CMP F4U Corsair 120 - 75.5" Review by's Erick Royer

F4U Corsair

Review by Erick Royer


Here it is...My Dream Plane! The F4U Corsair.

The F4U Corsair is considered to be the one of the finest carrier based fighters of the WWII era. Chance Vought's F4U Corsair was first flown in 1940 and was one of the outstanding naval/marine fighters of World War II. Production of the Corsair ran for nearly ten years, ending in early 1953 after more than 12,500 had been built.

The F4U was credited with an 11:1 ratio of kills to losses in action against Japanese aircraft and was the last piston engine fighter in production for any of the U.S. services. The Corsair was built around a powerful 2000 hp, double-bank radial engine. The distinctive feature of the F4U was the inverted gull-wing that provided less drag in flight, allowed for shorter landing gear to accommodate an oversized propeller, and enabled the wings to be folded directly over the canopy with room to spare on the hangar deck. The shorter landing gear permitted rearward retraction which in turn allowed for greater wing-fuel capacity.

Due to inadequate cockpit visibility, adverse stall characteristics at slow approach speeds, and a tendency for the tail-hook to not engage due to aircraft bounce when it hit the carrier deck, the F4U was restricted from carrier operations until late 1944. In the interim, Marine Corps and some Navy squadrons were actively engaged in Pacific combat operations beginning in early 1943 from land-based island locations. One Marine Corps squadron was credited with downing 135 aircraft over an eighteen month period and produced ten aces. One Marine pilot went so far as to down an enemy aircraft with his propeller.

Thanks to CMPs, you no longer have to spend months building, sanding, glassing, and painting to get a beautiful scale model of one of the most recognizable warbirds to that ever took to the sky.

GSP really did their homework on this model, with real working 3 piece split flaps, scale panel lines molded into the fiberglass, two color insignia blue and gray paint scheme, and real cloth covering. Provisions have been made on this aircraft for either fixed landing gear or mechanical retracts. Robart 615 HD Pneumatic Rotating Retracts would also fit perfectly with a little modification which I will cover in detail later on in this review. They even included a prepainted dummy radial engine.

This is going to be one beautiful bird!


  • Good parts fit
  • Very nice covering/paint job
  • Well constructed fiberglass fuselage, wing center section, and cowl.
  • Flap pushrod installation was difficult (see text)
  • Slight color difference between the outer wing tip panels and the wing center section


Kit Features
Required Items
  • Painted fiberglass fuselage, wing center section, and cowl
  • Fuel tank, tubing, clunk
  • Motor mount & bolts
  • Pushrods
  • Fixed landing gear and wheels
  • Canopy
  • Decals
  • Steerable tail wheel
  • Wing bolts, control horns, clevises.
  • Painted dummy cowl and air coolers for wing
  • Other assorted hardware
  • 5-6 channel radio with 7-8 servos
  • 2-stroke .91-1.20 cu in or 4-stroke .91-1.20 cu in
  • Servo Wire Extensions
  • Fuel Tubing
  • CA glue, epoxy, Loctite thread lock
  • Propeller
  • Standard building tools



Assembly of the F4U Corsair
LEFT: The parts as they come out of the box!

The Corsair arrived on my doorstep double boxed in perfect shape. I quickly opened the box and examined all of the parts. The picture above was borrowed from the GSP website and perfectly illustrates what is contained in the box. The fuselage, wing center section, and cowl are constructed of fiberglass and prepainted. The outer wing panels are constructed of foam and balsa, and the tail feathers are cloth covered balsa and painted to match. The instruction manual is typical of kits imported from China. It features a lot of drawings, but very little text.



The Corsair's wing is assembled from three separate pieces; the outer wing panels and the center section. The outer panels are foam core sheeted with balsa and covered in a cloth covering and painted The wing center section is constructed of molded fiberglass with plywood formers.

LEFT: Aileron Servo Hatches

RIGHT: Servo Mounting Plate

The wing assembly begins by removing the covering from the servo bay opening on each outer wing panel. Using a sharp knife, I removed the covering cutting about 1/8" inside the perimeter. I then ironed down this material with my iron to ensure that the covering would not peel up at a later date. Next you need to install the hardwood servo mounting blocks with epoxy to the 2 removable servo hatches. I used 5 minute epoxy on the blocks and clamped them in place. Once cured, I installed a Hitec HS-425BB servo on each hatch. I used a 12" servo extension on each aileron and slid them through the opening in the wing. I attached the servo hatch with the supplied screws.
LEFT: Aileron Attached to Wing

RIGHT: Aileron Linkage

Next I installed the control horn on each aileron and then epoxied the ailerons onto each wing panel. They give you CA type hinges but with the foam in the wing panel it is a good Idea to use either a finishing epoxy or 30 minute epoxy thinned with alcohol. At this time you will also attach the single flap panel to each outer wing. Once the ailerons were attached, I made up the pushrods for each wing and installed them to the servo and control horn. I tested their operation to ensure that everything worked smoothly without binding then I set the panels aside.

