Ranking the Top 10 Twin Engine Fighter Aircraft of WWII

When considering the pantheon of combat aircraft, particularly during World War II, single-engine fighters often dominate the discussion. Legendary machines like the Spitfire, Mustang, Zero, and Me 109 were the icons of air-to-air combat, excelling in speed and maneuverability. Yet, the role and effectiveness of the Twin Engine Fighter Aircraft were undeniably significant, filling crucial niches that single-engine designs often couldn’t. This raises a key question: why would air forces opt for a twin-engine configuration for a fighter, which inherently means a larger, heavier airframe, when the conventional wisdom for a fighter favors minimum size wrapped around maximum power?

The answer lies in the diverse requirements placed upon fighter aircraft during the conflict, extending beyond the classic close-in dogfight. The “ideal” minimum-sized, single-engine interceptor is superb for home or fleet defense where range is less critical. Speed, climb rate, maneuverability, and armament are paramount for this role. However, alternative missions demanded different characteristics.

One vital requirement was the long-range fighter escort. To accompany bomber formations deep into enemy territory and protect them from opposing fighters, aircraft needed extended endurance and range. This inevitably led to larger, heavier airframes, often requiring external drop tanks.

Another crucial role was night air defense. Effective night-fighters, even with ground radar assistance, needed to remain airborne for extended periods at appropriate altitudes for interception, demanding good endurance. Furthermore, Second World War radar sets were bulky and required a dedicated operator in addition to the pilot. These factors combined made a larger, twin-engine solution often more effective for dedicated night fighting.

A third significant role was the multi-purpose fighter-bomber. Depending on the required range, this could sometimes be a large single-engine aircraft, but longer-range strike missions often necessitated a twin-engine design capable of carrying a substantial ordnance load while retaining combat capability. This concept spurred several nations, including France, Germany, Italy, Poland, Japan, and the Netherlands, to explore dual-role fighter-bombers prior to WWII. The UK, Soviet Union, and USA initially focused more on specialized types during that period.

Illustration of Fokker G.1 twin boom twin engine aircraft

Thus, a list of the best twin-engine fighters must consider aircraft designed for these principal requirements: long-range escort, dedicated night-fighter, and long-range fighter-bomber. The lines between these roles were often blurred, as capable twin-engine platforms could often be adapted for multiple missions beyond their original intent.

Examining ww2 Twin Engine Fighter Aircraft provides an excellent case study in design trade-offs. The primary drivers for these aircraft were payload-range and endurance, in addition to the core fighter attributes of high speed and reasonable maneuverability, preferably at high altitudes. Achieving long range, long endurance, or bomb-carrying capacity, combined with heavy firepower, necessitated a large aircraft. Often, a crew of two or more was required, and the power demands frequently reached a point where two engines became necessary.

However, accommodating mission equipment, fuel, armament, stores, radar, and multiple crew members, plus two engines, resulted in greater weight and inertia. This made achieving the maneuverability of the best single-engine fighters a significant challenge. In some cases, superior speed or altitude performance could help compensate, and the ability to carry heavy cannon armament was always a valuable asset. Night-fighters, in particular, were sometimes less constrained by extreme maneuverability requirements, making their design space potentially easier, although the necessary mission systems often pushed the boundaries of available technology.

This list focuses on piston-engine aircraft that saw significant operational impact during World War II. Later war or technically advanced but operationally insignificant types like the Me 262 jet, Meteor jet, Dornier 335, and Grumman Tigercat are excluded for this reason. The ranking is largely based on the operational significance and overall contribution of the aircraft, rather than purely technical specifications.

10. Westland Whirlwind

Westland Whirlwind twin engine fighter aircraft on the ground

The Westland Whirlwind was conceived as a heavily-armed, single-seat, high-performance twin engine fighter aircraft. Aerodynamic cleanliness was a key focus of its design. Powered by two Rolls-Royce Peregrine engines housed in closely faired nacelles, its radiators were cleverly integrated into the inboard wing structure. The fuselage was notably slender, accommodating the cockpit, a potent armament of four 20-mm Hispano cannons, and the cruciform tail unit. Its cross-section was actually smaller than that of each engine nacelle.

Design work on the Whirlwind began in 1936 under specification F.37/35. The first prototype flew in October 1938, leading to a production order in January 1939 with an anticipated service entry by September 1939. However, development issues with the Peregrine engine caused significant delays, with production engines not arriving until January 1940. The aircraft finally entered service in July 1940 and became operational in December.

Despite initial engine troubles, the Whirlwind was well-regarded by its pilots for its pleasant handling, heavy firepower, and excellent visibility from the bubble canopy. Its low-altitude performance was particularly impressive, described as “superior to any contemporary single-engine fighter.” However, performance suffered at higher altitudes, partly because the Whirlwind was the sole operational aircraft using the Peregrine, while Rolls-Royce focused its development efforts on the widely used Merlin engine.

