1:72 Lockheed P-74A, "Charger" (s/n 44-64148) of USAAF 310th FS/58th FG, 5th Air Force; based at Clark Field (Philippines), April 1945 (Whif/kit conversion)

+++ DISCLAIMER +++

Nothing you see here is real, even though the conversion or the presented background story might be based historical facts. BEWARE!

 

 

Some background:

The P-74 "Charger" was a fighter aircraft built by Lockheed for the United States Army Air Forces (USAAF). Its configuration was unusual as it was designed as a twin boom pusher configuration, where the propeller is mounted in the rear of the fuselage, pushing the aircraft forward.

 

The P-74 entered service with the USAAF in late 1944, its conception dated back to 1939 when the U.S. Army Air Corps requested with the Circular Proposal R40C domestic manufacturers to develop high performance fighter types, allowing (even demanding) unusual configurations. Lockheed did not respond immediately and missed the chance to sign a development contract in mid-1940 until early 1941. Twenty-three proposals were submitted to R40C, and after a fist selection of ideas three companies, Vultee with the large XP-54 Swoose Goose, Curtiss with its XP-55 Ascender and Northrop's XP-56 Black Bullet were able to secure prototype contracts.

 

Vultee eventually won the competition, but all these innovative new aircraft suffered from various flaws or development delays, missing various performance goals, so that none ever entered service.

 

In the meantime, Lockheed had been working on the 1939 request in the background on a private venture basis, as it was clear that by 1944 a successor to the company's own P-38 Lightning had to be offered to the USAAC.

The new North American P-51 Mustang was also a sharp competitor, esp. for the Pacific conflict theatre where long range was needed. This role was filled out very well by the P-38, but it was a relatively large and complicated aircraft, so an alternative with a single engine was strived for. Even though jet engines already showed their potential, it was clear that the requested range for the new type could only be achieved through a piston engine.

 

This aircraft became the XP-74, originally christened “Laelaps”, following Lockheed’s tradition, after a female Greek mythological dog who never failed to catch what she was hunting. It was presented as a mock-up to USAAC officials on August 8th 1942 and immediately found sponsorship: with the disappointing results from the XP-54,55 and 56 was immediately ushered into the prototype stage. Its name, though, was rejected, and the more common name “Charger” was adopted.

 

Just like Lockheed’s successful P-38 the XP-74 Charger was designed as a twin-boom aircraft, but it was driven by only a single Packard (License-built Rolls Royce Merlin) V-1650 pusher engine in the aft part of the fuselage. The tail was mounted rearward between two mid-wing booms, with a four-bladed 12-ft propeller between them. The design also included a "ducted wing section" developed by the NACA that enabled installation of cooling radiators and intercoolers in the wing root section.

 

The advantages of a pusher design are that the view forward is unobstructed and armament can be concentrated in the nose, while a major drawback is difficulty in escaping from the aircraft in an emergency, as the pilot could get drawn into the propeller blades. Lockheed deliberated between systems that would eject the pilot, or jettison the propeller or the engine, via a system of explosive bolts. Lockheed eventually installed an early ejector seat which was driven by pressurized air, combined with a mechanism that would blow the canopy off. The system was successfully tested in summer 1943, even though skepticism remained among pilots.

 

Initial armament comprised one 20mm Hispano cannon and four 12.7mm Browning machine guns, the same as in the P-38, but two machine guns were relocated from the nose into the front ends of the tail booms because of the new aircraft’s smaller overall dimensions.

 

The first prototype was ready in October 1943, with a different engine and heavier armor fitted. The second prototype was built to this specification from the start, which would become the serial production standard, the P-74A.

The P-74A used the new V-1650-9 engine, a version of the Merlin that included Simmons automatic supercharger boost control with water injection, allowing War Emergency Power as high as 2,218 hp (1,500 kW). Another change concerned the armament: a longer weapon range was deemed necessary, so the gun armament was changed into four 20mm Hispano cannons, two of the placed in the fuselage nose and one in each tail boom front end. Each gun was supplied with 250 RPG.

 

Alternatively, a nose installment with a single 37mm cannon and two 12.7mm Browning MGs was tested on the first prototype, but this arrangement was found to be less effective than the four 20mm cannons. Another factor that turned this option down was the more complicated logistics demands for three different calibers in one aircraft.

 

The P-74A was ready for service in summer 1944, but its deployment into the Pacific region took until December – the 5th Air Force first units replaced most of its P-38 and also early P-47Ds with the P-74A.These new aircraft had their first clashes with Japanese forces in January 1945.

 

The P-74 was used in a variety of roles. It was designed as an intreceptor against bombers, but its good range and handling at all altitudes made it suitable for tasks like fighter sweeps against enemy airfields, support for U.S. ground forces and protection of sea convoys and transport routes.

While the P-74 could not out-turn the A6M Zero and most other Japanese fighters when flying below 200 mph (320 km/h), its superior speed coupled with a good rate of climb meant that it could utilize energy tactics, making multiple high-speed passes at its target. Also, its focused firepower was deadly to lightly armored Japanese warplanes.

