Heinkel He 100

Further Developments

In late 1944 the RLM went to manufacturers for a new high altitude fighter with excellent performance - the Ta 152H (a version of the Focke-Wulf Fw 190) was currently in limited production for just this task but Heinkel was contracted to design an aircraft, and Siegfried Günter was placed in charge of the new Projekt 1076.

The resulting design was similar to the He 100, but the many detail changes resulted in an aircraft that looked all new. It sported a new and longer wing for high altitude work, which lost the gull wing bend and was swept forward slightly at eight degrees. Flaps or ailerons spanned the entire trailing edge of the wing giving it a rather modern appearance. The cockpit was pressurized for high altitude flying, and covered with a small bubble canopy that was hinged to the side instead of sliding to the rear. Other changes that seem odd in retrospect is that the gear now retracted outward like the original Bf 109, and the surface cooling system was re-introduced. Planned armament was one 30 mm MK 103 cannon firing through the propeller hub, and two wing mounted 30 mm MK 108 cannons.

The use of one of three different engines was planned: the DB 603M with 1,825 hp (1,361 kW), the DB 603N with 2,750 hp (2,051 kW) or the Jumo 213E with 1,750 hp (1,305 kW). The 603M and 213E both supplied 2,100 hp (1,566 kW) using MW-50 water injection. Performance with the 603N was projected to be 880 kph (546 mph), which would have stood as a record for many years even when faced with dedicated racing machines. Performance would still be excellent even with the far more likely 2,000 hp (1.5 MW) class engines, the 603M was projected to give it the high speed of 855 kph (532 mph).

These figures are somewhat suspect though, and are likely just optimistic guesses that could not have been met — something Heinkel was famous for. Propellers lose efficiency as they approach the speed of sound, and eventually they no longer provide an increase in thrust for an increase in engine power. Even the advanced counter rotating VDM design is unlikely to have been able to effect this problem too much.

The design apparently received low priority, and it was not completed by the end of the war. Siegfried Günter later completed the detailed drawings and plans for the Americans in mid-1945.

Legacy

In 1939, it was reputedly one of the most advanced fighter designs, even faster than the later Fw 190, with performance unrivalled until the introduction of the Vought F4U Corsair in 1943. Nevertheless the aircraft was not ordered into production. The reasons the He 100 wasn't put into service seems to vary depending on the person telling the story, and picking any one version results in a firestorm of protest.

Some say it was politics that killed the He 100. However this seems to stem primarily from Heinkel's own telling of the story, which in turn seems to be based on some general malaise over the He 112 debacle. The fact is that Heinkel was well respected within the establishment regardless of Messerschmitt's success with the Bf 109 and Bf 110, and this argument seems particularly weak.

Others blame the bizarre production line philosophy of the RLM, which valued huge numbers of single designs over a mix of different aircraft. This too seems somewhat suspect considering that the Fw 190 was purchased shortly after this story ends.

For these reasons it seems safe to accept the RLM version of the story largely at face value; that the production problems with the DB series of engines was so acute that all other designs based on the engine were canceled. At the time the DB 601 engines were being used in both the Bf 109 and Bf 110 aircraft, and Daimler couldn't keep up with those demands alone. The RLM eventually forbade anyone but Messerschmitt from receiving any DB 601s, leading to the shelving of many designs from a number of vendors. Furthermore, the Bf 109 and Bf 110 were perceived as superior to their likely opponents, which made the requirement for an even more powerful aircraft less imperative.

The only option open to Heinkel was a switch to another engine, and the RLM expressed some interest in purchasing such a version of the He 100. At the time the only other useful inline was the Junkers Jumo 211, and even that was in short supply. However the design of the He 100 made adaptation to the 211 difficult; both the cooling system and the engine mounts were designed for the 601, and a switch to the 211 would have required a redesign. Heinkel felt it wasn't worth the effort considering the aircraft would end up with inferior performance, and so the He 100 production ends on that sour note.

For this reason more than any other the Focke-Wulf Fw 190 became the next great aircraft of the Luftwaffe, as it was based around the otherwise unused Bramo 139 (and later BMW 801) radial engine. Although production of these engines was only starting, the lines for the airframes and aircraft could be geared up in parallel without interrupting production of any existing design, which was exactly what happened.