Heinkel He 277
Encyclopedia
The Heinkel
He 277 was a four-engine, long range heavy bomber
design, a derivative of the He 177
, intended for production and use by the German
Luftwaffe
during World War II
. The main difference was in engine configuration. Rather than using two fire-prone Daimler-Benz DB 606 "power system" engines, each of which consisted of side-by-side paired Daimler-Benz DB 601
s, the He 277 was meant from the outset to use four BMW 801E
14-cylinder radial engine
s, each mounted in an individual nacelle
and each turning a three blade, four-meter diameter propeller. The design was never produced, owing both to the deteriorating condition of the German aviation industry late in the war, and the competition from other long-range bomber designs from other firms, competing for Germany's increasingly scarce aviation production capacity. Although not specifically built for it at first, partially due to the time-frame in the spring of 1942 in which its ultimate niche was requested for by the RLM, the He 277 essentially became Heinkel's entry in the important trans-oceanic range Amerika Bomber
competition, struggling to compete against both several other designs from rival firms in the competition for a truly trans-oceanic ranged bomber for the Luftwaffe, and Germany's own rapidly degrading ability, from Allied bombing damage to its aviation plants, to produce military aircraft of any sort.
from doing any work on a separately four-engined version of the 177 airframe, or even mentioning a new "He 277" design with four separate engines - by one account, in the late autumn of 1941 - until Heinkel brought the disagreement directly to Adolf Hitler
, who supposedly not only approved of calling the new, separately engined version of the 177 the "He 277", but overruled Goering's prohibition on working on the design (previously called the "He 177B" by Heinkel as a "cover designation" to hide its existence from Goering, and the RLM
.)
Statements by Goering himself in August 1942, however, seem to directly contradict elements of the oft-repeated story, as those statements seem to show that Goering thought that the He 177A actually had four separate engines, and derisively labeled the He 177A's coupled engine arrangements, the DB 606 and DB 610 "power systems" at that time as zusammengeschweißte motoren, or "welded-together engines", in his complaints about the He 177A's ongoing engine difficulties, and was anxious to see a truly four-engined version of Heinkel's heavy bomber fully developed and in production.
Facts that could have fostered the origin of the post-war aviation book storyline about the "He 177B"/He 277 controversy were that the RLM, in listing the He 177 development projects that they approved of the Heinkel firm doing work on as of February 1943 (six months after Goering's recorded engine complaint statements), only included the He 177 A-5 heavy bomber, A-6 high-altitude bomber, A-7 long-range version, and the "He 277" itself, with the RLM also expecting, during the late spring of 1943 (about one year after the mid-Spring 1942 Amerika Bomber proposal first arrived in Goering's offices) that a trio of He 277 V-series prototype aircraft, and construction of ten pre-production A-0 series machines were to be completed, as well as "progressive development" of the still-unbuilt and unfinalized design, were anticipated as coming from Heinkel's Schwechat
southern plant complex in Austria. The initial starting place for the He 277's fuselage design had been meant to originate with the last "coupled-engine" proposed variant of the He 177 itself, the long-range A-7, which itself was to be the basis for a four-engined variant of the Greif as the He 177A-10, then redesignated the He 177B-7 in the late summer of 1943. The considerable changes in the He 277's overall design philosophy evolved after the Amerika Bomber proposal's emergence in May 1942, from the changes in the He 277's general arrangement proposal drawings during that time period. The original proposal, which was meant to use the He 177A-7's fuselage as the starting point, evolved into designing a dedicated, new and wider He 219
-general pattern fuselage layout for the 277 from the Spring 1943 timeframe onward, which would be more capable of using a tricycle undercarriage then gaining favor with a few German aviation designers, even with the 277 not known to have been specifically considered by the RLM in the earlier timeframe for the Amerika Bomber proposal.
The main factor that seemingly required the lower-drag "coupled" powerplant format for the He 177A, the diving attack mandate by the RLM, which Heinkel himself vehemently disagreed with, was rescinded by Goering himself some five months before the "He 277"'s earliest-known February 1943 RLM approval date, and Heinkel started work on the He 177B as a straightforward, separately four-engined development of the 177A under the B-series designation at least as early as the late summer of 1943, when official Heinkel documents began referring to the He 177B, evidenced from an August 1943-dated, Heinkel factory-created general arrangement drawing of the He 177 V101 being labeled with the 8-177 RLM designation for the entire line of Greif airframes, and "B-5" elsewhere in the drawing's title block, as a fully RLM approved development of the original He 177 aircraft line, and not in any way directly related to the entirely separate He 277 advanced bomber design project, which by the summer of 1943 was considered to be Heinkel's Amerika Bomber aviation contract contender.
