Messerschmitt Me 263: German Rocket Fighter

Messerschmitt Me 263. Originally derived from the Me 163C program, it was handed over to Junkers as the Ju 248 before being redesignated the Me 263, though Junkers continued work on the project. It had retractable landing gear, a dual chamber HWK-509, greater fuel capacity, and a pressurized cockpit.

The Messerschmitt Me 263 Scholle (plaice) was a rocket-powered fighter aircraft developed from the Me 163 Komet towards the end of World War II. Three prototypes were built but never flown under their own power as the rapidly deteriorating military situation in Germany prevented the completion of the test program.

Although the Me 163 had very short endurance, it had originally been even shorter. In the original design, the engine had only one throttle setting, "full on", and burned through its fuel in a few minutes. Not only did this further limit endurance, in flight testing, pilots found the aircraft quickly exhibited compressibility effects as soon as they leveled off from the climb and speeds picked up. This led the RLM to demand the addition of a throttle, leading to lengthy delays and a dramatic decrease in fuel economy when throttled.

This problem was addressed in the larger Me 163C. This featured the same HWK 509B or -C dual chamber rocket engine already trialed on the Me 163B V6 and V18 prototypes; the main upper chamber was tuned for high thrust while the lower Marschofen combustion chamber was designed for a much lower thrust output (about 400 kgf maximum) for economic cruise. In operation, throttling was accomplished by starting or stopping the main engine, which was about four times as powerful as the smaller one. This change greatly simplified the engine, while also retaining much higher efficiency during cruise. Along with slightly increased fuel tankage, the powered endurance rose to about 12 minutes, a 50% improvement. As the aircraft spent only a short time climbing, this meant the time at combat altitude would be more than doubled.

Throughout development the RLM proved unhappy with the progress on the 163 project, and eventually decided to transfer development to Heinrich Hertel at Junkers. Lippisch remained at Messerschmitt and retained the support of Waldemar Voigt, continuing development of the 163C.

At Junkers, the basic plan of the 163C was followed to produce an even larger design, the Ju 248. It retained the new pressurized cockpit and bubble canopy of the 163C, with even more fuel tankage, and adding a new retractable landing gear design. On 25 September 1944 a wooden mock-up was shown to officials. The production version was intended to be powered by the more powerful BMW 109-708 rocket engine in place of the Walter power plant.

Prior to the actual building of the Ju 248, two Me 163Bs, V13 and V18, were slated to be rebuilt. V13 had deteriorated due to weather exposure, so only V18 was rebuilt, but had been flown by test pilot Heini Dittmar at a record-setting 1,130 km/h (702 mph) velocity on July 6, 1944 and suffered near-total destruction of its rudder surface as a result. It is this aircraft that is often identified as the Me 163D, but this aircraft was built after the Ju 248 project had started.

Hertel had hoped to install Lorin ramjet engines, but this technology was still far ahead of its time. As a stopgap measure, they decided to build the aircraft with a Sondergeräte (special equipment) in the form of a Zusatztreibstoffbehälter (auxiliary fuel tank): two 160 l (35 imp gal; 42 US gal) external T-Stoff oxidizer tanks were to be installed under the wings. This would lead to a 10% speed decrease but no negative flight characteristics. Although Junkers claimed the Ju 248 used a standard Me 163B wing, they decided to modify the wing to hold more C-Stoff fuel. This modification was carried out by the Puklitsch firm.

In November 1944, the aircraft was again redesignated as the Me 263 to show its connection with the Me 163. The two projects also got names - the Ju 248 Flunder (Flounder) and the Me 263 Scholle (Plaice). In early 1945, Junkers proposed its own project, the EF 127 Walli rocket fighter, as a competitor to the Me 163C and Me 263.

The first unpowered flight of the Me 263 V1 was in February 1945. Several more unpowered flights took place that month. The biggest problem had to do with the center of gravity which was restored with the addition of counterweights. Eventually, the production aircraft would have repositioned the engine or the landing gear installation to solve this problem. The landing gear was still non-retractable. The first flights gave the impression that it was suitable as it was for production.

