Lippisch P.15

[Justo Miranda]

- Lippisch P.15​

The systematic bombing of the German industry forced the decentralisation of the aeronautical production in multitude of small plants and workshops that manufactured components.

The chaos produced in the Reich transportation systems during the last months of the war, broke the well ordered production schedule up: some spare parts were scarce, others did not arrive on time to the assembly lines and there was overstock of others.In March 1945 the LFA-Wien decided to make the most of the situation by designing the Frankestein airplanes, built with the surplus parts. The same panic fighter concept used in the design of the North American Fisher P.75 and the Boomerang in Australia.

The Volksjäger of Heinkel, conceived as a fighter cheap to manufacture in large quantities and easy to be operated by young inexperienced pilots, was to be a costly failure. The wooden wing was wrongly designed, the landing speed was excessive, the twin tailfin generated too much drag, penalising performances, and the fuselage design did not allow the installation of heavy guns.

On 4 March 1945, the Lippisch design team proposed to the OKL to create a special assembly centre in the Wiener Neustadt Works (WNF) destined to the manufacturing of the P.15 fighter Diana. It was an airplane easy to operate, as stable at low speed as the Komet, able to transport 30 mm guns and to fly faster and higher than the He 162, although being powered by the same engine.

The P.15 used the frontal three quarters of the He 162 fuselage - there was an excess of production in the Khala subterranean complex- the wooden wings of a Me 163 B –from which there were many spares- the tailfin of a Junkers 248, the electronics of a Me 262 and the undercarriage of Salamander. The WNF just should build the central section of the wing, the air intakes and the internal air ducts. The installed engine could be a Jumo 004, a BMW 003 or one of the new HeS 011.

Wind tunnel tests made with a 1:25 scale model proved that the airplane was stable up to a critical number of 0.84 Mach. The little experiment served to prove the concept was effective and Lippisch used it again for the design of the transoceanic version (P.15, 3 March 1945) that combines different elements used in the Messerschmitt projects on which Lippisch had cooperated.

The 52º swept wing was an adaptation from the one at the Me P1112 S/2 (3 March 1945) the air intakes were based on the LP13 and Me P1092 (16 July 1943) whereas the tailfin and the canopy came from the LP14 and LP12 respectively. The air came from the turbojet through the S shaped pipes that surrounded the cockpit, passing across the wing roots. The armament was reduced to just two MK 108/30 cannon in the wing roots and the electronic equipment would be the same than the one developed for the Ju 248.

Technical data Lippisch P.15 Diana (4 April 1945)​

Type single seat jet fighter

Wings wood structure and cladding, 23º swept, aspect ratio 5:1

Fuselage metallic structure and cladding, non-pressurised cockpit, Heinkel Kartusche ejector seat

Landing gear tricycle type, from the He 162

Engine one Junkers Jumo 004 or one BMW 003 rated at 800 kp or one HeS 011 rated at 1,300 kp static thrust.

Fuel tanks in the fuselage, behind the pilot

Armament two MK 108/30 cannons in the wing roots and two MG 151/20 cannon in the nose

Wingspan 10.08 m

Length 6.40 m

Wing area 20 sq.m

Max. speed (with HeS 011) Mach 0.84

Endurance (with HeS 011) 45 min

Technical data Lippisch P.15 (3 March 1945)​

Type transonic jet fighter

Wings 52º swept back and a 7º thickness/chord ratio, metallic structure and cladding

Fuselage integrated in the wing, pressurised cockpit, metallic structure and cladding,

Landing gear tricycle type, based on the Messerschmitt P1112 S/2 one

Engine one HeS 011 turbojet of 1,290 kp thrust.

Fuel tanks two in the wings

Armament two MK 108 cannons of 30 mm in the wing roots

Wingspan 7.80 m

Length 8.10 m

Height 2.90 m

Wing area 22 sq.m

Max. speed Mach 1

 

[iverson]

Justo: I have seen the projects in your most recent posts before, often in your drawings. But your added commentary makes these latest offerings truly fascinating. Thank you!

 

[Justo Miranda]

 

[Basil]

Justo,
the concept of project P 15 from February 1945 is basically well known (source: Lippisch: Ein Dreick fliegt; and others). It was to use the wings of the Me 163 C and the canopy of the He 162 and some other parts of aircrafts already in production. Production was indeed planned in the WNF.
However, your representation of the project of march 3, 1945 (52 degree swept wing, etc) is pure fantasy, isn't it?

 

[Justo Miranda]

Justo,
the concept of project P 15 from February 1945 is basically well known (source: Lippisch: Ein Dreick fliegt; and others). It was to use the wings of the Me 163 C and the canopy of the He 162 and some other parts of aircrafts already in production. Production was indeed planned in the WNF.
However, your representation of the project of march 3, 1945 (52 swept wing, etc) is pure fantasy, isn't it?

