Experimental

Junkers Ju 390 New York Blitz Bomber

The Junkers JU-390 had the potential to extend the terror of the London Blitz to New York City. Although several prototypes were constructed and underwent testing, they were never deployed in combat.

Ultimately, the program didn’t succeed, but the concept of a transatlantic “New York Bomber” was intriguing. Had it been successful, it might have significantly influenced the course of the war, both tactically and psychologically.

There are questions about how Germany might have used such capability: whether they would have initiated a bombing campaign against American cities, or even if they could have been equipped to deliver nuclear weapons.

Contents

Development and Design

This aircraft emerged from a critical juncture in aviation history, where the quest for range and payload capacity shaped the design philosophies of military aircraft.

The Ju 390’s genesis was directly tied to the ambitious ‘Amerika Bomber’ project, an initiative aimed at developing a long-range strategic bomber capable of reaching the United States from Europe.

Read More: Lockheed CL-760 LARA Cold War Failure

The rationale behind this project was strategic and psychological – to extend the reach of the Luftwaffe to American soil, thereby altering the course of the war or at least its perceived trajectory.

The Ju 390 was an enlargement of the Ju 290, which in turn was based on the earlier Ju 90.
The Ju 390 was an enlargement of the Ju 290, which in turn was based on the earlier Ju 90.

In designing the Ju 390, Junkers engineers built upon the existing framework of the Ju 290, which itself was an enlargement of the earlier Ju 90 commercial airliner. This approach was partly dictated by the constraints of time and resources; developing an entirely new aircraft from scratch would have been more time-consuming and resource-intensive.

Read More: Fieseler Fi 167 Built for Carrier “Graf Zeppelin”

The Ju 390 was thus envisioned as an extended-range, enlarged version of the Ju 290, incorporating significant modifications to meet the extraordinary range requirements of the Amerika Bomber program.

The most striking feature of the Ju 390 was its size. It was one of the largest aircraft designs of its time, necessitated by the need to carry sufficient fuel for transatlantic flights.

Heavy Bomb Loads

The aircraft’s wingspan was extended significantly compared to the Ju 290, allowing for the installation of additional fuel tanks. This extension not only increased fuel capacity but also improved the aircraft’s overall lift, essential for carrying heavy bomb loads over long distances.

Powering the Ju 390 was a configuration of six engines. This multi-engine setup was crucial for providing the necessary thrust and range.

The Ju 390 was designed as part of the 'Amerika Bomber' project, intended to create a bomber capable of reaching the United States from Europe.
The Ju 390 was designed as part of the ‘Amerika Bomber’ project, intended to create a bomber capable of reaching the United States from Europe.

However, it also added complexity to the aircraft’s design and maintenance. The engines chosen were likely variations of the reliable BMW or Jumo engines used in other German aircraft, known for their power and relative efficiency.

Another design aspect of the Ju 390 was its defensive armament. Given its mission profile of deep penetration into enemy territory, the aircraft needed to be capable of defending itself against intercepting fighters.

Read More: Fieseler F 3 Flying Wing From 1932

As such, it was equipped with multiple machine guns and cannon positions, although the exact armament varied between prototypes and proposed designs.

The Ju 390’s design also had to account for the challenges of long-range navigation and crew endurance. The aircraft was equipped with advanced (for the time) navigation equipment, and the crew compartment was designed to accommodate the needs of the crew on extremely long missions. Comfort and operational efficiency for the crew were considerations, given the duration of the planned transatlantic flights.

Prototype and Testing

During World War II, the urgency of producing an effective long-range bomber led to a rapid development process, and the Ju 390 prototypes were central to this effort.

Two prototypes of the Ju 390 were constructed, each serving different purposes and undergoing various testing regimes. The first prototype, known as the Ju 390 V1, was essentially a modified version of the Ju 290.

The Ju 390 had an exceptionally large wingspan to accommodate additional fuel for long-range flights.
The Ju 390 had an exceptionally large wingspan to accommodate additional fuel for long-range flights.

It was constructed by extending the fuselage and wings of the Ju 290, thereby creating the necessary space for additional fuel storage and the required six-engine configuration. This prototype was intended to test the basic airworthiness and performance capabilities of the design, particularly its extended range and heavy payload capacity.

