The Heinkel He 277 was a four-engine, long-range
heavy bomber
Heavy bombers are bomber aircraft capable of delivering the largest payload of air-to-ground weaponry (usually bombs) and longest range (takeoff to landing) of their era. Archetypal heavy bombers have therefore usually been among the larges ...
design, originating as a derivative of the
He 177
The Heinkel He 177 ''Greif'' (Griffin) was a long-range heavy bomber flown by the ''Luftwaffe'' during World War II. The introduction of the He 177 to combat operations was significantly delayed, by both problems with the development of its ...
, intended for production and use by the
German
German(s) may refer to:
* Germany (of or related to)
**Germania (historical use)
* Germans, citizens of Germany, people of German ancestry, or native speakers of the German language
** For citizens of Germany, see also German nationality law
**Ger ...
Luftwaffe
The ''Luftwaffe'' () was the aerial-warfare branch of the German ''Wehrmacht'' before and during World War II. Germany's military air arms during World War I, the ''Luftstreitkräfte'' of the Imperial Army and the '' Marine-Fliegerabtei ...
during
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...
. The main difference was in its engines. The He 177 used two Daimler-Benz DB 606 "power system" engines, each of which consisted of two combined
Daimler-Benz DB 601
The Daimler-Benz DB 601 was a German aircraft engine built during World War II. It was a liquid-cooled inverted V12 engine, V12, and powered the Messerschmitt Bf 109, Messerschmitt Bf 110, and many others. Approximately 19,000 601's were pr ...
engines, each DB 606 weighed 1.5 tons. The He 177A-3 and its successors used two DB 610 "power system" engines, each of which consisted of two combined
Daimler-Benz DB 605
The Daimler-Benz DB 605 is a German aircraft engine built during World War II. Developed from the DB 601, the DB 605 was used from 1942 to 1945 in the Messerschmitt Bf 109 fighter, and the Bf 110 and Me 210C heavy fighters.
The DB 610, a p ...
engines, each DB 610 weighed 1.5 tons. Due to problems with both the DB 606 and the DB 610, the He 277 was intended to use four
unitized BMW 801E
The BMW 801 was a powerful German air-cooled 14-cylinder-radial aircraft engine built by BMW and used in a number of German Luftwaffe aircraft of World War II. Production versions of the twin-row engine generated between 1,560 and 2,000 PS ( ...
14-cylinder
radial engine
The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders "radiate" outward from a central crankcase like the spokes of a wheel. It resembles a stylized star when viewed from the front, and is ca ...
s, each mounted in an individual
nacelle
A nacelle ( ) is a "streamlined body, sized according to what it contains", such as an engine, fuel, or equipment on an aircraft. When attached by a pylon entirely outside the airframe, it is sometimes called a pod, in which case it is attached ...
and each turning a three-blade, four-meter diameter propeller.
The design was never produced and no prototype airframe was completed.
[Griehl & Dressel 1998, p. 203] The deteriorating condition of the German aviation industry late in the war and the competition from other long-range bomber designs from other firms, led to the design being cancelled. Although not specifically intended 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 ''
Reichsluftfahrtministerium
The Ministry of Aviation (german: Reichsluftfahrtministerium, abbreviated RLM) was a government department during the period of Nazi Germany (1933–45). It is also the original name of the Detlev-Rohwedder-Haus building on the Wilhelmstrasse ...
'' (RLM), the He 277 design became Heinkel's entry in the important trans-oceanic range ''
Amerikabomber
The ''Amerikabomber'' () project was an initiative of the German Ministry of Aviation (''Reichsluftfahrtministerium'') to obtain a long-range strategic bomber for the ''Luftwaffe'' that would be capable of striking the United States (specificall ...
'' competition, struggling to compete against other designs from rival firms in the competition for a truly trans-oceanic ranged bomber for the Luftwaffe.
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 Göring
Hermann Wilhelm Göring (or Goering; ; 12 January 1893 – 15 October 1946) was a German politician, military leader and convicted war criminal. He was one of the most powerful figures in the Nazi Party, which ruled Germany from 1933 to 1 ...
