Although it proved to be one of the fastest fighter aircraft in the world at the time of its development, the design was not ordered into series production.

Because there are no surviving examples, and since many factory documents - including all blueprints for the He 100 - were destroyed during a bombing raid, there is limited specific information about the design and its unique systems.

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.

At the end of October the design was submitted to the RLM, complete with details on prototypes, delivery dates and prices for three aircraft delivered to the Rechlin test center.

[3] It is reported that Ernst Heinkel lobbied for this "round" number in the hope that it would improve the design's chances for production.

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.

For the rest of the designed performance increase with the DB 601 powerplant, Walter turned to the experimental method of evaporative cooling.

The record flight was made using a special version of the DB 601 engine that produced 2,010 kW (2,700 hp) and had a service life of just 30 minutes.

However, although the Me 209 V1 (known erroneously as the "Me 109R", ignoring the July 1938-dated change in prefixes) officially won over the He 100 and held the world speed record for piston engined aircraft for roughly 30 years, some historians such as Erwin Hood, state that the Me 209 V1's flight was 450 meters above sea level due to the topography of where its flight was held (at Augsburg) compared to that the He 100 V8's location of 50 meters above sea level (in Mecklenburg), thus their speed comparisons are not valid as the higher an aircraft goes, the lower the density of the atmosphere is, thus there is less drag.

However, Heinkel documents indicate that the pre-production were only designated He 100A-0, and that all of the He 100s built were essentially the same, with even the prototypes later updated to the production standard before they were exported to the Soviet Union.

In addition, the Luftwaffe test pilots disliked the high wing loading, which resulted in landing speeds so great that they often had to use brakes right up to the last 100 m (330 ft) of the runway.

V2 was completed in March, but instead of moving to Rechlin it was kept at the factory for an attempt on the 100 km (62 mi) closed circuit speed record.

A course was marked out on the Baltic coast between Wustrow and Müritz, 50 km (30 mi) apart, and the attempt was to be made at the aircraft's best altitude of 5,500 m (18,000 ft).

As a result, the output was boosted to 1,800 PS; 1,776 hp (1,324 kW), although it required constant maintenance and the fuel had to be drained completely after every flight.

On one of the pre-record test flights by the Heinkel chief pilot, Gerhard Nitschke, the main gear failed to extend and ended up stuck half open.

At this point, a number of changes were made to the design resulting in the "100C" model, and with the exception of V8 the rest of the prototypes were all delivered as the C standard.

On 9 June, the gear failed inflight, but the pilot managed to land the aircraft with little damage, and it was returned to flying condition in six days.

V10 was originally to suffer a similar fate, but instead ended up being given the racing wings and canopy of the V8 and displayed in the German Museum in Munich as the record-setting "He 112U".

While not in the same league as the later escort fighters, this was at the time a superb range, which suggests that a production Heinkel 100 might have offset the need for the Bf 110.

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

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.

Performance with the 603N was projected to be 880 km/h (550 mph), in the same class as the Messerschmitt Me 262 pioneering jet fighter then entering service testing, which would have stood as a record for many years, even against specialist racing machines.

Performance would still be excellent even with the far more likely 1,500 kW (2,000 hp)-output and above class aviation piston engines, which eventually proved to be a severe technological barrier for the German aero-engine industry during the war years.

The advanced contra-rotating Vereinigte Deutsche Metallwerke (VDM)-origin propeller design is unlikely to have been able to counteract this problem.

In 1939, it was reputedly one of the world's most advanced fighter designs, even faster than the later Fw 190, with performance unrivalled until the introduction of the Vought F4U Corsair in 1943, with the similarly-powered Republic XP-47J hitting 505 mph (813 km/h) in early August 1944.

The reason why the He 100 was not put into service seems to vary depending on the person telling the story, and picking any one version results in a firestorm of protest.

Others blame the bizarre production line philosophy of the RLM, which valued huge numbers of single designs over a mix of different aircraft.

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.

[citation needed] A full scale mockup of a He 100D-1 is on display at the Planes of Fame Air Museum in Chino, California.