Read More: XFV-12 Designed to Take on the British

The Ju 390 V1’s maiden flight in 1943 marked a significant milestone in the project. Initial flight tests were focused on assessing the aircraft’s handling characteristics, stability, and engine performance.

Given the aircraft’s size and complexity, these initial tests were crucial in determining the feasibility of the design. The flight tests also aimed to identify any aerodynamic issues arising from the modifications, such as changes in the aircraft’s center of gravity or structural integrity under different flight conditions.

Beyond basic flight testing, the Ju 390 V1 reportedly undertook a long-range test flight that, according to some sources, brought it near the U.S. and Canadian coastlines.

Even Longer Wingspan

This flight, if it indeed took place, would have been a bold demonstration of the aircraft’s range capabilities, though the details and veracity of this mission remain a topic of historical debate and speculation.

Read More: Clark Gable Served & Flew Combat Missions 

The second prototype, the Ju 390 V2, was constructed as a dedicated long-range reconnaissance aircraft. It featured further modifications from the V1, including an even longer wingspan and increased fuel capacity.

It was powered by six BMW or Jumo piston engines.
It was powered by six BMW or Jumo piston engines.

The purpose of the V2 was to test the aircraft’s suitability for long-range maritime reconnaissance missions, a role that became increasingly important as the war progressed. This prototype was equipped with specialized reconnaissance equipment, including cameras and advanced (for the time) sensory devices.

The testing of the Ju 390 V2 involved evaluating its endurance and effectiveness in simulated reconnaissance missions over the Atlantic. These tests were critical in determining the aircraft’s operational potential in detecting and monitoring Allied shipping convoys, a key strategic objective for the German military at that time.

Read More: Gloster Meteor F8 Fighter “Prone Position”

The V2’s tests also provided valuable data on the aircraft’s performance under different weather conditions and over extended periods, which were essential for its intended role.

Throughout the testing phase, both prototypes of the Ju 390 faced numerous challenges. The complexity of the aircraft’s design and the need for long-range performance placed considerable demands on its airframe, engines, and crew. Moreover, the rapidly changing circumstances of the war meant that resources and priorities were constantly shifting, impacting the extent and focus of the testing program.

Ju 390 Operational History and Performance

Despite its potential as a long-range aircraft, the Ju 390’s actual deployment and performance were constrained by the broader context of the war and the limitations inherent in its design.

Read More: Conroy Tri-Turbo-Three

The Ju 390 V1, the first prototype, saw a limited operational history. After its initial test flights, which were focused on assessing its flight characteristics and technical capabilities, there were plans to utilize this prototype for extended range testing, including the possibility of long-range reconnaissance or even direct combat missions.

It was designed to have a range of over 9,500 kilometers (5,900 miles), sufficient for transatlantic missions.
It was designed to have a range of over 9,500 kilometers (5,900 miles), sufficient for transatlantic missions.

However, the extent to which the V1 was used operationally is not extensively documented. There are unconfirmed reports, often surrounded by myth, that the Ju 390 V1 may have undertaken a reconnaissance flight that approached the North American coastline, but these claims are not substantiated by concrete historical evidence.

Read More: Focke-Wulf Fw 189c was Unique & Obscure

The second prototype, the Ju 390 V2, was more focused on reconnaissance roles, particularly maritime surveillance. Its operational use was primarily centered around testing its effectiveness in long-range maritime reconnaissance missions over the Atlantic Ocean.

These missions were aimed at identifying and tracking Allied shipping convoys, which were crucial to the Allied war effort. The V2’s enhanced fuel capacity and extended wingspan were specifically designed to increase its endurance and range for these missions. However, like the V1, the operational use of the V2 was limited and curtailed by the deteriorating war situation for Germany.

Ju 390 Impressive Range

In terms of performance, the Junkers Ju 390 demonstrated impressive long-range capabilities, which were its primary design objective. The aircraft’s range was estimated to be over 9,500 kilometers (5,900 miles), enough to potentially conduct transatlantic flights.