, 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 Heinkel
Dr. Ernst Heinkel (24 January 1888 – 30 January 1958) was a German aircraft designer, manufacturer, ''Wehrwirtschaftsführer'' in Nazi Germany, and member of the Nazi party. His company Heinkel Flugzeugwerke produced the Heinkel He 178, th ...
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 (; 20 April 188930 April 1945) was an Austrian-born German politician who was dictator of Nazi Germany, Germany from 1933 until Death of Adolf Hitler, his death in 1945. Adolf Hitler's rise to power, He rose to power as the le ...
, who supposedly not only approved of calling the new, separately engined version of the 177 the "He 277", but overruled Göring's prohibition on working on the design (previously called the "He 177B" by Heinkel as a "cover designation" to hide its existence from Göring, and the
RLM.)
![Bundesarchiv Bild 183-B19957, Edgar Petersen](https://upload.wikimedia.org/wikipedia/commons/1/12/Bundesarchiv_Bild_183-B19957%2C_Edgar_Petersen.jpg)
Statements by Göring himself in August 1942 in response to ''
Oberst
''Oberst'' () is a senior field officer rank in several German-speaking and Scandinavian countries, equivalent to colonel. It is currently used by both the ground and air forces of Austria, Germany, Switzerland, Denmark, and Norway. The Swedish ...
''
Edgar Petersen __NOTOC__
Edgar Petersen (26 April 1904 – 10 June 1986) was a German bomber pilot in the Luftwaffe during World War II and recipient of the Knight's Cross of the Iron Cross of Nazi Germany.
Biography
Petersen was instrumental, as ''Geschwaderko ...
's reports - in his capacity as the ''Kommandeur der Erprobungstellen'' (commander of all Luftwaffe test stations), themselves headquartered at
''Erprobungsstelle Rechlin'' - on solving
the serious problems with the original Heinkel He 177A's powerplants, however, seem to directly contradict elements of the oft-repeated story, as those statements seem to show that Göring thought that the He 177A actually had four separate engines, and in late August 1942 Göring derisively labeled the He 177A's coupled engine arrangements, the 1.5 tonnes-apiece DB 606 and DB 610 "power systems" at that time as monstrous ''zusammengeschweißte Motoren'', or "welded-together engines",
[Griehl & Dressel 1998, pp. 52–53] 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. The earliest-dated initiative to be undertaken by Ernst Heinkel himself to trial a true "four-engined" design format for the original He 177 dated back to 17 November 1938, before the construction of the He 177 V3 and V4 prototype airframes had even been started, when Heinkel had personally asked the
RLM to set aside the He 177 V3 and V4 airframes for a trial installation of four separate
unitized Junkers Jumo 211
The Jumo 211 was a German inverted V-12 aircraft engine, Junkers Motoren's primary aircraft engine of World War II. It was the direct competitor to the Daimler-Benz DB 601 and closely paralleled its development. While the Daimler-Benz engine ...
[Griehl and Dressel 1998, p. 14.] powerplants to overcome the concerns that the RLM ''Technischen-Amt'' technical department's director
Ernst Udet
Ernst Udet (26 April 1896 – 17 November 1941) was a German pilot during World War I and a ''Luftwaffe'' Colonel-General (''Generaloberst'') during World War II.
Udet joined the Imperial German Air Service at the age of 19, and eventually ...
and Heinkel had expressed about the RLM's specific dive-bombing priority for the He 177A, but was turned down for the trial fitment.
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 Göring's recorded engine complaint statements, and 18 months after the first-ever consideration by the RLM for any He 177 proposed variant to have four "individual" powerplants, as the paper-only "He 177H" high-altitude predecessor to the later He 274 in October 1941,
[Griehl & Dressel 1998, p. 177] only included the He 177 A-5 heavy bomber, A-6 high-altitude bomber, A-7 long-range version, and the "He 277" itself, defining the February 1943 date as the earliest reliable date of any official German government mention of such an "He 277"-designated aircraft, as this date also indicates the time by which the RLM had issued the Heinkel firm
the ''8-277'' airframe design number for the project.
