TYPE: Fighter aircraft

ACCOMMODATION: Pilot only

POWER PLANT: Two Lockheed L-1000 axial-flow turbojets 2,345 kp thrust each

PERFORMANCE: 625 mph

COMMENT: The Lockheed L-133 was an exotic design started in 1939 which was proposed to be the first jet fighter of the United States Army Air Forces (USAAF) during World War II.
The radical design was to be powered by two axial-flow turbojets with an unusual blended wing-body canard design capable of 612 mph in level flight. The USAAF rejected the 1942 proposal, but the effort speeded the development of the USAAF’s first successful operational jet fighter, the Lockheed P-80 Shooting Star, which did see limited service near the end of war. The P-80 was a less radical design with a single British-based Allison J33 engine, with a conventional tail, but it retained a wing which was the same shape as the outer wing sections of the Lockheed P-38 Lightning.
The Lockheed aviation company was the first in the United States to start work on a turbojet-powered aircraft, the L-133 design started in 1939 as a number of “Paper Projects” by engineers around Clarence L. „Kelly“ Johnson. By 1940 preliminary work on a company-financed turbojet-fighter had been started, which progressed to several different versions on the drawing board. In the meantime, Lockheed was working on an axial-flow L-1000 turbojet engine of their own design, which was intended to power the culmination of the twin-engine jet fighter project, the Model L-133-02-01.
Throughout World War II, the development of a jet-powered fighter had the potential to bring a decisive advantage in the air battles of the war; as history played out, only Germany built significant numbers of jet fighters before the war ended, but they reached service in the Luftwaffe too late to make a difference.
On March 30, 1942, Lockheed formally submitted the L-133-02-01 to the USAAF for consideration. Powered by two L-1000 turbojets and featuring a futuristic-appearing canard design with slotted flaps to enhance lift, the single-seat fighter was expected to have a top speed of 612 mph in level flight, but a range of only 310 mi.
The L-133 had a main wing shape that was essentially identical to the outer wing sections of the Lockheed P-38 Lightning. In many respects the L-133 was far ahead of its time, with futuristic features including: canard layout, blended wing-body planform, and two engines in a very low-drag integral fuselage location.
The USAAF considered the L-133 to be too advanced for the time, and did not pursue the project. The experience gained with the design served Lockheed well in the development of the USAAF’s first operational jet fighter, the P-80 Shooting Star. Although entering combat service after the war had ended, the P-80 was less advanced than the L-133. Because the USAAF didn’t give the L-133 project the go-ahead, the advanced engines intended for the L-133 had long pauses in their development. The most expedient engine choice for the P-80 thus became the Allison J33, based on British centrifugal compressor designs. The P-80 was a cheap-to-build single-engine aircraft with a conventional wing and tailplane design, not using the blended wing-body and canard layout of the L-133 (Ref.:24).

TYPE: High Altitude Fighter

ACCOMMODATION: Pilot only

POWER PLANT: One Wright R-2160-6 Tornado super-charged liquid-cooled radial engine, rated at 2,500 h.p. and driving 6-bladed Hamilton Standard contra-rotating propellers,

PERFORMANCE: 453 m.p.h.

COMMENT: The Republic XP-69 was an American fighter aircraft proposed by Republic Aviation in 1941 in response to a requirement by the United States Army Air Corps for a high-speed fighter. Manufacturers were encouraged to consider unorthodox designs; although the design was ordered as a prototype it was canceled because of delays with the engine that was to power it.
he United States Army Air Corps began the R40-C fighter competition in February 1940. The competition encouraged manufacturers to propose unorthodox high-speed fighter aircraft that met the requirements of Type Specification XC-622. The specification called for a single-engined high-performance fighter aircraft, with a maximum speed between 425 and 525 mph, armed with both machine guns and cannons, and be capable of landing on a 3,000 ft long grass runway
Republic was one of six companies selected for the competition, and one of the aircraft proposed to the USAAC by Republic was the AP-12 Rocket. As proposed, the AP-12 was to be powered by a 2,500 hp Wright R-2160-3 Tornado 42-cylinder liquid-cooled radial engine mounted in the mid-section of the aircraft’s streamlined, cigar-shaped fuselage, behind the cockpit, which drove a pair of three-bladed contra-rotating propellers. It was to be armed with four nose-mounted machine guns firing through the propeller arc, and a single 20 mm cannon firing through the propeller hub. The AP-12 placed 13th out of 26 contestants, forcing Republic to go back to the drawing board to improve its proposal.
In July 1941, Republic submitted an improved design, the AP-18. The AP-18 had little in common with the AP-12. It retained the original aircraft’s R-2160 engine, which was now mounted in the nose of a completely new small-cross section airframe. The large radiator was to be mounted under the fuselage. The pressurized cockpit was to feature a bubble canopy, and an armament of four .50 in machine guns and two 37 mm cannons mounted in a laminar flow wing was planned.
In December 1941, the United States Army Air Forces (successor to the USAAC) ordered two prototypes of the AP-18 under the designation XP-69. A mockup was built and was inspected by the USAAF in June 1942. Construction of the first prototype began in November of that year. However, due to development troubles and delays with the R-2160 engine, the XP-69 project was canceled in favor of a parallel development, the Republic XP-72, on May, 1943. By that time engineering on the project was 75% complete and the prototype was still in the early stages of construction (Ref.: 24).