Read More: Me 609 the Concept Heavy Fighter

This extraordinary range was a significant achievement, considering the technological limitations of the time. However, the actual combat effectiveness and operational reliability of the Ju 390 in a wartime context remained largely untested.

After the war, the Ju 390's technological innovations influenced long-range aircraft design in both military and civilian aviation.
After the war, the Ju 390’s technological innovations influenced long-range aircraft design in both military and civilian aviation.

The aircraft’s size and complexity presented several challenges. Its massive airframe and six-engine configuration made it a substantial target for enemy fighters and anti-aircraft defenses.

Although it was equipped with defensive armaments, these were unlikely to be sufficient against well-coordinated enemy attacks, especially during extended missions far from friendly forces. Additionally, the maintenance and operational demands of such a large and complex aircraft were significant, posing logistical challenges.

Read More: The X-44 Manta: Revolutionising Aerial Warfare

Another factor affecting the Ju 390’s operational history was the shifting priorities within the German military-industrial complex.

As the war progressed and Germany’s strategic position weakened, resources and focus were redirected towards more immediate and pressing needs, such as fighter aircraft and defensive technologies. This shift meant that ambitious projects like the Ju 390 were deprioritized and eventually sidelined.

Technical Challenges and Limitations

The Junkers Ju 390 project, while ambitious in its scope, encountered several technical challenges and limitations that significantly impacted its development and potential operational effectiveness.

These challenges were reflective of the complex nature of designing and producing an advanced, long-range aircraft under the pressing conditions of World War II.

Read More: Grumman AF Guardian Crucial Role

One of the primary technical challenges faced by the Ju 390 was its sheer size and the complexity that came with it. The aircraft’s extended wingspan and enlarged fuselage, necessary for the increased fuel capacity required for transatlantic flights, resulted in a significantly heavier and more cumbersome aircraft.

It required a large crew, typically around ten people, to operate due to its size and complexity.
It required a large crew, typically around ten people, to operate due to its size and complexity.

Managing the aerodynamic and structural stresses on such a large airframe was a considerable engineering challenge. The increased weight also demanded more powerful engines to ensure adequate performance, which in turn added to the complexity of the aircraft’s design and maintenance.

The six-engine configuration of the Ju 390 presented its own set of challenges. While multiple engines were essential for the required range and payload, they also introduced increased maintenance demands and mechanical complexity.

Read More: The He 111Z, a Tug for the Me 321 Cargo Glider

Ensuring the reliability of six engines on long-duration flights was a significant concern, as engine failure could have dire consequences, especially over vast oceanic distances where emergency landings were not feasible.

Ju 390 15-Hour-Plus Flights

Another technical limitation was the aircraft’s vulnerability to enemy interception. Due to its size, the Ju 390 was a large and relatively slow target, making it susceptible to Allied fighter aircraft and anti-aircraft artillery.

While it was equipped with defensive armaments, these were unlikely to be sufficient to fend off determined attacks by smaller, more agile fighters. The aircraft’s long mission duration and the distances involved also made it challenging to provide adequate fighter escort throughout the entirety of its flights.

P-75 Eagle – The Unstable Interceptor

Moreover, the Ju 390’s design did not adequately address the issue of crew endurance for extremely long missions. The physical and psychological strain on the crew during potentially 15-hour-plus flights, with the constant threat of enemy interception, was a significant concern.

The first prototype, Ju 390 V1, made its maiden flight in 1943.
The first prototype, Ju 390 V1, made its maiden flight in 1943.

The aircraft needed to be equipped with not just the necessary navigation and communication equipment for such long missions, but also provisions for the basic needs and comfort of its crew.

Resource constraints were another critical limitation. As the war progressed, Germany faced increasing shortages in materials, fuel, and skilled labor.

Read More: Martin P-6M SeaMaster – The End of Martin

These shortages impacted the Ju 390 project, as did the competing demands of other military projects that were deemed more critical to the immediate war effort. The result was a lack of focus and resources necessary to fully address the technical challenges and bring the Ju 390 to full operational status.

Lastly, there were strategic limitations to the concept behind the Ju 390. The idea of bombing the United States was more a psychological weapon than a feasible military strategy. The logistical challenges of mounting such operations, coupled with the limited number of aircraft that could be produced and the risks involved, made it an impractical endeavor in the broader context of the war.