Test flights were later stopped because of fuel shortages for the Bf 110 towplanes. As the Me 263 was not a part of the Jägernotprogramm (Emergency Fighter Program), it was difficult to get the resources it needed. For the time being the plane was not expected to enter production but further development was allowed. The V2 and V3 were not yet ready. The V2 was to get the retractable landing gear and the V3 would have the armament built in. The next month both the V1 and the V2 had the two-chambered HWK 109-509C installed, correcting the center-of-gravity problems. They flew only as gliders.

In April, the Americans occupied the plant and captured the three prototypes and the mock-up. The V2 was destroyed but another prototype ended up in the US. The rest was handed over to the Russians, who then created their own Mikoyan-Gurevich I-270 interceptor.

Role: Fighter-interceptor

Manufacturer: Messerschmitt/Junkers

Designer: Alexander Lippisch

First flight: 8 February 1945 (unpowered)

Primary user: Luftwaffe

Number built: 3

Developed from: Messerschmitt Me 163 Komet

Crew: 1

Length: 7.89 m (25 ft 11 in)

Wingspan: 9.5 m (31 ft 2 in)

Height: 3.17 m (10 ft 5 in)

Wing area: 17.8 m2 (192 sq ft)

Airfoil: root: Me 1.8 25 14-1.1-30 ; tip: NACA 00008-1.885-20

Empty weight: 2,210 kg (4,872 lb)

Gross weight: 5,310 kg (11,707 lb)

Powerplant: 1 × Walter HWK 109-509C-3 liquid-propellant rocket engine, 19.61 kN (4,410 lbf) thrust

Maximum speed: 950 km/h (590 mph, 510 kn)

Landing speed: 145 km/h (90 mph; 78 kn)

Range: 125 km (78 mi, 67 nmi)

Endurance: 15 minutes at 11,000 m (36,089 ft)

Service ceiling: 16,000 m (52,000 ft)

Rate of climb: 150 m/s (30,000 ft/min)

Armament: 2 × 30 mm (1.18 in) MK 108 cannon in the wing roots

Bibliography

Christopher, John. The Race for Hitler's X-Planes. The Mill, Gloucestershire: History Press, 2013.

Käsmann, Ferdinand C.W. Die schnellsten Jets der Welt (in German). Berlin: Aviatic-Verlag GmbH, 1999.

Myhra, David. "Messerschmitt Me 263", Schiffer Publishing, 1999.

Me 163 variants.

Messerschmitt Me 263.

The Me 263 V1 with the upper wing surfaces tufted with threads for analyzing airflow over the wings.

The Me 263 clearly seems to show a motor fitted. There are visible combustion chamber openings, with twin fuel dump pipes - the pipes must be part of the motor, not the airframe. So if the tufted-wing Me 263 V1 (set up for airflow and therefore flight testing) had the motor fitted, it could have flown under power.

Me 263 cockpit.

Wind tunnel model of the Me 263.

Messerschmitt Me 263 fuselage wreck among several V-1's.

Cutaway of tail of Me 263.

Me 263 cockpit.

Portion of Me 263 after an example captured by the Americans was blown up.

Messerschmitt Me 263 nose mock-up.

 

Junkers Ju 248 V1.

Me 263.

Heinkel He 280: German Turbojet-powered Fighter

Heinkel He 280 V1 DL+AS, taking off for its first flight on 2 April 1940.

Originally called the He 180, the Heinkel He 280 was an early turbojet-powered fighter aircraft designed and produced by the German aircraft manufacturer Heinkel. It was the first jet fighter to fly in the world.

The He 280 harnessed the progress made by Hans von Ohain's novel gas turbine propulsion and by Ernst Heinkel's work on the He 178, the first jet-powered aircraft in the world. Heinkel placed great emphasis on research into high-speed flight and on the value of the jet engine; after the He 178 had met with indifference from the Reichsluftfahrtministerium (RLM) (the German Reich Aviation Ministry), the company opted to start work on producing a jet fighter during late 1939. Incorporating a pair of turbojets, for greater thrust, these were installed in a mid-wing position. It also had a then-uncommon tricycle undercarriage while the design of the fuselage was largely conventional.