At this time the manual would have you attach the wing panels to the center section. Because I am going to use the Robart Retracts, I decided to wait to make it easier to work on the wing center section.
The next step was to install the remaining 2 of the 3 flap sections to the wing center section. Again these were attached with CA type hinges and epoxy. Note: Because the finish on the plane was done with a flat paint, you will need to be very careful not to get too messy when using epoxy or you may jeopardize the finish. With the flaps installed, the next step was to install the control horns on the inner flap panel on each wing.
LEFT: Stock Flap Cables

RIGHT: Stock Flap Cable Exit. Note 2 Inner Flaps Attached

The kit is designed to have a single servo in the wings center section that will operate the flaps in a push-pull fashion. I setup the cables as instructed and was planning on using a standard servo. With the flaps connected, I hooked up the radio to test their operation and I quickly noticed a problem. The servo I chose was simply too weak to move the flaps correctly. I switched to a 100 oz. servo and was able to get them to work. I did have a problem with the retraction and deployment angles being different and inconsistent each time the flaps were activated. There is nothing worse than having one flap operate at a different angle from the other or worse yet, causing you a trim problem when one does not retract all the way. This was something that I decided to modify.
My plan after discussing with other GSP corsair owners was to install a servo in each wing to control the flaps. I decided to use the Hitec 225MG servos because they are powerful and small. I marked where their location and cut a hole on either side of the wing center section on the bottom side. Because this is just fiberglass, it would be necessary to install a small piece of plywood for the servo screws to catch in each opening. I used 5 minute epoxy to hold them in. Once installed, I simply created a pushrod with a Z Bend on the servo horn and a clevis on the control horn.
LEFT: Flap Servo Installation

RIGHT: Flap Deployed

I connected the flap servos with a Y Connector and tested their operation. I then noticed that one flap went up as the other went down. It would be necessary to either install a servo reverser on one of the servos or use a programming mix in my radio. Because I was using the Futaba 9C, I decided that I would mix channels 6 and 7 together for the flaps. Another advantage to the setup is the ability to set the end points individually with the radio. This will ensure that they go up and down in the exact same positions. They worked flawlessly. This is a simple modification that takes only
a few minutes and does not hurt the aesthetics of the finished model. I would highly recommend it.
Alternative Flap Servo Installation: If you would like to use 2 servos and do not want to cut the bottom of the wing, an alternative would be to mount the 2 mini servos in the wing center section and use the existing pushrods. There is a servo tray in the center that houses 2 standard servos, one for mechanical retracts and the other is for the flaps. You could easily modify the tray and install the 2 servos for the flaps.


There are a few options to consider when it comes to the landing gear. The kit comes with fixed landing gear wires and mounting hardware. This would be the simplest method of putting legs and feet on this bird as long as you do not mind having the gear down all the time. Once you see how beautiful this plane is, you will understand why I could not settle for a fixed gear. The Corsair was begging for rotating retracts.
The manual includes some hardware and instructions on installing a pair of mechanical rotating retracts. The retracts would be activated by a servo in the wings center section. A series of pushrods and bell cranks would then connect the servo horn to the retracts. I considered this option, but was concerned about using all those mechanical linkages. I wanted to ensure that the retracts would be reliable. There is nothing worse than having a retract fail on landing. So I turned to our friends at Robart and decided that a pair of 615HD Rotating Retracts, Oleo Struts, and scale tires would be the answer.

Installing the Robart Retracts was a little more involved than perhaps I was hoping for. (See inset below for installation details.) It was not difficult, but it did take a couple extra hours to install them properly. You need to begin by enlarging the opening in the fiberglass to the size of the retract base including the mounting flanges. This was easily accomplished with a Dremel tool and a cutoff wheel. The next step is to enlarge the opening in the wooden mounting rails that are already in the wing for the fixed landing gear. The body of the retract is about 1/2" wider than the opening presently in the mounting assembly. I used my Dremel again with a sanding drum to enlarge the opening. The Robart retracts will also require the mounting rails to be raised so they are flush with the wings lower surface. Note: the mechanical retracts and the fixed landing gear are designed to recess in the wing. The rails are already installed in the wing and therefore no modifications would be required. I took a small piece of cardboard and placed it in the opening against the existing mounting rail and traced along the wings outer surface. This gave me an exact template of the mounting block extensions.

LEFT: Plywood Retract Mounts

RIGHT: Retract Mounts Installed

LEFT: Retract Installed

RIGHT: Retract Extended

In order for these retracts to work properly, it is very important that the mounting rails are flat and even or the mechanics in the retracts could bind hampering their performance. In order to assure that the mounts would work correctly, I decided to laminate several pieces of 1/4" aircraft plywood together so that it was large enough for all 4 mounts. The mount ended up being about 1 1/4" high at the thickest spot. They would also have to be tapered towards the wings leading edge. I used a belt sander to get the correct taper until they matched my template. Now that I was sure they would fit, using a band saw, I cut the laminated plywood into 4 separate mounts measuring 3/8" wide. This assured me that they were all exactly the same height and angle.