Due to engine delays pushing its operational debut past the Battle of Britain, and the shift in air combat tactics towards higher altitudes, only two RAF squadrons, 263 and later 137, operated the Whirlwind. They were primarily used for escorting light bombers and for low-level strike missions against airfields and infrastructure in occupied Europe, transitioning to a fighter-bomber role before being replaced by Typhoons in 1943. A total of 114 Whirlwinds were built.

A notable engagement in August 1941 saw four Whirlwinds attacked by 20 Me 109s during an airfield strike. Despite being outnumbered five-to-one, the Whirlwinds held their own, destroying two Me 109s while three of the four were damaged – a creditable result demonstrating the aircraft’s quality, especially at low levels. At 15,000 ft, the Whirlwind reportedly reached 360 mph, faster than the contemporary Me 109E’s 348 mph. Its reported maximum range of 800 miles significantly exceeded the Bf 109 E’s 410 miles.

Ultimately, delays prevented the Whirlwind from achieving wider operational significance, though its three years of service without major modification indicated a sound basic design.

[Bibliography: Westland 50, JWR Taylor & MF Allward, 1965; Warplanes of the Second World War, William Green, 1961; The Complete book of Fighters, William Green and Gordon Swanborough, 1994; Warplanes of the Third Reich, William Green, 1970]

9. Nakajima J1N1-S Gekko

Nakajima J1N1-S Gekko Japanese twin engine night fighter aircraft

The Nakajima J1N Gekko (“Moonlight”) originated from a 1938 Japanese Navy requirement. Recognizing that their Type 96 carrier fighters lacked the range to escort bombers to distant Chinese air bases, leading to unescorted bombing losses, the Navy sought a long-range fighter. This resulted in a specification for a three-seat, twin engine fighter aircraft with long range (1300 nautical miles), heavy armament (20-mm cannon plus machine guns), and a maximum speed of 322 mph. Initial trials of the J1N1 were disappointing; the aircraft was deemed overweight and lacking maneuverability, though its range and speed were adequate.

Redesigned as a long-range, land-based reconnaissance aircraft with armament removed to save weight, the J1N1-C entered service, with 54 delivered by March 1943.

Wrecked Nakajima J1N1-R Gekko twin engine aircraft on airfield

A pivotal moment occurred in 1943 when a J1N1-C received a field modification: two 20-mm cannons firing obliquely upward and two firing obliquely downward. This modified aircraft, designated J1N1-C Kai, was tested in a night-fighter role. Its success in shooting down two B-24 Liberators prompted the Navy to initiate the development of a dedicated night-fighter version, the J1N1-S Gekko.

The Gekko became the most important Japanese fighter aircraft used by the Navy for night fighting. Between March 1943 and December 1944, 423 J1N1s were built, primarily as J1N1-S and J1N1-Sa night-fighters differing in armament and equipment. Operational experience showed the downward-firing guns were less effective, so they were removed, and an additional upward-firing cannon was fitted. Most J1N1-S and -Sa aircraft were equipped with air intercept radar, though some Sa variants replaced the radar with a forward-firing 20-mm cannon.

The aircraft proved very effective against B-24s but struggled against the faster B-29s. Its performance was respectable, with a maximum speed of 315 mph at 19,000 ft and a normal range of 1580 miles. A total of 479 J1N1 variants were built, with at least two-thirds serving as night-fighters.

Though conceived as a long-range escort fighter and initially deployed as a reconnaissance platform, the J1N1 ultimately found its greatest success and operational significance as the Japanese Navy’s primary twin engine night-fighter.

[Bibliography: Japanese Aircraft of the Pacific War, RJ Francillon, 1970; Warplanes of the Second World War, William Green, 1961; The Complete book of Fighters, William Green and Gordon Swanborough, 1994]

8. Northrop P-61 Black Widow

The P-61 Black Widow was the maiden major project for Northrop Aircraft Inc. and holds the distinction of being the first aircraft purpose-designed as a night-fighter. Developed in response to a USAAC specification from October 1940, the P-61 was a massive machine. This large, twin-engine, twin-boom aircraft was heavily armed with four 20-mm cannons and four 0.5-in machine guns. The main production version, the P-61B, had an empty weight of 22,000 lbs and a maximum take-off weight of 32,400 lbs – figures approximately 10,000 lbs heavier than a Beaufighter.

Built on a truly American scale, the Black Widow was the heaviest aircraft ever designated as a “Pursuit” (P) type. It boasted formidable armament and was equipped with a Western Electric SCR-720 Air Intercept radar. Despite its size, it was reportedly surprisingly agile and was described as a “pilot’s airplane.”

Given its remarkable capabilities, why does this aircraft sit at number 8 on this list of twin engine fighter aircraft? Like the Westland Whirlwind, the primary issue was timing. Although specified in October 1940, production P-61As weren’t delivered until October 1943, followed by the P-61B from July 1944. Operational deployments commenced in early 1944 in Europe and the Far East.

