Kitty Hawk 1/48 XF5U-1
|KIT #:||KH 80135|
The Chance Vought XF5U "Flying Flapjack" was an experimental U.S. Navy fighter aircraft designed by Charles H. Zimmerman for Chance Vought Aircraft during World War II. This unorthodox design consisted of a flat, somewhat disc-shaped body (hence its name) serving as the lifting surface. Mr. Zimmerman’s concept was that a aircraft design that used the propellers to cancel the airflow vortices that occur naturally at the wing tips of a conventional aircraft resulting in enhanced lift with a much smaller wing surface and facilitating high speed due to improved stream lining. Two piston engines buried in the body drove propellers located on the leading edge at the wingtips with the rotation direction opposite to the tip vortices retaining the high pressure air below the wing. Developed from the original flying prototype V-173, the XF5U was larger and of metal construction with surface covering of metalite, a balsa wood/aluminum sheet composite. Powered by two 1,600 hp Pratt & Whitney R-2000 radial engines, the configuration was designed to create a low aspect ratio aircraft capable of low take off and landing speeds but a high top speed. The propellers were to have built in cyclic movement that Zimmerman termed “teetering blades”. Although no armament was installed in the two prototypes it was envisioned that the operational aircraft would be armed with six .50 caliber machine guns or four 20mm cannon and up to 2,000 pounds of bombs or drop tanks. One prototype for produced for static testing and although the other prototype was used for limited taxi testing it never was flown. With the increasing interest in jet aircraft the US Navy cancelled the contract on March 17, 1947 and both prototypes were subsequently destroyed.
Released in 2015 Kittyhawk’s 1/48th scale XF5U-1 was a surprise from a relatively main stream albeit new company producing a model of a aircraft that never proceeded past the prototype stage. Other than the rare and difficult to obtain Hasegawa 1/72nd scale version all other kits were produced as very limited run and sometimes rather expensive kits. Kittyhawk’s version provides for a fictional operational aircraft and includes decal markings for three versions; two dark sea blue aircraft and a natural metal version. Apparently removed from distribution due to copyright issues were decals for a anime character version. The anime decal was literally cut away from the included decal sheet that also provides a large and stern image of “Uncle Sam” with the admonishment “I Need You” embellished with red and white stars. Close inspection of the kit components reveals that some changes and additional parts would be needed to reproduce accurately the one prototype for which there is a photographic record. The most obvious changes needed include: 1) plugging of the six machine gun ports (the prototype was never armed), 2) installation of bulges in the outer landing gear doors, 3) revision of the oleo strut prominent on each main landing gear leg, 4) change in main landing gear wheel configuration from the circular spokes to triangular spokes on the actual prototype, 5) landing light in the nose omitted and 6) ventral mast and antenna cable may have been present on the actual aircraft but reference photos are unclear on this item. The kit also includes two 1,000 pound bombs and non-descript bomb racks (Vought’s specification supported up to two 1,000 pound bombs or 150 gallon drop tanks being carried). The kit includes four large sprues of parts molded in a relatively soft, light gray plastic, a small sprue of clear parts, a small photo-etch fret containing the cockpit seat harness, and two decal sheets. Surface detail consists of finely engraved panel lines and recessed and raised rivet detail. One of the unique features of the kit manufacturing is that the sprue injection gates for the plastic parts are located on the flat or mating surface of most parts that differs from most manufacturers that place the gates adjacent to finish surface. A couple of the plastic parts (gun sight, elevator horns) are extremely small and delicate and care must be exercised in removing them from the sprue without damage. I find these difficult to clean up due to their delicate nature and I found that I needed to change my removal method if I were to use a sprue cutter and often used a very fine Czech Master razor saw instead to separate the part from the sprue and then remove the excess plastic with a sharp #15 scalpel blade. I decided to build a fictional operational aircraft so proceeded with construction planning on using the dark sea blue color scheme implemented by the U.S. Navy in June, 1944 that was destined to be the basic specification for naval aircraft colors until 1947.
