Heinkel HE280

The Heinkel HE 280 was developed in response to the need to make military use of the new turbojet engines being designed in the late 1930's. The company had already built and flown the world's first turbojet the experimental HE178 in August 1939 and had continued to develop Ernst Heinkels turbojet engine designs. The design of the aircraft began in 1939 as a private initiative under the designation HE180. The design team lead by Robert Lusser produced a typical Heinkel fighter fuselage with elliptical wings, dihedralled tailplane with twin fins and rudders. It had retractable tricycle undercarriage and was equipped with a unique compressed-air powered ejection seat, the first aircraft to incorporate such a feature.


The first flights of the HE280 were without engine cowlings to prevent leaking fuel from collecting inside the nacelles.


The first prototype was completed in the summer of 1940 but difficulties and delays with the development of its two HeS 8 turbojets meant that its first flight was as a glider on the 22nd Sept 1940. It flew with ballast in place of the engines undertaking more than forth unpowered flights before its engines were ready in March 1941. Its first powered flight took place on the 2nd April with Fritz Schäfer at the controls and it was demonstrated to Ernst Udet, head of RLM's development wing, on 5 April 1941, he showed little enthusiasm although this was not limited only to Heinkel as at that time the jet program was receiving very little funding and most companies were expereincing serious technical issues, not unlike in Britain who were in the middle of their own program to develop the W2B/23 powered Gloster F9/40 Meteor.



In a contest between an HE280 and a Focke-Wulf Fw190 in 1941, the HE280 was able to complete four laps of an oval course before the FW190 had completed its third as the aircraft was light enough to still perform adequately on the reduced power of the early HeS 8 (1,102lbs) with a maximum take-off weight of just 4,296 kg (9,470lbs). Its performance however was not enough to overcome reservations about Its tricyle undercarriage, it being considered a liability given the state of many operational airfields and issues was with the HeS 8 engines which were designed to produce over 1,500lbs of thrust. Its rival, the ME262 at the time had a conventional tailwheel layout although it would later also get a tricyle undercarriage layout, in common with the Gloster E28/39 Pioneer and Meteor.

A significant advantage of the HE280 was that its engines ran on kerosene, much cheaper to produce and easier to refine than the high-octane fuel used by piston-engine aircraft, it was not however a factor in the ongoing engine development problems. A number of solutions included using a new engine under development the HeS 30 (Designated the 109-006 designed to produce 1,760 lbs of thrust) or even the rather desperate option of using up to eight Argus As 014 pulse jets (These powered the V1 flying bomb), the end result was that little progress was made over the next year. The situation did not improve until 22nd December 1942 when HE280-v3 fitted with a pair of refined HeS 8 engines was involved in a mock dogfight with and FW190, it easily demonstrated its superior speed leading to the RLM placing an order for 20 pre-production test aircraft and 300 production airframes.

The continued problems with the HeS 8 led to the RLM ordering Heinkel to abandon its development and the development of the HeS 30 in favour of the HeS 11, a much more advanced (and problamatic) design. It was during this phase of the project that HE280 -v1 was re-engines with pulse jets and towed aloft to test them. The bad weather however caused the aircraft to ice up before the engines could be tested and forced the pilot Helmut Schenk to put the compressed air ejection seat to use, it worked perfectly, pushing him well clear of the aircraft was was destroyed. The second prototype HE280-v2 was also re-engines with the Jumo 004 and the fourth through sixth prototypes designated to run with BMW 003 powerplants.



A great model of HE280-v2 showing the clean lines of the design by Matt Swan from the Eduard 1/48 Hi-Tech (ProfiPack) kit


HE280-v2 flew successfully with the Jumo 004 engines for the first time on 16 March 1943 although as they were much larger and heavier than the HeS 8 the performance of the aircraft was less than impressive compared to the ME262 which had started its flight test program, with no sign of smaller lighter weight engines for which the HE280 was designed the production order was cancelled on the 27th March 1943 with Heinkel ordered to concentrate on bomber development and design.

Specifications (HE280-v5)
Wing span:40ft (12.2m)
Length:34ft 1½ in (10.4m
Height:10ft (3.06m
Empty weight:7,073lb (3,217 kg)
Max weight:9,482lb (4,270 kg)
Engines:2 x HeS 8A (109-001A) turbojet engines of 1,643lbs thrust.
Max Speed:559mph (900kmh)
Range:404miles (650km)
Ceiling:37,730ft (11,500m)
Armament:6 x MG151 20m cannons (Only three ever fitted).

Prototypes

Nine prototypes were built, some of these were started before the cancellation of the program but still completed and used as research aircraft