In total, there were three separate efforts, the movement toward which had been initiated by Herr Heinkel himself as early as November 1938, to develop "true four-engined versions" of the A-series Greif: the He 177B, which culminated in four prototype examples being built, with three getting airborne before the war's end; the He 274, of which only two prototypes were started before the end of World War II and completed and flown in France after the war's end; and the He 277, for which only had a few airframe parts had been in the process of completion, with no completed prototypes at any time, before or after the end of the war.
powerplants of 1,471 kW (2,000 PS, 1,973 hp) output each at take-off, with each engine turning a propeller of up to four meters in diameter, a fully retracting conventional or nosewheel landing gear, with main gear assemblies that possessed twinned main wheels on each unit, retracting forward (for the nosewheel version, rearwards for a conventional gear arrangement) into the inner engine nacelles, and a heavily glazed and "greenhouse"-framed clear view "stepless" cockpit. Its fully glazed front section somewhat resembled a blended combination of an aerodynamically refined, rounded-off well-framed version of the Bristol Blenheim
Mk.I's fully glazed "stepless" nose shape, and pilot accommodation-enclosing upper section somewhat resembling what was used on the British Avro Lancaster
heavy bomber, with a rearward extension atop the fuselage to just forward of the inner engine cowls. The fuselage outlines themselves were deep, and almost slab-sided in cross-section, with its general sideview profile lines being strongly reminiscent of the smaller He 219
night fighter, in a sort-of "Heinkel-familial" manner with the smaller aircraft. This similarity with the 219 even extended to the depictions of the He 277's fuselage-mounted defensive armament emplacements as proposed by Heinkel, with one forward and two aft-facing "steps" along the slightly rounded dorsal and ventral surfaces of the fuselage, much like the smaller night fighter's earliest prototypes had, for the 277's manned aft dorsal and remote aft ventral turret defensive weapons mounts, and a twin tail
empennage
assembly that added aerodynamic stability, and made mounting a traversable defensive tail turret easier.
In a May 1943 Heinkel factory document showing possible offensive bombload configurations and flight consumable (fuel, etc.) weights for the He 277, two differing bomb bay sizes (interior dimensions of 1.5 x 7.5 meters for the He 277's tailwheel version, and 1.75 x 7.0 meters for the tricycle undercarriage version) were considered, with the latter bomb bay configuration existing within a 1.90 meter width fuselage. The lightest warload of six 500 kg (1,100 lb) SC 500 bombs for each bomb bay configuration, gave the tricycle-geared, 1.9 meter exterior width wider-fuselage version, considering a larger load (12,200 kg/26,895 lb) of fuel, a possible stated maximum range of 11100 km (6,897.2 mi), equalling the potential range capability of the earlier-designed Me 261
, an indicator of what could have been achieved had the 277 been in full consideration from its beginnings, for the Amerika Bomber design competition.
Defensive armament comprised, as envisioned, a forward, remotely operated "chin turret" under the extreme nose with twin MG 151/20
cannon much as the 177B-series was intended to use, twin dorsal turrets each armed with a pair of MG 151/20 cannon, a ventral turret for lower rearwards defense, just behind the bomb bay's rear edge with another pair of MG 151/20 cannon, and a manned HL 131V tail turret with a quartet of MG 131 heavy machine guns.
, and later, the Ta 400
), Junkers
(the Ju 390
), from Messerschmitt AG (the Me 264
), and from his own firm's He 274
four-engined, high-altitude development of the He 177.
The first of these designs that the He 277 was pitted against, mostly to determine the "most producible" bomber that could also be license-built, given Germany's limited aircraft production capacity to arm the Luftwaffe with, and partially to determine the best long-range bomber design to fulfill the needs of the spring 1942-issued Amerika Bomber
program documents, the Messerschmitt Me 264 ended up being the first design to challenge the He 277's chance for production. The Me 264 was a purpose-built long range bomber, using a tricycle landing gear configuration from the start, that was already flying in prototype form with four engines as early as late December 1942, a full year after Nazi Germany had declared war on the United States, five months after the Eighth Air Force
had begun flying bomber missions against Nazi-occupied France, and two months before the earliest-known mention of RLM approval of the 277 itself.