While P-61s performed useful roles, initially in countering V1 flying bombs at night in the UK and later in night intruder operations in Europe, they arrived when large-scale German night bomber raids had largely ceased. In Europe, they were mainly used in tactical roles.

Ten squadrons were sent to the Pacific theatre to support operations against Japan from bases in the Philippines, Iwo Jima, and New Guinea. However, they faced a similar situation, as Japanese night raids on US bases had mostly ended by their arrival. The first victories in the Far East came over Saipan in June and July 1944.

Consequently, despite its fearsome appearance and effectiveness in the night-fighter role, the major threat the Black Widow was designed to counter had largely vanished by the time it reached operational theaters. The aircraft was undoubtedly effective in air-to-air combat and as a tactical strike platform, but its opportunity to make a significant operational impact on the strategic bombing campaigns had passed.

[Bibliography: The American Fighter, E Angelucci and P Bowers, 1985; US Army Air Force Fighters Part 2 William Green and Gordon Swanborough, 1978; American Combat Planes, Ray Wagner, 1982, Northrop P-61 Black Widow, Warren Thompson, Wings of Fame, Vol. 15, 1999]

7. Heinkel He 219 ‘Uhu’

Model of Heinkel He 219 Uhu German twin engine night fighter aircraft

There appears to be a broad consensus among aviation historians that the Heinkel He 219 “Uhu” (“Eagle-Owl”) was the most effective dedicated night fighter aircraft developed by Germany during the Second World War. However, relatively few were built, and it never achieved the operational impact it could have had if it had entered service earlier than June 1943.

The aircraft’s origins trace back to a Heinkel private venture proposal in the summer of 1940 for a multi-role heavy fighter capable of reconnaissance and torpedo bombing. This proposal incorporated several advanced features for the time, including a pressurized crew compartment, tricycle landing gear, remotely controlled defensive gun turrets, and ejection seats.

At the time, this sophisticated design garnered little official interest, possibly due to its complexity and perceived risk, or the belief that existing aircraft like the Me 110 and Ju 88 could fulfill these roles adequately.

By 1942, however, the RAF’s night bombing campaign had become so effective that Josef Kammhuber, commanding Germany’s night air defenses, urgently pressed for better equipment. In response, Heinkel was asked to adapt its earlier project into a dedicated night-fighter design. Detailed design work on the He 219 began in January 1942 but was hampered by RAF bombing raids on Marienehe, forcing the relocation of the design team to Vienna.

As development progressed, General Kammhuber continued to push Heinkel for rapid delivery of production aircraft. Simultaneously, Erhard Milch, in charge of aircraft production, strongly opposed the Uhu’s development, arguing that existing types could handle the role. Furthermore, development of the intended Daimler-Benz DB 603G engine encountered difficulties, leading initial aircraft to be fitted with the less powerful DB 603A.

Despite these challenges, a pre-production He 219A-0 underwent operational testing on June 11, 1943, achieving remarkable success by destroying five bombers in a single sortie. Tragically, the aircraft was lost on landing due to flap failure.

The production He 219A was a heavily armed, advanced twin engine fighter aircraft, drawing on the technologies from Heinkel’s 1940 proposal and powered by the DB 603A engine. Armament was typically formidable, often including two 30-mm cannons in a Schräge Musik (oblique upward-firing) installation behind the cockpit, two 20-mm cannons in the wing roots, and two 20- or 30-mm cannons in an under-fuselage tray. Aircraft were fitted with Liechtenstein SN-2 radar, operated by a crewman seated behind the pilot.

Operationally, the He 219A was highly successful against RAF night bombers, with numerous pilots achieving impressive scores, including multiple kills on single missions. It was popular with crews for its effectiveness, heavy armament, and relative ease of maintenance.

In late 1944, the RAF began adding Mosquito night-fighters to bomber streams, increasing losses for the German night-fighter force. Increasing Allied fighter-bomber attacks further reduced the He 219’s operational strength.

A total of 294 He 219 variants were built. While outstanding in service, its impact was limited by production delays, internal bureaucratic disagreements, and the worsening military situation for Germany.

[Bibliography: Warplanes of the Third Reich, William Green, 1970; War Planes of the Second World War, William Green, 1960; German Aircraft of the Second World War JR Smith and Anthony Kay, 1972]

6. Kawasaki Ki 45 Toryu

Kawasaki Ki 45 Toryu Japanese twin engine fighter aircraft

Japan observed Europe’s interest in the “strategic fighter” concept during the 1930s – aircraft combining long range, high performance, and heavy armament for bomber escort, long endurance patrols, and other potential roles. This led to a 1936 outline requirement for such an aircraft. However, preliminary studies by Nakajima, Kawasaki, and Mitsubishi revealed the inevitable compromises inherent in such a demanding specification needed clarification.