Next I test fit the new mounts in the wing. They worked out perfectly with the mounting surface lining up with the wings outer surface. I checked the opening with the new mounts to ensure that the retract would fit correctly then I permanently installed them in the wing using a very generous amount of 30 minute epoxy. I made sure to coat all sides of the new mounting blocks heavily. I did not what them to break loose on takeoff or landing. I let them cure overnight before installing the retracts.

I decided not to use the plastic wheel wells because they would restrict how far the retract would settle into the wing leaving the tire exposed on the wings surface. This would surely cause some trim problems in flight.

Robart 615HD Retracts

When looking for a pair of high quality rotating retracts to fit this Corsair, there are really very few options to consider. I looked to Robart because of their high quality, very realistic finished appearance and reliability.

Robart Retract Components Including: Scale Wheels, 90 Deg Rotating Retracts, Oleo Struts, and Air Tank

The Robart 615HD retracts are constructed of an aluminum base and internal mechanics to keep them light. There is a preinstalled 3/16" strut wire on each retract that can be cut down to size.

I used Robart 188VR air supply kit which consists of the air tank, filler valve, T connectors, hose, quick disconnects, control valve, and even a pressure gauge. Everything that I needed to setup the retracts is included in this kit.

A pair of 380 functional Oleo Struts in a straight mount design were also used to further dress up the aircraft while adding shock absorption.

Installing the oleos to the retract wire is a very simple task. You need to determine how much wire to cut off the retract to allow the oleo to end up in the proper position. On the Corsair, because of the gull wing, the actual length of the retracts is rather short. In this installation both the oleos and the gear wire would have to be cut. I cut the wire on the retracts with my Dremel tool and cutoff wheel to a length of 3/4". Next I temporarily placed the retract back in the wing and aligned the oleo over the wire to determine where they would need to be cut. I simply centered the axle opening in the center of the wheel well and marked them at the retract.

Completed Retracts ready to be installed in the Corsair.

The oleos were cut also with a Dremel and cutoff wheel. The next step is to install the bushing inside the oleos for the proper wire diameter. They supply you with 2 sizes. I held the bushing in place with JB Weld. Two small holes are then drilled in the top of the oleos for the setscrews that will attach them to the gear wire. The holes are then tapped with a 6-32 tap. I installed the setscrews and placed the oleos over the retract wire, positioned them correctly, and tightened the setscrews. This will make an impression in the wire. Next, remove the oleo and grind a flat spot in the gear wire using a Dremel or a file. This will prevent the oleo from rotating on the wire.

Robart Air Tank Installed on the Top of the Fuselage with Silicone Adhesive.

Once complete, I reinstalled the oleos on the retracts and installed a pair of 3" scale Robart wheels. These really dressed up with model giving it a very scale appearance. The retracts were permanently installed with 4 screws.

The last step was to hook up the plumbing and control valve to operate the retracts. I followed the schematic that Robart includes with the air tank kit. This really simplifies the process. I connected the control valve to the center of the wing where the retract and flap servos were supposed to go. I am controlling the valve with a standard servo.

The Robart Air Fill Outlet and Pressure Gage is Installed on the Front of the Fuselage.

The Robart retracts worked perfectly and give the model a very scale appearance. I would highly recommend them for this model.

The last step in the wing assembly was to install the outer wing panels. The first thing that I did was to scuff the fiberglass on the ends of the center wing section to ensure a good bond. Each panel has a dihedral brace. Using a generous amount of 30 minute epoxy, I attached the wing panels to the wing center section and held them in place with masking tape. Lay the wing on a flat surface, face up, and measure to make sure that the distance from the surface to each wing tip is exactly the same.

Once cured I noticed that the joint was pretty noticeable for each outer wing panel so I went to the local Home Depot and with a sample of the blue paint. They were able to match me a quart of flat latex that was a perfect match. This paint will also come in handy in the event that the fiberglass ever gets dinged.

The final detail is to install the 2 oil cooler scoops on either side of the wing. These are held in place with 30 minute epoxy.

Now it is time to attach the wing to the fuselage. The first step is to drill our the two holes for the leading edge wing dowels. There are plus (+) signs molded into the fiberglass to indicate where the holes must be drilled. One really nice feature of the wing assembly is that the dowels are actually made from steel. Once the holes are drilled, I applied some 30 minute epoxy into the holes and pressed the pins in place.

LEFT: Steel Pins on the Wing Center to Attach the Wing to the Fuselage.