The four-engined Me 264's development, because of the need to use scarce strategic materials in its construction, and because of the better performance estimates that the Focke-Wulf Ta 400 and He 277 possessed, was stopped in May 1943.
Because of the US involvement in the European Theater, the Luftwaffe now found that it had a serious need for a well-armed, long range bomber, which the Luftwaffe found could not be achieved with the 1,120 kW (1,500 hp) class engines it had for such a four-engined bomber, and that six engines of that same class would be needed on a strategic bomber design for a successful mission from Europe to attack the US and safely return to base, with enough of an offensive bombload to be effective, and to have enough defensive firepower for protection for a safe return. The Blohm & Voss firm's aviation division had already settled on six engines with success, as early as 1940, on the prototypes of the Bv 222 Wiking flying boat
maritime patrol aircraft. This emerging need for six engines for such an aircraft was also recognized by Messerschmitt AG, when that firm fielded a paper project for a six-engined "Me 264B", that had a stretched wingspan outwards to 47.5 meters (155 ft 10 in), with two additional BMW 801 radial engines outboard of the existing four powerplants.
In March 1943, Focke-Wulf came up with a six-engined version of their proposed Fw 300 bomber, originally powered with just four BMW 801E radials. Their more advanced Ta 400 design, first proposed in October 1943 with a tricycle landing gear setup and meant to be powered with a half-dozen of the same engines as the 277 was meant to use, was joined by the Ju 390, a Junkers six-engined version of the developed version of their early-war Junkers Ju 90
airliner, the operational Junkers Ju 290
maritime patrol bomber, and also using six of the same BMW radials as the 277.
By October 1943, Ernst Heinkel had compared the Messerschmitt and Junkers four-engined designs, and the six-engined Bv 222, Ju 390 and Ta 400 designs to his own He 277 project, with the following conclusions:
Of these competing types, only three of the Me 264 design, and a verified pair of the Ju 390 aircraft were ever built, solely as flyable prototypes, and none of these aircraft saw any action against the Allies.
The He 274, because of its own intended high-altitude role, was only a potential competitor with the He 277 for Heinkel's own company engineering and production staff, and the He 274's production had already been outsourced by the end of 1941 to the French Societe Anonyme des Usines Farman, or "SAUF" firm in Suresnes
to partially allow Heinkel to work on other projects, like the He 277 and the more advanced Heinkel He 343
jet powered medium bomber design.
, a composite of earlier developments of the Junkers Ju 88 twin-engined fast medium bomber
design, with a few core components being purpose-designed solely for it, that were brought together to create a four-engined heavy bomber while using already-available components. Two prototype Ju 488s had been completed by the start of the summer of 1944, but were each sabotaged to unairworthy status by the French resistance by mid-July of 1944, before either one had ever been flown.
In April 1944, simultaneously with the four He 177B prototypes either flying (He 177 V101 to V103) or nearing completion (V104) at the Heinkel-Sud facility at Schwechat, the RLM ordered Heinkel to cease any further work on the He 277 project, and all components were also ordered to be scrapped, without any complete examples of the 277 ever having been completed by Heinkel.
Heinkel
Heinkel Flugzeugwerke was a German aircraft manufacturing company founded by and named after Ernst Heinkel. It is noted for producing bomber aircraft for the Luftwaffe in World War II and for important contributions to high-speed flight.-History:...
He 277 was a four-engine, long range heavy bomber
Heavy bomber
A heavy bomber is a bomber aircraft of the largest size and load carrying capacity, and usually the longest range.In New START, the term "heavy bomber" is used for two types of bombers:*one with a range greater than 8,000 kilometers...
design, a derivative of the He 177
Heinkel He 177
The Heinkel He 177 Greif was the only operational long-range bomber to be operated by the Luftwaffe. Starting its existence as Germany's first purpose-built heavy bomber just before the war, and built in large numbers during World War II, it was also mistakenly tasked, right from its beginnings,...
, intended for production and use by the German
Nazi Germany
Nazi Germany , also known as the Third Reich , but officially called German Reich from 1933 to 1943 and Greater German Reich from 26 June 1943 onward, is the name commonly used to refer to the state of Germany from 1933 to 1945, when it was a totalitarian dictatorship ruled by...