I enjoy building model kits mainly in a out of the box format but my desire for ease of building often meets the reality of needing to make a more realistic replica so some changes would be needed. The instruction manual consists of fairly detailed diagrammatic instructions following the recommended build sequence and are very clear. After studying the instructions I decided to deviate from the recommended sequence due to concerns about alignment of the slightly complex landing gear. Construction begins with the cockpit tub and decals are provided for the instrument panel and side consoles. The canopy is designed for a closed canopy build although it can be built open. In the interest of keeping the finished model easier to clean many of my builds are done with a closed canopy. Testors Model Master Interior Green was used for all the interior parts except the instrument panel and consoles. After painting, the painted surfaces were given a coat of Future to provide a gloss surface for the decal application. The unpainted photo etch seat harness was installed using cyanoacrylate glue and then painted. The next build sequence calls for the main landing gear bays and the tail wheel bay to be assembled including installation of all the gear components except the doors. I assembled the bays but did not assemble the landing gear parts planning to install the landing gear parts only after completion of painting. This provided the advantage of avoiding inevitable breakage of the rather fragile parts, simplifying the masking for painting, and allowing adjustment of the gear installation to allow accurate orientation. After the gear bays were assembled, the exhaust ducting was assembled and these components, together with the completed cockpit were cemented to the lower fuselage half. Fit for the landing gear bays was perfect and no issues were encountered. However, test fitting was needed for the cockpit utilizing the top half of the fuselage to ensure correct placement of the cockpit onto the lower fuselage half. Slight trimming of the outside cockpit sidewalls was needed to obtain the optimum fit. Once this was accomplished the cockpit tub was glued in place using Tamiya Extra Thin. After the glue had set the attachment areas to the lower fuselage was reinforced with a small amount of 5 minute epoxy to prevent any possible displacement. This was followed by gluing the top fuselage half to the bottom again using Tamiya Extra thin applied in small sections around the joint while maintaining alignment by masking tape space around the periphery. Care in shaving away the sprue injection gate plastic from the mating surfaces, careful test fitting and some minor fine filing of the mating surfaces ensured a seam free joint. The engine intakes were then installed and this provided the least precise alignment of parts leading to some filling being required with my usual mix of thinned Bondo. Several applications were made and after sanding the Bondo was sealed with Mr. Surfacer 500 followed by final polish sanding. In my experience the Mr. Surfacer dries with a density similar to the plastic and ensures a invisible seam once final polish sanding is performed. Any surface detail obscured was restored by scribing with a Czech Master fine razor saw. The flying control surface components were then assembled; note each horizontal stabilizer has a clear part representing a light. Fit here was relatively poor and it was necessary to build up the lens to be flush with the stabilizer surface using several applications of gap filling cyanoacrylate cement and polish sanding. In retrospect it would be easier to insert and glue a length of clear sprue of the same diameter of the hole and then carve it flush with the surface and sand it smooth. Interestingly, on the available photos of the prototype aircraft these lights are not readily visible. The balance horns were left off for installation after final painting. The most prominent and interesting components of the model are the large articulated propellers. In the actual aircraft the blades were made of varnished mahogany and close examination of the available black and white aircraft photos reveals visible wood grain so finishing them with a simulated wood grain was a challenge to be met. The hubs were assembled and the seams addressed but the blades were cleaned up to be assembled only after painting was complete. Instead of using the bombs and bomb racks provided in the kit a 1,000 pound bomb from a Monogram P-38 and a 150 gallon drop tank from a Monogram P-61 was substituted. Once all painting, clear coating, decal application and final clear coating was completed, all the small parts including the intricate arresting hook assembly were installed. The landing gear installation was fairly precise but leaving it to late assembly allowed perfect alignment of both main struts that would not have occurred if they were installed per the recommended build sequence. Parts C26 and C27 are supposed to represent the landing gear dampers but comparison to photos of the aircraft reveal they are completely incorrect. The kit parts look like coil springs whereas the aircraft used a pneumatic or hydraulic piston. This component is very prominent in the aircraft photos so replacements were made from scratch using K&S 1/16 inch O.D. aluminum tubing, hypodermic needles and the ends of the original plastic parts. Once attached to the front of the landing gear legs with Tamiya Extra Thin and reinforced with a small amount of cyanoacrylate they look much more realistic. In addition, the outer main gear doors are missing a bulge (this existed only on the outer doors, not the inner doors). This was added by cutting a section from a thick cylindrical piece of sprue and gluing it in the correct position to the door surface as referenced to photographs. Note that the gear door hinge parts are individual and very delicate and care must be exercised in removing them from the sprues and gluing them to the gear doors in the correct position. To ensure a maximum strength join, all the hinge parts were glued to the bare plastic gear doors using Tamiya Extra Thin cement and allowed to cure for several days before handling. All small parts were individually painted by airbrush prior to final assembly.
