Heinkel He 177 - Experimental Weapon Loads

Experimental Weapon Loads

In addition to carrying a variety of bombs, torpedoes, and guided weapons the He 177 was tested with a number of unorthodox offensive armaments. The first of these experimental weapon schemes known to have been tested were the twelve examples of the He 177 A-1/U2 Zerstörer variant, which was armed with a pair of limited-traverse 30 mm MK 101 cannons in the extreme front of a dramatically enlarged Bola ventral gondola, and intended for ground attack, train busting, and possibly long-range anti-ship raids. Later, when assigned to flak-suppression sorties in the area of Stalingrad during the winter of 1942, Luftwaffe forward maintenance units modified a small number of He 177s, fitting a 50 mm Bordkanone BK 5 cannon within the aircraft's undernose Bola gondola, with the long barrel protruding well forward, beyond the glazed "fishbowl" nose. This variant was unofficially dubbed the Stalingradtyp. Although a small number of He 177 A-3/R5 models were to be built from scratch, with the larger PaK-40-based, autoloading 75 mm Bordkanone BK 7,5 ventral cannon, structural problems caused by the weapon's recoil meant that the Stalingradtyp did not see combat use outside of the original, BK 5-armed improvised handful. Five He 177 A-5s were experimentally equipped in January 1944 with batteries of thirty-three obliquely mounted 21 cm (8-1/4 in) calibre rocket mortar tubes, likely derived from components of the Nebelwerfer infantry barrage rocket system, to create the Grosszerstörer ("Big Destroyer") flying battleship, meant to break up and destroy the tight combat box defensive formations used by USAAF daylight bombers over Germany. The bomb bays and fuselage-housed auxiliary fuel tanks were removed on these aircraft in order to provide space for the spin-stabilized 21 cm (8 in) rockets and their firing tubes. The tubes were inclined to fire upward at an angle of 60° to the horizontal axis of the aircraft and slightly to starboard. The tubes could be fired individually, simultaneously, or in two salvoes of fifteen and eighteen. Tests with fixed balloon targets showed the potential of this system, and limited operational trials against US Eighth Air Force bomber streams were authorized. The aircraft were operated by Erprobungskommando 25, flying out of the Baltic coastal Erprobungstelle facility at Tarnewitz. The intended mode of operation called for the Grosszerstörer He 177s to follow the enemy bomber formations, passing below (as with a Schräge Musik cannon fitment) and to port of the target, maintaining a difference of altitude of 2,000 m (6,560 ft) beneath the targets at the time of the attack from below. A few trial daylight operations were flown but no contact was made with Allied bomber formations, and as the escort fighters were becoming ever more numerous - in the manner of air superiority-purpose "fighter sweeps" well ahead of the massed USAAF bomber formations, starting in early 1944 - the entire scheme was abandoned.

Experimental defensive weapons fitments were also tried on small numbers of 177s set aside for such trials, mostly at the Erprobungstellen test detachment fields. One such fitment was to an He 177A-1, s/n 15155 with Stammkennzeichen GI+BP, which was the first-ever example of an He 177 to be fitted with an experimental, remote control twin-gun "chin turret" at the front of its Bola undernose gondola. The type of guns to be fitted was not recorded, but the date of which GI+BP was written off from a mishap in May, 1943 would place the fitment of its experimental "chin turret" simultaneously with the lead-up to the May 1943 service introduction of the "gunship" USAAF Flying Fortress, the YB-40, which pioneered the same type of forward defensive armament on the best known American heavy bomber to attack Nazi Germany. Similarly, the much-anticipated Hecklafette HL 131V "quadmount" manned tail turret, armed with a quartet of MG 131 machine guns, was first tried in the late spring of 1943 on a pair of A-3 examples set aside as the V32 and V33 prototypes, but never made it to production status.