As discussed earlier, meeting significant armament and endurance requirements increases aircraft size and weight, demanding more power and making it harder to achieve fighter-like speed and maneuverability. Clarity on the balance between roles was provided with revised requirements in December 1937, allowing the Ki 45 project to proceed.

Intended primarily for long-range bomber escort, the three initial prototypes proved unsatisfactory, mainly due to engine and engine installation issues. Performance was disappointing, and air combat trials showed it was inferior in maneuverability to even the Kawasaki Ki 10 biplane and Nakajima Ki 27 monoplane fighters.

Despite these setbacks, the decision was made to proceed with a developed version, the Kawasaki Ki 45-Kai, which began flight testing in July 1940. The Ki 45-Kai featured more powerful 14-cylinder, 1050 hp Nakajima Ha-25 engines, replacing the initial 9-cylinder, 820 hp Nakajima Ha-20 Otsu.

Flight test results justified the continuation, with the prototype achieving a maximum speed of 323 mph. For production, the design team further refined the structure and aerodynamics, making the production Ki 45-Kai effectively a new design. Changes included a slimmer fuselage, different wing planform, and slimmer engine nacelles. The engines were again changed to the more reliable Mitsubishi Ha-102, with similar power.

The production Toryu proved highly satisfactory, displaying surprising maneuverability and good performance. It was armed with a forward-firing 20-mm cannon and two 12.7-mm machine guns, plus a 7.92-mm defensive rear gun. Maximum speed was 335 mph at 20,000 ft, and maximum range on internal fuel was 1404 miles – both commendable figures for a twin engine fighter aircraft.

Initial combat experience in China in November 1942 highlighted the Toryu’s surprising agility; it was described as the most maneuverable twin-engined type fielded by any WWII combatant, able to outmaneuver the P-38 Lightning “with ease” and perform complex aerobatic maneuvers “with élan.”

Variants followed, including a ground-attack version (Ki 45-Kai-Otsu), a night-fighter (Ki 45-Kai-Ko) with two upward-firing 20-mm cannons behind the cockpit, and a dual-role day/night fighter (Ki 45-Kai-Hei) with changes to forward armament, including a 37-mm Ho 203 cannon. The Toryu was extensively used defending the Japanese home islands against B-29 raids, with its 37-mm cannon proving highly effective.

A further variant, the Ki 45-Kai-Tei, added two forward-firing 20-mm cannons to supplement the 37-mm cannon, intended for anti-shipping but largely diverted to night-fighter units. Total production across all variants was 1691. The aircraft proved highly effective in all its roles, particularly as an escort and japanese fighter aircraft night-fighter.

[Bibliography: Japanese Army Fighters, William Green and Gordon Swanborough, 1976; Japanese Aircraft of the Pacific War, RJ Francillon, 1970]

5. Messerschmitt Bf 110

The 1930s saw a renewed interest in the “strategic fighter” concept across several European nations. While envisioned in World War 1, this concept’s revival in the thirties may have been influenced by economic considerations; a single type capable of multiple roles could reduce development costs and simplify production.

Around 1934, near-simultaneous projects emerged: the Potez 63 in France, the PZL 38 Wilk in Poland, and the Messerschmitt Bf 110 in Germany. All three were twin-engined with relatively slender fuselages and twin fins.

Designing these aircraft presented challenges. The required range and armament essentially mandated a twin-engine layout, which meant higher weight and inertia compared to the single-engine fighters they would face. This inevitably suggested inferior maneuverability. Nevertheless, there was a belief that heavy cannon armament and high speed could enable tactics to overcome any maneuverability disadvantage.

The first Bf 110 prototype flew on May 12, 1936. Persistent engine development issues meant the initial Bf 110B-1 model used Junkers Jumo 210Ga engines and was primarily used for training, unsuitable for combat. The refined Bf 110C began deliveries to the Luftwaffe in January 1939. By August 31, 1939, 159 aircraft had been accepted, and full production was underway.

The Bf 110C boasted a maximum speed of 336 mph at 19,700 ft and a maximum range on internal fuel of 876 miles. Armed with two 20-mm cannons, four forward-firing machine guns, and one defensive rear gunner, the Bf 110C seemed poised to be an effective heavy fighter.

Early operations against the Polish Air Force were promising, with low losses. Its armament was effective but difficult to bring to bear against agile targets. It proved capable as a bomber interceptor, notably shooting down 9 of 12 Wellingtons during a December 1939 raid on Wilhelmshaven, and performed well in the Norwegian campaign.

Heading into the Battle of Britain in September 1940, confidence in the Bf 110 was high. This confidence was quickly eroded when engaging the fast and agile RAF Spitfires and Hurricanes. While effective where the Luftwaffe held air superiority, this was not the case over Britain. The Bf 110 suffered significant losses, with 120 lost in August 1940 alone.