RIGHT: Wing Mount Holes

In the fuselage there are 2 corresponding plus (+) signs that will also need to be drilled out to accept the wings pins. Once this step is done, fit the wing into the fuselage. On my model, everything lined up perfectly.

Next measure from each wingtip to the rear center of the fuselage to ensure that the wing is square. Tape the rear of the wing to the fuselage so it does not move. Drill 2 holes through the wing into the fuselage in the marked locations for the wing hold down bolts. Remove the wing and install 2 blind nuts in wing mount block in the fuselage. Reinstall the wing and fasten with the supplied 4-40 wing bolts.

That completes the assembly of the wing so we are onto the fuselage!
The Fuselage is beautifully constructed of fiberglass with a few plywood formers. The finish is expertly painted in 2 colors, and like the wing center section, it features molded panel lines.
LEFT: Shot of the Inside Rear Fuselage.
Fuselage assembly beings by installing the tail surfaces. Place the U shaped connector rod in the opening for the horizontal stabilizer. You will not attach it at this time but if you forget to put it in the opening you will not be able to install it once the horizontal stabilizer is installed.

New Product
Midwest Products Aero Stand

With the GSP Corsair having a painted fiberglass fuselage, I wanted to be sure that I was very careful while working on it. My new Midwest Products Aero Stand was the perfect solution.
The Corsair Fuselage on my Midwest Products Aero Stand.

The portable work station designed with comfort in mind! At the field or in the shop, Aero Stand is the easiest way to get your plane up and ready to fly. Three position cradle adjusts to 4", 7" and 11" widths. Folds down easily for transport. The overall height of the unit is 31" and the width is 27".

The Completed Corsair on the Aero Stand at the Field.

If you are like I was, you probably have a stand made from PVC pipe and some foam. Not anymore. This stand is very rugged and allows me to walk around my model while I work on it. This is something I was just never able to do with my PVC stands.

Whether you fly a 40 size trainer or a giant scale aerobat, the Aero Stand provides you with an excellent, ergonomic work stand for your model.

This stand goes with me where ever I go!

Slide the stabilizer into the slot in the fuselage and measure to the wing tips to ensure that it is in square. Then mark the top and bottom surface of the stabilizer along the fuselage side. Remove the stabilizer and then remove the covering just inside the lines you made. Note: Save this piece of covering that you remove. It will come in handy if you need to ever get the paint matched. I brought mine to Home Depot and was able to get both the gray and blue mixed to a perfect match. The stabilizer gets installed to the fuselage with 30 minute epoxy. Be sure that the stabilizer is installed level as well as square. Once satisfied, hold it in place with masking tape.
LEFT: Horizontal Stab and Elevators Installed

RIGHT: Elevator Pushrod and Control Horn

Next you install the elevator halves. The horizontal stabilizer and control surfaces have already been slotted to accept CA hinges. You will need to drill a hole in each elevator half for the U shaped connector rod. This rod allows both halves to work as one. Ad some epoxy in the holes on the elevator halves and use thin CA on the hinges. It is important to be sure that both elevator halves are aligned perfectly as you do not have any room for adjustment once the epoxy has cured.
The next step is to install the tail wheel wire. You will need to cut a slot in the vertical stabilizer as indicated in the instructions. There is a piece of copper tubing that you need to slide over the tail wheel wire, then you bend the top of the tail gear wire according to the drawing.
You need to drill a hole in the rudder for the tail wheel wire. Fill the hole with 30 minute epoxy before installing the rudder to the vertical fin. The rudder, like the elevator halves, installs with CA hinges using thin CA. Install the tail wheel to the wire using the supplied collar.
LEFT: Tailwheel Wire Installed with Brass Tube

RIGHT: Rudder Installed with Pushrod

Next, install the rudder and elevator control horns as shown in the instructions. You will need to construct the elevator and rudder pushrods. This process is very simple as long as you follow the diagrams in the manual. They have you use heat shrink tubing to secure the wire to the pushrod. I prefer to use thread wrapped around the pushrod ends and then soak it in thin CA. This provides a much stronger connection. The pushrods are made from a hardwood dowel and 2-56 wire on either end. They seemed to work well, but I did notice that the elevator pushrod would bow at the extremes of the elevator movement. After the test flight, I might change this to a Dave Brown fiberglass rod if needed.
LEFT: Use Thread Soaked with Thin CA to Attach Music Wire Pushrod to the Hardwood Dowel.



The next step is to mount the engine. I chose the RCV 90SP to power this aircraft. The two main reasons that I chose this engine are its ability to swing a larger more scale prop, and it compact design would not require any cutting of the cowl for head clearance.

RCV 90SP Engine Installed on Mounting Block to Bring the Prop Hub 168mm Away from the Firewall.

According to the manual, the distance between the firewall and the front of the prop hub needs to be 168mm. With the engine being only 120mm it was necessary to build a mounting block on the firewall that was approximately 48mm thick.