 

Because of its late service introduction, only 305 P-74s were ever produced until the end of hostilities, and they were exclusively used in the Pacific theatre. The P-74's service record shows mixed results, but usually because of misinformation. P-74s have been described as being harder to fly than traditional, single-engined aircraft, but this was because of inadequate training in the first few months of service.

Another drawback was the ejection seat system – it worked basically well, but the tank for the pressurized air turned out to be very vulnerable to enemy fire. Several P-74s literally exploded in midair after cannon fire hits, and this poeblem could only be cured when the tank section behind the cockpit received a more rigid structure and additional armor. Anyway, the P-74 was quickly retired after WWII, as the USAAF focussed on P-47 and P-51.

 

 

General characteristics

Crew: 1

Length: 10.45 m (34 ft 3 in)

Wingspan: 11.6 m (38 ft 0 in)

Height: 3.97 (13 ft 0 in)

Wing area: 22.2 m² (238.87 ft²)

Empty weight: 3,250 kg (7,165 lb)

Loaded weight: 4,150 kg (9,149 lb)

Max. take-off weight: 4,413 kg (9,730 lb)

 

Powerplant:

1× Packard (License-built Rolls Royce Merlin) V-1650-9 ,

rated at 1,380 hp (1,030 kW) and 2,218 hp (1,500 kW) w. water injection

 

Performance

Maximum speed: 640 km/h (343 knots, 398 mph)

Cruise speed: 495 km/h (265 knots, 308 mph)

Range: 1,105 mi (1,778 km)

Ferry range: 1,330 nmi (1,530 mi, 2,460 km)

Service ceiling: 11,000 m (36,090 ft)

Rate of climb: 15 m/s (2,950 ft/min)

 

Armament

4× 20 mm (0.79 in) Hispano-Suiza HS.404 cannons with 250 RPG

2× hardpoints for up to 2,000 lb (907 kg) of bombs, 6 or 10× T64 5.0 in (127 mm) H.V.A.R rockets

 

 

The kit and its assembly:

This whif was inspired by a CG rendition of a Saab J21 in a natural metal finish and with (spurious) USAAF markings, probably a skin for a flight simulator. Anyway, I was more or less enchanted by the NMF on the Saab – I had to build one, and it would become the P-74, the only USAF fighter code that had never been used.

 

The kit is the venerable Heller Saab J21A, an “old style” design with raised panel lines. But it is still around and affordable. No big mods were made to the kit during its transition into a USAAF fighter, even though I changed some minor things:

● Main landing gear was completely exchanged through struts from an Airfix A-1 Skyraider and the wheels from a Hasegawa P-51D; thin wire was added as hydraulic tubes

● New propeller blades: instead of the three-bladed original I added four much broader blades with square tips (from a Heller P-51D) to the original spinner

● Different exhaust stubs, which actually belong to a Spitfire Merlin (Special Hobby kit)

● Underfuselage flap was slightly opened

● A pilot figure was added to the nice cockpit

● The gun barrels were replaced with hollow styrene tubes

 

 

Painting and markings:

NMF was certain, but the rest…? I wanted to have a colorful aircraft, and eventually settled for a machine in the Pacific theatre of operations. When I browsed for options I eventually decided to apply broad black stripes on wings and fuselage, typical 5th Air Force markings that were used e. g. on P-47Ds and P-51Ds.

 

Overall design benchmark for my aircraft is a P-47D-28 of 310th FS/58th FG. The tail would be all white, and the rudder sported red and white stripes, early war insignia. The red nose trim and the deep yellow spinner were taken over from this aircraft, too. The blue individual code number is a personal addition, as well as the nose art, which was puzzled together from a Czech 'Perdubice' Meeting MiG-21 and leftover bits from a Pacific use P-51.

 

The aircraft was basically painted with Aluminum Metallizer (Humbrol 27002) and Polished Steel Metallizer (Modelmaster), and some panels were contrasted with Aluminum (Humbrol 56).

The anti-glare panel in front of the cockpit was painted in Olive Drab (Humbrol 66), the red nose trim with Humbrol 19. The tail was painted with a mix of Humbrol 34 & 196, for a very light grey, and later dry-painted with pure white.

 

The black ID stripes as well as the red and blue rudder trim were not painted, but rather created through decal sheet material (from TL Modellbau), cut to size and shape to fit into their respective places. The tail was a PITA, but for the black stripes this turned out to be very effective and convenient - an experiment that willcertainly see more future use.

 

Cockpit interior was painted in Humbrol 226 (Cockpit Green) and Zinc Chromate Green from Model Master, the landing gear wells received a chrome yellow primer (Humbrol 225) finish.

The landing gear struts were kept in bare Aluminum.

 

For weathering the kit received a rubbing treatment with grinded graphite, which adds a dark, metallic shine and emphasizes the kit’s raised panel lines. Some dry painting with Aluminum was added, too, simulating chipped paint on the leading edges, and on the black ID stripes some dark grey shading was added.

 

 

A relatively simple whif, but I love how the Saab 21 looks in the unusual, shiny NMF finish - and the USAAF markings with the prominent ID stripes suit it well, even though it looks a bit like a circus attraction now?

Done