During the summer of 1940, the first prototype airframe was completed; however, it was unable to proceed with powered test flights due to development difficulties with the intended engine, the HeS 8. Thus, it was initially flown as a glider until suitable engines could be made available six months later. The lack of state support delayed engine development, thus setting back work on the He 280; nevertheless, it is believed that the fighter could have been made operational earlier than the competing Messerschmitt Me 262, and offered some advantages over it. On 22 December 1942, a mock dogfight performed before RLM officials saw the He 280 demonstrate its vastly superior speed over the piston-powered Focke-Wulf Fw 190; shortly thereafter, the RLM finally opted to place an order for 20 pre-production test aircraft to precede a batch of 300 production standard aircraft.

However, engine development continued to hinder the He 280 program. During 1942, the RLM had ordered Heinkel to abandon work on both the HeS 8 and HeS 30 to focus on the HeS 011. As the HeS 011 was not expected to be available for some time, Heinkel selected the rival BMW 003 powerplant; however, this engine was also delayed. Accordingly, the second He 280 prototype was re-engined with Junkers Jumo 004s. On 27 March 1943, Erhard Milch, Inspector-General of the Luftwaffe, ordered Heinkel to abandon work on the He 280 in favor of other efforts. The reason for this cancellation has been attributed to combination of both technical and political factors; the similar role of the Me 262 was certainly influential in the decision. Accordingly, only the nine test aircraft were ever built, at no point did the He 280 ever attain operational status or see active combat.

Development

Background

During the late 1930s, the Heinkel company had developed the He 178, the world's first turbojet-powered aircraft; successfully flying the aircraft for the first time on 27 August 1939. However, an aerial demonstration of the He 178 had apparently failed to interest attending officials from the Reichsluftfahrtministerium (RLM) (the German Reich Aviation Ministry) either in the aircraft itself or jet propulsion in general. Unknown to Heinkel, the Reich Air Ministry had already begun work on discretely developing its own jet technology independently of his company's efforts.

Despite having been unable to secure state backing for further work, Heinkel was undeterred in the potential value of the turbojet. Instead, the company independently decided to undertake work on what would become the He 280 during late 1939. This internal project to develop a jet-powered fighter aircraft, which had been started under the designation He 180, was headed by the German aeronautical designer Robert Lusser. The project was greatly aided by the earlier He 178 program, which had not only served as a proof of concept but also yielded invaluable data gathered from flight testing; however, the design of the He 178 was deemed to be unsuitable for further development; particularly as mounting the engine within the fuselage had been judged to be impractical.

For the He 280, a pair of turbojets were used, each one installed in a mid-wing position, which was viewed as a more straightforward arrangement. Despite its novel propulsion, the design had adopted numerous relatively orthodox features, such as a typical Heinkel fighter fuselage, semi-elliptical wings, and a dihedralled tailplane with twin fins and rudders. The He 280 was furnished with a tricycle undercarriage that had very little ground clearance; this arrangement was considered by some officials to be too frail for the grass or dirt airfields of the era; however, the tricycle layout eventually gained acceptance. One particularly groundbreaking feature incorporated onto the He 280 was its ejection seat, which was powered by compressed air; it was not only the first aircraft to be equipped with one but would also be the first aircraft to successfully employ one in a genuine emergency. In contrast to the Messerschmitt Me 262, another German jet fighter, the He 280 had a smaller footprint and is believed to have been more maintainable.

Test Flying

During the summer of 1940, the first prototype airframe was completed, however, the HeS 8 turbojets that were intended to power it had encountered considerable production difficulties. On 22 September 1940, while work on the engine continued, the first prototype commenced glide tests, having been fitted with ballasted pods in place of its engines, towed behind a He 111. It was another six months before Fritz Schäfer flew the second prototype under its own power, on 30 March 1941. After landing, Schäfer reported to Heinkel that, while somewhat difficult to exercise control during turns, an experienced pilot would have an easy time flying the He 280.