The kit comes with a spacer block that you might need to use if installing a 2 stroke engine. I used this block as my template. I ended up making the block from a 2x4 and some 1/4" plywood which I laminated together with 30 minute epoxy.

One problem I quickly noticed is the 3/4" hole in the center of the mounting block that is included with the kit. This hole allows for the fuel tank lines to pass through. The RCV 90SP has a flat radial mounting plate on the rear of the engine that would prevent the fuel lines from entering the engine compartment. My solution was to bore a 3/4" hole through the mounting block in the same position as the one that came with the kit. Then I bored a second hole at a 45 degree angle from the top of the block. This allows the fuel lines to enter the engine area without disrupting the mounting plate.

Hole Bored at a 45 Degree Angle to allow Fuel Lines to Enter the Engine Area.

The first thing I did was mount the engine to the mounting block. I marked the hole locations and drilled 4 holes through the block. On the back side of the block, I bored out the holes about 1/4" deep and with a large enough diameter for the blind to be countersunk. Because of the thickness of the mounting block, I was not able to use the supplied screws. I purchased some 2 1/2" screws for mounting the engine and 3" for mounting the block to the firewall.

Two Sets of Bolts Mount the Engine. One Attaches the Engine to the Mounting Block and the Other Attaches the Mounting Block to the Firewall.

The next step was to position the mounting block on the firewall so the prop shaft is centered in the cowl. Once aligned. drill 4 holes through the block and into the firewall. I installed 4 blind nuts in the back side of the firewall.

I was going to epoxy the mounting block to the firewall, but decided not to in case I decide to change engines in the future.

With the engine installed I drilled a hole for the throttle pushrod and installed the tube. I held it in place with some thick CA.

Throttle Linkage
(Note: The picture above shows a remote glow driver. I decided to replace this with an on-board glow driver - see review below)
RCV 90SP Closer Look

The RCV 90 SP features a unique compact design.

The RCV SP line of engines has been getting some raised eyebrows over the past year. Its unique design leave people scratching their heads wondering how this little power house works. The SP series consists of 3 engine sizes; 60, 90, 1.20.

I borrowed the following information from the RCV Engines website, as I feel they do a much better job explaining the engine that I could.

The RCV 4-cycle engine has only one more moving component than a 2-cycle engine -the rotating cylinder itself. The cylinder is suspended between two bearings which allow it to rotate freely around the piston; the piston, and crank are entirely conventional. A gear formed around the base of the cylinder meshes with a gear on the crank. As the piston reciprocates and the crank turns, the cylinder rotates around the piston..

At the top end of the rotating cylinder there is a single port leading to the combustion chamber. This is surrounded by a fixed timing ring with three radially arranged ports; inlet, ignition and exhaust. This simple valve arrangement serves the combustion chamber as the engine cycles through the conventional 4-cycles: induction, compression, power and exhaust. Ignition is achieved through a standard 4-cycle glow plug exposed once only during each complete cycle.

The rotating cylinder is effectively combined with the rotary valve in a single component hence - RCV - Rotating Cylinder Valve.

(Courtesy of


  • Maximum Power: 1.3 BHP
  • Length: 120mm (4.72")
  • Displacement: 15cc (.09 cubic inch)
  • Power Output: 1.6 BHP at 11,000 RPM
  • Practical RPM Range at the prop: 1,200 - 6,000 RPM
  • Practical RPM Range at the crankshaft: 2,400 - 12,000 RPM
  • Crankshaft Thread Size: 5/16" UNF
  • Weight: w/o Muffler - 28.6 oz. (785g)

The manufacturer recommends this motor be run on fuel containing 10% nitro methane and oil content at a minimum of 15% including a maximum of 6% castor. I used a special fuel made specifically for this engine from Coopers Custom Blended Fuels.

One of the largest advantages of the RCV 90SP engine is its broad range of propeller sizes.

2 Blade Prop - 16x14, 17x13, 18x12, 20x10
3 Blade Prop - 15.75x13
4 Blade Prop - 15.5x12

After discussing with Otto Kudrna, a US distributor and technical support rep, for the RCV product line, I decided that I would try Zinger 18x12 and Zinger 20x10 wood props to see what would give me the best performance. It is so hard to imagine a 90 size 4 stroke swinging a 20x10 prop and getting any performance out of it, but with the 2:1 gear reduction, the 90SP is a real powerhouse.

Zinger 18x12 Wooden Prop that I Painted Black with Yellow Tips.

Download the manual in PDF format - Click here

Download the sales sheet for the RCV SP series engine line in PDF format - Click here


The manual illustrates how to install a conventional 2 or 4 stroke engine to this model. The required hardware for those installations are included in the kit.

With the engine installed, the next step is to install the fuel tank. I use a 3 line setup on my planes with a supply line, vent line, and fill/drain line. The fuel tank fits through the firewall and locks in position on the front of the servo tray. I held it in place with tie straps.

