Heinkel He 277 - The He 277 Design's Features

The He 277 Design's Features

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 801E 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, protruding above the 277's forward dorsal fuselage decking level as the Lancaster's cockpit glazing did, with a rearward extension atop the fuselage to just forward of the inner engine cowls that faired-in the forward upper dorsal turret's forward surfaces. 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 11,100 km (6,900 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.