Luftwaffe
Luftwaffe
Luftwaffe is a generic German term for an air force. It is also the official name for two of the four historic German air forces, the Wehrmacht air arm founded in 1935 and disbanded in 1946; and the current Bundeswehr air arm founded in 1956....
during World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
. The main difference was in engine configuration. Rather than using two fire-prone Daimler-Benz DB 606 "power system" engines, each of which consisted of side-by-side paired Daimler-Benz DB 601
Daimler-Benz DB 601
|-See also:-Bibliography:* Mankau, Heinz and Peter Petrick. Messerschmitt Bf 110, Me 210, Me 410. Raumfahrt, Germany: Aviatic Verlag, 2001. ISBN 3-92550-562-8.* Neil Gregor Daimler-Benz in the Third Reich. Yale University Press, 1998-External links:...
s, the He 277 was meant from the outset to use four BMW 801E
BMW 801
The BMW 801 was a powerful German air-cooled radial aircraft engine built by BMW and used in a number of German military aircraft of World War II. The engine's cylinders were in two rows of seven cylinders each, the bore and stroke were both 156 mm , giving a total capacity of 41.8 litres...
14-cylinder radial engine
Radial engine
The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders point outward from a central crankshaft like the spokes on a wheel...
s, each mounted in an individual nacelle
Nacelle
The nacelle is a cover housing that holds engines, fuel, or equipment on an aircraft. In some cases—for instance in the typical "Farman" type "pusher" aircraft, or the World War II-era P-38 Lightning—an aircraft's cockpit may also be housed in a nacelle, which essentially fills the...
and each turning a three blade, four-meter diameter propeller. The design was never produced, owing both to the deteriorating condition of the German aviation industry late in the war, and the competition from other long-range bomber designs from other firms, competing for Germany's increasingly scarce aviation production capacity. Although not specifically built for it at first, partially due to the time-frame in the spring of 1942 in which its ultimate niche was requested for by the RLM, the He 277 essentially became Heinkel's entry in the important trans-oceanic range Amerika Bomber
Amerika Bomber
The Amerika-Bomber project was an initiative of the Reichsluftfahrtministerium, the Nazi Germany Air Ministry, to obtain a long-range strategic bomber for the Luftwaffe that would be capable of striking the continental United States from Germany, a range of about 5,800 km...
competition, struggling to compete against both several other designs from rival firms in the competition for a truly trans-oceanic ranged bomber for the Luftwaffe, and Germany's own rapidly degrading ability, from Allied bombing damage to its aviation plants, to produce military aircraft of any sort.
The "He 177B" versus He 277 controversy
For many years after the war, a substantial number of aviation history books and magazine articles that dealt with late World War II German military aviation developments consistently stated that Reichsmarschall Hermann Goering, early in World War II, was becoming so frustrated by the 177A's ongoing engine problems, caused by the twin DB 606 "coupled" powerplants selected for the He 177A design in the pre-war years, that he forbade Ernst HeinkelErnst Heinkel
Dr. Ernst Heinkel was a German aircraft designer, manufacturer, Wehrwirtschaftführer in the Third Reich, and member of the Nazi party. His company Heinkel Flugzeugwerke produced the Heinkel He 178, the world's first turbojet aircraft and jet plane, and the Heinkel He 176, the first rocket aircraft...
from doing any work on a separately four-engined version of the 177 airframe, or even mentioning a new "He 277" design with four separate engines - by one account, in the late autumn of 1941 - until Heinkel brought the disagreement directly to Adolf Hitler
Adolf Hitler
Adolf Hitler was an Austrian-born German politician and the leader of the National Socialist German Workers Party , commonly referred to as the Nazi Party). He was Chancellor of Germany from 1933 to 1945, and head of state from 1934 to 1945...
, who supposedly not only approved of calling the new, separately engined version of the 177 the "He 277", but overruled Goering's prohibition on working on the design (previously called the "He 177B" by Heinkel as a "cover designation" to hide its existence from Goering, and the RLM
Reich Air Ministry
thumb|300px|The Ministry of Aviation, December 1938The Ministry of Aviation was a government department during the period of Nazi Germany...
.)
