What if? Heinkel He 100 G-2; "10+ Rot"; 2. Gruppe, I./JG 4; Mizil, Romania; Sep. 1944

[dizzyfugu]

Teil 2 der He 100 Experimente - denn mit "the Jägermeister" (http://www.phoxim.de/forum/index.php?topic=9787.0) war es nicht getan. 

Kaum hatte ich die Bilder auf FlickR gepostet war ein Modellbauer aus Kanada (Handle "Franclab") inspiriert, über Nacht ein Profil einer fiktiven He 100 anzulegen, quasi als inspirierte Antwort:




Wer sich auskennt: diese "G"-Version hat es nie gegeben, das Cockpit stammt von einer FW 190, und Anstrich und Markierungn sind auch fiktiv... dennoch, sehr subtil. DAS fand ich wiederum so toll, dass ich kurzerhand mit dem Bau eben dieser Maschine begann! Und dies ist binnen einer Woche daraus geworden... 




Some background:
Following the RLM’s selection of the Bf 109 as its next single-seat fighter (beating Heinkel’s He 112, based on a tactical requirement dating back to 1933), Ernst Heinkel became interested in a new fighter that would leap beyond the performance of the Bf 109 as much as the Bf 109 had over the biplanes it replaced. Other German designers had similar ambitions, including Kurt Tank at Focke-Wulf. There was never an official project on the part of the RLM, but new designs were important enough to fund projects from both companies to provide "super-pursuit" designs for evaluation. This would result in the single-engined He 100 fighter, and the promising twin-engine Fw 187 Falke Zerstörer-style heavy fighter.






The He 100 was a radical, new approach with the aim of ultimate performance in a simple airframe. Walter Günter, one half of the famous Günter brothers, looked at the existing He 112, which had competed against the Bf 109 in 1936 and already been heavily revised into the He 112B version. Looking at the aircraft’s potential he decided it had reached the end of its evolution. So he started over with a completely new design, called "Projekt 1035".

Learning from past mistakes on the 112 project, the design was to be as easy to build as possible, yet 700 km/h (440 mph) was a design goal. To ease production, the new design had considerably fewer parts than the 112 and those that remained contained fewer compound curves. In comparison, the 112 had 2,885 parts and 26,864 rivets, while the P.1035 was made of 969 unique parts with 11.543 rivets. The new straight-edged wing was a source of much of the savings; after building the first wings, Otto Butter reported that the reduction in complexity and rivet count (along with the Butter brothers' own explosive rivet system) saved an astonishing 1.150 man hours per wing.






The super-pursuit type was not a secret, but Ernst Heinkel preferred to work in private and publicly display his products only after they were developed sufficiently to make a stunning first impression. As an example of this, the mock-up for the extremely modern-looking He 100 was the subject of company Memo No.3657 on 31 January that stated: "The mock-up is to be completed by us... as of the beginning of May... and be ready to present to the RLM... and prior to that no one at the RLM is to know of the existence of the mock-up."

In order to get the promised performance out of the aircraft, the design included a number of drag-reducing features. On the simple end were a well-faired cockpit and the absence of struts and other drag-inducing supports on the tail. The landing gear (including the tail wheel) was retractable and completely enclosed in flight.






The He 100 was based on the DB 601 power plant, the same engine as the Bf 109 (and also used in the Bf 110 heavy fighter). In order to achieve the designed performance increase, drag reduced as well as weight and frontal area: the engine was mounted directly to the forward fuselage, which was strengthened and literally tailored to the DB 601, as opposed to conventional mounting on engine bearers. The cowling was very tight-fitting, and as a result the aircraft had something of a slab-sided appearance.

Walter turned to the somewhat risky and still experimental method of cooling the engine via evaporative cooling. Such systems had been in vogue in several countries at the time. Heinkel and the Günter brothers were avid proponents of the technology, and had previously used it on the He 119, with promising results. Evaporative or "steam" cooling promised a completely drag-free cooling system. The DB 601 was a pressure-cooled engine in that the water/glycol coolant was kept in liquid form by pressure, even though its temperature was allowed to exceed the normal boiling point. Heinkel's system took advantage of that fact and the cooling energy loss associated with the phase change of the coolant as it boils.




Beyond the technical risk of the cooling system, the engine itself became a problem: the production priority for Messerschmitt aircraft caused a serious shortage of advanced aero engines in Germany during the late 1930s, as there was insufficient capacity to support another aircraft using the same engines. The only available alternate engine was the Junkers Jumo 211, and Heinkel was encouraged to consider its use in the He 100. However, the early Jumo 211 then available did not use a pressurized cooling system, and it was therefore not suitable for the He 100's innovative evaporative cooling system. Furthermore, a Jumo 211-powered He 100 would not have been able to outperform the contemporary DB 601-powered Bf 109 because the supercharger on the early Jumo 211 was not fully shrouded.

In order to provide as much power as possible from the DB 601, the 100 used exhaust ejectors for a small amount of additional thrust. The supercharger inlet was moved from the normal position on the side of the cowling to a location in the leading edge of the left wing. Although cleaner-looking, the long, curved induction pipe most probably negated any benefit.






One aspect of the original Projekt 1035 was the intent to capture the absolute speed record for Heinkel and Germany. Both Messerschmitt and Heinkel vied for this record before the war. Messerschmitt ultimately won that battle with the first prototype of the Me 209, but the He 100 briefly held the record when Heinkel test pilot Hans Dieterle flew the eighth prototype to 746.606 km/h (463.919 mph) on 30 March 1939.
The third and eighth prototypes were specially modified for speed, with unique outer wing panels of reduced span. The third prototype crashed during testing. The record flight was made using a special version of the DB 601 engine that offered 2,010 kW (2,700 hp) and had a service life of just 30 minutes.

