Heinkel He 277

infobox Aircraft
name =He 277
type =Heavy Bomber
manufacturer =Heinkel


caption =
designer =
first flight =December 1943
introduction =
retired =
status =
primary user =Luftwaffe
more users =
produced =
number built =~15
unit cost =
developed from =Heinkel He 177
variants with their own articles =Heinkel He 274

The Heinkel He 277 was a four-engined derivative of the Heinkel He 177, used 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 engines, which consisted of paired Daimler-Benz DB 601s, the He 277 used four Daimler-Benz DB 603s, each mounted in an individual nacelle. Only a few aircraft were built due to the deteriorating military situation in Germany.

In an effort to overcome the problems being experienced with the DB 606 double engines of the He 177, Heinkel proposed in 1940 that the twin DB 606 engines be replaced by four individual engines. At that time, only the first prototypes of the He 177 were flying, and the RLM could not conceive the possibility that the difficulties encountered by the DB 606 might prove insurmountable. Although the RLM rejected the proposal, work continued unofficially at Heinkel on the He 177B with four individual engines. By late 1941, the tendency of the DB 606 engines to ignite was becoming increasingly serious, but while the RLM agreed to a switch from coupled to individual engines for the Heinkel He 274, as it embodied so much redesign that it no longer possessed any commonality with the Heinkel He 177 from which it originally stemmed, it was adamant in its refusal to allow similar engine changes to the He 177. It was not until May 1943 that official backing for the development of the He 177B was obtained in response to Hitler's request for a heavy bomber to facilitate effective strikes on London by day and night at high altitude. Heinkel claimed that the He 177B would be more than capable of meeting these demands, and was promptly given instructions to proceed immediately with its development and production as the He 277. Converted from an He 177A-3/R2 airframe with four DB 603A engines, the He 277 V1 flew at Vienna-Schwechat in the closing months of 1943. The second prototype, He 277 V2, was a conversion of a standard He 177A-5/R8 airframe and was flown on 28 February 1944. Minor directional instability displayed by the V1 and V2 resulted in the fitting of a twin fin and rudder tail unit to the He 277 V3, which had carried the earlier designation He 177B-5/V101. This aircraft's first flight, marked with the "Stammkennzeichen" (factory radio code) NN+QQ and which had serial number 535 550, was achieved on December 20, 1943. The main production version was to be the He 277B-5/R2 intended for heavy bomber operation over long ranges and powered by four DB 603A engines. Only eight He 277B-5/R2 were completed before all bomber production was terminated in favor of the Emergency Fighter Program.

One notable "paper" development for the He 277 and 274, which was foreseen as early as its existence as the He 177B, was for the changeover to a tricycle landing gear with the twin-tail versions. A general arrangement drawing proposal of the He 177B-5 and later the He 274, showed a nosewheel arrangement, marking the first (and only known) attempt to contemplate a nosewheel landing gear setup on a German piston-engined bomber in any size during the war, not including the Messerschmitt Me 264 "Amerika-Bomber", despite this feature long being used on American medium bombers such as the B-26 Marauder and B-25 Mitchell. Most projected developments of the He 277 were meant to adhere to the unbelieveably complex four-strut main landing gear system that the original He 177 Greif had used.

Prior to the termination of all bomber development, work had started on two further variants, the B-6 and B-7. The He 277B-6 introduced a longer wingspan with more powerful Junkers Jumo 213F engines rated at 1,536 kW (2,060 hp). Other changes included enlarged fins and rudders and a new fuselage nose of improved aerodynamic shape similar to that of the He 177A-6/R2. The He 277B-7 was a model derived from the He 177A-7 and featuring extended outer wing panels to increase the wingspan to 36.00 m (118 ft 1⅓ in). Only one example of the B-7 was actually completed, this with Daimler-Benz DB 603A engines. The sole B-7 was eventually destroyed to prevent capture by the invading Soviet forces.

pecifications (He 277B-5)

aircraft specifications/switch
plane or copter?=plane
jet or prop?=prop
ref=
crew=7
capacity=
length alt=22.14 m
length main=72 ft 8 in
span alt=31.43 m
span main=103 ft 1¾ in
height alt=6.66 m
height main=21 ft 10½ in
area alt=100.00 m²
area main=1,076.39 ft²
airfoil=
empty weight alt=21,800 kg
empty weight main=48,060 lb
loaded weight alt=
loaded weight main=
useful load alt=
useful load main=
max takeoff weight alt=44,500 kg
max takeoff weight main=98,105 lb
more general=
engine (prop)=Daimler-Benz DB 603A
type of prop=12-cylinder inverted-vee engine
number of props=4
power alt=1,305 kW
power main=1,750 hp
power original=
max speed alt=570 km/h at 5,700 m
max speed main=354 mph at 18,700 ft
cruise speed alt=460 km/h
cruise speed main=286 mph
never exceed speed alt=
never exceed speed main=
stall speed alt=
stall speed main=
range alt=6,000 km
range main=3,728 miles
ceiling alt=15,000 m
ceiling main=49,210 ft
climb rate alt=
climb rate main=
loading alt=
loading main=
thrust/weight=
power/mass alt=
power/mass main=
more performance=
armament=
* 8 × 7.92 mm MG 81 machine guns in forward and rear fuselage barbettes
* 3 × 13 mm MG 131 machine gun in two dorsal turrets
* 1 × 15 mm or 20 mm MG 151 cannon in nose
* up to 3,000 kg (6,612 lb) of disposable stores
avionics=

ee also

aircontent
related=
* Heinkel He 177
similar aircraft=
* Heinkel He 274
sequence=
lists=
* List of World War II military aircraft of Germany
* List of military aircraft of Germany
* List of WW2 Luftwaffe aircraft prototype projects
see also=

References

;Notes;Bibliography
* Green, William. "Warplanes of the Third Reich". London: Macdonald and Jane's Publishers Ltd., 1970 (4th Impression 1979). ISBN 0-356-02382-6.
* Gunston, Bill & Wood, Tony. "Hitler's Luftwaffe". London: Salamander Books Ltd., 1977. ISBN 0-86101-005-1.