MPM 1/72 XF5F Skyrocket

 "SNUB-NOSE LIGHTNING"
GRUMMAN XF5F-1 "SKYROCKET" BETHPAGE, NEW YORK - SPRING 1940
PILOT: BOB HALL

With the USAAC already having a twin-engine, long ranged pursuit escort fighter on the drawing board and both Germany and Great Britain also testing examples of this type aircraft, the Navy Bureau of Aeronautics approached Grumman Aircraft for a proposal on a twin-engine pursuit escort fighter for fleet operations. Grumman's approach was the G-34 (XF5F-1), which was to be developed through three distinct versions with a short-nose and one with a long nose.

The model I have done depicts the first configuration of the short-nose version, which first flew on April 1, 1940 with R. A. "Bud" Gillis at the controls. Bob Hall, now a retired Grumman vice-president, took over the test program until November 1940, when "Connie" Converse assumed the test pilot role leading to the final Naval demonstrations in the short-nose version. Bob Hall completed a total of twenty-five flights averaging 3/4 of an hour in the first configuration during the one and a half months following the initial flight.

These tests showed excessively high engine temperatures and a second configuration was made using modifications in the oil-cooling duct along with changes in the gear doors. Altogether the XF5F-1 went through four basic modifications after configuration one. During the second modification the exhaust systems was given ejector exhausts, which replaced the exterior exhausts. The third modification was the addition of the fuselage-to-wing fillets and new balanced rudders. The final modification was the extension of the nose past the leading edge of the wing, lengthened engine nacelles with two side opening gear doors which covered the tires, enlarged and revised rudders, and deletion of the canopy side braces. The propellers were also given spinners in the final modification.

The XF5F-1 was last flown on December 11, 1944. Due to an undercarriage retraction failure the plane had to belly land and damage was so extensive that the unique plane was struck off the active list. Although the XF5F-1 never was put into production, it and its USAAC cousin XP-50 served as the testbed for Grumman's F7F series of twin-engine fighters. The XF5F-1 was never really given a name by Grumman, it was said that a newsman viewing the aircraft during 1941 stated that it "climbed like a skyrocket" and the name stuck. One wonders what brand of cat this nimble little aircraft would have been given had it reached production. The test plane had done 211 flights totaling 155.7 hours during its nearly five years of testing.

Interior: 

MPM's interior was very basic containing floorboard, seat, control stick, and instrument panel placard. They also include a photoetched instrument panel with acetate instruments, but the layout of the instruments was entirely incorrect and the photoetched panel was too wide for the cockpit once the fuselage halves were joined.

I scratch-built an instrument panel from sheet styrene using the kit's placard as a rough template and sanding to get the fit I needed. The resulting panel was painted semi-gloss black and done up with Waldron-punched disks of white decal stock and Reheat Models decal instruments.

Side panel areas were done using sheet and strip styrene. The interior was painted interior green with radio boxes, throttle, etc. picked out in flat black. I sanded the headrest from the roll-over pylon and attached a new one from a Waldron-punched disk of sheet styrene after all painting was done. I also cut away the instrument panel shroud as the shroud molded into each fuselage half would not allow the kit's vacuform canopy to fit. I constructed a new one from thinner sheet styrene and attached it after cementing the fuselage halves together.

The pilot came from some resin figures I picked up from Meteor Productions at the IPMS Nationals. I threw away the plastic bag's nametag and for the life of me can't remember who makes them. I will say that they are excellent, as the arms are cast separately and allow for different positions. I primed the figure in primer gray and hand painted it with acrylics and ink washes. The shoulder harnesses were done with masking tape and buckles cut from True Details photoetched belts.

I had to do much re-engineering to get the landing gear to appear in the retracted position. I started by cutting out a small depression for each wheel in each upper wing half, so that the wheels would fit flush with the bottom of the nacelles as per reference photos. I then had to engineer a piece of sheet stock to fit in front of the nacelles prior to attaching the cowlings and engines, so that the landing gear struts and wheels could be pushed from the wheel bay opening through the gear bay and into the plastic attachment. The interior of the gear bay was painted bright silver and given a light black wash before installing the gear.

Engines:

The engines and propellers included in MPM's kit were not even suitable for use. I ordered two Engines n' Things resin Wright Cyclone 1820 F series engines from Uncle Tom at Aviation Usk along with two Aeroclub Curtiss Electric white metal props (the "Skyrocket" first used Hamilton Standard propellers, but these were replaced by Navy order before first flight to Curtiss Electric hollow-steel props weighing 79 pounds less). I had to cut the blades on one prop and reverse them, as the Skyrocket utilized counter-rotating propellers to offset torque. I had to do much cutting away and sanding to the inside of the cowlings in order for these engines to fit. The engines were painted Polly Scale Oxidized Aluminum with pushrods picked out in silver and gear case painted engine gray. I added exhausts and a collector ring to each engine, these being made of plastic rod and solder respectively and painted burnt iron. I also constructed a bulkhead for the rear of the engines in each cowling to eliminate the see-through effect into the gear compartment in the nacelles.

Modifications to the exterior entailed cutting out for the wing navigation lights and drilling for the landing light and what I surmise to be a camera aperture in the port wing, altering the kit landing gear doors in order to show the plane in configuration one, and adding antenna posts and insulated aerial lead-ins from hypo tubing. I also made some attachment pins to the rear tail fins from .025 wire, as the kit pieces had nothing to aid in their attachment.

The actual XF5F-1 was painted overall in aluminum lacquer, with exception of the top surface of the wing, which was painted yellow. After masking the canopy, engine fronts and landing gear openings, I shot the entire model with Krylon Bright Aluminum Lacquer, transferring the paint from the can and shooting it with the airbrush. This is super-thin, super-hard paint and dries immediately. It can be masked safely with no worry whatsoever of it lifting when the tape is pulled away. The only problem with this paint is clean up, as it requires lacquer thinner for this duty. It can be polished with SNJ powder if one wishes for a shinier metal finish, which was not required for the Skyrocket. The propellers were also painted bright aluminum and were polished after masking and painting the tips.

Even though the lacquer dried quickly. I waited a day before masking the fuselage and undersurface of the wings. The model was then painted Polly Scale Chrome Yellow. After removing the masking (not those of the canopy, engines, and landing gear) I sprayed the entire model with a light coating of Min-Wax Polycrylic to prepare it for decaling.

I used the kit decals for the U.S. Navy and identification codes, but the kit's national insignia decals, although opaque and in register, were too small. I substituted insignias of the proper size from SuperScales sheet for early World War II markings. When dried the entire model was washed and all control recesses were given a black wash of India ink. The model was then given an overspray of polycrylic followed by a finishing coat of Polly Scale Semi-Gloss Clear. This was rubbed out after a day and fuselage and wing navigation lights were simulated with Kristal Kleer and painted clear red and clear green as needed. The camera aperture and landing light were also done with Kristal Kleer. The canopy separation line was simulated with black decal stock.

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