[Griehl & Dressel 1998, p. 179] The RLM was also expecting, during the late spring of 1943 — about one year after the mid-Spring 1942 ''Amerikabomber'' proposal first arrived in Göring's offices — that a trio of He 277 V-series prototype aircraft, and construction of ten pre-production He 277A-0 series service test 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 () is a town southeast of Vienna known for the Vienna International Airport and Schwechater beer. The city is home to the refineries of the Austrian national oil company OMV.
Geography
Schwechat is named after the river Schwechat, whi ...
southern plant complex in Austria.
[Griehl & Dressel 1998, p. 104] 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,
[Griehl & Dressel 1998, p. 196] 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, as both the A-7 and B-7 had omitted the manned rear dorsal turret of the earlier A-series versions for lighter weight.
The considerable changes in the He 277's overall design philosophy evolved after the ''Amerikabomber'' 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
The Heinkel He 219 ''Uhu'' (" Eagle-Owl") is 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 Lichtenstein S ...
-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 ''Amerikabomber'' 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 Ernst Heinkel vehemently disagreed with since the original ''Greif's'' beginnings in the late 1930s, was rescinded by Göring himself some five months ''before'' the "He 277's" earliest-known February 1943 RLM approval date. The Heinkel firm 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 ''Typenblatt'' 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,
[Griehl & Dressel 1998, p. 166] 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 ''Amerikabomber'' aviation contract contender. The first development of the original He 177A to fly with four "individual" engines – using a quartet of
He 219
The Heinkel He 219 ''Uhu'' (" Eagle-Owl") is 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 Lichtenstein S ...
-style annular radiators to cool its likely-
unitized Daimler-Benz DB 603
The Daimler-Benz DB 603 was a German aircraft engine used during World War II. It was a liquid-cooled 12-cylinder inverted V12 enlargement of the DB 601, which was in itself a development of the DB 600. Production of the DB 603 commenced in ...
powerplants – was the second He 177B prototype, the He 177 V102, on December 20, 1943.
[Griehl & Dressel 1998, p. 163]
Trio of separate efforts
In total, there were three separate efforts, the movement toward which had been initiated by Ernst Heinkel 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 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.
Design features
![Duxford Blenheim](https://upload.wikimedia.org/wikipedia/commons/2/29/Duxford_Blenheim.jpg)
The general arrangement ''Typenblatt'' drawings that Heinkel's firm was developing for the He 277 by mid-1943 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 801
The BMW 801 was a powerful German air-cooled 14-cylinder-radial aircraft engine built by BMW and used in a number of German Luftwaffe aircraft of World War II. Production versions of the twin-row engine generated between 1,560 and 2,000 PS ( ...
E 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. The undercarriage options considered for the design included either 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. The Heinkel firm's previous experience with designing flightworthy, retractable tricycle undercarriage-equipped airframes extended as far back as late 1939 with the
Heinkel He 280
The Heinkel He 280 was the first turbojet-powered fighter aircraft in the world. It was inspired by Ernst Heinkel's emphasis on research into high-speed flight and built on the company's experience with the He 178 jet prototype. A combination ...
jet fighter prototype, and further strengthened with the unexpectedly successful
Heinkel He 219
The Heinkel He 219 ''Uhu'' (" Eagle-Owl") is 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 Lichtenstein S ...
A night fighter, which also used a tricycle undercarriage.
