Two Minute Read, WWII

The Dornier Do 335 was a Bomber & Bomber Hunter

The Dornier Do 335, nicknamed “Pfeil” (Arrow), stands out due to its unique push-pull configuration. This innovative design featured two engines mounted along the centerline, with one at the front and one at the back, providing distinct advantages over conventional single-engine fighters of its era.

The arrangement allowed the Do 335 to achieve higher speeds and provided better power efficiency, setting it apart from its contemporaries.


Development of the Arrow

The design deviated significantly from typical fighter aircraft of its time, primarily due to its push-pull engine configuration. This setup incorporated one engine in the nose and another at the rear of the fuselage, each driving its own propeller.

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The front engine drove a conventional tractor propeller, while the rear engine, located behind the cockpit, drove a pusher propeller at the tail via an extended driveshaft that passed through the fuselage. This configuration effectively eliminated the torque and gyroscopic effects common in single-engine fighters, leading to exceptional handling characteristics.

Front view Do 335
The Do 335’s 30 mm cannon fired through the aircraft’s nose cone.

Aerodynamically, the Do 335 was a step ahead with its sleek, streamlined fuselage that reduced drag and improved speed. The aircraft’s structure was a blend of a metal frame with a fabric-covered rear fuselage and wooden wing panels.

Its tricycle landing gear, a relatively unusual feature at the time, allowed for better ground handling and visibility on takeoff and landing.

Unrivalled Performance

Performance-wise, the Do 335 was remarkable. Powered by two Daimler-Benz DB 603A engines, each capable of producing up to 1,750 horsepower, the Do 335 reached top speeds that surpassed almost every other piston-engine fighter of the era.

It could climb to 26,250 feet in just under 15 minutes and had a maximum speed of around 474 mph (763 km/h), which was exceptional for a piston-engine aircraft.

For armament, the Do 335 was heavily equipped with one firing 30 mm MK 103 cannon mounted in the forward engine’s propeller hub and two 15 mm MG 151/15 cannons mounted in the wings.

This made it a formidable adversary in air-to-air combat. Additionally, it could carry up to 1,000 kg of bombs, enhancing its role versatility as a fast attack bomber.

The standard armament included the MK 108 30mm cannon - the Pneumatic Hammer. Photo credit - Gaijin War Thunder.
The standard armament included the MK 108 30mm cannon – the Pneumatic Hammer. Photo credit – Gaijin War Thunder.

Operational history of the Do 335 was limited due to its late introduction during the war. The German Luftwaffe received the first production aircraft only in late 1944. By the war’s end, fewer than 40 of these aircraft had been completed, including prototypes, pre-production, and production units.

They were tested in various roles, from intercepting high-altitude reconnaissance missions to ground attacks. However, the full potential of the Do 335 was never realized in combat due to the rapidly deteriorating war conditions for Germany.

Post-war, the Allied forces evaluated the captured Do 335s, noting their advanced design and performance characteristics. Despite its limited use, the Do 335 influenced post-war aircraft design, particularly in the exploration of push-pull configurations and advanced aerodynamics.

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Operational History

By late 1944, the Luftwaffe was in dire straits, with dwindling resources and mounting losses. Amidst these challenges, the Do 335 was put into limited production, with approximately 37 units built, including pre-production models. Only a handful of these aircraft reached operational units.

One of the few units to actively test the Do 335 was the Erprobungskommando 335, a special evaluation squadron based at Rechlin, the Luftwaffe’s main testing facility.

The powerful engines gave the 335 a higher top speed than any contemporary Allied fighter.
The powerful engines gave the 335 a higher top speed than any contemporary Allied fighter. Photo credit – Gaijin War Thunder

The primary operational use of the Do 335 during the war included conducting a few reconnaissance and test missions. Given its speed, which allowed it to outrun any Allied fighter, the Do 335 was ideally suited for fast reconnaissance.

Moreover, it served as an interceptor. However, the chaotic situation at the end of the war and the limited number of aircraft available prevented any significant combat deployment. Many planned missions were either aborted due to mechanical issues or because of the rapid advance of Allied ground forces.

The Pfeil Never Engaged Allied Fighters

Despite being designed as a high-speed interceptor, there are no documented instances where the Do 335 engaged directly with enemy aircraft in a dogfight.

Its missions were predominantly focused on high-speed test flights, and there are anecdotal references to its involvement in interception missions against Allied bomber formations. However, the exact details of these missions are not well recorded, and it appears the Do 335 did not achieve any confirmed air-to-air victories.

In addition to the standard fighter and reconnaissance roles, there were attempts to utilize the Do 335 in a ground attack capacity. The aircraft’s ability to carry a significant payload made it suitable for such missions, but again, these efforts did not materialize into significant operational use due to the end of the war.