On 5 April 1941, Paul Bader performed an exhibition flight before various Nazi officials, including Ernst Udet, General-Ingenieur Lucht, Reidenbach, Eisenlohr and others. However, the RLM eventually favored development of the Me 262, a rival jet-powered fighter. Yet, Heinkel was given Hirth Motoren for continued turbine development. One benefit of the He 280 which did impress Germany's political leadership was the fact that the jet engines could burn kerosene, a fuel that required much less expense and refining than the high-octane fuel used by piston-engine aircraft. However, government funding was lacking at the critical stage of initial development; the aviation author Robert Dorr largely attributes this lack of support to the personal opposition voiced by Udet.

Over the next year, progress was slow due to the ongoing engine problems. A second engine design, the HeS 30 was also under development, both as an interesting engine in its own right and as a potential replacement for the HeS 8. In the meantime, alternative powerplants were considered, including the Argus As 014 pulsejet that powered the V-1 flying bomb. It was proposed that up to eight would be used.

By the end of 1942, however, the third prototype was fitted with refined versions of the HeS 8 engine and was ready for its next demonstration. On 22 December, a mock dogfight was staged for RLM officials in which the He 280 was matched against a piston-powered Focke-Wulf Fw 190 fighter, in which the jet demonstrated its vastly superior speed, completing four laps of an oval course before the Fw 190 could complete three. Finally, at this point the RLM became interested and placed an order for 20 pre-production test aircraft that were to be followed by a batch of 300 production standard aircraft.

Engine Troubles and Cancellation

Engine problems continued to plague the project. During 1942, the RLM had ordered Heinkel to abandon work on both the HeS 8 and HeS 30 to focus all development on a follow-on engine, the HeS 011, which proved to be a more advanced and problematic design. Meanwhile, the first He 280 prototype was re-equipped with pulsejets, and towed aloft to test them. Bad weather caused the aircraft to ice up before the jets could be tested; the situation led to pilot Helmut Schenk becoming the first person to put an ejection seat to use. While the seat worked perfectly, the aircraft was lost and never recovered.

As the HeS 011 was not expected to be available for some time, Heinkel selected the rival BMW 003 powerplant; however, this engine also suffered problems and delays. Accordingly, the second He 280 prototype was re-engined with Junkers Jumo 004s. The following three airframes were earmarked for the BMW motor which would never become available in actuality. The Jumo engines were considerably larger and heavier than the HeS 8 that the aircraft had been designed for, and while it flew well enough on its first powered flights from 16 March 1943, it was clear that this engine was unsuitable. The aircraft was slower and generally less efficient than the Me 262.

Less than two weeks later, on 27 March, Erhard Milch, Inspector-General of the Luftwaffe, ordered Heinkel to abandon work on the He 280 to instead focus his company's attention on bomber development and construction. The termination of the project has been attributed to multiple factors. A major contributor was competition from the Jumo 004-powered Me 262, which appeared to possess most of the qualities of the He 280, but had the advantage of being better matched to its engine. Yet it was believed that the He 280 could have been in service sooner and may have been useful even just as a stopgap measure for the Me 262. The aviation authors Tim Heath and Robert Dorr both note that, in light of Heinkel having become unpopular amongst influential Nazis while Willy Messerschmitt was a favoured figure, there were political factors at play in the cancellation of the He 280. Heinkel remained interested in jet propulsion and sought out other opportunities to design aircraft harnessing such engines; this would lead to the single-engined Heinkel He 162 that would be selected as the winner of the Emergency Fighter Program in October 1944.

Prototypes

He 280 V1

Stammkennzeichen-coded as "DL+AS".

1940-09-22: First flight.

1942-01-13: Crashed due to control failure. Pilot ejected safely.

He 280 V2

Coded as "GJ+CA".

1941-03-30: First flight.

1943-06-26: Crashed due to engine failure.

He 280 V3

Coded as "GJ+CB".

1942-07-05: First flight.

1945-05: Only the empennage was found at the Heinkel-Sud factory complex at Wien-Schwechat, Austria.

