Category Archives: Medium Bomber

Medium Bomber

North American AJ-1 “Savage”, Naval Air Test Center, Patuxent River, (Anigrand Models, Resin)

TYPE: Carrier-borne medium bomber

ACCOMMODATION: Crew of three

POWERPLANT: Two Pratt & Whitney R-2800-44W Double Wasp radial engines, rated at 2,400 hp each plus one Allison J33-A-10 turbojet engine, rated at 2,040 kp thrust


COMMENT: The North American AJ-1 “Savage” was designed shortly after WW II to carry atomic bombs and this meant that the bomber was the heaviest aircraft thus far designed to operate from an aircraft carrier.
At the end of World War II, the U.S. Navy began a design competition on August 1945 for a carrier-based bomber which could carry a 4,536 kg bomb that was won by North American Aviation. Later that year, the Navy decided that it needed to be able to deliver atomic bombs and that the AJ Savage design would be adapted to accommodate the latest Mark 4 nuclear bomb the next step in development from the more sophisticated imploding Plutonium sphere design Mark 3 “Fat Man” used on Nagasaki. A contract for three XAJ-1 prototypes and a static test airframe was awarded on June 1946. The first prototype made its maiden flight two years later on July 1948. That same year the US Navy began an interim capability program employing the Lockheed P-2 “Neptune” carrying a crash program reproduction of the smaller simpler all uranium ‘gun’ design Mark 2 “Little Boy” nuclear bomb as its first carrier launched nuclear bomber aircraft until the “Savage” was in service. The “Neptune” launched using Jet Assisted Take-Off (JATO) rockets but could not land on existing carriers; if launched they had to either ditch at sea after its mission or land at a friendly airbase.
The AJ-1 was a three-seat, high-wing monoplane with tricycle landing gear. To facilitate carrier operations, the outer wing panels and the tailfin could be manually folded. The two piston engines were mounted in nacelles under each wing with a large turbocharger fitted inside each engine nacelle, and an Allison J33-A-10 turbojet that was fitted in the rear fuselage. Only intended to be used for takeoff and maximum speed near the target, the jet was fed by an air inlet on top of the fuselage that was normally kept closed to reduce drag. To simplify the fuel system, both types of engines used the same grade of avgas. Self-sealing fuel tanks were housed in the fuselage and each wing. The aircraft usually carried 300-US-gallon tip tanks and it could house three fuel tanks in the bomb bay with a total capacity of 1,640 US gallons. Other than its 5,400 kg bombload, the bomber was unarmed.
Two of the three prototypes crashed during testing, but their loss did not materially affect the development of the aircraft as the first batch of “Savages” had been ordered on October 1947. The most significant difference between the XAJ-1 and the production aircraft was the revision of the cockpit to accommodate a third crewman in a separate compartment. The first flight by a production aircraft occurred in May 1949 and Fleet Composite Squadron FIVE (VC-5) became the first squadron to receive a “Savage” in September. The squadron participated in testing and evaluating the aircraft together with the Naval Air Test Center (NATC) in order to expedite the “Savage’s” introduction into the fleet. The first carrier takeoff and landing made by the bomber took place from the USS “Coral Sea” on April and August 1950, respectively.
When first deployed, the AJ-1 was too large and heavy to be used by any American aircraft carrier except for the “Midway” class. The modernized “Essex” class carriers with reinforced decks and the very large “Forrestal” class could also handle the “Savage”. The aircraft was not popular aboard ship as it was too big and cumbersome that it complicated any other flight operations the ship was required to conduct. One problem was that the wings had to be folded one at a time by a crewman on top of the fuselage with a portable hydraulic pump, a time-consuming process, so that the bomber could be moved out of the way to allow other aircraft to land or take off. One pilot reported that the AJ-1 was “a dream to fly and handled like a fighter”, when everything was working properly. The aircraft, however, was not very reliable, possibly because it was rushed into production before all the problems could be ironed out. The bomber was replaced by the Douglas A3D “Skywarrior” beginning in 1957. In total140 aircraft were built plus three prototypes (Ref.: 24).

