ok the story first....and it is a bit long......
Well an almost unknown and unusual Luftwaffe bomber that I thought I'd like to share. I have to admit that it may not be 100% accurate as there are no details available on the He-177Z A6/R3’s that I have been able to find.
Of all the Heinkel bombers produced during the Second World War the least documented and most unusual was the little known He-177Z* “Zwilling” project, born out of time where desperate measures were being looked at to help stem the growing flow for Allied conveys coming across the Atlantic. From which produced Ernest Heinkel an ultra long range aircraft of unrivalled abilities. Which if delays, shortages in strategic materials and political interference had not occurred, may have had a dramatic effect in the supply of materials to the UK?
*occasionally referred to in some text as the He-377, recovered documentation shows this designation was never used for this aircraft and was reserved for a project that never left the drawing board
A small group of designers at Henkel’s Vienna-Schwechat works were given the task of designing an aircraft to meet the RLM’s requirements. It became quickly apparent that a radically new design could not be achieved with the resources available in the time frame required. With the He-177 slowly losing favour with the RLM due to reliability issues with the DB 606 engines which were causing heating and fire issues with the He-177A3’s. So an innovative design was drawn up using two He-177’s airframes with a new centre wing section housing the third engine. With the design having 80% commonality with the existing He-177 production and development costs could be kept to a minimum.
The initial prototype was built from two early development He-177’s, V13 and V14 (Wk-Nr 00 0024 & 0025) in August 43. The prototype V1 required with only additional strengthening required for the new centre wing section which was made up from the inner sections main wings. Additional strengthen was require after initial flight tests around the undercarriage mounts due to the additional weight. These were early preproduction aircraft fitted with the Daimler Benz BD 606 (2600 HP)** coupled engines. Though using under powered and running notoriously unreliable engines, early flight testing showed the aircraft to have good handling qualities and exceptionally stable. Under the right conditions with one of the coupled DB 605’s shutdown, level flight could still be maintained.
** in later testing these were changed out to the more reliable and more powerful DB 610’s after the engine fire!
With success of the initial flight trials seven further development aircraft were planned but later cancelled due to lack of funding and resources. Aircraft V1 was kept as the sole development aircraft. Despite a few minor undercarriage mishaps and an engine fire in the centre coupled engine*** development continued successfully. During this time He-117Z V1 and He-177A-3 V21 carried out trails with the Hs 293 remote controlled bomb as well as other missiles and bombs at Peenemünda.
*** The engine fire occurred during high altitude trails and seriously damaged the centre wing section. The aircraft only managed to remain in-flight and land due to the innovative design and strength of the new wing section.
With the introduction of the He-177A-5 and its engine improvements He-117Z V1 and replaced a newer aircraft made up from He-177 V101 & 102. This was fitted initially with the DB 610C-2 (2950 HP) then for most of its life with the more powerful DB613B-0 (3200 HP) before finishing with the last and most powerful coupled DB engine, the DB627D (+3600 HP). This engine comprised of two DB 603N two-stage supercharged engine with after cooler, each developing 1900 HP continuous and 2750 HP max at sea level. These we to be the engines fitted to the He-177Z A6-R3.
The He-177Z V2 entered into development trails without issues and the additional power from the new DB engines improved all handling aspects of the aircraft. The success of these trial prompted Heinkel into series production planning.
Aircraft V3, V4, and V5 followed on shortly thereafter, these aircraft were made up from He-177A5 airframes and were eventually converted**** to operational He-177Z A5/R2’s with the DB 613B-0 engines.
****(V3 and V5 only, V4 was lost during a over water weapons test)
After demonstrations to the RLM were given in April 44, permission was given for limited production shortly thereafter. With the worsening start of the war and growing allied bombings, development and production suffered. Only eight 8 of the He-177Z A5/R2’s were built and released onto service September 44 with KG40 first before moving to KG100.
In parallel to development to the other He-177Z’s, aircraft V6 was to be a different aircraft altogether. To closer match the RLM requirements of offensive armaments and large calibre cannon was to be fitted in the nose of the aircraft. Initially He-177 V18 was used as a development aircraft and was fitted with a 30mm Mk101 cannon, this was later changed to a single then double Rheinmetall BK 3.7 auto cannon. *****
***** unconfirmed reports were that a 7.5cm Pak 42 or 8.8cm Pak 43 were fitted, but it is suggested that the shock of firing was too great for the airframe and caused engine issues.
Ultimately a single Rheinmetall BK 5 auto cannon was selected and fitted into a streamline pod under the right hand side cockpit gondolier. Fitted with special 5 round magazines, these cannons provided to be very effective against the new convoy escort ships and devastating against long range patrol aircraft.
New advances in radar development prompted the idea of fitting radar to the aircraft to aid in target acquiring and identification. Telefunken has just developed a variation of their new centimetre radar, the FuG 240 Berlin which used a dish antenna rather than the earlier antenna arrays. Given the size of the new radar a bomber the size of the He-177Z would be perfect. Aircraft V6 tried various combinations of Air to Surface and Air to Air radars during testing ******
******even a version of the FuG 244 “Bremen was tested in a airborne early warning (AEW) system, this was planned for the He-477 “Amerika” Bomber
Trails were completed on V6 quite quickly after a very intensive few months at the end of 44. By early February 45 the first three (3) production aircraft, A6/R3’s, were completed (these were the only ones to be complete by war’s end. These were originally intended to be A5/R3’s (R2’s with the new more powerful DB627D engines). These had quickly been upgraded to the A6 standard which was fitted with FuG 240S (surface scan radar) in special nose mount and normal FuG 240 radar in a tail mount for air defence. Plus a power turret from a He-177 A6 to replace the single 20mm cannon for the earlier models. These three aircraft were quickly dispatched to KG100 and started operational missions at the start of mid-April 45 with immediate success. In just two weeks shipping losses of around 120,000 tons were achieved, which included the CVE HMS Campania. These were mostly to the newly operation Anti-shipping missiles produced by Henschel, but a few were by the nose mounted Rheinmetall BK 5 auto cannon.
None of these amazing aircraft survived the war, with all aircraft being destroyed less they fall in the hands of the Allies.
