The conventional account holds that the Heinkel He-177B was merely an illicit forerunner of the He-277, however the He-177B was actually developed as an entirely different aircraft, with different tail fin, tailplane and intended to use Jumo 211 engines. The story of the He-277 and He 177B are extraordinarily muddled and hard to decypher, even open to different interpretations. A number of He 177B prototypes were in fact converted to He 277. This picture depicts He 177B prototype NE+OD with the "OD" visible under the starboard inner engine.
On 19 November 1938 whilst ordering the first prototype He-177A Reichs Luft Ministerium (RLM) suggested to Designer Ernst Heinkel that he also develop four prototypes with a conventional engine layout just in case the paired DB 603 engine concept failed. RLM designated these as the He-177B. It was proposed by RLM that four prototype He-177B aircraft be fitted with 986hp Jumo 211 engines individually housed in their own nacelles.
The prototype He-177A first flew 9 November 1939. Shortly afterwards a series of crashes of the prototype He-177A raised concerns about the He-177A's viability. During November 1940, distressed with the difficulties of the coupled engine concept, Heinkel proposed to RLM that he should place the He-177B into production, however RLM opposed on grounds that he lacked the production capacity and that it would slow other projects.
Modern commentators claim that the He-177B designation was created by Ernst Heinkel to conceal development of the He-277, however this is incorrect since the designation was created by RLM and not by Heinkel. Goering actually favoured a conventional layout. RLM opposed placing the He 177B into production on grounds that Heinkel lacked the production capacity and to do so would draw from production capacity for other types. Four pre-production prototypes with four individual engines were built by the Rostock-Marienehe factory probably with Jumo 211 engines stipulated by RLM. In May 1943 orders were placed for 1,900hp DB 603G engines to power these aircraft.
In 1945 prototype He-177 B-0 V101 with Luftwaffe codes (Stammkennzeichen) NN+QQ was found destroyed on a compass turntable at Cheb airfield in Western Czechoslovakia. Sources in the modern Czech republic commented online that the aircraft destroyed at Cheb was deliberately torched by the Germans to prevent it's capture. The aircraft in question at Cheb was fitted with four Jumo 222 engines. These engines whilst more powerful than the Jumo 211, thought to have been fitted on He-177B aircraft and were not true high altitude engines like the Jumo 213F, or DB 603G fitted to the He-227 B series.
Use of the Jumo 222A engine appears to date construction of the V101 aircraft to late 1942, or early 1943, since only a very small number of these engines were produced in the second half of 1942. This otherwise promising, but trouble proned engine in the 2000hp class was abandoned as a high altitude engine.
The He-277 B-5 was an entirely different aircraft from the outset with a tail empennage which appears borrowed from the Ju-290 or He-219 Uhu. Also unlike He-177 B-0 examples the He-277 B-5 was pressurised for high altitude bombing.
Modern conjecture that the He-277 was merely an He-177 B under another name are misleading since the He-277 was actually developed from the He-177 A8 high altitude type using the same presurised cockpit developed by the A7 intended for export to Japan.
The He-177B designation was already granted to Heinkel by RLM in November 1938, long before either the He-274 or the He-177 A8 designation were created. Whilst the second prototype He-277 flew with an "H" tail, photographs survive showing He177 B-0 airframe "NE+OD" with a conventional tail suggesting that the He177 B-0 was already flying before the He277 project began. Clearly one project morphed into the other, through various machinations to defeat Goering, however for the He177 B-0 to be flying prior to the He277 first flight, implies these two had to be quite separate aircraft types.
He-177 B-0 prototype identities:
In an effort to establish some facts the following table sets out probable identities of the V101 to V-104 aircraft. Many of these appear to have had more than one identity. Sources as to their previous identities clash, both with each other, with GL/C number sequences and with factory werke number sequences. Often for one sequence to fit the known facts it clashes with other sources. For example, the aircraft registered GA+QQ is also claimed from some sources to be the V102. This table gives the best explanation suggested by various sources.