted of the plane, cowl, and canopy assembly. As I have already mentioned, the main wing and tail were already attached to the plane, but this wasn't the most surprising detail. The pushrods for the ailerons and elevator, as well as all their covers were already in place!
The detail of the canopy and battery hatch was even more surprising. The canopy was already painted and attached to the battery hatch, and the hatch already had the front retaining pins and latch glued in place. I was starting to feel guilty that I didn't have more work to do.

Installing The Gear

Mounting The Motor
The first step in assembling the P-47 is the installation of the motor. If you buy the recommended Speed 300 setup from Hobby Lobby, the final prep work simply requires attaching the capacitors and power leads, installing the pinion, and then inserting the motor into the gearbox.


p47_motor.wmv (1.28 MB)
(Click the picture above to view the video)
The P-47's firewall is already attached to the plane with the correct thrust built in, so once the motor and gearbox assembly is ready, it is slid into the hole in the firewall, and then held in place with the supplied screws. Since the firewall already has three pre-drilled holes for the Speed 300 gearbox's mounting flanges, this step goes very quickly. The only concern is to make sure to not over tighten the screws and strip out the holes.
p47_cowl.wmv (1.14 MB)
(Click the picture above to view the video)
After the power system has been attached, the pre-painted cowl is pushed onto the front of the plane. The cowl fits perfectly and tightly, so it doesn't require glue or tape to stay on. Even after several flights with the P-47, the cowl didn't show any signs of loosening.



p47_prop2.wmv (1.84 MB)
(Click the picture above to view the video)
With the cowl on the plane, the propeller can be installed. This step simply requires that the propeller be put on the prop-adapter and then on the plane, and then tightened on the drive shaft. There is one difference from the standard installation thought, as the kit includes two special parts, a new propeller retaining plate and a spinner. The retaining plate replaces the stock retaining plate that comes with the prop-adapter, and it serves a special purpose. The new retaining plate has a lip that holds the spinner on the plane. The spinner is a marvelous touch and gives the plane a very scale look.
Since the plane comes built with pre-installed pushrods, pushrod covers, aileron and elevator control horns, and plastic "scuff guards" for the belly and the wing, the next step in getting the P-47 ready to fly is the installation of the radio gear, which by the way, except for a few finishing details, is the last step in getting the plane ready to fly.
Aileron Servo


p47_aileron.wmv (3.54 MB)
(Click the picture above to view the video)
The first servo that is installed is the aileron servo. If you use the Hitec HS-81 servo recommended by Hobby Lobby, you will need to enlarge the aileron servo-mounting hole slightly by trimming a little foam from each side of the hole. (I used a pencil to trace the edges of the servo onto the foam, and then trimmed inside the lines.) After trimming a small amount of foam from the mounting location, the servo is test fitted in the hole. Keep doing this until the servo fits, but be careful not to trim too much foam, since the servo should fit snuggly. (Be careful on this step, especially since an Exacto blade cuts through this foam easily.)
Once the servo fits snuggly, it is glued in place with 5-minute epoxy. The aileron pushrods can be attached to the aileron servo after the servo is installed, but I found it easier to do this first.
To get the servo ready for installation, the pushrod connectors are installed in the control horn, and then a small piece of tube, which is supplied in the kit, is pushed into each connector. Since the wires for the ailerons are smaller than the holes in the connectors, the white plastic tubes are used to shim the holes. With these, once the screws in the connectors are tightened, the wires are securely held in place.
After I had the connectors ready, I taped the elevator pushrod to the side of the fuselage to get it out of the way. I then inserted the aileron pushrod wires through the white tubes in the connectors on the aileron servo, and then secured the aileron servo in the plane with 5-minute epoxy. Make sure that you don't push the aileron servo all the way down in the mounting hole, as it should be positioned so that the servo arm moves in-line with the aileron pushrods.
Elevator Servo


p47_elevator1.wmv (2.43 MB)
(Click the picture above to view the video)
If you use the Hitec HS-55 servo recommended by Hobby Lobby, the elevator servo installation goes very quickly. The first step is getting the elevator servo installed is "building" the light plywood component plate, which holds the elevator servo, the receiver, the battery, and the ESC. The plate has only two parts, and they are pre-notched so that they fit together snuggly in one step with CA glue or epoxy.
After the glue on the plate is dry, the elevator servo is screwed to the plate. The plate is then installed in the plane, on top of the two stringers that run along the inside of the plane. The plate should be positioned 50 millimeters forward of the rear opening of the battery hatch. Since I was using 5-minute epoxy, I marked this location with a magic marker first.
Unlike the aileron servo installation, I decided to insert the elevator pushrod wire in the elevator's control arm connector after the plate and elevator servo were installed, because I didn't want to fiddle with these items while the glue on the plate was drying.
After the glue was dry, I removed the elevator's control arm and attached the pushrod connector. Just as was done with the aileron connectors, a short piece of white plastic tube is inserted in the connector so that the pushrod wire is nice and tight once the connector's screw is tightened. Finally, the elevator pushrod tube is glued to the notch in the back of the tray to keep it from moving around.
Receiver
Once the plate was installed and the glue was dry, I put some Velcro (included in the kit) on the back of the Hitec 555 receiver, and then put it in the tray, in the location indicated in the instructions. Finally, I attached the servo leads to the receiver.
Battery


p47_battery.wmv (956 KB)
(Click the picture above to view the video)
Next came the battery installation, but since the location of battery would be different for batteries of different weights, and since I wanted to be able to move the battery back and forth in the plane so that I could adjust the CG as required, I put a long strip of Velcro down the center of the tray.
ESC
Finally, the ESC is hooked up to the motor and attached with Velcro at the front of the tray. The Jeti 10 came with leads that were much longer than needed, so I shortened them a bit when I soldered on the "Speed 400" connectors.

