For years fellas have been building the Top Flite Gold Edition P-51 kit. It’s beauty, scale accuracy and solid flying performance kept it as one of the top choices for P-51 lovers. But what about all those guys who don’t have the time, room or desire to build? Well, at last, Top Flite brings to market the Giant P-51 ARF. Based very closely on the kit’s design, the introduction of this famous P-51 offering in ARF form has caused quite a buzz. But does assembly result in a plane that’s as attractive and easy to fly as it’s kit cousin? That’s just what we’re about to find out!
Distributed exclusively by:
P.O. Box 9021
Champaign, IL 61826-9021 USA
Beautiful ARF offering
Designed for Robart Retracts
Stable, scale flight envelope
Longer than average assembly
Designed around bare minimum powerplant
Kit Name: Top Flite Giant P-51D Mustang ARF
Price: $499.99 retail price
Wing Area: 1245 sq. in.
Flying Weight as tested: Total: 20 lbs. 14 oz. (dry)
Engine Used: U.S. Engines .41cc
Prop: Top Flight 18×8
Transmitter: Futaba 9CAP
Receiver: Futaba 8 Channel Receiver
Servos: (7) Hobbico CS-65 servos: ailerons, flaps, elevators and rudder
(3) Futaba 3004 Servos: throttle, gear and tailwheel
(1) HiTec HS-81: kill switch
Battery: 3000 Mah Nimh 5 cell battery (6.0 volt)
Manufacturer: Top Flite
Everything arrived safe and sound. Opening the boxes revealed a nicely covered airframe and lots of accessories, most being individually packed to help prevent damage and to organize the contents. The Mustang comes with fixed gear or you can optionally drop in Robart Retracts. Another really nice feature is the 5″ P-51 Spinner. Quite a value. First we reveal the holes in the flaps and ailerons but cutting away the covering.
These surfaces use hingepoints. I like to use a polyurethane glue and make sure to have plenty of paper towel pieces for cleanup. For a detailed step-by-step method of installation, check out the RCU How-To on hingepoint installation HERE. Next we cut the covering from the servo bay and gear openings.
Make sure to leave about 1/4″ or so material so you can iron the edges inside the plane. Now we can prepare to make the servo plates. The blocks on the wire side of the servo need shortened. Place the hatch on the bay and install 6 screws.
Remove the plate and harden the screw holes in the wing with CA. Then center the servo arm in the cutout and clamp it to the plate. Then clamp the two servo mounting blocks against the servo and epoxy in place. Install the servo with screws and the plate into the wing. Install the linkage.
Place the control horn under the pushrod for alignment and mark the holes. Drill and harden the holes with CA then install the horn with screws. I did note that the flap control horns needed some of the bottom removed to allow for full travel. A nice design feature is that they setup the flap servos so that you won’t require a servo reverser. Attach the extensions to the servo leads and pull them through the wing. My Robart Retracts weren’t in yet so I skipped onto the engine install. The ARF is designed to use the Great Planes Engine Vibration Isolation Mount.
The U.S. Engines 41cc needs some standoffs, and Top Flite includes some laser cut pieces just for this purpose. We glue them together… I used dowels coated with vaseline to align the plates. Next we bolt the mounting plate onto the motor with that standoffs in between. Then the mount is bolted to the firewall with rubber grommets. A quick check of the cowl revealed the carb would need cut out for, but basically nothing else… sweet!
We attach cowl mounting blocks next, but first need to round the outsides to match the contour of the cowl. While the epoxy set firm, I temporarily joined the wings together with the joiner and bolted the wing on. This allowed me to align the stab. First we center the stab in the opening, then use a string with tape as a measure to make sure the tip of each side was the same distance from the center of the fuse. Then we mark around the stab top and bottom, both sides.
Using a soldering iron, we “melt” the covering about 1/16″ inside the lines and re-insert back into the fuse. Just before the bare wood enters the fuse apply 30 minute epoxy to the bare wood and slide the stab in place. Have paper towels and denatured alcohol handy to remove the excess. Before it sets up, recheck each measurement and align the stab visually with the wing.
We now can install the elevators. Pin the center of the CA hinges and install the surfaces. Place 4-5 drops of CA on each side of the hinges and remove the pins. Do the same for the rudder. Top Flite includes a cockpit kit (yet another great value) to help make the P-51 really look scale. I opted not to install it at this time as I think I may spend some time detailing it and weathering it this winter.
Back the nose. We drill two holes through each mounting block and into the firewall. We then pin it in place with epoxy covered dowels. The next couple pics gives you an idea of the insides of the plane… everything looks very well designed and constructed.
The instructions have you remove the muffler earlier to make it easy to install onto the plane… however, I think this is really unneccessary. But I had already done it so I reinstalled it and used HiTemp sealant to seal it tight. Now we can make room for the carb. Mark the inside of the cowl where the carb touches it and dremel out a small opening.
