Heavy fighter
An exception was the American Lockheed P-38 Lightning,[1][2][3] which proved an effective heavy fighter; even against smaller, lighter, single-engine aircraft and particularly in the Pacific theater.
The G.I was designed to serve on the heavier end of the spectrum of heavy fighters, as a jachtkruiser[7] or a bomber destroyer, and was comparable to early models of the German Messerschmitt Bf 110.
[8][9] Prior to the Nazi German invasion of the Netherlands, the G.I was actively involved in air-border patrols in order to ensure neutrality and the integrity of Dutch airspace.
[10] Although reports are fragmentary and inaccurate as to the results, G.I fighters were employed over Rotterdam and the Hague, contributing to the loss of 167 Ju 52s, scoring up to 14 confirmed aerial kills.
[17][18] The basic design was close to the original specification; that of either a 2 or 3 seat, dual-engine heavy fighter, armed with two 20 mm Hispano-Suiza HS.404 cannons in gondolas under the fuselage and a rearward-facing machine gun for defense.
One factor contributing to the high losses was the near-complete lack of spares, rendering 70 63.11s unserviceable even prior to the German invasion; many aircraft were destroyed on the ground by enemy bombing and strafing attacks, and entire units were wiped out without conducting a single mission.
While the Bréguet 690 was not selected to serve as France's primary heavy fighter, the French Air Force's command staff was still intrigued by the sturdy and versatile design.
Six to eight were shot down by German flak, two more 693s were lost while attempting to return to base, and of those that made it home safely, one was written off (most of the twenty four crewmen survived or were captured alive, although three died during the attack and some of the survivors were badly wounded).
Eventually Bf 110s were converted to interceptors, and were particularly successful in the later marks of the Bf 110G series from 1942 to 1943 onwards as night fighters, serving as the primary aircraft of the Luftwaffe Nachtjagdgeschwader night fighter wings, using various versions of the Lichtenstein radar for nocturnal interception of RAF Bomber Command heavy bombers, as well as finding some use as ground-attack aircraft.
Due to their relatively large size, these were mostly used as night fighter-bomber destroyers, as there was ample room to install airborne intercept radar systems as well as heavy armament.
Twelve airframes, designated " He 177 A-1/U2", carried twin 30 mm MK 101 cannon in an enlarged ventral gondola and was intended for ground attack, train busting, and possibly long-range anti-shipping raids.
Five A-5 variants were built, armed with up to 33 spin-stabilized 21 cm (8¼ in) calibre rockets obliquely mounted (firing upwards) in the fuselage, designed to break up and destroy the combat box defensive formations used by USAAF daylight bombers over Germany.
[32] Towards the end of the war, the Dornier Do 335 Pfeil was developed as a twin-engine dedicated zerstörer (eschewing the usual German wartime practice of assigning multiple roles to heavy fighters), designed with a relatively unique push-pull configuration, which placed its fuselage-mounted twin DB 603 engines' propellers on opposing ends of the fuselage, and potentially allowed much better maneuverability, while essentially using the same engines as the conventional-layout twin-engine Me 410.
The centre-line thrust design of the Do 335, the first-ever front-line combat fighter to use it, did allow dramatically higher speeds (just over 750 km/h or 465 mph) than many other twin-piston-engine aircraft of its era, but was never produced in quantity.
A parallel single-seat twin Merlin engine fighter the de Havilland Hornet entered service in the immediate post-war period and served until 1955.
It was designed as a twin-engine bomber interceptor to climb quickly and carry heavy armament at high speed, with the lighter Bell P-39 Airacobra meeting the single-engine version of the same requirement.
This range allowed a team of sixteen early P-38 models to intercept and kill Japanese Admiral Isoroku Yamamoto while he was traveling aboard a transport aircraft.
In 1945, with the large-scale use of jet aircraft becoming commonplace, the United States Army Air Forces put forward technical specifications to the US aerospace industry, requesting both day and night interceptors.
While the XP-89 would eventually emerge as the winner, due to multiple issues with both competing aircraft, the first Scorpions would not reach operational Air Defense Command interceptor units until 1951.
With no other night interceptors to call on from 1945 to 1951, the P-61 Black Widow was charged with protecting American airspace from the growing threat of Soviet strategic bombers.
[44] The first XP-82 prototype was equipped with a removable centerline gun pod housing eight additional .50 caliber M3 Brownings, but this did not feature on production aircraft.
[citation needed] The Twin Mustang was increasingly out-classed by jet aircraft, and was eventually replaced in Korea by Republic F-84 Thunderjets and North American F-86 Sabres.
Primarily stationed in Alaska out of Adak Island (and later out of Ladd Air Force Base) as part of the 449th Fighter (All-Weather) Squadron (F(AW)S), a winterized variant, known as the F-82H was developed specifically for this task.
The winterized Twin Mustang would perform long-range aerial patrols over the extremes of American airspace around Alaska, with the area being viewed as a possible ‘back door’ for Soviet strategic bombers.
Its design was based around a 75 mm cannon capable of destroying large heavy bombers with one hit, but interest in the project waned and the 83 ft (25 m)-wingspan aircraft did not progress beyond a single mockup.
[48] Post-war, the Grumman F7F Tigercat was the first twin-engine fighter aircraft to enter service with the United States Navy, using two Pratt & Whitney Double Wasp radial engines, achieving a top speed of 460 mph (740 km/h).
It was among the fastest piston-engine aircraft ever built, and heavily armed with four 20mm M2 cannon and four 0.50 in (12.7 mm) Browning AN/M2 heavy machine guns, with hard points for bombs or a torpedo.
During the interwar period the USSR set about developing heavily armed twin-engine fighters to function in the heavy-fighter role, particularly as interceptors and bomber destroyers.
Twin-engine designs such as the Tupolev ANT-29 or Petlyakov VI-100 were proposed, but never made it past the prototype stage, and the USSR entered World War II without a viable heavy fighter.
After the German night bombing raids of Moscow in 1941, the People's Commissariat of Defense of the Soviet Union (NKO) sought to rapidly correct this deficiency.