Statements by Goering himself in August 1942, however, seem to directly contradict elements of the oft-repeated story, as those statements seem to show that Goering thought that the He 177A actually had four separate engines, and derisively labeled the He 177A's coupled engine arrangements, the DB 606 and DB 610 "power systems" at that time as zusammengeschweißte motoren, or "welded-together engines", in his complaints about the He 177A's ongoing engine difficulties, and was anxious to see a truly four-engined version of Heinkel's heavy bomber fully developed and in production.
Facts that could have fostered the origin of the post-war aviation book storyline about the "He 177B"/He 277 controversy were that the RLM, in listing the He 177 development projects that they approved of the Heinkel firm doing work on as of February 1943 (six months after Goering's recorded engine complaint statements), only included the He 177 A-5 heavy bomber, A-6 high-altitude bomber, A-7 long-range version, and the "He 277" itself, with the RLM also expecting, during the late spring of 1943 (about one year after the mid-Spring 1942 Amerika Bomber proposal first arrived in Goering's offices) that a trio of He 277 V-series prototype aircraft, and construction of ten pre-production A-0 series machines were to be completed, as well as "progressive development" of the still-unbuilt and unfinalized design, were anticipated as coming from Heinkel's Schwechat
Schwechat
Schwechat is a city south-east of Vienna known for the Vienna International Airport and Schwechater beer. It is also home to the refineries belonging to the Austrian national oil company OMV.- Geography :...
southern plant complex in Austria. The initial starting place for the He 277's fuselage design had been meant to originate with the last "coupled-engine" proposed variant of the He 177 itself, the long-range A-7, which itself was to be the basis for a four-engined variant of the Greif as the He 177A-10, then redesignated the He 177B-7 in the late summer of 1943. The considerable changes in the He 277's overall design philosophy evolved after the Amerika Bomber proposal's emergence in May 1942, from the changes in the He 277's general arrangement proposal drawings during that time period. The original proposal, which was meant to use the He 177A-7's fuselage as the starting point, evolved into designing a dedicated, new and wider He 219
Heinkel He 219
The Heinkel He 219 Uhu was a night fighter that served with the German Luftwaffe in the later stages of World War II. A relatively sophisticated design, the He 219 possessed a variety of innovations, including an advanced VHF-band intercept radar...
-general pattern fuselage layout for the 277 from the Spring 1943 timeframe onward, which would be more capable of using a tricycle undercarriage then gaining favor with a few German aviation designers, even with the 277 not known to have been specifically considered by the RLM in the earlier timeframe for the Amerika Bomber proposal.
The main factor that seemingly required the lower-drag "coupled" powerplant format for the He 177A, the diving attack mandate by the RLM, which Heinkel himself vehemently disagreed with, was rescinded by Goering himself some five months before the "He 277"'s earliest-known February 1943 RLM approval date, and Heinkel started work on the He 177B as a straightforward, separately four-engined development of the 177A under the B-series designation at least as early as the late summer of 1943, when official Heinkel documents began referring to the He 177B, evidenced from an August 1943-dated, Heinkel factory-created general arrangement drawing of the He 177 V101 being labeled with the 8-177 RLM designation for the entire line of Greif airframes, and "B-5" elsewhere in the drawing's title block, as a fully RLM approved development of the original He 177 aircraft line, and not in any way directly related to the entirely separate He 277 advanced bomber design project, which by the summer of 1943 was considered to be Heinkel's Amerika Bomber aviation contract contender.
In total, there were three separate efforts, the movement toward which had been initiated by Herr Heinkel himself as early as November 1938, to develop "true four-engined versions" of the A-series Greif: the He 177B, which culminated in four prototype examples being built, with three getting airborne before the war's end; the He 274, of which only two prototypes were started before the end of World War II and completed and flown in France after the war's end; and the He 277, for which only had a few airframe parts had been in the process of completion, with no completed prototypes at any time, before or after the end of the war.