LEFT: Fuel Tank Installed

Next I installed the cowl. This was probably my favorite part of the model's assembly process. Why? Because only 2 small openings were required in the cowl; one for the needle valve and one for the exhaust exit. These were easily done with a Dremel tool and a sanding drum. The RCV 90SP fits perfect inside the cowl even with the muffler attached. I did use some rubber tubing to extend the exhaust just out the bottom opening of the cowl.

The Cowl is held in place by a plywood ring that gets screwed to the firewall. The ring is about 1/2" larger than the diameter of the fuselage. This leaves the required gap around the cowl to give the model a very scale appearance. I was concerned about cooling the engine and creating an escape are for the air to pass over the engine. To accomplish this I cut the plywood ring in half and only used the top portion and a small block for the bottom screw. This left me an opening from 3 to 6 o'clock and 6 to 9 o'clock. I painted the plywood black and installed it to the firewall with 4 self tapping screws.

LEFT: Dummy Radial Engine Installed with Epoxy

RIGHT: Finished Cowl with Radial Engine Installed

The kit also came with a really nice plastic radial engine to dress up the front of the plane. This was another pleasant surprise. With the RCV 90SP I was not required to remove any of the cylinder heads from the radial dummy engine. I did cut out the area between each cylinder with a hobby knife to allow air to enter the engine compartment. The radial engine fit perfectly over the front of the 90SP. I mounted the radial to the cowl and held it in place with some 5 minute epoxy. Then I slid the cowl onto the nose of the plane. I had to drill 4 holes through the cowl into the plywood ring mounting blocks and then I attached it with 4 screws. The finished result could not be any more scale like if I tried. This RCV 90SP is an awesome engine choice for anyone wishing to keep the scale appearance of a model.

Completed Canopy with Pilot.

The last finishing touch of the fuselage is to install the canopy. The canopy is molded plastic and has been painted to reflect the window frame. All that needed to be done was remove the extra plastic around the outside and install it on the plane with 4 screws. I also ran a bead of canopy glue just to ensure that it would not come off in flight.




I chose the Futaba 9CAP system for the GSP Corsair. There are several reasons for my selection. First off, the 9CAP is quite possibly the easiest computer radio in the world to program. It gives me a lot of freedom to setup the plane any way I want. Second, I like the 2 slider controls on either side of the transmitter. These are perfect for flap control because they do not require you to remove your thumbs from the sticks to operate the flaps.

Complete Corsair with Futaba 9C Radio.

By this point the servos for the ailerons, flaps, and retract control are already installed. The throttle, rudder, and elevator are all that were left. These three servos install in the openings on the servo tray in the fuselage. I connected the elevator and rudder pushrod to the servo horn using a Z bend. I used an EZ connector to install the throttle.

Throttle, Rudder, and Elevator Servos Installed with the Receiver.


I used a 600 MAH battery to power this plane. According to my calculations, this battery should give me about 6-7 flights before I need to recharge it.

I installed a Dubro Quick Switch Charge Jack in the side of the fuselage to control the receiver switch and have access to the charge jack.

I needed to use servo extensions on the ailerons (12"), flaps (12"), and the retract servo (12"). These were all secured to the servo leads with heat shrink tubing.

Finally I connected all the servo leads to the receiver and using double sided foam tape, I mounted it between the elevator and rudder servos on the servo tray.

Receiver and On-Board Glow Batteries Installed on Either Side of the Engine Mounting Block.
(Note: Batteries have since been wrapped in foam to protect them from vibration.)

At this time all that was left was to check the CG on the plane. I bolted the wing on and set the Corsair up on my Great Planes CG Machine with the CG set to 100mm per the manual. I made sure the retracts were up before I tried to adjust the CG. Note: When a plane has rotating retracts that fold up back into the wing, always check the CG with the them retracted in the wing. The CG will shift forward a bit when you lower them for landing. If you balance the plane with them down, the CG could shift too far back in flight making the plane uncontrollable. Much to my dismay, the plane was balancing tail heavy. The CG range in the manual is 95-105 mm from the leading edge. I readjusted the CG machine to 105mm and it was still tail heavy. I removed the receiver battery from under the fuel tank and placed in on the cowl in the same position as the engine mounting block. It was getting better but still tail heavy. I placed a second 600 Mah battery in the same position and it began to balance slightly nose heavy, just the way I like it.

LEFT: Corsair on the Great Planes CG Machine and Digital Scale.

Now I have a dilemma. I do not need 2 batteries in the plane and I hate to add lead to a model. So, I decided to add a McDaniel On-board Glow Driver. This system offers me a few benefits. With the glow plug being so close to the prop, it provides me some safety. It requires a 4.8 volt battery pack which helps me with the nose weight that I need. And it can be programmed to light the glow driver at a low throttle setting giving me a much lower reliable idle. The control unit only weighs 3 oz. and it fit perfectly under the fuel tank. I drilled a hole in the firewall to pass the glow plug and battery wires through. On the side of the fuselage, I installed the charge jack and LED for the system.