Trial and error will eventually provide you with a nice cut out. Now we can align the cowl properly and mark and drill the mounting holes. I used a clear plastic strip to determine my screw positions. Next we assemble the tank. I used tie wraps to secure the line to the tank. (Which is gas friendly only… a glow stopper must be purchased if you are going to use a glow engine.
The tank is setup for a 2 or line system. I chose the 3 line, the plugged everything up tight and filled with a little gas. I’ve come to test all my fuel tanks overnight this way, and it has all but eliminated leaking tank problems. The tank is then cushion mounted to a plate and installed into the fuse and held in place with 2 screws. 3 holes are drilled in the firewall to allow the lines to pass through.
I next installed the throttle cable & servo, but found the guide tube hole to be too low for a standard servo, so I filed it up about 5/16″ for a straighter shot. I jumped around a little bit while waiting on the retracts. I assembled the tailwheel doors by first sanding notches where the hinges go, then gluing them on with CA & milled fiberglass.
Then wooden hooks are attached that will hold the rubber bands and the doors are then glued to the fuse. Next I installed the pushrods and control horns on the tail surfaces and installed the matching servos in the fuse. Again a nice design allows you to mount the servos in such a way that a reverser is not needed on one of the elevator servos.
Boy I hoe those retracts get here soon… I jumped onto installing the decals… I cut them out and placed them with tape in the approximate locations. Once satisfied, they were applied by spraying a light mist of water (with a small drop of dish detergent in a whole bottle) and then using a squeegee to remove all water from under the decal. I went ahead and painted and balanced the prop with a DuBro Prop Balancer. Then canopy was then attached with screws. I did place a strip of double sided tape along the front of the cowl to help hold it in place.
They’re here! The Robart retract mains and tailwheel have arrived. I spent some time with these as they were my first install. As it turns out they are MUCH more simpler that I first thought, and are very easy to install. There is no reason why any retract capable plane shouldn’t have a set of Robarts in them. Click HERE for a video on air retract basics. As mentioned before, the plane is designed with these in mind making for simple, drop in installation. The gear covers would be installed next, though I opted to wait til I had the first few flights on her before I installed them. With the mains plumbed and installed I could finally glue the wing together and epoxy the dowels in the leading edge. It was a perfect fit. The wing is held together with a clap on the rear and rubber bands around the dowels.
In addition, a clamped was used in the wheel wells to help hold the two halves together tightly. I propped us the wing to let gravity hold them together as well. This last pic shows the “harnesses” for the servos & retracts.
The tail wheel uses a pull system and a separate servo “Y”d with the rudder servo. It also has two “ears” that kick the doors open and help prevent the door from jamming under the retract. The air canister is installed in the fuse with laser cut brackets. Nice touch Top Flite! There is even a laser cut valve mount.
Every gas engine should have a kill switch. I used the Great Planes Ignition Engine Kill Switch which provides an external switch and an internal one kicked with a servo. I also used DuBro threaded rod tool to insert the threaded rod into the nyrod. This is a simple little thing that REALLY is nice to have.
The finished installation of the kill switch is clean and neat. BTW… I mounted mine so that the outside switch is DOWN for on and up for off. I figure if vibration and gravity are going to work on it… down is where I want ON to be. Now we install the air scoop. First we dremel holes in it for the wing hold down bolts to pass through. We mark the wing for it’s position and cut the covering out with a soldering iron. Wing hold down plates are also installed and the whole assembly is epoxied in place. I placed some wax paper between the scoop and fuse to make sure they didn’t get glued together. NOTE: I strongly recommend gluing two tubes from the air scoop to the bolt holes to make it easy to get the screwdriver on the screws. Without them has proven trying sometimes.
A wing fairing is now cut to fit and epoxied in place. I took my time and kept placing the fairing on the wing, then cutting a bit more til I was happy withe the fit. The wing fillets and wing guns are glued in place by removing the covering underneath and medium or thick CA to attach them. And finally, the exhaust parts are attached. You first have to glue a stick of balsa inside, then plane it flat with the plastic. Rough up the paint where the exhaust ports go and glue on with epoxy.
Balancing required 2 people and I found that I had to install a 3000 mah NiCD battery at the rear fuse opening to achieve the front end of the suggested balance range. Again, if a lighter 50cc engine was used, the battery would move forward, no problems. That’s pretty much it, I set the throws as instructed, and tested the gear out thoroughly.
The engine was run in a tank, an we waited for the next decent flying day.
Decent central Ohio flying time is getting hard to come by in December. Patiently we waited for a day that would offer milder temperatures and low winds. That day finally arrived. With winds less than 5mph and temps in the lower 40’s we assembled this beauty in less than 5 minutes, including pressurizing the air tank.
The U.S. 41cc engine started on every spring release, but died within a few seconds each time. Each time we choked it by placing the hand over the velocity stack and turning the prop over a few times (with the ignition killed of course). On the 5th attempt, the engine had warmed up enough to run reliably.