As the Battle of Britain concluded, the Bf 110 found its niche in a new role as a twin engine night-fighter, while also continuing as a fighter-bomber. Initially, unmodified Bf 110Cs were used, but improvements followed, integrating ground control radar (Würzburg) and an infrared sensor (Spanner-Anlage).

Numerous Bf 110 variants were produced to counter increasing weight, incorporate more powerful engines, and utilize improved equipment and armament. Originally planned for replacement by the Me 210, production of the improved Bf 110G was restarted. The primary night-fighter version, the Bf 110G-4, was built in many sub-variants but designed from the outset for airborne intercept radar.

Armament generally included two forward-firing 20-mm cannons and four nose machine guns, plus either two defensive rear machine guns or a Schräge Musik installation of two upward-firing 30-mm cannons. Radar included the Liechtenstein C-1 or later SN-2, supplemented by Rosendaal-Halbe equipment designed to home in on RAF Monica tail-warning radars. Though perhaps not the ideal night-fighter, the Bf 110 formed the backbone of the Luftwaffe’s night defense, aided by the Himmelbett integrated air defense system until mid-1943, when RAF “Window” (chaff) severely disrupted Himmelbett.

Deprived of this integrated system, the German night-fighter force adopted Wilde Sau (“wild boar”) tactics, relying more on aircraft-based target detection. Here, the Bf 110 was hampered by its relatively poor performance and endurance. Improvements were made to onboard radars, and additional fuel tanks helped mitigate some issues. By 1944, Bf 110s constituted almost three-quarters of the German night-fighter force.

Production continued until March 1945, with over 6000 aircraft built across all variants. Despite its failure in the Battle of Britain, the Bf 110 made a major contribution to the Luftwaffe, particularly as a night-fighter, but also as a fighter-bomber, in close air support, and reconnaissance roles. Its operational use across various roles highlights its versatility as a ww2 twin engine fighter aircraft.

[Bibliography: Warplanes of the Third Reich, William Green, 1970; War Planes of the Second World War, William Green, 1960]

4. Bristol Beaufighter

Graphic representation of Bristol Beaufighter twin engine fighter aircraft

Development of the Bristol Beaufighter began in November 1938, targeting a requirement for a cannon-armed long-range escort and night fighter aircraft. Essentially a fighter derivative of the Beaufort bomber already in production, the Beaufighter leveraged the Beaufort’s wings and tail, significantly speeding up development. The prototype’s first flight occurred on July 17, 1939.

The Beaufighter was exceptionally heavily armed, featuring four 20-mm cannons in the lower fuselage and six 0.303-in machine guns in the wings. Fighter Command aircraft were initially equipped with the AI Mark IV air interception radar. The Beaufighter I entered RAF squadron service on July 26, 1940, achieving its first night-fighter success on November 19, 1940.

Early Beaufighters were powered by the 1400 hp Bristol Hercules III, pending availability of the 1600 hp Hercules VI. The 1250 hp Merlin XX was also used in the Beaufighter II. Later variants like the VIF and VIC used the Hercules VI or XVI, while the later Beaufighter X, XIC, and Australian-built 21 employed the 1735 hp Hercules XVII. The suffix F denoted Fighter Command aircraft, and C denoted Coastal Command.

The Beaufighter excelled in two primary roles: with Fighter Command as a day or night-fighter, and with Coastal Command as a formidable anti-shipping aircraft. Coastal Command also used it for anti-submarine patrols, often escorting convoys to deter surfaced U-boat attacks. Night-fighter operations included defending Great Britain and night intrusion over occupied Europe. Day fighter operations were prominent in North Africa, the Mediterranean, and the Far East.

From 1941, the Beaufighter VI replaced the I and II in production as Hercules VI engines became available. Coastal Command aircraft were modified to carry torpedoes and, from 1943, eight rocket projectiles (four under each wing). Fighter Command’s VIF aircraft were fitted with AI Mark VIII centimetric radar, which was also adopted in the Coastal Command Beaufighter Mk X for enhanced anti-submarine and anti-shipping capabilities.

As Mosquito night-fighters entered service, Beaufighter night-fighter operations gradually decreased. However, the aircraft continued to serve effectively as a heavily armed long-range strike fighter on all fronts. In the Pacific, RAAF Beaufighter 21s served as long-range bomber escorts and conducted strike and anti-shipping missions. Coastal Command Beaufighter X aircraft were successful against convoys off Europe in the North Sea and Mediterranean.

Bristol Beaufighter twin engine aircraft flying over Italy

When production ended, 5,562 Beaufighters had been built in Britain, plus 364 Australian-built Beaufighter 21s. Serving from July 1940, the aircraft’s robustness, heavy armament, and effectiveness across roles (night-fighter, anti-shipping, strike, escort) made it a significant ww2 twin engine fighter aircraft on all major fronts. The last RAF Beaufighter flight was as late as 1960.