The main crew accommodation of the He 277 consisted of a heavily glazed and "greenhouse"-framed clear view "stepless" cockpit, a common feature of many late-war German bomber airframes and new designs. Immediately aft of the heavily glazed nose, the cockpit glazing over the crew seating and pilot accommodation-enclosing upper section that was blended with the nose glazing's contours, protruding above the 277's forward dorsal fuselage decking level, with a rearward extension atop the fuselage that faired-in the forward upper dorsal turret's forward surface, extending rearwards 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
The Heinkel He 219 ''Uhu'' (" Eagle-Owl") is 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 Lichtenstein S ...
night fighter. 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 — the aft ventral emplacement being moved rearwards by roughly two meters, in comparison with the early He 219V-series prototypes, to accommodate the aft end of the He 277's bomb bay. The
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 aircra ...
empennage
The empennage ( or ), also known as the tail or tail assembly, is a structure at the rear of an aircraft that provides stability during flight, in a way similar to the feathers on an arrow.Crane, Dale: ''Dictionary of Aeronautical Terms, third ed ...
assembly of the He 219 night fighter was also a likely inspiration for the 277's own similar unit, that added aerodynamic stability when compared to the 177A's single vertical tail — proven to be true from the first flights of the He 177B-series' four-engined He 177 V102 twin-tailed prototype from late December 1943 onwards — and made mounting a powered traversable defensive tail turret easier.
[Griehl & Dressel 1998, p. 195] Provision was shown on the Heinkel ''Typenblatt'' general arrangement drawing for a quartet of ETC-family underwing hardpoint racks, two per wing panel on either side of the outboard pair of BMW 801 engines, potentially allowing external ordnance loads or
drop tank
In aviation, a drop tank (external tank, wing tank or belly tank) is used to describe auxiliary fuel tanks externally carried by aircraft. A drop tank is expendable and often capable of being jettisoned. External tanks are commonplace on modern ...
s to extend the bomber's capabilities or range.
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
Tricycle gear is a type of aircraft undercarriage, or ''landing gear'', arranged in a tricycle fashion. The tricycle arrangement has a single nose wheel in the front, and two or more main wheels slightly aft of the center of gravity. Tricycle ge ...
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 , 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 ''Amerikabomber'' design competition.
[Griehl & Dressel 1998, p. 184]
Defensive armament comprised, as envisioned, a five-turret complement of defensive ordnance positions, with only two of these directly manned, and the remainder all remotely operated: a forward, remotely operated ''Fernbedienbare Drehlafette'' FDL 151Z "chin turret" under the extreme nose with twin
MG 151/20
The MG 151 (MG 151/15) was a German 15 mm aircraft-mounted autocannon produced by Waffenfabrik Mauser during World War II. Its 20mm variant, the 20 mm MG 151/20 cannon, was widely used on German Luftwaffe fighters, night fighters, figh ...
cannon much as the 177B-series was intended to use, with a 20º "upwards"-tilted axis of traverse in the turret mount design to provide a small degree of elevated fire, twin dorsal turrets – a second remotely operated FDL 151Z forward emplacement, otherwise similar in appearance to the proposed chin turret, and a manned ''Hydraulische Drehlafette'' HDL 151Z rear dorsal emplacement – each armed with a pair of MG 151/20 cannon, with both dorsal turrets providing aftwards-section defensive fire upwards and to the sides and rear; an aft remotely operated FDL-family ventral turret for lower rearwards defense, just behind the bomb bay's rear edge with another pair of MG 151/20 cannon with the gunner laying prone, facing rearwards in a starboard-side offset position that possessed a slightly-protruding ventral
blister-like gondola for the gunner's position to sight the rear ventral remote turret, and a manned ''Hecklafette'' HL 131V tail turret with a quartet of
MG 131
The MG 131 (shortened from German: ''Maschinengewehr'' 131, or "Machine gun 131") was a German 13 mm caliber machine gun developed in 1938 by Rheinmetall-Borsig and produced from 1940 to 1945. The MG 131 was designed for use at fixed, flexible ...
heavy machine guns. The ''Hecklafette'' four-gun turret had also been planned to be used on some of the other ''Amerikabomber'' competing airframes for their own tail-mounted defensive armament, in addition to Heinkel's own A-6 and A-7 proposed versions of the original He 177A airframe, and the nascent He 177B-5 to be in production at ''
Arado Flugzeugwerke
Arado Flugzeugwerke was a German aircraft manufacturer, originally established as the Warnemünde factory of the Flugzeugbau Friedrichshafen firm, that produced land-based military aircraft and seaplanes during the First and Second World Wars.