After wiping down the model with isopropyl alcohol to remove oil and residue the, landing gear openings and cockpit were masked off in preparation for painting. As a separate step all clear parts were carefully trimmed of flash and the sprue gates removed using a microsaw or sprue cutter followed by careful trimming with a sharp #15 scalpel blade before being dipped in Future and allowed to dry for at least two weeks. Note that clear part number xxx appears to be a unused part. The two part canopy was masked with Tamiya tape strips and Micro Scale Micromask and then attached to the fuselage using a small strip of Blue Tack. This would allow painting of the frame when the rest of the aircraft was painted.
|COLORS & MARKINGS|
After the model surface was carefully wiped with a lint free cloth wet with isopropyl alcohol to remove surface oils and removal of all fibers with a tack cloth, the model was airbrushed with Tamiya Flat Aluminum acrylic thinned 50% with lacquer thinner for the primer coat. I normally base coat with Rustoleum spray can gloss black enamel but since this model was to be in a gloss Dark Sea Blue I wanted to experiment with the Tamiya looking toward future use of this color for possible paint chipping/wear under a camouflage paint. Rustoleum gloss Black enamel is the same product available at Home Depot and most hardware stores in a large aerosol can. Compared to most dedicated hobby paints it is very inexpensive per volume. I decant this from the can into small jars and airbrush this usually with minimal thinning with toluene using a Badger Anthem 155 airbrush at about 15 psi. (Note for safety purposes my workshop includes a 100 cubic foot per minute outside venting spray booth and a 3M respirator with organic filters and nitrile gloves are always used when airbrushing enamel or lacquer paints). The finish is very glossy and in my experience gives good coverage. I allowed several days for the base coating to dry before airbrushing Testors Model Master Dark Sea Blue with ten drops of white enamel added per ¼ ounce of blue paint and thinned about 30% with a 50/50 mix of generic toluene and naptha. With this thinning ratio the paint density control is excellent and provides perfect finish surface with very fine control. Two thin color coats were applied and the goal was to have a minimally weathered paint finish consistent with a relatively new aircraft. Since MM Dark Sea Blue is a gloss paint no additional gloss coat is needed prior to decal application.
Trying to simulate a wood grain finish for the wood propellers was a new technique for me in modeling that had not been previously attempted. After studying various techniques found on the internet blogs, reviews, and YouTube videos, I decided to use artist’s oils for the task. I expected this process to be a challenge since part of the propeller near the hub is black and the tips are yellow. To simplify the process I decided to use Microscale yellow decal film for the tips. Each propeller blade was finish sanded and then primed with airbrushed Rustoleum gloss black. Once thoroughly dry, the entire propeller was airbrushed with Tamiya Acrylic XF-57 Buff thinned 25% with lacquer thinner. The propeller was then hand brushed using Windsor & Newton Burnt Umber oil paint thinned with toluene and a flat sable brush. Leaving brush marks was a desired outcome to simulate the wood grain. Due to the nature of the oil paint drying was allowed for about two weeks. Additional wood grain actually visible in the black and white photos of the XF5U-1 prototype with the articulated propellers was then simulated using Windsor & Newton Paynes Grey oil color applied with a fine 000 brush. Since this entire process was experimental several attempts were needed until I was satisfied with the results. After adequate time to dry the entire propeller was airbrushed with Testors GlossCoat lacquer thinned about 30% with lacquer thinner. I expected problems with lifting from masking for the black sections of the props but using but this turned out to be relatively minimal using 3M removable tape that has the same adhesive as 3M POST IT flags. Repeat airbrushing of the Testors GlossCote was needed on a couple of props but fortunately no color lifting occurred. Application of Microscale Insignia Yellow decal film provided the color for the tip.