Consolidated PBY-6A ‘Catalina’ (Revell, Parts scratch-built))

TYPE: Patrol bomber flying-boat and amphibian

ACCOMMODATION: Crew of seven to nine

POWER PLANT: Two Pratt & Whitney R-1830-92 “Twin-Wasp” radial engines, rated at 1,200 hp each

PERFORMANCE: 196 mph at 6.700 ft

COMMENT: The PBY was originally designed as a patrol bomber, an aircraft with a long operational range intended to locate and attack enemy transport ships at sea in order to disrupt enemy supply lines. With a mind to a potential conflict in the Pacific Ocean, where troops would require resupply over great distances, the US Navy in the 1930s invested millions of dollars in developing long-range flying boats for this purpose. Flying boats had the advantage of not requiring runways, in effect having the entire ocean available. Several different flying boats were adopted by the Navy, but the PBY was the most widely used and produced.
Although slow and ungainly, Consolidated PBY “Catalinas” distinguished themselves in World War II. Allied forces used them successfully in a wide variety of roles for which the aircraft was never intended. PBYs are remembered for their rescue role, in which they saved the lives of thousands of aircrew downed over water. “Catalina” airmen called their aircraft the “Cat” on combat missions and “Dumbo” in air-rescue service.
Consolidated and Douglas both delivered single prototypes of their new designs, the XP3Y-1 and XP3D-1, respectively. Consolidated’s XP3Y-1 was an evolution of the XPY-1 design that had originally competed unsuccessfully for the P3M contract two years earlier and of the XP2Y design that the Navy had authorized for a limited production run. Although the Douglas aircraft was a good design, the Navy opted for Consolidated because the projected cost was only $90,000 per aircraft.
Consolidated XP3Y-1 design (company Model 28) had a parasol wing with external bracing struts, mounted on a pylon over the fuselage. Wingtip stabilizing floats were retractable in flight to form streamlined wingtips and had been licensed from the British Saunders-Roe company. The two-step hull design was similar to that of the P2Y, but the Model 28 had a cantilever cruciform tail unit instead of a strut-braced twin tail. Cleaner aerodynamics gave the Model 28 better performance than earlier designs. Construction is all-metal, stressed-skin, of aluminum sheet, except the ailerons and wing trailing edge, which are fabric covered
The Consolidated XP3Y-1 had its maiden flight on March 1935, after which it was transferred to the US Navy for service trials. The XP3Y-1 was a significant performance improvement over previous patrol flying boats. The Navy requested further development in order to bring the aircraft into the category of patrol bomber, and in October 1935, the prototype was returned to Consolidated for further work, including installation of 900 hp R-1830-64 engines. For the redesignated XPBY-1, Consolidated introduced redesigned vertical tail surfaces which resolved a problem with the tail becoming submerged on takeoff, which had made lift-off impossible under some conditions. The XPBY-1 had its maiden flight on May 1936, during which a record non-stop distance flight of 3,443 miles was achieved.
Around 4.051 aircraft were built, and these operated in nearly all operational theatres of World War II. The “Catalina” served with distinction and played a prominent and invaluable role against the Japanese. This was especially true during the first year of the war in the Pacific, because the Consolidated PBY “Catalina” and the Boeing B-17 “Flying Fortress” were the only aircraft available with the range to be effective in the Pacific.
The Consolidated PBY “Catalina” was built in seven major variants, the last, PBY-6A, was equipped with search radar in a radome above the cockpit, a taller fin and rudder and amphibious undercarriage (Ref.: 24).

Lockheed PV-2 Harpoon, VB-139 (Academy, Parts scratch-built)

TYPE: Patrol bomber

ACCOMMODATION:  Crew of four or five

POWER PLANT: Two Pratt & Whitney R-2800-31 Double Wasp radial engines, rated at 2,000 hp each

PERFORMANCE: 282 mph at 13,700 ft

COMMENT:  The Lockheed PV-2 Harpoon , ordered by the US Navy on June, 1943, differed in several respects from the Lockheed PV-1 Ventura. The power plant and general configuration remained unchanged, but wing span and fuel capacity were increased, larger fins and rudders were fitted, and the armament was improved. Delivery of a batch of 500 Harpoons began in March 1944. These aircraft served primarily in the Pacific area for the last year of the WWII (Ref.: 23).

Lockheed PV-1 Ventura (Academy Models)

TYPE: Patrol bomber

ACCOMMODATION: Crew of four or five

POWER PLANT: Two Pratt & Whitney R-2800-31 Double Wasp radial engines, rated at 2,000 hp each

PERFORMANCE: 312 mph at 13,800 ft

COMMENT:  The Ventura had been developed initially from the commercial Lockheed Model 18 to a British specification for an improved successor of the Lockheed Hudson. Powered by more powerful engines it was larger and heavier than the Hudson. First flight was made on July 1941 and the RAF ordered 873 aircraft. Further contracts were placed by the USAAF as B-34 which had a larger bomb-bay as well by the US Navy under the designation PV-1. Deliveries of the Navy variant began in December 1942 which procured a total of 1,600 PV-1. These aircraft served primarily in the Pacific area until the end of the WWII (Ref.: 23).