The He 277 design's features
The general arrangement "Typenblatt" drawings that Heinkel's firm was developing for the He 277 show an advanced design of heavy bomber, with a 133 square meter area (1.431.6 sq. ft.) "shoulder mount", 40 meter (131 ft 3 in) span wing design, four separate BMW 801EBMW 801
The BMW 801 was a powerful German air-cooled radial aircraft engine built by BMW and used in a number of German military aircraft of World War II. The engine's cylinders were in two rows of seven cylinders each, the bore and stroke were both 156 mm , giving a total capacity of 41.8 litres...
powerplants of 1,471 kW (2,000 PS, 1,973 hp) output each at take-off, with each engine turning a propeller of up to four meters in diameter, a fully retracting conventional or nosewheel landing gear, with main gear assemblies that possessed twinned main wheels on each unit, retracting forward (for the nosewheel version, rearwards for a conventional gear arrangement) into the inner engine nacelles, and a heavily glazed and "greenhouse"-framed clear view "stepless" cockpit. Its fully glazed front section somewhat resembled a blended combination of an aerodynamically refined, rounded-off well-framed version of the Bristol Blenheim
Bristol Blenheim
The Bristol Blenheim was a British light bomber aircraft designed and built by the Bristol Aeroplane Company that was used extensively in the early days of the Second World War. It was adapted as an interim long-range and night fighter, pending the availability of the Beaufighter...
Mk.I's fully glazed "stepless" nose shape, and pilot accommodation-enclosing upper section somewhat resembling what was used on the British Avro Lancaster
Avro Lancaster
The Avro Lancaster is a British four-engined Second World War heavy bomber made initially by Avro for the Royal Air Force . It first saw active service in 1942, and together with the Handley Page Halifax it was one of the main heavy bombers of the RAF, the RCAF, and squadrons from other...
heavy bomber, with a rearward extension atop the fuselage to just forward of the inner engine cowls. The fuselage outlines themselves were deep, and almost slab-sided in cross-section, with its general sideview profile lines being strongly reminiscent of the smaller He 219
Heinkel He 219
The Heinkel He 219 Uhu was a night fighter that served with the German Luftwaffe in the later stages of World War II. A relatively sophisticated design, the He 219 possessed a variety of innovations, including an advanced VHF-band intercept radar...
night fighter, in a sort-of "Heinkel-familial" manner with the smaller aircraft. This similarity with the 219 even extended to the depictions of the He 277's fuselage-mounted defensive armament emplacements as proposed by Heinkel, with one forward and two aft-facing "steps" along the slightly rounded dorsal and ventral surfaces of the fuselage, much like the smaller night fighter's earliest prototypes had, for the 277's manned aft dorsal and remote aft ventral turret defensive weapons mounts, and a twin tail
Twin tail
A twin tail is a specific type of vertical stabilizer arrangement found on the empennage of some aircraft. Two vertical stabilizers — often smaller on their own than a single conventional tail would be — are mounted at the outside of the aircraft's horizontal stabilizer...
empennage
Empennage
The empennage , also known as the tail or tail assembly, of most aircraft gives stability to the aircraft, in a similar way to the feathers on an arrow...
assembly that added aerodynamic stability, and made mounting a traversable defensive tail turret easier.
In a May 1943 Heinkel factory document showing possible offensive bombload configurations and flight consumable (fuel, etc.) weights for the He 277, two differing bomb bay sizes (interior dimensions of 1.5 x 7.5 meters for the He 277's tailwheel version, and 1.75 x 7.0 meters for the tricycle undercarriage version) were considered, with the latter bomb bay configuration existing within a 1.90 meter width fuselage. The lightest warload of six 500 kg (1,100 lb) SC 500 bombs for each bomb bay configuration, gave the tricycle-geared, 1.9 meter exterior width wider-fuselage version, considering a larger load (12,200 kg/26,895 lb) of fuel, a possible stated maximum range of 11100 km (6,897.2 mi), equalling the potential range capability of the earlier-designed Me 261
Messerschmitt Me 261
-References:NotesBibliography* Donald, David, ed. Warplanes of the Luftwaffe. London: Aerospace Publishing, 1994. ISBN 1-874023-56-5.* Green, William. Warplanes of the Third Reich. New York: Galahad Books, 1986. ISBN 0-88365-666-3...
, an indicator of what could have been achieved had the 277 been in full consideration from its beginnings, for the Amerika Bomber design competition.
Defensive armament comprised, as envisioned, a forward, remotely operated "chin turret" under the extreme nose with twin MG 151/20
MG 151 cannon
The MG 151 was a 15 mm autocannon produced by Waffenfabrik Mauser starting in 1940. It was in 1941 developed into the 20 mm MG 151/20 cannon which was widely used on many types of German Luftwaffe fighters, fighter bombers, night fighters, ground attack and even bombers as part of or as...
cannon much as the 177B-series was intended to use, twin dorsal turrets each armed with a pair of MG 151/20 cannon, a ventral turret for lower rearwards defense, just behind the bomb bay's rear edge with another pair of MG 151/20 cannon, and a manned HL 131V tail turret with a quartet of MG 131 heavy machine guns.