Hi ...
'' by November 1944, and meant to be fitted onto not only the incomplete He 177 V104 B-series "finalized" prototype airframe as the B-5's production prototype, but also
a projected "C-version" of the He 219 night fighter. This increasing demand for
an advanced "quadmount" gun turret within the Heinkel firm's own range of late-war combat aircraft designs, that had not even been produced by the Borsig firm responsible for it, beyond a small number of test units and engineering mockups led to an alternative twin-cannon "HL 151Z" version to be planned for. This newly conceived twin-cannon adaptation was meant to use new elevation gun-mount assemblies with the HL 131V's core traverse shell, with each new elevation unit configured to take a single
MG 151/20
The MG 151 (MG 151/15) was a German 15 mm aircraft-mounted autocannon produced by Waffenfabrik Mauser during World War II. Its 20mm variant, the 20 mm MG 151/20 cannon, was widely used on German Luftwaffe fighters, night fighters, figh ...
cannon per turret side. Only a few ground test examples of the twin-cannon variant tail turret had been produced by March 1944. One of these twin-cannon experimental tail turrets was mounted on an He 177A airframe for testing, possibly any of the He 177 V32 through V34 prototypes already configured to take the original HL 131V turret. Some sideview line drawing depictions of purported "He 277" aircraft, usually in the same aviation history volumes that purveyed the erroneous "He 177B/He 277" storyline, also show what could be an early He 177A-7-based depiction of the later ''Amerikabomber'' competitor bearing the He 177A's "Cabin 3" standard cockpit and a quartet of the
He 219
The Heinkel He 219 ''Uhu'' (" Eagle-Owl") is 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 Lichtenstein S ...
-derived
unitized DB 603 inverted V12 engines actually used on the four He 177B-series prototypes (He 177 V101 through V104) for power, with
the abandoned ''Bugstandlafette'' BL 131V quadmount remote turret as a "chin turret" in place of the FDL 151Z system as depicted in the Heinkel firm's factory ''Typenblatt'' drawings — the BL 131V had already been abandoned in 1943 as too heavy (reducing offensive bombload by a full tonne) and slowing the earlier He 177A airframe by some 30 km/h in top airspeed due to drag, making even the chance of its proposed existence on any He 277 design proposals unlikely.
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
Focke-Wulf Flugzeugbau AG () was a German manufacturer of civil and military aircraft before and during World War II. Many of the company's successful fighter aircraft designs were slight modifications of the Focke-Wulf Fw 190. It is one of the ...
(the
Fw 300, and later, the
Ta 400),
Junkers
Junkers Flugzeug- und Motorenwerke AG (JFM, earlier JCO or JKO in World War I, English: Junkers Aircraft and Motor Works) more commonly Junkers , was a major German aircraft and aircraft engine manufacturer. It was founded there in Dessau, Germ ...
(the
Ju 390), from
Messerschmitt AG
Messerschmitt AG () was a German share-ownership limited, aircraft manufacturing corporation named after its chief designer Willy Messerschmitt from mid-July 1938 onwards, and known primarily for its World War II fighter aircraft, in partic ...
(the
Me 264), and from his own firm's
He 274
The Heinkel He 274 was a Nazi Germany, German heavy bomber design developed during World War II, purpose-designed for high-altitude bombing with pressurized crew accommodation.
Due to the Allied advance through Northwest Europe, the prototypes ...
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 ''
Amerikabomber
The ''Amerikabomber'' () project was an initiative of the German Ministry of Aviation (''Reichsluftfahrtministerium'') to obtain a long-range strategic bomber for the ''Luftwaffe'' that would be capable of striking the United States (specificall ...