[Bibliography: Bristol Aircraft since 1920, CH Barnes, 19644; War Planes of the Second World War, William Green, 1961; Wikipedia – Bristol Beaufighter]

3. Junkers Ju 88

Including the Junkers Ju 88, initially designed as a Schnellbomber (high-speed bomber), on a list of twin engine fighter aircraft might seem unusual. However, its specification called for an aircraft capable of carrying an 1100-lb bombload at 310 mph (or cruising at 280 mph) with a quick climb rate, resulting in an exceptionally versatile platform. Though a fast medium bomber at heart, the Ju 88 was developed into numerous variants excelling not only in bombing but also as a long-range day-fighter, fighter-bomber, night fighter aircraft, and reconnaissance aircraft.

The first prototype flew on December 21, 1936. Ten test aircraft were built before the first production Ju 88A entered operational test units.

The first operational sortie was a September 26, 1939 attack on Royal Navy ships. Ju 88A series aircraft were active in the Norwegian campaign and attacked British radar installations, ports, and airfields during the Battle of Britain. From 1942, they were heavily involved in the Mediterranean theatre, attacking Malta, naval forces, and land targets. They also saw extensive use on the Eastern Front, including attacks on Moscow and famously against Arctic convoys PQ 16 and PQ 17.

No fewer than 18 variants of the Ju 88A were produced. The major shift came with the Ju 88A-4, introducing the more powerful Jumo 211J engine and a larger wing. Variants were created for specific roles like balloon cable cutting, training, tropical operations, low-level attack, and anti-shipping.

The Ju 88B was an updated version with a revised nose and BMW 801 engines, primarily used for long-range reconnaissance with additional fuel tanks.

The next significant variant was the Ju 88C fighter. Its development was initially low priority until RAF night raids on the Ruhr forced the Luftwaffe to rapidly build a night fighter aircraft capability. The Ju 88C-2 contributed to this, armed with two 20-mm cannons and two 7.9-mm machine guns. Early missions were night intruder sorties over RAF bomber bases in Holland. These ceased in October 1941, and Ju 88C-2 units redeployed to the Mediterranean.

Like the Ju 88A, C-variants proliferated. The C-4 used the A-4 airframe, increasing nose armament to four 20-mm cannons, adding three defensive rear guns, and the ability to carry six more forward guns for strafing. The C-6 was similar, intended as a day fighter-bomber. Its main theatre was the Mediterranean, escorting convoys, raiding Malta, harassing shipping, and attacking RAF Coastal Command in the Western Approaches.

By 1943, Ju 88C-6s were used for train-busting on the Eastern Front and increasingly as night-fighters, supplementing Bf 110s. The introduction of “Window” severely hampered the Bf 110 in Wilde Sau operations due to its limited performance and endurance.

Two radar-equipped variants, the Ju 88C-6c (Jumo 211) and Ju 88 R-1 (BMW 801), were used extensively and successfully as night-fighters, aided by continuous improvements in AI radar and detection equipment capable of picking up RAF Monica and H2S signals. Armament increased, often incorporating two 20-mm cannons in a Schräge Musik installation, three forward 20-mm cannons, three machine guns, and a defensive rear gun. By 1944, German night-fighter tactics, largely relying on the Ju 88C-6, were inflicting significant losses on RAF Bomber Command.

Ju 88 development continued. The Ju 88D was a specialized long-range reconnaissance version with extra fuel and cameras, built in large numbers (around 1500).

Later Ju 88C night-fighters suffered from handling issues due to increasing weight. The Ju 88G series addressed this with a larger, more angular tail for stability. Armament was revised, typically four 20-mm cannons in an under-fuselage tray, with later G models adding a pair of Schräge Musik 20-mm cannons. 700-800 Ju 88Gs were built, compared to 3,200 Ju 88Cs, with sources differing on which was more crucial for German night defense.

Other models included the ultra-long-range Ju 88H, the anti-tank Ju 88P (with heavy cannons, built in small numbers), and the Ju 88S (a faster bomber variant). Around 250 Ju 88s were used as the lower, explosive component of the Mistel composite aircraft, guided by an upper Bf 109 or Fw 190. These saw operational use attacking bridges.

With approximately 15,000 built in many variants, the Ju 88 was a highly significant aircraft for the Luftwaffe. Its initial role as a high-speed medium bomber expanded dramatically to include day and ww2 twin engine fighter aircraft roles, night fighting, anti-shipping, reconnaissance, and even serving as a guided weapon platform, seeing service on all fronts throughout the war.

[Bibliography: Warplanes of the Third Reich, William Green, 1970; War Planes of the Second World War, William Green, 1960; German Aircraft of the Second World War JR Smith and Anthony Kay, 1972]

2. Lockheed P-38 Lightning

Lockheed P-38H Lightning twin engine fighter aircraft in flight

The Lockheed P-38 Lightning originated from a 1936 USAAF proposal for an “interceptor,” distinct from traditional “pursuit” aircraft. This marked an effort to develop a longer-range, more heavily armed fighter than the short-range, single-engine, lightly armed types common in the US at the time. This thinking was likely influenced by European developments like the Potez 630 and Messerschmitt 110, as well as heavily armed single-seaters like the Me 109 and RAF 8-gun fighters.

