Wood in the construction of the IX proved a natural choice as it was relatively available, readily accessible and required very little training to work with. Considering the manufacturing restrictions imposed against the German war machine at this time, it made perfect sense. Wood could in many ways take on battlefield punishment better than metal, all the while keeping the flying surfaces generally in check despite. With a wing full of wood, this could potentially make the Ho 229 a beast to bring down with machine gun fire unless leveling a critical hit against a component such as the cockpit or one of the engines. it was suspected that the wing could receive a blast as great as a 20mm projectile and still keep its integrity.
Though revolutionary at its core, the Ho IX further pushed the design curve by incorporating level wings integrated into an upward-angled fuselage. Internally, the wings themselves were already ahead of the current age of flight time so the general outward shape only served to further the Ho IXs "science fiction" type looks.
Stealth and the Ho IX
The charcoal and sawdust mixture is of special note here for has long been thought by some to be the first true attempt at making an aircraft take on "stealth" like qualities intended to absorb incoming radar signals and deflate the outgoing signature. It is stated by sources that the mixture balance was purposely engineered to absorb the electromagnetic waves put out by British early warning ground-based radar systems defending the British mainland - the system largely responsible for the British victory over Germany in the Battle of Britain. Britain utilized a series of inter-connected radar and radio stations to detect and react to incoming flights of German bombers and fighters in a network that would become collectively known as "Chain Home". Though this attempt at stealth technology was rather infant at the time and thusly never truly tested before, the mixture was found to be quite effective in 2008 under experimentation accomplished in a documentary by Northrop Grumman and the National Geographic Channel - an amazing fact considering the age that the Ho IX was developed in. The test proved the mixture to work as advertised and the result created a reduced radar signature for a new-build Ho 229. The signature was less than that of a standard (and rather smallish) Messerschmitt BF 109 fighter. The Ho 229 was further helped by the small forward and shallow side profiles made up only by the cockpit and engine bulges, the rest being nothing more than wing surface area. Additionally, the Ho 229 was constructed largely of wood as opposed to radar reflecting metals as in other German warplanes.
The Design Evolves
NOTE: German naming designations differed somewhat from conventional American systems used throughout the war. While American aircraft most often followed a simple "X" indicating a prototype or a "Y" to indicate a developmental model, the Luftwaffe utilized V1, V2, V3 and so on to indicate changing prototype and early developmental models. Similarly whereas the US Army Air Force utilized a simple A, B, C, etc.. protocol for production models, the Germans relied on A-0, A-1, A-2, etc... to signify changing production models (as in "Ho 229 A-2").
Work on the Ho IX began in 1942. The Ho IX V1 became the first prototype constructed and intedned to fit the BMW 109-003-1 series turbojets. However, the radius of said engine had changed by this point and were therefore unable to fit inside of the completed IX airframe. As such, the IX became a powerless glider for the duration of its life with additional flight testing carried out at Oranienburg through the summer of 1944. V1 was found near Leipzig around April 14th, 1945, by the US 3rd Army Corps, 9th Armored Division. First flight of the system was achieved on March 1st, 1944 and proved successful.
The Ho IX V2 became the series first "true" prototype and also became the first to fit turbojet engines when it was unveiled in December of 1944. The V2 was another "one-off" build (single example) and sported 2 x Junkers Jumo 109-004B-1 series engines. Goring ordered 40 into production under designation Ho 229 before the V2 had even flown. A successful flight was later achieved at Oranienburg though V2 was eventually lost to an accident on February 18th, 1945, resulting from an engine failure while undergoing a one-engine landing test. V2 would become the only aircraft in the series to achieve flight and log in any substantial hours (approximately 2) in the air. Despite the setback, a further 20 re-production aircraft were ordered and the entire project was greenlighted onto a fast path under Jager-Notprogramm on March 12th, 1945.
Horten Hears a Gotha
While the Horten brothers were responsible for the design and early construction efforts of the Ho IX flying wing, their creation was handed over to Gothaer Waggenfabrik (Gotha, GFW) by the Air Ministry for further development and intended production. Gotha was the air firm known best for its production of multi-engined wartime bombers in World War 1. As such, the designation of the Horten IX now incorporated the Gotha brand name into the new designation of "Gotha Ho 229". Horten brother involvement in the Ho 229 was all but over as Gotha took over the reins.