Competing bomber designs
Throughout the time that the He 277 design was being worked on, Ernst Heinkel was facing competition from other developing heavy bomber designs, and large four-engined aircraft proposals that showed promise as heavy bombers, from Focke Wulf (the Fw 300Focke-Wulf Fw 300
-See also:-References:* Herwig, Dieter and Rode, Heinz. Luftwaffe Secret Projects - Strategic Bombers 1935-45. Midland Publishing Ltd., 2000. ISBN 1-85780-092-3....
, and later, the Ta 400
Focke-Wulf Ta 400
|-See also:-References:NotesBibliography* Griehl, Manfred. Luftwaffe over America. London: Greenhill Books, 2006. ISBN 978-0-7607-8697-0....
), Junkers
Junkers
Junkers Flugzeug- und Motorenwerke AG , more commonly Junkers, was a major German aircraft manufacturer. It produced some of the world's most innovative and best-known airplanes over the course of its fifty-plus year history in Dessau, Germany. It was founded there in 1895 by Hugo Junkers,...
(the Ju 390
Junkers Ju 390
The Junkers Ju 390 was a German aircraft intended to be used as a heavy transport, maritime patrol aircraft, and long-range bomber, a long-range derivative of the Ju 290...
), from Messerschmitt AG (the Me 264
Messerschmitt Me 264
|-See also:-References:NotesBibliography* Duffy, James P. Target: America. Westport, Connecticut: Praeger Publishers, 2004. ISBN 0-275-96684-4....
), and from his own firm's He 274
Heinkel He 274
The Heinkel He 274 was a German Luftwaffe heavy bomber developed during World War II, purpose-designed for high-altitude bombing with pressurized crew accommodation.- He 177 ancestry :...
four-engined, high-altitude development of the He 177.
The first of these designs that the He 277 was pitted against, mostly to determine the "most producible" bomber that could also be license-built, given Germany's limited aircraft production capacity to arm the Luftwaffe with, and partially to determine the best long-range bomber design to fulfill the needs of the spring 1942-issued Amerika Bomber
Amerika Bomber
The Amerika-Bomber project was an initiative of the Reichsluftfahrtministerium, the Nazi Germany Air Ministry, to obtain a long-range strategic bomber for the Luftwaffe that would be capable of striking the continental United States from Germany, a range of about 5,800 km...
program documents, the Messerschmitt Me 264 ended up being the first design to challenge the He 277's chance for production. The Me 264 was a purpose-built long range bomber, using a tricycle landing gear configuration from the start, that was already flying in prototype form with four engines as early as late December 1942, a full year after Nazi Germany had declared war on the United States, five months after the Eighth Air Force
Eighth Air Force
The Eighth Air Force is a numbered air force of the United States Air Force Global Strike Command . It is headquartered at Barksdale Air Force Base, Louisiana....
had begun flying bomber missions against Nazi-occupied France, and two months before the earliest-known mention of RLM approval of the 277 itself.
The four-engined Me 264's development, because of the need to use scarce strategic materials in its construction, and because of the better performance estimates that the Focke-Wulf Ta 400 and He 277 possessed, was stopped in May 1943.
Because of the US involvement in the European Theater, the Luftwaffe now found that it had a serious need for a well-armed, long range bomber, which the Luftwaffe found could not be achieved with the 1,120 kW (1,500 hp) class engines it had for such a four-engined bomber, and that six engines of that same class would be needed on a strategic bomber design for a successful mission from Europe to attack the US and safely return to base, with enough of an offensive bombload to be effective, and to have enough defensive firepower for protection for a safe return. The Blohm & Voss firm's aviation division had already settled on six engines with success, as early as 1940, on the prototypes of the Bv 222 Wiking flying boat
Flying boat
A flying boat is a fixed-winged seaplane with a hull, allowing it to land on water. It differs from a float plane as it uses a purpose-designed fuselage which can float, granting the aircraft buoyancy. Flying boats may be stabilized by under-wing floats or by wing-like projections from the fuselage...
maritime patrol aircraft. This emerging need for six engines for such an aircraft was also recognized by Messerschmitt AG, when that firm fielded a paper project for a six-engined "Me 264B", that had a stretched wingspan outwards to 47.5 meters (155 ft 10 in), with two additional BMW 801 radial engines outboard of the existing four powerplants.