No

 

[Zizi6785]

 

[Basil]

Justo,
the concept of project P 15 from February 1945 is basically well known (source: Lippisch: Ein Dreick fliegt; and others). It was to use the wings of the Me 163 C and the canopy of the He 162 and some other parts of aircrafts already in production. Production was indeed planned in the WNF.
However, your representation of the project of march 3, 1945 (52 swept wing, etc) is pure fantasy, isn't it?

No

The sketch (383.jpg) is indeed an original Lippisch sketch - one of several for a design possibility of the P 15 (these different layouts can be regarded as a sort of Lippisch brainstorming).
Am I right that the attachment (615.jpg) in your post above (52 degree delta, wing of Messerschmitt P 1112, etc.) as well as the last paragraph in post #1 is pure phantasy? If so, it would be helpful to designate it as fictional or to post it under the topic "Discussion and Speculation".

 

[newsdeskdan]

Justo,
the concept of project P 15 from February 1945 is basically well known (source: Lippisch: Ein Dreick fliegt; and others). It was to use the wings of the Me 163 C and the canopy of the He 162 and some other parts of aircrafts already in production. Production was indeed planned in the WNF.
However, your representation of the project of march 3, 1945 (52 swept wing, etc) is pure fantasy, isn't it?

No

The sketch (383.jpg) is indeed an original Lippisch sketch - one of several for a design possibility of the P 15 (these different layouts can be regarded as a sort of Lippisch brainstorming).
Am I right that the attachment (615.jpg) in your post above (52 degree delta, wing of Messerschmitt P 1112, etc.) as well as the last paragraph in post #1 is pure phantasy? If so, it would be helpful to designate it as fictional or to post it under the topic "Discussion and Speculation".

I published all the drawings from Lippisch's 'brainstorming' session on the P 15 in Luftwaffe: Secret Designs of the Third Reich. The only known period data on the P 15 is a three-page project outline dated 'Vienna, March 4, 1945.' This lists the components as coming from the Me 163 C (wings), He 162 (cockpit and main undercarriage - the He 162's own undercarriage having come from the Bf 109 G), Me 163 B (controls). The introduction mentions Ju 248 bzw. 263 components but none are actually cited as being included.
There is no known contemporary drawing of how those bits were meant to fit together, though Lippisch apparently had one drafted in the 1970s for inclusion in his book Ein Dreieck Fliegt.
There is no data at all for Lippisch's hand-drawn sketches, which accompany the project outline on the microfilm reel where it is recorded, and which do indeed appear to be rather fantastical. There is certainly nothing anywhere to suggest that Lippisch was even aware of the Messerschmitt P 1112, let alone that he intended to include components from it in his P 15 design. Assuming that the P 15 sketches were made before March 4, 1945 (the fantasy being presumbly rejected in favour of something made from existing bits, which was then described in the March 4 report), it may in fact pre-date the P 1112 entirely.
The P 1112 was brought into being following the selection of the P 1111 as the 'optimal solution' next-gen single jet fighter during the Feb 27-28 1-TL-Jaeger comparison meeting (with the Focke-Wulf Nr. 279 design, aka Entwurf Multhopp, aka Huckebein being selected as the 'immediate solution').
Messerschmitt's designers quickly realised, post-meeting, that the P 1111 design was unworkable and therefore set about correcting its flaws in the P 1112. So Lippisch, based in Vienna, would have had to travel to Messerschmitt's Oberammergau offices between Mar 1 and Mar 4 (a 10-hour round trip away via modern roads), been given access to see the company's top secret drawings just as they were being made (one is dated March 3), and then been so confident that this brand new design would enter production in exactly the form of the first sketch that he wanted to base his P 15 on it. He would then have had to race back to Vienna in time to meet Knemeyer, have a brainstorming session, then create the P 15 project outline the following day. If this did happen, nobody mentions it.
Alternatively, Knemeyer might have grabbed the drawing from Messerschmitt's designers on March 3 then raced over to meet Lippisch the following day and handed it to him - another highly unlikely (since Knemeyer didn't want something that looked like the P 1112 - he wanted something quick and easy to make from existing bits) though technically not impossible scenario.
It seems more likely to me that the P 15 sketches were simply products of Lippisch's own imagination, drawing on his many earlier tailless designs. As far as I'm aware, not only was there never a production order for the P 1112, but no final design for it - particularly for its wings - had even been selected by the time the war ended.

 

[Basil]

I totally agree.
Therefore - as already discussed earlier - it would be helpful especially for the less specialized forum readers if fictional drawings or fictional text passages are marked as such or placed in the suitable forum section.