LEFT: McDaniel On-Board Glow Control Unit Wrapped in Foam

RIGHT: Glow Clip Attached to Engine.


MCDaniel RC Electronics
Model 471
4.8 Volt Pulsed Digital On-Board Glow Driver

McDaniel Electronics offers On-Board Glow Plug Driver Systems for engines with one to ten glow plugs. They deliver power for starting and maintaining idle during taxiing and power down flight maneuvers.

The Driver is controlled by your transmitter either by using an available channel with an on/off switch, or it can be paralleled with your throttle servo using a "Y" cord for automatic operation at low throttle settings. The control unit features a fully adjustable set point for the unit to turn on and off.

It has a remote L.E.D. to mount on the dashboard (or any convenient place), visibly to show when glow plug power is switched on. The unit features an external Deans Charge Jack for charging and external boosting. The system runs off of a separate 4.8V battery pack.

The Driver's electronics are packed in a plastic box for protection. The included PlugLock is prewired for your glow plug connection. The leads are supplied 18" long and may be lengthened or shortened as needed. A special battery connector with heavy duty wire for your battery pack is also included.

The total on board weight without batteries for the model 471 is approx 3.0 oz.

The 4.8 Volt Battery and charger is not included with the system but can be purchased directly from McDaniel RC.



  • Works with 4.8V or 6.0V receivers

  • Fully AM-FM-PCM Compatible

  • Automatic shut-down when Rx is powered off

  • Fully Adjustable on/off set point

  • Can be used with a separate channel to activate or can be linked to the throttle channel

  • Lightweight control unit

  • LED for external status indication

  • Prewired Deans Charge Jack

  • Takes only a few minutes to install and setup




Completed F4U Corsair Ready For Flight
Gear Down On Stand


Gear Up On Stand




Radio Setup, Flight Testing and Evaluation
Radio Setup

With all the servos installed it was time to setup the radio. My first step was to be sure all the servos were operating in the correct directions. I used the servo reversing function of the transmitter where needed.

As I mentioned earlier, to get proper operation of the flaps, I needed to mix 2 channels together so I can reverse the direction of one of the servos. I installed the right flap in channel 6 and the left flap in channel 7. Using PMix 1, I linked the two channels together and set the rate to -100 to reverse their operation. I also adjusted the end points for each servo to ensure that both flaps deployed and retracted to the same positions. I assigned the flaps to the slider lever on the left hand side of the transmitter. This will let me lower the flaps with the index finger of my throttle/rudder hand.

The retract servo is installed on channel 5. The control valve for the retracts does not require much travel. I adjusted the end points to limit its movement. The retracts are assigned to switch B.

I went through the rest of the channels and adjusted the end points as needed. Next I set the dual rates as indicated in the manual.

Elevator Hi - 25mm
Lo - 15mm
Aileron Hi - 25mm
Lo - 20mm
Rudder Hi - 45mm
Lo - 30mm
Flaps max. full deployment


The day has finally come when to get this bird in the air. It is the beginning of December in Connecticut. Normally this time of year we do not have much, if any snow on the ground. This year was an exception. We received a snow storm a week ago that left 10 inches behind. They temperature has not risen above freezing all week so there is still a good layer of snow on our flying field. The hunt for a field begins. I contact a local small airport near my house and explained the situation. Because the airport is not that busy they were able to shut it down for a couple hours to allow us to use the 5000 foot paved and plowed runway for our test flights.


Arriving at the field the temperature was very cold, approaching 25 degrees. There was a slight crosswind. We attached the wing to the plane and pumped the air tank up to 100 psi using a foot pump that I converted for this purpose.

The engine was sent to me already broken in. Otto Kudrna, was kind enough to make sure the engine had the required amount of break in to ensure me a successful first flight. There are no special break-in procedures for the RCV 90SP. They just require a couple gallons to be run through it before it starts "coming into its own".

As promised a couple quick flips of the prop and the engine was purring like a kitten. I make a couple adjustments to the needle valve and was happy to see a maximum RPM of about 4950 rpm with the Zinger 18x12 wood prop. Before taking off, I changed to the Zinger 20x10 and noticed a slight drop in RPM, 4850 to be exact. I did notice the plane seemed to be pulling harder. While the 20x10 prop will produce more thrust, the plane will lose some forward speed, so I decided to use the 18x12 for the initial test flight. These RPM numbers may seem low to you, but it is important to remember that the prop shaft is gear reduced 2:1 over the crankshaft speed. This is one of the reasons why this engine can swing such a large diameter and pitch prop. Using a larger pitch will make up for the slower RPM. I was surprised how easy this engine is to start. They do provide a hex starter on the crankshaft of the engine for the use of a starter wand, but it really was not needed. A simple electric hand starter will work, or in my case, just flipping it by hand.