Despite all these successes, the He 100 did not catch up immediately: it took until 1941 that series production was started - or better: allowed. The reason for this delay is subject to debate. Officially, the Luftwaffe rejected the He 100 for years to concentrate single-seat fighter development on the Messerschmitt Bf 109, despite its shortcomings. Following the adoption of the Bf 109 and Bf 110 as the Luftwaffe's standard fighter types, the RLM also announced a "rationalization" policy that placed fighter development at Messerschmitt and bomber development at Heinkel.




Based on the "D" model, which was a refined version of the prototypes and pre-production aircraft, the "G" model became the final evolution of the He 100 and was in late 1943 finally put into service as a pure interceptor, when massive Allied bomber raids started to threaten Germany.

The He 100 G had the D's enlarged horizontal stabilizer, but the big change was the eventual abandonment of the surface cooling system, which proved to be too complex and failure-prone. Instead a larger and simpler version of the D’s retractable radiator was installed, and this appeared to completely cure the vaporization system problems with only a little sacrifice in top speed and rate of climb. The radiator was inserted in a "plug" below the cockpit, and as a result the wings were widened slightly.

Armament was also improved: the engine-mounted 20mm MG FF Motorkanone (firing through the propeller hub) was replaced by the new, very powerful and compact MK 108 30mm cannon. The original pair of 7.92mm MG 17 machine guns in the wing roots (synchronized to fire through the propeller disc) was replaced by a pair of more powerful 13mm MG 131 machine guns, necessitating characteristic bulges on the wings’ upper surface – the MG 131s were placed behind the landing gear wells, their barrels running through them.




This initial G-1 type was soon followed by the G-2 variant, which featured a new canopy with a lowered spine, offering a much better all-round view. The first He 100 G-2s were delivered in early 1944, and many of these aircraft had additional weapons installed, e. g. a pair of 20mm MG 151/20 machine cannons in the outer wings – the “leftover” internal space from the defunct vaporization cooler system was effectively recycled . From late 1944 on, these machines were also outfitted with the more powerful DB 601E engine, even though there was no dedicated designation of this version.

While the aircraft didn't match its original design goal of 700 km/h (430 mph) once it was loaded down with weapons, and despite the larger canopy and the external radiator, it was still capable of sustained speeds in the 644 km/h (400 mph) range. Additionally, the low drag airframe proved to be good for both speed and range: as a result the He 100 had a combat range between 900 and 1.000 km (560 to 620 mi) compared to the Bf 109's 600 km (370 mi). While not in the same league as the later escort fighters, this was at the time a superb range and might have offset the need for the Bf 110 to some degree.






The He 100 only filled a niche role, though, and the Bf 109 and Fw 190 became the backbone of the Jagdwaffe (Fighter Force). The He 100 did not prove flexible enough to be used in different roles, as its external ordnance load was very limited. In spite of its successes in the interceptor role and the fact that it was well liked by its pilots, the He 100 never was able to rival both Bf 109 and also the later Fw 190. Production numbers remained low, only a total of about 300 aircraft were built (50 G-1 and 250 G-2, 150 of them powered by the DB 601E) until early 1945, when production ceased and was switched to other types, including jet and rocket fighters.


General characteristics:
Crew: One (pilot)
Length: 8.2 m (26 ft 11 in)
Wingspan: 9.4 m (30 ft 10 in)
Height: 3.6 m (11 ft 10 in)
Wing area: 14.6 m2 (157 sq ft)
Empty weight: 1,810 kg (3,990 lb)
Max takeoff weight: 2,500 kg (5,512 lb)
   
Powerplant:
1× Daimler-Benz DB 601E supercharged V12 piston engine, rated at up to 1,350 PS (993 kW) at sea-level with 2,700 RPM and up to 1,450 PS (1,066 kW) at 2.1 km altitude with 2,700 rpm

Performance:
Maximum speed: 685km/h (425 mph; 378 kn)
Cruising speed: 552 km/h (343 mph; 298 kn)
Range: 1,010 km (628 mi; 545 nmi)
Service ceiling: 11,000 m (36,089 ft)
Time to altitude: 2.2 minutes to 2,000 meters (6,600 ft), 7.9 minutes to 6,000 meters (20,000 ft)

Armament:
1x 30mm MK 108 cannon, firing through the propeller hub
2x 13mm MG 131 machine guns or 20mm MG 151/20 machine cannons in the wing roots
2x hardpoints under the wings, each able to carry up to 250kg (550lb), including bombs, drop tanks or unguided missiles; optional placement of additional guns (e .g. 2x MG 131 or 2x MG 151/20) in this position instead of external stores


Zum Bau nur soviel: Basis ist wieder der Special Hobby Bausatz, fast OOB gebaut aber eben mit implantierter neuer Cockpit-Scheibe und einigen Änderungen wir Kanülen-MGs oder einer Metallachse im Propeller, damit dieser bei den Bildern frei drehen kann.










Der Anstrich und alles andere orientiert sich an Franclabs Profil, und ich bin erstaunlich nahe herangekommen (Farben sind RLM 75/83/65 vom ModelMaster). Selbst eine "10" in der richtigen Typo war aufzutreiben!








Was am Profil nicht ganz stimmt (jetzt kommt der Nietenzähler durch...  ) ist das Pik-Ass-Emblem, das nicht zum Rumpfstreifen passt - gehörte jeweils zu unterschiedlichen Einheiten (JG 53 vs. JG 4, bzw. JG 77 als Ölschutzstaffel in Rumänien). Der Rest war/ist aber recht plausibel, das hätte alles von Ort, Zeit und Einheit so hinkommen können!