Taxiing with the P-51 was effortless and with the elevator held full up, there was no tendency to nose over, even with our field grass a little thicker and moist than normal.
We lined up on the runway and smoothly and at moderate speed fed in throttle… Very little correction was needed to track straight down the runway. Maybe a little right rudder. I was fairly nervous as I have heard conflicting reports about the U.S. Engines 41 providing enough power. As the Big Beautiful Doll neared the end of the runway I could help but think how awesome the take-off was. It looked, at least in my minds eye, like what the full-scale bird would like. The tail came up within 50 feet and it just slowly gained speed. As the end of the runway loomed, I started to wonder if it was going to lift off, and as I began to think about adding elevator (just a hint was added) the plane lifted off and was airborn.
As I watched the P-51 climb to a respectable height, I just felt overwhelmed with feeling of history and pride this plane instilled in American history. This Mustang is big and beautiful, just like it’s name.
But enough of the nostalgia, I had a plane to fly. A flip of the gear switch tucked the Robart Retracts away as designed and the P-51 gained some performance immediately. Even then, I can say I felt “on the edge”. The 41 took it off and flew it around adequately, but there was no reserve of power. Having flown mostly aerobatic planes that were fairly “overpowered”, this experience was different entirely.
For me, I’d have to say that I’d rather have more power. Maybe one of the new slim 50cc offering out there. While the 41 fit well in the cowl, I’d have to say I’d trade a little of the cowl for a lot more power. The Fuji 50 was considered from the beginning, but it would require a good deal of cowl cutting perhaps ruining this plane’s great looks.
With that said, it flew quite nicely. Very stable with no tendency to snap with responsible elevator input or at low speeds. Rolls required some down elevator mixed in when inverted, and loops were possible. The loops were a little elliptical as the plane would lose momentum nearing the top of the loop. More power would pull this sweetheart through some gorgeous, big loops. It would dive and pick up speed well and looked really neat as it zipped across the early evening sky. Slow speeds were tested and this plane just flew regardless of speed.
The Robarts were dropped and a check pass was ran to make sure all was well, and sure enough… the performed flawlessly. A few passed were made to determine approach speed, and also determine what the effect deploying full flaps would have on the plane. Much to my surprise, I saw no change in the attitude of the plane other than it slowing down. Nice… very nice
As I made a few approaches I noticed that the engine wasn’t dialed in on the low end and I couldn’t get it stay at the little bit of power I wanted… it was either a couple clicks to fast or at idle. Not the fault of the engine but rather it being new and somewhat a cold day.
Because of this I found it hard to slow down. In addition, the daylight was quickly starting to fade causing me approach at a higher altitude than I would like, again adding to the approach speed.
After a couple passes I had to go for it, and the plane landed hot. Even then, the plane slowed quickly and was very stable thanks to the shock-absorbing Robart struts. As I mentioned the grass was a little higher and thicker than normal and it really drug on the wheels… in the end the plane nosed over and busted a prop. I had done several slow speed passes earlier at complete idle and am very comfortable with the plane’s slow flight ability, and know that it will slow down for approach nicely. The clean lines and heavier wingloading will require a platter approach to prevent picking up speed, but she should glide right in and touch down softly.
The flying season is pretty much over, but you can bet I look forward to flying her much more this coming spring, and stepping into that WWII era when the Big Beautiful Doll ruled the skies.
The P-51D Mustang ARF is Top Flite’s first ARF offering, and judging from the construction quality, design features and great flying performance, we’re sure to see more ARF offerings from them. Who knows… perhaps there will be a gorgeous Jug in our future. While I’d recommend a more powerful engine for this P-51, seasoned warbird pilots would have no problem flying it with the U.S. Engines 41. The assembly is a bit longer than other ARFs, but that’s to be expected when outfitted with retracts, flaps, gas engine, etc. Without a doubt, if the P-51 has been calling you but you just didn’t want to build form a kit… the Top Flite P-51D Mustang ARF is a top notch offering.
Top Flite, Hobbico and U.S. Engines
Distributed exclusively by:
P.O. Box 9021
Champaign, IL 61826-9021 USA
Email: [email protected]
Additional products used: Hobbico CS Series Servos, Vibration Reduction Mount, Milled Fiberglass, Dead Center
Engine Mount Hole Locator, Ignition Engine Kill Switch Harness
Robart Mfg., Inc.
P.O. Box 1247
625 N. 12th St.
St. Charles, IL 60174
Web Site: www.robart.com
E-mail: [email protected]
480 Bonner Road, Wauconda, IL 60084
Products used: threaded rod tool
Futaba Corporation of America
Distributed Exclusively in the U.S.A., Canada and Mexico by:
Great Planes Model Distributors
P.O. Box 9021; Champaign, IL 61826-9021
Products used: Futaba 9CAP transmitter, FP-R148DF receiver, 3004 Standard Servos