One final check over all the controls and we lined the plane up into the wind. The throttle was slowly advanced and the tail quickly came off the ground. After about 125 feet the elevator was gently pulled back and the Corsair broke ground. At about 50 feet in altitude, the retracts were raised. The climb out was very scale like and graceful. The RCV 90SP was pulling this plane with authority.

A procedure turn was executed and some slight elevator and aileron trim changes were necessary to keep the plane straight and level. The Corsair was very stable in the air and experienced no bad tendencies during normal flight. We climbed a few mistakes high and chopped the throttle to idle and gently pulled up on the nose to see how she was going to stall. The plane started to get mushy and the nose fell. I was happy to see that it would not drop a wing and snap. To recover, simply hold the nose down and add power.

High speed flight was very scale. The plane did not rocket around like a 40 size pattern ship, but it grooved along at a pretty good pace. There were no trim changes required.

It was time for the infamous Corsair low pass and victory roll. The throttle was lowered and a pass was made down the runway at about 25 feet off the deck. Once past the center power was added, the nose was pulled up to a 30 degree angle and a full left aileron roll was executed. Beautiful! When on Lo Rate the rolls were pretty slow. The high rate setting was more acceptable.

The Corsair was not designed to be an aerobatic airplane so you should not expect it to perform like one. It will perform graceful large loops and semi-axial rolls. The Split-S was also not a problem. Other than those basic maneuvers no other aerobatic were performed. This quite possibly one of the most recognized warbirds in existence, and that is the way it was flown, very scale.

Now we need to test the flaps. Back up about 2 mistakes high and the the throttle was slowly reduced to about 1/3. Flaps were added in 10 degree increments. Each time the flaps were increased you had to hold more pressure on the down elevator stick to keep the plane from ballooning. This could be mixed out with the radio at a future date. The trick to keep it from ballooning is to find the correct flying speed for the amount of flaps that you have deployed. The Corsair will fly considerably slow with full flaps. Just be careful in the turns. You do not want to stall it.

Next, we tried a touch and go with and without flaps to see how well they worked for landing approaches. We setup for a normal landing and lowered the retracts on the downwind leg. As we approached final the power was lowered to 1/4. The braking effect that you get with the 18x12 is awesome, The plane slowed right down for a gentle main wheel landing. Power was brought back to full and the touch-and-go was complete. I was wondering how much flaps would be required if any due to the fact that the plane slowed down real well. On the next touch-and-go, the flaps were deployed to about 20 degrees on final. The plane slowed very well. So much so that the power had to be kept at just under half to prevent it from stalling. The final landing was very scale-like.

All in all the CMPs Corsair performed as I hoped it would. It flew with plenty of authority and displayed no bad tendencies. The RCV engine performed very well. I guess I had it in the back of my mind that this engine was not going to be powerful enough. I was wrong. I have a new favorite warbird engine now! The Robart retracts worked very well. During the test flights they were cycled 4 times and there was still some air reserved for a couple more cycles. The Oleo struts did a good job of absorbing the initial shock of the landing. We were spoiled having such a nice paved runway to fly off of. It will be hard going back to our grass field in the spring!



I am very impressed with the CMPs F4U Corsair. The finish on the model it excellent and they put a lot of effort into scale details. The flight performance is everything I hoped for from a corsair of this size - excellent! The assembly process could be completed in 4-5 nights if you build it as shown in the manual without retracts. Mine took quite a bit longer due to the modifications that I made. Rest-assured that even in its stock configuration, this aircraft is well worth the money. I recently noticed that GSP has some new warbirds coming out including a Hellcat, Spitfire, and Focke Wulf. If you are not into spending 100's of hours on constructing and finishing a warbird from a kit, then look to CMPs, you will not be disappointed!

The RCV 90SP impressed the heck out of me! For a power plant that is so small and lightweight, it really puts out a bunch of power. The compact design makes it easy to install in just about any warbird and the 2:1 gear reduction gives you the ability to swing that large 2, 3, or 4 blade scale propeller. Look to RCV for your next warbird project!

The Robart retracts are a beautiful addition to any scale model. The 615 Rotating Retracts, Oleo Struts, and Scale Tires really enhance the appearance of this Corsair. As long as they are properly installed, they are very reliable. Be sure to add a set of Robart Retracts to your next model!

An finally, the McDaniel On-board Glow Driver. This is the first time I have used a device like this. I am so used to attaching a glow driver to the plug, starting the engine, waiting for it to warm up, and then removing the driver. Not anymore! The McDaniel system is very reliable and makes starting the Corsair a real dream. It does not take up much room or ad a lot of weight. This product is a big hit in my book and I am sure I will have several more models using one of these in the near future!