Finishing Touches

The plane was just about done, and all that was left were a few minor details. The first thing I did was glue a small piece of white tube on the ends of the pushrod wires of the ailerons and elevators next to each control horn, which helps to keep the wires from pulling out of the horns while the plane is in flight.
Next, I cut out and assembled the two halves of the pilot, and then painted the pilot with water-based acrylic paint. After the paint was dry, I sprayed it with a sealer coating of clear finish, and when that was dry, I glued the pilot into the canopy/battery hatch assembly using 5-minute epoxy.




p47_extras1.wmv (2.11 KB)
(Click the picture above to view the video)
The final step to getting the P-47 ready is putting on the water-slide decals. Of course, this isn't a required step, but I think the plane looks much better with its markings. I doubt anyone would say that applying water-slide decals is fun, and I have never really like doing either, but as with anything in life, with more practice I have become better at this task.
The decals for the P-47 are more fragile than others I have used, so care much be used when applying them to the plane. One of the main things to remember is that the decals need to be adequately wet and coming off the backing before they can be applied. Before attempting to put them on the plane, make sure you know where they go and try to get them in the correct location on the first attempt. Even when these decals are very wet, once they are on the plane, they stick very well, and they should not be handled much or they will tear. If your decals tear, don't fret. With a small of pressure and with water if needed, they can usually be manipulated in place. On my plane, every chevron decal tore before I could apply them, but I was able to apply the pieces and work them together until the seams disappeared. Some of the decals cover seams in the battery hatch and cowl, so after these decals were dry, I used a new Exacto blade to cut a seam in the decals.
By the way, it took longer to write the review to this point than it did to build the plane!

Getting Ready To Fly

With the plane built, it was time to install the battery for the correct CG. I opened the hatch, put the battery in a "guesstimated" location, and then balanced the plane using the pre-marked CG indentions under the main wing. (During this step, make sure you have all of the gear in place and secure in the plane, including the battery hatch.) It only took a few tries to set the correct CG, and once done, I marked the battery location on the tray using a magic marker. With these marks, if I needed to remove and charge the battery, I wouldn't have to find the correct mounting location again.
I checked the control throws of the ailerons and elevator, and with the pushrod connectors in the recommended locations on the control arms, the control throws were nearly perfect. Of course, I made sure the controls were all moving the correct way, performed a range check with motor off and then on, and then waited for a sunny day for the first flight.

Flying

On the day of the test-flight, I charged up the flight pack and met one of my flying buddies, Adrian Cruz, at the field. He took the pre-flight pictures and then set up to take the in-flight video. Since the sun was in our face from our usual flying spot at the side of the field, we walked out to about mid-field so that we could have the sun to our backs. I tried holding the plane various ways until I found a grip that felt right for my hand, which was about mid-wing, right at the CG. I gave a grunt, which in "guy speak" meant I was ready to go, and with camera rolling, I gave the P-47 a light toss. I tossed it a bit high, but it pulled away with power and I corrected the attitude quickly. For the first half of the flight, I was simple trying to set the trims. They were a little off, and the plane wanted to pitch up a little, but once I had them set correctly, the plane was rock solid and flew smoothly.
At about 39 seconds into the video, you can see the first stall test. Because it entered the stall with one wing high, it dropped its other wing a little, but not violently, and it recovered as soon as I applied power. Usually when a stall is entered straight and level, the P-47 drops the nose without dropping a wing. In the video, there is a transition at the one minute mark, which starts the second part of the video. This is from the latter half of the flight, and here the plane's trim is perfect. I started feeling more secure flying the plane, so I brought it by for a few quick, low passes, a.k.a., strafing runs! (The plane wasn't quite as close as it appears in the video. My video camera was set up with a little zoom, so please don't turn me into the AMA for unsafe flying...LOL)
alfa_p47.wmv (5.2mb)
(Click the picture above to view the video)
After a few passes, I brought the P-47 in for a landing. The P-47 slows down enough, and is still controllable at slower speeds, but you can't let it get too slow, especially when it is low, because it will stall. You can see the plane catching the weeds, even though most of the weeds are not visible at the resolution that I used for the video. My first concern was that the weeds had dinged up the leading edge of the wing or the bottom of the plane, but the wing was fine and the plastic protectors under the fuselage and wing did their job marvelously.

Conclusion

The Alfa P-47 is a beautiful semi-scale plane, whether sitting on the bench or flying. Just as it was with the full-scale P-47, the Alfa P-47 is well matched to its motor, and its motor does an excellent job of pulling this plane through the air.
The building that is left to the modeler, which is very little, goes very quickly and is very easy. Having been a fan and flyer of foam planes since I started in this hobby, I have seen their design and quality progress over the past few years, and I really hope this plane is the forbearer of things to come. The finish and details of the plane is better than I have seen on any other ARF foam plane to date. Now I can't wait to see the Mustang that Alfa is producing next!
Overall, the Alfa P-47 simply is a fantastic, fun plane. It is a nice easily portable sized warbird, and it makes for a nice park flyer as well. Even though it is has a fairly good roll at full throws, it is still stable and smooth in flight, so I think that a novice pilot could fly it with the help of an instructor, but I cannot not recommend it for beginner pilots. For modelers who have experience with a low wing aileron plane, this plane should not be a problem.

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