He 280 V4

Coded as "GJ+CC".

1943-08-31: First flight.

1944-10: Struck off charge at Hörsching, Austria.

He 280 V5

Coded as "GJ+CD".

1943-07-26: First flight.

Did not receive any jet engines.

He 280 V6

Coded as "NU+EA".

1943-07-26: First flight.

powered by Junkers Jumo 109-004A engines

Crew: 1

Length: 10.2 m (33 ft 5.5 in)

Wingspan: 12.00 m (39 ft 4.3 in)

Height: 3.19 m (10 ft 5.75 in)

Wing area: 21.51 m2 (231.5 sq ft)

Airfoil:

Root: 13%

Tip: 9%

Gross weight: 5,205 kg (11,475 lb)

Powerplant: 2 × Junkers Jumo 109-004A Orkan axial-flow turbojet engines, 8.24 kN (1,852 lbf) thrust each

Maximum speed:

752 km/h (467 mph, 406 kn) at sea level

818 km/h (508 mph; 441 kn) at 6,000 m (19,685 ft)

810 km/h (503 mph; 437 kn) at 8,500 m (27,890 ft)

Range:

615 km (382 mi, 332 nmi) at 9,000 m (30,000 ft)

314 km (195 mi; 170 nmi) at sea level

Service ceiling: 11,400 m (37,390 ft)

Rate of climb: 21.2 m/s (4,170 ft/min)

Thrust/weight: 0.32

Guns: 3 × 20 mm MG 151/20 cannon

He 280 V7

Coded as "NU+EB" and "D-IEXM".

1943-04-19: First flight.

Flew a total of 115 towed flights. Flew powered with Heinkel-Hirth 109-001 engines until an engine failure, reverting to a glider.

He 280 V8

Coded as "NU+EC".

1943-07-19: First flight.

He 280 V9

Coded as "NU+ED".

1943-08-31: First flight.

Bibliography

Buttler, Tony (2019). Jet Prototypes of World War II: Gloster, Heinkel, and Caproni Campini's Wartime Jet Programmes. Bloomsbury Publishing.

Dorr, Robert F. (2013). Fighting Hitler's Jets. Voyageur Press.

Dressel, Joachim (1991). Heinkel He 280: The World's First Jet Aircraft. West Chester, Pennsylvania, US: Schiffer.

History Office (2002). Splendid Vision, Unswerving Purpose. Aeronautical Systems Center, Air Force Materiel Command.

Forsyth, Robert (2016). He 162 Volksjäger Units. Bloomsbury Publishing.

"Harbinger of an Era...The Heinkel He 280". Air International. Vol. 37, no. 6. November 1989. pp. 233–241, 260.

Heath, Tim (2022). In Furious Skies: Flying with Hitler's Luftwaffe in the Second World War. Pen and Sword History.

Christopher, John (2013). The Race for Hitler's X-Planes: Britain's 1945 mission to capture secret Luftwaffe technology. The Mill, Gloucestershire, UK: History Press.

Koehler, H. Dieter (1999). Ernst Heinkel – Pionier der Schnellflugzeuge. Bonn, Germany: Bernard & Graefe.

LePage, Jean-Denis G.G. (2009). Aircraft of the Luftwaffe, 1935-1945: An Illustrated Guide. McFarland.

Munson, Kenneth (1978). German Aircraft Of World War 2 in colour. Poole, Dorset, UK: Blandford Press.

Heinkel He 280 V1 DL+AS.

Heinkel He 280 V1 prototype.

He 280.

He 280.

He 280.

He 280 V1 was towed aloft as a glider for testing as the He S 8A engines were not then finished.

He 280 V3 GJ+CB.

He 280 V3 GJ+CB.

He 280 V3 GJ+CB.

He 280 V3 GJ+CB.

He 280 V3 GJ+CB.

He 280 V3 GJ+CB.

He 280 V3 GJ+CB.

He 280.

He 280.

He 280 V7 NU+EB, before installation of the turbojets.

Heinkel He 280.