Building on the initial concept, a detailed specification for a twin engine fighter aircraft was issued in February 1937. Lockheed Aircraft Corporation responded with its distinctive twin-boom Model 22 design in April 1937, competing against proposals from Bell, Curtiss, Douglas, and Vultee. Lockheed won the contract for a single XP-38 prototype.

The design was innovative, utilizing Allison V1710 engines with large turbo-superchargers for high-altitude performance. The twin booms housed the engines, main landing gear, and turbo-superchargers, connected by the tailplane and elevators. The central fuselage pod contained the armament, nose gear, and cockpit. This configuration promised high aerodynamic and structural efficiency and exceptional performance.

Initial flight testing revealed issues, and development was slowed by the loss of the prototype in a landing accident. Thirteen YP-38s were ordered, the first flying on September 17, 1940, despite the USAAF having already ordered 66 P-38s in July. Testing was further delayed by high-speed handling problems caused by compressibility and poor airflow around the wing-fuselage intersection.

These difficulties were compounded by delays in turbo-supercharger production. It wasn’t until late 1941, just before US entry into WWII, that the first combat-ready P-38E versions became available. Development had taken four and a half years, nearly a year longer than America would be at war.

The production P-38E offered impressive performance: 395 mph at 25,000 ft, 500-mile normal range, 975-mile maximum range, and armament of one 20-mm cannon and four 0.50-in machine guns. Uprated engines (V-1710-49/53, -51/55, -89/91) led to subsequent P-38F to P-38H designations. Engine ratings increased, though the war emergency rating remained limited by cooling issues.

Armorer installing machine gun on Lockheed P-38 twin engine fighter aircraft

Alongside engine changes, progressively larger drop tanks were developed. A demonstration flight with 900 US gallons covered 2907 miles over 13 hours. The P-38’s exceptional range with external tanks became a crucial asset in the Pacific War.

The P-38J introduced significant engine cooling improvements, allowing more power and boosting combat performance at altitude. Earlier models struggled to fully utilize engine power due to inadequate intercoolers in the wing leading edge. The P-38J relocated intercoolers to larger chin intakes and improved tail boom radiators. This increased cruise power to 1100 hp at 32,500 ft and provided a 1600 hp war emergency rating at 26,500 ft. A clean P-38J reached 413 mph at 30,000 ft, and with 300-gallon drop tanks, its range exceeded 2000 miles.

Operationally, P-38s first deployed to Europe in July 1942 via North Atlantic ferry flights (“Operation Bolero”). Early P-38s transferred to the Mediterranean for the North Africa campaign and invasion of Italy. Fighting was intense, and while effective in combat, substantial losses occurred.

P-38 operations in the Pacific began in August 1942 from Port Moresby, New Guinea. The aircraft’s long range, aided by drop tanks, was invaluable for bomber escort and combat air patrols.

The arrival of the P-38J transformed its utility in Europe with greatly enhanced high-altitude performance. From early 1944, they served as long-range bomber escorts. Post-D-Day, P-38s joined low-altitude fighter sweeps targeting airfields and targets in occupied Europe. Some P-38Js were modified with a bombardier station for pathfinding on strike missions. The aircraft was also widely used for photo-reconnaissance (designated F-4A/B from P-38E/F, and F-5A/B from P-38G/J).

In air combat, the Lightning could be out-maneuvered by single-engine Luftwaffe fighters but used its speed, altitude performance, and heavy, centralized armament to achieve success, typically by diving attacks and avoiding turning fights. These tactics were especially successful in the Pacific against highly maneuverable but vulnerable japanese fighter aircraft. The top three USAAF aces of WWII – Major Richard I. Bong (40 victories), Major Thomas McGuire, and Colonel H. MacDonald – all achieved their scores in P-38s.

10,035 Lightnings of all variants were completed by the end of WWII. The P-38 saw continuous service, proving effective as a bomber escort, air defender, interdictor, strike, and reconnaissance platform. Used in all theaters, its greatest contribution was in the Pacific, but it also significantly impacted operations in North Africa, the Mediterranean, and Europe, cementing its place as a premier twin engine fighter aircraft.

[Bibliography: The American Fighter, E Angelucci and P Bowers, 1985; US Army Air Force Fighters Part 2 William Green and Gordon Swanborough, 1978; American Combat Planes, Ray Wagner, 1982]

1. de Havilland DH 98 Mosquito

The de Havilland Mosquito perhaps best embodies the ultimate realization of the “strategic fighter” ideal pursued by designers in the mid-1930s. The goal was a fast, heavily armed twin engine fighter aircraft with sufficient range for bomber escort, coupled with the speed, maneuverability, and firepower needed for air combat. Achieving these basic attributes would then open possibilities for additional roles.