Strategic Implications

As a part of the ambitious ‘Amerika Bomber’ project, the Ju 390 was more than just an aircraft; it was a symbol of Nazi Germany’s aspiration to extend the reach of its military power and influence the strategic landscape of the war.

Read More: Grumman F6F Hellcat – Big Cat, Sharp Teeth

The primary strategic intention behind the Ju 390 and the Amerika Bomber program was to develop a capability for long-range bombing missions against the United States. This goal was rooted in the hope of impacting American morale and forcing the U.S. to divert military resources to homeland defense.

The mere possibility of German aircraft reaching American cities was intended to create a psychological impact, sowing fear and uncertainty far from the European battlefields.

However, the strategic value of the Ju 390 and its potential impact on the war were subject to considerable debate. While the idea of striking the U.S. mainland was a powerful propaganda tool, the practicality of such missions was questionable.

Read More: Focke-Wulf Ta 152 – FW 190 But Better?

The logistical challenges of mounting long-range bombing missions across the Atlantic were immense, involving not only the technical capabilities of the aircraft but also issues of navigation, crew endurance, and the risk of interception by Allied forces.

Ju 390 Resource Shortages

Moreover, the Ju 390’s development came at a time when Germany was increasingly on the defensive. The resources required for the production and operation of such a complex aircraft were enormous, and by the time the Ju 390 was being tested, Germany was facing significant resource shortages and competing military priorities.

This raised questions about the allocation of scarce resources to a project that, while strategically ambitious, offered uncertain returns in the face of pressing needs on various fronts.The strategic implications of the Ju 390 also extended to the broader context of aerial warfare and long-range bombing strategies.

Read More: Dornier Do 24 – The Plane That Fought On All Sides

The project highlighted the growing importance of air power in determining the outcome of the war and the continuous push for technological advancements in aviation. However, it also underscored the limitations and risks associated with overly ambitious military projects, especially in a rapidly changing war environment.

Furthermore, the Ju 390’s development and the Amerika Bomber program as a whole can be seen as reflecting the broader strategic mindset of the Nazi leadership, characterized by grandiose ambitions and a willingness to invest in high-risk, high-reward projects.

This approach, while yielding some notable technological advancements, often led to impractical and resource-intensive endeavors that did not always align with the realities of Germany’s strategic situation as the war progressed.

Ju 390 Post-War Legacy

Its legacy, while overshadowed by more successful aircraft of the era, provides insights into the evolution of long-range aviation technology and the broader implications of wartime engineering efforts.

Read More: The V-1 Flying Bomb, Was it Really a Menace?

In the post-war period, the Ju 390’s influence could be seen in the continued interest in developing long-range bombers and reconnaissance aircraft. The concept of an aircraft capable of flying vast distances with significant payload capacities remained a strategic priority for many nations during the Cold War.

The technological challenges and lessons learned from the Ju 390 project, such as managing the complexities of large, multi-engine aircraft and maximizing fuel efficiency for extended range, informed subsequent designs in both military and civilian aviation sectors.

Moreover, the Ju 390 contributed to the understanding of the logistical and operational challenges associated with long-range flight operations.

Allied Powers

Its development highlighted the importance of factors such as crew endurance, navigation over vast uncharted territories, and the maintenance demands of large aircraft. These aspects became crucial considerations in the design and operation of post-war long-range bombers and transport aircraft.

Read More: P-39 Airacobra – An Unconventional Fighter

The Ju 390 also had an indirect impact on post-war aviation through the dispersion of German aviation technology and expertise. After the war, Allied powers, notably the United States and the Soviet Union, absorbed much of the technological and intellectual capital from the German aviation industry.

Engineers and technologies that had contributed to projects like the Ju 390 were integrated into post-war aviation development programs, influencing the design of a new generation of aircraft.

From a historical perspective, the Ju 390 serves as a poignant reminder of the ambition and scale of Nazi Germany’s military projects. It stands as an example of how wartime conditions can accelerate technological advancements, but also how these advancements can be curtailed by the realities of resource constraints and shifting strategic priorities.