The kit decal was used for the large insignia and although thick it responded well to Microsol Microset and a separate application of a small amount of Walther’s Solvaset to conform to the raised rivet detail. On the undersurface the insignia decal needs to be measured and carefully cut to allow placement to the fuselage undersurface as well as to the gear doors. By June 2, 1945, Admiral John S. McCain, Commander of Task Force 38, had changed the tail and wing numbering system from symbols to block letters. In conformance to this the model was marked with the letter “B” of the U.S.S. San Jacinto, CVL-30, using Micro Scale 45 degree letters and assigned the number “69”. In retrospect I probably should have applied the number “69” in large numerals between the twin rudders as well but since there really were no operational aircraft it would still be speculation. The kit decals include the black walkway areas that are visible on pictures of the prototype. Apparently these areas were actually a protective surface material actually taped to the surface of the aircraft so presumably they would not have existed on an operational aircraft and therefore they were omitted. After the decals were allowed to dry for several days the model was then given two light coats of Testors GlossCote airbrushed thinned 30% with lacquer thinner. As the coats are misted on with care to avoid a “wet” coat no reaction with the enamel was encountered.
The complex landing gear parts were installed as were remaining small parts including a ventral pitot tube. To facilitate a reasonably strong bond a hole was drilled in the pitot tube base using a #80 drill and a short length of brass wire glued in place with CA glue. The pitot was then glued to the fuselage with a second #80 hole facilitating attachment. Handling the oddly shaped model was made simple by the use of egg crate style soft foam pads that I use for all my aircraft modeling in lieu of any stand or purpose designed rack. One must be very careful as final assembly proceeds to avoid parts breakage or misalignment while adhesive is setting. After all the underside parts were installed the canopy was removed, the masking removed and the area under the windscreen painted with Vallejo Nato Black. After the paint was dry the gun sight was attached followed by the canopy with Testors Clear Parts cement. The nose parts were then attached followed by the nose cone also attached with Testors Clear Parts cement. This was followed by the very delicate arresting hook assembly and the elevators with their balance horns. Lastly the large propellers were attached with a press on fit and no glue was needed allowing removal.
The XF5U-1 is one of the many experimental aircraft that arose out of the frantic search for military advantage during World War II that occurred on both sides of the conflict. Although the revolutionary aerodynamic concept proposed by Mr. Zimmerman never reached operational status it remains one of the more unique appearing curiosities of aviation. Kittyhawk’s early willingness to stray from the tried and true but often redundant kits of aircraft manufactured in multiple iterations provides a unique addition to any scale modeler’s collection and unique conversation piece. I would not recommend it for the absolute beginner due to the very small and fragile plastic parts and the need to deviate from the instruction assembly sequence but any moderately experienced modeler should have no difficulty. Sitting next to a Kyushu J7W1 Shinden, Horten, XP-55 or XP-58 it would look right at home on a flight line of “what if” aircraft of World War II.
Naval Fighters Number 21, Chance Vought V-173 and XF5U-1 Flying Pancakes, Steve Ginter, 1992
1 March 2019
If you would like your product reviewed fairly and fairly quickly, please contact the editor or see other details in the Note to Contributors.
Back to the Main Page Back to the Review Index Page Back to the Previews Index Page