A captured Do 335 in American service for evaluation purposes and now the only  remaining example.
A captured Do 335 in American service for evaluation purposes and now the only remaining example.

Allied Capture

The impending defeat of Germany led to the capture of several Do 335s by Allied forces. Notably, American, British, and French technical squads were keen to study the advanced technology of the Do 335.

After a thorough evaluation, including flight tests by Allied pilots, the aircraft were recognized for their advanced design and performance, although they also noted some reliability issues with the complex engine setup.

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Ejection Technology

In most aircraft, the pilot’s ejection path is clear of obstructions. However, in the Do 335, the rear-mounted engine and its associated propeller presented a potentially lethal hazard for a traditional bailout procedure. To mitigate this risk, the aircraft incorporated an innovative and complex ejection system.

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This system integrated several components to ensure pilot safety during ejection. Primarily, it employed an explosive bolt mechanism that would first jettison the rear propeller. Activating the ejection sequence would detonate these bolts, releasing the propeller blades and thus clearing the path behind the cockpit.

Following the detachment of the rear propeller, the pilot could then safely eject upwards and out of the aircraft without the risk of striking the still-spinning propeller.

The Do 335 utilised pilot ejection technology.
The Do 335 utilised pilot ejection technology.

The ejection seat itself was a conventional design for the era but was adapted to include an additional set of explosive charges that would blow the canopy clear off the aircraft just before the seat was ejected.

This sequence of events had to be perfectly timed to ensure that the propeller was clear, the canopy was no longer in place, and the seat could then propel the pilot upward to safety.

The development and implementation of this ejection system underscored the innovative but complex nature of the Do 335’s design. Such a system was necessary due to the aircraft’s unique layout and operational requirements, and while it added safety features that were cutting-edge at the time, it also introduced additional mechanical and procedural complexities.

Testing and perfecting this ejection system under combat conditions would have been challenging, and the system’s reliability was critical for the pilot’s survival during an emergency.

The Do 335 Wasn’t Perfect

Pfeil, while innovative and advanced for its time, faced several design challenges and limitations that hindered its effectiveness and operational potential. One of the primary drawbacks of the Do 335’s design was its complexity, particularly the push-pull engine configuration.

This setup, while beneficial for reducing aerodynamic drag and improving speed, made the aircraft mechanically complicated. Maintenance and repairs were more difficult and time-consuming than on more traditional single-engine aircraft, which could be a significant disadvantage in the fast-paced environment of wartime operations.

This was the ideal scenario for the 335. Bomber hunting.
This was the ideal scenario for the 335. Bomber hunting. Photo credit – Gaijin War Thunder.

Another significant issue was the cooling system for the rear engine. Placing an engine in the rear required an intricate system of ducts to ensure adequate airflow for cooling.

This arrangement was prone to problems, especially in combat scenarios where damage could easily compromise the cooling system, leading to engine overheating and potential failure.

The aircraft’s weight also contributed to its challenges. The Do 335 was heavier than many contemporary fighters, largely due to its twin-engine configuration and the robust framing needed to support it. This weight impacted its agility, making it less manoeuvrable than lighter single-engine fighters, which could be a critical disadvantage in dogfights.

Visibility from the cockpit was another concern. The rear engine’s placement and the aircraft’s wide fuselage obstructed the pilot’s rearward view, which is a critical aspect during aerial combat and landing approaches.

Why Did the Do 335 Never See Mass Production?

The Dornier Do 335 was never put into larger-scale production due to a combination of factors stemming from both its late development during World War II and external wartime conditions impacting Germany. One of the primary reasons was the timing of its introduction.

By the time the Do 335 was ready for potential mass production, Germany was facing significant resource shortages and strategic challenges. These included a critical lack of materials and fuel, as well as the constant bombardment of industrial facilities by Allied forces, which severely disrupted manufacturing capabilities.

Moreover, the complexity of the Do 335’s design contributed to its limited production. Its innovative push-pull configuration, while offering notable advantages in speed and power, required sophisticated manufacturing processes that were not only time-consuming but also more expensive compared to simpler, more established aircraft designs.

This complexity made it less attractive in a wartime scenario where speed and volume of production were crucial.

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Additionally, the Luftwaffe had begun to shift its priorities towards jet-powered aircraft by the time the Do 335 was being evaluated for mass production. Jet technology promised greater advancements in speed and performance that were seen as more crucial for countering Allied air superiority.

This shift in focus resulted in resources being reallocated away from propeller-driven designs like the Do 335 to more revolutionary jet fighters such as the Messerschmitt Me 262.

Lastly, the overall deteriorating war situation for Germany reduced the feasibility of introducing new aircraft types into large-scale production. With the war drawing to a close and Germany increasingly on the defensive, there was little opportunity to integrate and utilize a new aircraft type effectively within the remaining timeframe.