'' 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. The Me 264 prototypes were already flying their test programs with power of exactly the same choice that Heinkel had asked for on November 17, 1938,
for the He 177 V3 and V4 prototypes: with four
Junkers Jumo 211
The Jumo 211 was a German inverted V-12 aircraft engine, Junkers Motoren's primary aircraft engine of World War II. It was the direct competitor to the Daimler-Benz DB 601 and closely paralleled its development. While the Daimler-Benz engine ...
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
The Eighth Air Force (Air Forces Strategic) is a numbered air force (NAF) of the United States Air Force's Air Force Global Strike Command (AFGSC). It is headquartered at Barksdale Air Force Base, Louisiana. The command serves as Air Force ...
had begun flying bomber missions against
Nazi-occupied France
The Military Administration in France (german: Militärverwaltung in Frankreich; french: Occupation de la France par l'Allemagne) was an interim occupation authority established by Nazi Germany during World War II to administer the occupied zo ...
, and two months before the RLM's earliest-known mention of any recorded approval for the He 277 design itself — the later fitment of a quartet of the BMW 801 radials to each example of the trio of Me 264 prototypes also potentially challenged the availability of the same engine design that the He 277 was meant to use, had the Me 264 gone into production with them.
The four-engined Me 264's development, because of the need to use scarce
strategic materials
Strategic material is any sort of raw material that is important to an individual's or organization's strategic plan and supply chain management. Lack of supply of strategic materials may leave an organization or government vulnerable to disru ...
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.
[Griehl & Dressel 1998, p. 187]
Because of the US involvement in the European Theater commencing in mid-August 1942, 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 on hand for such a four-engined bomber. Such ongoing difficulties in
developing high-output aviation powerplants of over 1,500 kW apiece, that could be used in combat with proven reliability — which excluded the DB 606 engines of the earlier He 177A variants, which themselves proved to be seriously troublesome from the start of the He 177A's combat service in 1942 — meant that six engines of the under-1,500 kW (2,000 PS) power output levels that they could produce 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 to achieve a safe return.
[Griehl & Dressel 1998, p. 188] It was events on the date of July 3, 1943 that seemed to cement this viewpoint in the RLM's mind – no production decisions on the still-unfinalized He 277's design had emerged by that date, and the continuing problems in Dessau with the high-output
Junkers Jumo 222
The Jumo 222 was a German high-power multiple-bank in-line piston aircraft engine from Junkers, designed under the management of Ferdinand Brandner of the Junkers Motorenwerke.
Such was the projected performance of the engine compared to c ...
engine had set back its development, making its use with the He 277, first proposed on that date, even more problematic. The
Blohm & Voss
Blohm+Voss (B+V), also written historically as Blohm & Voss, Blohm und Voß etc., is a German shipbuilding and engineering company. Founded in Hamburg in 1877 to specialise in steel-hulled ships, its most famous product was the World War II battle ...
firm's aviation division had already settled on six engines with success, as early as 1940, on the prototypes of the
BV 222
The Blohm & Voss BV 222 ''Wiking'' (Pronounced "Veeking") was a large, six-engined German flying boat of World War II. Originally designed as a commercial transport, it was the largest German seaplane to attain production status during the war. ...
''Wiking''
flying boat
A flying boat is a type of fixed-winged seaplane with a hull, allowing it to land on water. It differs from a floatplane in that a flying boat's fuselage is purpose-designed for floatation and contains a hull, while floatplanes rely on fusela ...
maritime patrol aircraft, itself possessing a substantial 46 meter wingspan, with 255 square meters of area. 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 and the same ''Hecklafette'' four-gun tail turret as the He 277. Eventually, the Heinkel firm received an order on
July 23, 1943 from the
Reich Air Ministry
The Ministry of Aviation (german: Reichsluftfahrtministerium, abbreviated RLM) was a government department during the period of Nazi Germany (1933–45). It is also the original name of the Detlev-Rohwedder-Haus building on the Wilhelmstrasse ...
