He 277 ✙
The fire hazard of tandem power plants became a serious problem for long-range bombers, and Heinkel was forced to secretly develop a four-engine long-range bomber based on the He 177 from Goering.
The new aircraft was named Not 277, although for conspiracy purposes it was originally referred to as "Not 177B". In May 1943, after Hitler met with the leaders of the aviation industry, official permission was obtained to continue the work. The new dual-purpose heavy bomber was called upon to bomb London by day at night and from a height inaccessible to fighters, as well as to operate on Allied convoys in the Atlantic. Heinkel said that "Not 177B" fully meets these requirements, and was immediately issued an assignment to complete the work.
The standard He 177A-3/R2 fuselage was taken from the assembly line and redesigned for four Daimler-Benz DB 603A engines - 12-cylinder, liquid-cooled with frontal radiators.
Experienced He 277 V1 flew at the end of 1943, under the designation He 177B-0. The second prototype He 277 V1 was converted from He 177A-5/R8 and made its maiden flight on February 28, 1944.
Not 277 V3, also having insufficient directional stability, was redesigned with the installation of a two-fin tail unit. Like its predecessor, the V3 was armed with a Rheinmetall-Borzig bow turret with four 7.9 mm MG 81 machine guns. Similar weapons were installed in the tail turret. One 7.9 mm MG 81 machine gun was in a ball mount in the nose, a pair of 13 mm MG 131 in the upper, remotely controlled turret. Another MG 131 machine gun was placed in the turret with manual guidance.
After the conference on May 25, 1944, Goering said that the new heavy bomber is the "core of combat aviation" and demanded that it be immediately put into mass production at a rate of at least 200 aircraft per month! But Goering's plans were already unrealistic.
On July 3, 1944, the production of bombers was discontinued, and an "urgent fighter program" was adopted. They managed to release only eight serial He 277s, and even two or three of them flew, but all of them were soon scrapped.
Before the completion of all work on the bomber, there were two more options in development. Not 277B-6 and B-7. Not 277V-6 had a wing of increased span up to 40 m, four 12-cylinder liquid-cooled Junkers Jumo 213F engines with a capacity of 2060 hp each. from. In addition, the V-shape of the stabilizer was increased, the end washers were increased. Not 277B-6 / R1 received a tail turret "Rheinmetall-Borzig" HDL 131V with four MG 131 machine guns. This turret was well armored, but had a number of such features that the Luftwaffe air gunners had to thank fate for not reaching it. to combat units.