The P-61 Black Widow was an advanced twin-engine twin-boom night fighter that was designed by Northrop. The P-61 was designed from the ground up as a dedicated radar carrying night fighter, the first aircraft in history to do so. With four .50 cals and four 20 mm cannons, the P-61 would become one of the US’ most deadly aircraft of the war.
The P-61 was first conceived by Jack Northrop in 1940 to fulfil a demanding British requirement for an aircraft that could defend against German aircraft bombing British cities at night. The aircraft had to be able to loiter for at least eight hours, carry radar to detect incoming aircraft and be fast enough to intercept them.
Conveniently, the US Air Corps were looking for an aircraft of very similar requirements, and Jack Northrop, already ahead with his design, jumped at the opportunity. Northrop was awarded a contract for two prototypes in early 1941, under the designation of XP-61.
The P-61 Black Widow was an incredibly unique looking aircraft. Its twin boom tails resembled the P-38, while its stepped central fuselage contained three crew members, a gun turret and radar.
The P-61’s 20 mm cannons were mounted in the belly. Mounting all eight guns in the fuselage meant they were closer together, creating a more focused beam of fire than wing mounted guns that would converge at a set range. This focused fire made hitting targets from further away easier. Without the guns in them, the wings could carry more fuel.
The turret was remotely controlled with a system similar to that used in the B-29, and could be operated by both the gunner and radio operator who each had controls. The crew were located in the central ‘gondola’, the nose of which contained the SCR-720A radar. Behind this was a two-step canopy. The pilot sat in the lower level, while the gunner sat on the upper level above and behind.
The radar operator was secluded from the rest of the crew in the rear compartment, surrounded by a pointed plexiglass canopy. He monitored the radar scopes and operated the radios.
The SCR-720A radio set had a range of about 5 miles. Once a target was found, the operator would verbally direct the pilot towards the target, who would then use a smaller scope in the cockpit to follow the target when in close proximity.
The turret could rotate 360 degrees, and elevate 90 degrees, covering all the sky above and to the sides of the P-61. Targets behind could be engaged by the radar operator, and the turret could be locked to the 20 mm guns in the belly for use by the pilot.
The aircraft was powered by two 2,250 hp Pratt & Whitney R-2800-65W Double Wasp radial engines, driving 12 ft four bladed propellers. This gave the P-61 a top speed of 366 mph, good for its size, but underwhelming against similar aircraft like the British Mosquito.
The aircraft’s career was rather brief and lacklustre, only reaching squadrons in mid 1944 and having minimal engagements with enemy aircraft, compared to its contemporaries. In Europe the P-61 often gave up its night fighting role to assist in ground attack missions. It faired well in the air against most German designs, but came up short against the latest Germany had to offer, usually simply being too slow to keep up.
During the war, the P-61 Black Widow was often compared with the British Mosquito, a beloved and war winning design. A few competitions were set up to compare the two aircraft, where the Mosquito won out with its incredible speeds. The P-61 was however able to outmanoeuvre the Mosquito.