Category Archives: Fighterbomber

Fighterbomber

Fighter, Fighterbomber

Republic XP-47H Thunderbolt (Airmodel, Vacuformed, Parts from Matchbox, Pavla, and scratch built)

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TYPE: Fighter, fighter bomber

ACCOMMODATION: Pilot only

POWER PLANT: One Chrysler XI-2220-11 inverted-Vee in-line engine, rated at 2,500 hp

PERFORMANCE: 414 mph

COMMENT: While the production of the Republic P-47 Thunderbolt had been emerging in ever-mounting quantities, Republic’s engineers had been investigating other ways in which the Thunderbolt could be improved. Two P-47D-15-RAs were assigned for testing the Chrysler XI-2220 engine, a 16 cylinder inverted-Vee liquid-cooled unit which transmitted its power to a propeller shaft by way of gears located midway along the crankshaft. The design was such as to produce an extremely finely-streamlined cowling of low frontal area, despite the engine’s ability to produce 2,500 hp. The converted aircraft were designated Republic XP-47H and remembered to a pre-war project, the Republic XP-69. Extensive redesign of the P-47 airframe was necessary to install the XI-2220-11 engine, with which was associated a General Electric CH-5 single-stage turbosupercharger in a modified installation in the rear fuselage. The first flight was not made until July 1945 and in one of the 27 flights a top speed of 414 mph had been recorded. The second XP-47H flew briefly after the war ended (Ref.: 9).

Fighter, Fighterbomber

Republic XP-47J Thunderbolt (Matchbox, Parts from Pavla, Parts scratch-built)

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TYPE: Fighter, fighter bomber

ACCOMMODATION: Pilot only

POWER PLANT: One Pratt & Whitney R-2800-57 Double Wasp radial engine plus one General Electric CH-5 turbosupercharger, rated at 2,800 hp at 32,500 ft

PERFORMANCE: 505 mph at 34,500 ft

COMMENT: In 1942 studies made by Republic culminated in proposals for a “lightweight” P-47 with an improved engine installation. Construction of two prototypes was authorized, but within a few weeks it became clear to Republic and the USAAF that the more radical development of the P-47 powered by a 3,000 hp Pratt & Whitney R-4300 Wasp Major, than proceeding as the Republic P-72 held greater promise than the P-47J within a similar timescale, and work on the latter project was limited to a single XP-47J. This sole prototype had a lightened wing structure, a more powerful variant of the R-2800 radial engine, driving a four-bladed propeller with a large spinner and a fan to assist the flow of cooling air through a narrow annulus around the spinner. A separate intake scoop beneath and behind the engine cowling provided air for the General Electric CH-5 supercharger in the rear fuselage. The first flight was made in November 1943, and on August 1944 a speed of 505 mph was recorded, at 34,450 ft. This was the highest known speed achieved up to that time in level flight by a propeller driven aircraft and established the XP-47J as one of the few such aircraft to have broken through the 500-mph “barrier” (Lit.: 9).

Fighterbomber, Medium Bomber, Postwar

Martin XB-51 (Anigrand, Resin)

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TYPE: Ground attack aircraft

ACCOMMODATION: Pilot and operator/navigator

POWER PLANT: Three × General Electric J-47-GE-13 turbojet engines, rated at 2,700 kp each

PERFORMANCE: 645 mph

COMMENT: In early 1945, USAAF issued requirement for a new attack bomber for low-level bombing and close support as a successor to the Douglas A-26 Invader. Martin Company proposed its design and won the competition with designation, XA-45. Soon later USAAF revised its requirement for better close-support bombing. Martin accepted the new requirement and was received contract for two prototypes, the project was redesignated XB-51. The first XB-51 made its first flight on Oct 1949. The aircraft was powered by three jet engines: one at the extreme tail with an intake at the base of the tailfin, and two underneath the forward fuselage in pods. The innovative, variable incidence wings were swept at 35° and with 6° anhedral. The main landing gear consisted of dual sets of wheels in tandem in the fuselage with outrigger wheels at the wingtips. Crew provision was for a pilot under a “fighter”-type bubble canopy and for an operator/navigator in a compartment located lower than and to the rear of the cockpit. It became the fastest ground support bomber at the time. Although test flights were satisfying Martin XB-51 never went into production. Noteworthy is the fact that the design can be traced back to a German WWII-project Messerschmitt Me P.1102/105 that was to be powered by three Heinkel-Hirth HeS-109-011 turbo-engines, one in the extreme tail and two in pods under the extreme forward fuselage and provided with variable-sweep wings, too (Ref.: 24)

Fighter, Fighterbomber

Curtis XP-60C (Anigrand, Resin)

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TYPE: Interceptor, Fighter, Fighter-bomber

ACCOMMODATION: Pilot only

POWER PLANT: One Pratt & Whitney R-2800-53 engine, rated at 2,000 hp

PERFORMANCE: 414 mph

COMMENT: In 1940 the Curtiss Aircraft Company proposed a new design for the eventual replacement for the Curtiss P-40. The new aircraft, the Curtiss XP-60, went through a long series of prototype versions with different engines. Installation of the British Rolls-Royce Merlin engines led to the development of the XP-53, soon redesignated XP-60. Delayed deliveries of the Merlin engines necessitated the installation of Wright (XP-63C) as well as Chrysler (XP-60B) engines. To improve the performance of the XP-60C the engine was changed again, this time a Pratt & Whitney R-2800 with contra-rotating propellers was installed. During its first flight the results were generally satisfactory. Changing the contra-props into a four-bladed propeller led to the XP-60E. But the performance was poorly, too,  and further work on this design was abandonded. (Ref.: 8)