In March 1943, Focke-Wulf came up with a six-engined version of their proposed Fw 300 bomber, originally powered with just four BMW 801E radials. Their more advanced Ta 400 design, first proposed in October 1943 with a tricycle landing gear setup and meant to be powered with a half-dozen of the same engines as the 277 was meant to use, was joined by the Ju 390, a Junkers six-engined version of the developed version of their early-war Junkers Ju 90
Junkers Ju 90
The Junkers Ju 90 was a 40-seat, four-engine airliner developed for and used by Deutsche Luft Hansa shortly before World War II. It was based on the rejected Ju 89 bomber...
airliner, the operational Junkers Ju 290
Junkers Ju 290
The Junkers Ju 290 was a long-range transport, maritime patrol aircraft and heavy bomber used by the Luftwaffe late in World War II.-Design and development:...
maritime patrol bomber, and also using six of the same BMW radials as the 277.
By October 1943, Ernst Heinkel had compared the Messerschmitt and Junkers four-engined designs, and the six-engined Bv 222, Ju 390 and Ta 400 designs to his own He 277 project, with the following conclusions:
Of these competing types, only three of the Me 264 design, and a verified pair of the Ju 390 aircraft were ever built, solely as flyable prototypes, and none of these aircraft saw any action against the Allies.
The He 274, because of its own intended high-altitude role, was only a potential competitor with the He 277 for Heinkel's own company engineering and production staff, and the He 274's production had already been outsourced by the end of 1941 to the French Societe Anonyme des Usines Farman, or "SAUF" firm in Suresnes
Suresnes
Suresnes is a commune in the western suburbs of Paris, France. It is located from the center of Paris. The nearest communes are Neuilly-sur-Seine, Puteaux, Rueil-Malmaison, Saint-Cloud and Boulogne-Billancourt...
to partially allow Heinkel to work on other projects, like the He 277 and the more advanced Heinkel He 343
Heinkel He 343
The Heinkel He 343 was a four-engine jet bomber project.-Design and development:It was designed by the German Ernst Heinkel Flugzeugwerke in the beginning of 1944. 20 of these aircraft were ordered. For shortening the development time and for re-use of existing parts, its general design was...
jet powered medium bomber design.
End of the He 277 project
The last competing aircraft design that threatened the He 277's chance for increasingly scarce production capacity was the Junkers Ju 488Junkers Ju 488
-References:* Filly, Brian. Junkers Ju 88 in Action, part 2. Carrollton, TX: Squadron/Signal Publications, Inc., 1991.* Green, William. War Planes of the Second World War:Volume Ten Bombers and Reconnaissance Aircraft. London:Macdonald, 1968....
, a composite of earlier developments of the Junkers Ju 88 twin-engined fast medium bomber
Schnellbomber
A Schnellbomber is a high-speed bomber. The concept developed in the 1930s when it was believed that a very fast bomber could simply outrun its enemies....
design, with a few core components being purpose-designed solely for it, that were brought together to create a four-engined heavy bomber while using already-available components. Two prototype Ju 488s had been completed by the start of the summer of 1944, but were each sabotaged to unairworthy status by the French resistance by mid-July of 1944, before either one had ever been flown.
In April 1944, simultaneously with the four He 177B prototypes either flying (He 177 V101 to V103) or nearing completion (V104) at the Heinkel-Sud facility at Schwechat, the RLM ordered Heinkel to cease any further work on the He 277 project, and all components were also ordered to be scrapped, without any complete examples of the 277 ever having been completed by Heinkel.
Specifications (He 277 basic configuration)
See also
- Amerika BomberAmerika BomberThe Amerika-Bomber project was an initiative of the Reichsluftfahrtministerium, the Nazi Germany Air Ministry, to obtain a long-range strategic bomber for the Luftwaffe that would be capable of striking the continental United States from Germany, a range of about 5,800 km...
External links
- http://www.century-of-flight.net/Aviation%20history/photo_albums/timeline/ww2/Heinkel%20He%20277.htm (contains elements from the controversy mentioned at the start of this article)