's technical department (''Technischen Amt'') — for Heinkel's engineering shops to design a set of wings for the 277's unfinalized design that could accept a quartet of the troubled Jumo 222 engines, alongside the still "paper-only" concept also being ordered to be designed and buildable with the desired six-engine format the RLM was now favoring for an ''Amerikabomber'', intended to be upwards of a 170 square meter (1,830 sq. ft.) wing area of 45 meter (147 ft 7 in) span to possibly accommodate either four Jumo 222s or six BMW 801s.
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
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. During the war, the ''Luftwaffe'' impressed them as military transports.
...
airliner, the operational
Junkers Ju 290
The Junkers Ju 290 was a large German, four-engine long-range transport, heavy bomber and maritime patrol aircraft used by the Luftwaffe late in World War II that had been developed from an earlier airliner.
Design and development
The Junkers ...
maritime patrol bomber, and also using six of the same BMW radials as the 277, with both the earlier four-engined A-8 variant of the Ju 290, and the Ju 390A-1 each meant to have a pair of the He 277's ''Hecklafette'' quad-gun tail turrets, but with one each in the planned tail position an
in a new nose-mount version
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 mentioned by Dr. Heinkel — outside of the thirteen BV 222 six-engined maritime patrol flying boats actually built — 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 () is a commune in the western suburbs of Paris, Île-de-France. Located in Hauts-de-Seine, from the centre of Paris, it had a population of 49,145 as of 2016. The nearest communes are Nanterre, Puteaux, Rueil-Malmaison, Saint-Cloud an ...
to partially allow Heinkel to work on other projects, like the He 277 and the more advanced
Heinkel He 343
The Heinkel He 343 was a quadjet bomber project designed by the German aircraft manufacturer Ernst Heinkel Flugzeugwerke during the final years of the Second World War. It was intended to perform aerial reconnaissance and fighter-bomber operatio ...
jet powered medium bomber design, both of which each had a few airframe components in the process of manufacture for prototype airframes, but with both designs never able to be completed as flyable aircraft.
End of the project
The last competing aircraft design that threatened the He 277's chance for increasingly scarce production capacity was the
Junkers Ju 488
The Junkers Ju 488 was a proposed four-engined German heavy strategic bomber under development in World War II. It was based on the twin-engined Ju 188 series but with additional engines mounted on a new wing inner section. One prototype was begu ...
, 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.
[Griehl & Dressel 1998, p. 201] 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
The French Resistance (french: La Résistance) was a collection of organisations that fought the German occupation of France during World War II, Nazi occupation of France and the Collaborationism, collaborationist Vichy France, Vichy régim ...
by mid-July 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-Süd'' 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,
only three months before the
''Jägernotprogramm'' took over all German military aircraft production priorities on July 3, 1944 — with only the
Heinkel He 162
The Heinkel He 162 ''Volksjäger'' (German, "People's Fighter") was a German single-engine, jet-powered fighter aircraft fielded by the Luftwaffe in World War II. Developed under the Emergency Fighter Program, it was designed and built quickly ...
''Spatz'' lightweight jet fighter contract winner allowed to progress into production by the RLM from Heinkel's firm from that time forward.
Specifications (He 277 basic configuration)
From Griehl, Manfred and Dressel, Joachim. ''Heinkel He 177-277-274'', Airlife Publishing, Shrewsbury, England 1998, pp. 159 & 184.
''not built/completed, design only''
See also
References
Bibliography
* Green, William. ''Warplanes of the Third Reich''. London: Macdonald and Jane's Publishers Ltd., 1970 (4th Impression 1979). .
* Griehl, Manfred and Dressel, Joachim. ''Heinkel He 177-277-274'', Airlife Publishing, Shrewsbury, England 1998. . (Primary reference for article)
* Gunston, Bill & Wood, Tony. ''Hitler's Luftwaffe''. London: Salamander Books Ltd., 1977. .
* Wagner, Ray and Nowarra, Heinz. ''German Combat Planes: A Comprehensive Survey and History of the Development of German Military Aircraft from 1914 to 1945''. New York: Doubleday, 1971.
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)
{{RLM aircraft designations
Abandoned military aircraft projects of Germany
1940s German bomber aircraft
World War II heavy bombers of Germany
He 277