Fighterbomber

Beechcraft XA-38 Grizzly (Anigrand, Resin)

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TYPE: Heavy ground attack aircraft

ACCOMMODATION: Crew of two

POWER PLANT:  2 × Wright R-3350-43 Duplex Cyclone engines, rated at 2,300 hp each

PERFORMANCE: 370 mph at 17,000 ft

COMMENT: The Beechcraft XA-38 Grizzly was a ground attack aircraft, fitted with a forward-firing 75 mm cannon with 20 rounds mounted in a fixed position on the nose to attack heavily armored targets such as tanks and bunkers. Additionally, there were two forward firing machine guns. Defensive armament consisted of remotely controlled ventral and dorsal turrets directed by periscope sights. The first prototype flew on 7 May 1944 and the aircraft proved satisfactory in all respects and better than expected. But after testing it became obvious it would not be ready for the projected invasion of Japan, and furthermore it used the same engines required by the Boeing B-29 Superfortress which had priority. So no orders were given and the XA-38 program was canceled after two prototypes had been completed. (Ref.: 23)

Fighter, Fighterbomber

Boeing F8B-1 (Sword)

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TYPE: Fighter, Interceptor, Ground attack aircraft

ACCOMMODATION: Pilot only

POWER PLANT: One  Pratt & Whitney R-4360-10, rated at 3,000 hp

PERFORMANCE: 432 mph

COMMENT: The estimated excellent performance of  this aircraft, designed for the US Navy, was of great interest for the US Army Air Force, too. So the third (of three) prototype was delivered to the US Army Air Force and tested at Eglin Air Force base. But the advent of new jet fighters led to the cancellation of many wartime piston-engined projects. So consequently, the USAF lost interest in pursuing the project and the prototype was scrapped.

Fighterbomber

Vultee XA-41 (Anigrand, Resin)

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TYPE: Dive bomber, ground attack aircraft

ACCOMMODATION: Pilot only

POWER PLANT: One Pratt & Whitney R-4360 radial engine, rated at 3,000 hp

PERFORMANCE: 363 mph

COMMENT: The Vultee XA-41 was originally ordered as a dive bomber. After combat experience led the U.S. Army Air Corps to believe dive-bombers were too vulnerable to enemy fighters, the contract was amended to change the role to low-level ground attack. Although the XA-41 was a potent weapons system, the design was overtaken by more advanced technology, and never entered production.
The Vultee engineering team decided early in the design process to build the XA-41 (company Model 90) around the 3,000 hp Pratt & Whitney R-4360 “Wasp Major” radial engine. The large wing resembled that of the two-seat attack aircraft/dive bomber Vultee A-31/A-35 “Vengeance including a straight leading edge, forward-tapered trailing edge and pronounced dihedral on the outer wing panels. Designed to carry both a large internal load and external stores, the XA-41 was large for a single-engine aircraft. The single-place cockpit, set in line with the wing root, was 15 ft off the ground when the airplane was parked. As operational priorities shifted during its development phase, the original order for two XA-41 prototypes was cancelled, although the USAAF pressed for the completion of one prototype as an engine testbed for the R-4360, the same engine used by the Boeing B-50 “Superfortess” bomber.
Flying for the first time on February 1944, the sole XA-41 proved to have good performance with a maximum speed of 354 mph reached in testing and superb maneuverability, being able to out-turn a P-51B “Mustang”. However, with the reduction in military orders due to the approaching end of the war, no production contract was placed, and the aircraft was used as an engine testbed for the USAAF as well as being evaluated by the U.S. Navy in comparison with other contemporary attack aircraft, especially the Douglas AD-1 “Skyraider” and Martin AM-1 “Mauler”. After its Navy trials, the XA-41, bearing civil registration, was consigned to the Pratt & Whitney division of United Aircraft to continue engine tests. These continued until 1950 before the XA-41 was scrapped (Ref.: 24).

 

Fighterbomber

Republic P-47N-25-RE Thunderbolt, 73 FS, 318 FG (Sword)

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TYPE: Long-range escort fighter

ACCOMMODATION: Pilot only

POWER PLANT: Pratt & Whitney R-2800-77 ‘Double Wasp’ radial engine, rated at 2,800 hp

PERFORMANCE: 460 mph at 30,000 ft

COMMENT: The Republic P-47N was the last Thunderbolt variant to be produced. It was designed as an escort fighter for the Boeing B-29 Superfortress bombers flying raids on the Japanese home islands. Increased internal fuel capacity and drop tanks had done much to extend the Thunderbolt’s range during its evolution, and the only other way to expand the fuel capacity was to put fuel tanks into the wings. Thus, a new wing was designed with two 50 U.S. gal fuel tanks. The redesign proved successful in extending range to about 2,000 miles, and the squared-off wingtips improved the roll rate. The P-47N entered mass production with the uprated R-2800-57 engine, with a total of 1,816 built. The very last Thunderbolt to be built, a P-47N-25, rolled off the production line in October 1945. Thousands more had been on order, but production was halted with the end of the World War II in August 1945.

Fighterbomber

Republic P-47D-30-RA Thunderbolt, 509 FS, 405FG (Revell)

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Fighterbomber

Republic P-47D-25 Thunderbolt, 512 FS, 406 FG (Revell, Parts from Pavlamodel)

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