Some aircraft projects become famous because they flew. Others are remembered because they show how far designers were willing to push an idea. The Lippisch P.15 belongs to that second category.
With its striking appearance and uncompromising design character, the P.15 reflects the atmosphere of late-war German aviation, when ambitious concepts were being explored under extraordinary technical and strategic pressure. It is a fascinating example of how aerodynamic thinking, military requirements and industrial improvisation could collide in a single aircraft project.
The Lippisch P.15 “Diana”: Germany’s Frankenstein Jet Interceptor
An in-depth technical development and historical blog profile
In the final, agonizing months of World War II, Nazi Germany’s aviation industry was in a state of utter chaos. Under relentless Allied strategic bombing, regular aircraft production lines were shattered, supply chains were virtually non-existent, and critical materials such as aluminium and high-grade alloys were scarcer than ever.
Yet, out of this desperation emerged the Emergency Fighter Program, or Jägernotprogramm, a final radical initiative aimed at producing cheap, high-performance jet interceptors capable of breaking through the Allied bomber fleets. It was during this twilight period, in March 1945, that the aerodynamicist Dr. Alexander Lippisch and Colonel Knemeyer conceived the Lippisch P.15, also known as the Diana.
The “Frankenstein” Production Strategy
The most remarkable aspect of the Lippisch P.15 was not only its futuristic aerodynamic profile, but also its industrial strategy. There was no time or material available to design, tool and test completely new airframe components. Instead, Lippisch designed the P.15 as a composite vehicle, combining components and production knowledge associated with aircraft already moving through existing assembly lines.
- Wings and tail structure: Borrowed directly from the rocket-powered Messerschmitt Me 163C Komet. Because Lippisch’s central fuselage section was wider than the original rocket body, the overall wingspan was slightly extended, altering the roll characteristics and total lifting surface.
- Nose and forward fuselage: Adapted from the Heinkel He 162 Volksjäger. This approach would have allowed the cockpit layout, instrumentation and canopy-production knowledge to be used without beginning the pilot-survival and forward-fuselage design process from scratch.
- Landing gear system: Intended to use a retractable undercarriage derived from the mass-produced Messerschmitt Bf 109. This would have represented a major operational change from the dangerous, unguided landing skids associated with the Me 163, allowing the P.15 to operate from conventional runways.
Aerodynamics, Air Intakes and Propulsion
Dr. Lippisch was a pioneer of delta-wing and tailless aircraft design. The P.15 embodied that vision through a highly streamlined, tailless swept-wing planform intended to reduce drag and simplify the aircraft’s external form.
Unlike the volatile Walter rocket motor powering the Komet, the P.15 was designed around a conventional, albeit highly advanced, air-breathing powerplant: the Heinkel HeS 011A turbojet engine. The engine was deeply buried inside the rear central fuselage to preserve a clean aerodynamic shape.
To feed air to the concealed turbojet, Lippisch engineered two sharp, triangular intakes blended into the wing roots. The arrangement was intended to minimise parasite drag while directing airflow towards the compressor stage of the HeS 011 engine.
Projected Technical Data and Performance
The figures below are projected or estimated values associated with the proposed design. They should be read as historical reference data, not as verified flight-test results or approved airworthiness information.
| Parameter | Estimated value or specification |
|---|---|
| Aircraft classification | Single-seat jet interceptor fighter |
| Powerplant options | 1 × Heinkel HeS 011A turbojet, approximately 1,300 kg / 2,866 lb thrust |
| Planned wingspan | 10.08 metres / 33 ft 1 in |
| Fuselage length | 6.40 metres / 21 ft |
| Heavy nose armament | 2 × 30 mm MK 108 autocannons in a nose-mounted capsule |
| Heavy wing armament | 2 × 30 mm MK 108 autocannons at the wing roots |
| Estimated top speed | Approximately 950–1,000 km/h / 590–621 mph |
Historical Fate: A Final “Paper Project”
The final blueprints for the Lippisch P.15 “Diana” were reportedly completed between April and May 1945, as the Soviet Red Army breached Berlin and American forces overran industrial centres in central Germany. Although senior commands had tentatively ordered prototype construction from the Weserflug company, the collapsing regime ran out of time.
No structural components were completed and no mock-up was constructed. The aircraft remained entirely on paper, making it a quintessential entry in the speculative “Luft ’46” aviation genre and a striking example of the desperate design solutions considered during the final months of the war.
Following the war, Dr. Lippisch’s extensive work on tailless swept wings was captured by the United States under Operation Paperclip. His design principles influenced the development of early American delta-wing aircraft, most notably the Convair XF-92, and contributed to the wider development path that led to aircraft such as the F-102 Delta Dagger and F-106 Delta Dart.
In this video, we look at the story behind the Lippisch P.15, the ideas that shaped it and the reasons it has earned such a memorable place in aviation history.
Historical reference material from Online Aviation Library. This article is not current approved airworthiness data.