The Mosquito’s outstanding capability stemmed primarily from the controversial decision to omit defensive armament. This not only reduced the crew to two but eliminated the weight, volume, and drag associated with defensive guns and a third crew member. This bold choice, combined with the availability of excellent, progressively developed Merlin engines and de Havilland’s expertise in wooden construction (unusual for a combat aircraft), led to the aircraft’s remarkable success.

Initially, four roles were foreseen: Bomber, Reconnaissance, and Day or Night fighter aircraft. Eventually, the Mosquito adapted to many more: Fighter-Bomber, Night Intruder, Pathfinder, Maritime Strike, Trainer, and Target Tug.

The design originated from specification P.13/36, calling for a twin-engine medium bomber with maximum cruising speed, suitable for reconnaissance. It required a 4000-lb bomb load and a 3000-mile range. De Havilland’s wooden, unarmed proposal was initially passed over for the Avro Manchester, but the concept of a high-speed, twin-engine, wooden bomber without defensive armament persisted. On December 29, 1939, approval was given for a prototype, followed by a contract for 50 bombers, later revised to 30 bombers and 20 fighter variants.

The bomber prototype first flew on November 25, 1940, the fighter prototype on May 15, 1941, and the reconnaissance prototype on June 10, 1941.

Bomber variants included the B Mk IV, VII, IX, XVI, XX, 25, and 35. Key variants were the B Mk IV (238 built) and the B Mk XVI (Merlin 72/3 or 76/7 engines, pressurized cockpit; 833 built), capable of carrying the 4000-lb “Cookie” bomb. Canadian-built B VII, XX, and 25 variants (Packard Merlin engines) totaled 670.

Mosquito bombers were extensively used by the Pathfinder Force, with some aircraft completing over 200 missions. Equipped with navigation aids like Oboe, H2S, Gee, or Loran, they served as target markers, significantly improving Bomber Command’s night bombing accuracy.

Initial Mk IVs carried four 500-lb bombs, but later aircraft could carry a 4000-lb bomb in a modified bay. B XVI Mosquitos, with two-stage Merlin supercharging and pressurized cockpits, were better suited for the 4000-lb bomb and capable of 419 mph at 28,500 ft. The bomber Mosquito’s speed, payload, and range made raids on Berlin a routine possibility.

Fighter-bomber variants were armed with four 20-mm cannons and four 0.303-in machine guns, plus internal bombs (typically two 250-lb) and external loads (two 500-lb bombs, external tanks, or 8 rocket projectiles). Variants included the FB VI, XVIII, 21, 24, 26, 40, and 42. The most important was the FB VI (2305 built), the most numerous Mosquito variant. Other major types were the Canadian FB 21 and Australian Mk 40 (212 built). The 27 Mk XVIII aircraft, converted FB VIs carrying a 57-mm cannon for anti-shipping, are also notable.

Fighter-bomber Mosquitos were capable, flexible, high-performance twin engine fighter aircraft widely used with distinction in roles like low-level precision bombing, night intrusion/interdiction, and anti-shipping across all theaters – Western Europe, North Africa, and the Far East.

Night-fighter roles were planned from the start. The second prototype was an NF II with AI Mk IV radar. Differences between night-fighter variants mainly involved powerplants and radar equipment.

Mosquito night-fighter variants included the Mk II, NF XII, NF XIII, NF XV, NF XVII, NF XIX, NF 30, NF 36, and NF 38. Significant types included the NF XII and XVII (Mk II conversions with AI Mk VIII and US AI Mk 10 centimetric radars), the Mk XIII (similar to XII but based on the FB VI airframe), and the NF XIX (Mk XIII with a ‘universal’ radome for US or UK radars). The NF 30, 36, and 38 were high-altitude night-fighters with two-stage Merlin engines; 794 were built, though NF 38s (101 built) were delivered post-war.

Beyond combat variants, eight Photo-reconnaissance variants were produced. The PR XVI was the most numerous (433 built), serving as a highly valued high-altitude platform for the RAF and US 8th AF. The PR 34 was a very long-range reconnaissance aircraft with additional internal and larger external tanks, capable of over 3500 miles range; 231 were built.

Five trainer marks were produced, with the T III being the most common (364 built). Target-tug conversions were also made. Post-war, Torpedo-capable Sea Mosquito TR 33 aircraft served with the Fleet Air Arm.

The Mosquito delivered everything expected and more. Its success across bomber, strike, night-fighter, and reconnaissance roles was enabled by the initial bold design decision to omit defensive armament, coupled with continuous engine development and advancements in radar/navigation systems.

7,871 Mosquitos were built, serving effectively from its first operational mission in September 1941 through the end of World War II and into the early 1960s. Its exceptional performance, versatility, and significant operational impact across multiple critical roles firmly establish the de Havilland DH 98 Mosquito as the top twin engine fighter aircraft of World War II.