Now under the Gotha label, the Ho 229 advanced into a V3 prototype featuring 2 x Junkers Jumo 109-004C turbojet engines of 2,205 thrust in a revised engine intake. The engines were further moved forward in the fuselage and construction of the type was undertaken at Friedrichroda. An primitive-form ejection seat was added to allow for a pilot escape at speeds higher than conventional aircraft could cruise at. However, the end of the war would bring about an end to the V3 prototype and cancel any production dreams.
Further models of the Ho 229 were planned. The Ho 229 V4 was to be a two-seat all-weather fighter/nightfighter that was in the early stages of construction at Friedirchroda by the end of the war. The basic internal airframe was all that was completed of the type. The Ho 229 V5, of similar role to the V4, was also in the early stages of construction when overtaken. The V6 was a proposed single-seat fighter fitting alternate cannon armament but never proceeded past the mock-up stage. In essence this became an armament test prototype.
The Ho IXb was a planned two-seat trainer whose airframe was also considered for a nightfighter role. Neither form was ever constructed. The two-seat trainer was also known as the Ho IXb V6 and the nightfighter became the Ho IXb V7.
The Ho 229 A-0 was the official intended designation of a fast-production form of the Ho 229 flying wing. This model would have been based on the Ho 229 V6 prototype though none of the A-0's were ever produced (though 40 were on order by war's end). These differed somewhat from earlier Ho IXs in that they fitted 4 x MK 103 30mm cannons (in place of the original 2 x MK 108 systems) and held an external ordnance capacity of 2 x 2,205lb bombs. The A-0 would have been the definitive Ho 229 production model.
Armament
For whatever reason, the German Air Ministry required the production version of this bomber to also serve as a fighter - a special two-for-one initiative one can suppose. With a projected top speed of over 500 miles, this seemed feasible even against the top Allied fighters of the time. As such, the original Ho IX was fitted with 2 x 30mm MK 108 series cannons produced by Rheinmetall-Borsig. The MK 108 began life as a private venture in response to a German 1940 requirement for a weapon system capable of downing Allied bombers (the bane of the German war machine). Production of the system ran from 1943 through the remaining war months of 1945 and served on many German aircraft. The firing action was of a blowback design and a rate-of-fire of 650 rounds-per-minute was possible. Coupled with High Explosive (HE) ammunition, the MK 108 was a proven and reliable "bomber-killer".
Later revisions saw the production Ho 229 fitting 4 x MK 103 30mm cannons. The MK 103 was designed by Rheinmetall-Borsig as a further development of the MK 101 heavy autocannon. The MK 103 was equally adept at engaging land and air targets and fired from a belt-fed mechanism. The firing action was both gas an recoil actuated. Comparatively, the MK 108 fired the same projectiles of the MK 103 but through a smaller cartridge containing less propellant.
R4M "Hurricane" air-to-air/air-to-surface high-explosive rockets were also envisioned for the aircraft. The rocket was produced by the Heber AG company and put into action from 1944 and into 1945. As a bomber, the Ho IX could field 2 x 1,100lbs (envisioned as higher in the final production model), making for one complete fighter-bomber system.
Where Are They Now?
Not much is left of the legacy regarding the Ho 229 beyond a scant few airframes and a handful of black and white (and some color) pictures. The Ho IV and the Ho 229 V3 were captured by the Americans and shipped off to Northrop for further research. The Ho IV glider ended up at the Planes of Fame Museum in Chino, California. The Ho 229 V3 prototype airframe has been sitting in the Paul E. Garber Restoration Facility at Suitland, Maryland for some years now under the control of the National Air & Space Museum. Though at least five other Ho 229 airframes were recovered at the Gothaer Waggonfabrik plant, these were subsequently destroyed (under orders initiated through Operation Paperclip - the destruction of all advanced German materials and research for fear of them falling into Soviet hands) by General George S. Patton's 3rd Army troops in April of 1945.
Reimar Horten in Argentina
Despite the sudden end to the Ho 229 in Germany, brother Reimar Horten attempted to bring the HO VIII design back into the fold in the post-war years. Having relocated to Argentina by this time, the experimental tailless cargo transport derivative of the Ho VIII flew as the I.A.38 on December 9th, 1960. Though completed in 1959, mechanical issues with the engines forced the year-long delay. Performance was deemed sub-par no thanks to the under-performing engines and the entire project was therefore cancelled. Construction was of all-metal while the wings were shoulder-mounted and swept. Power was handled by 4 x IA 16 El Gaucho radial piston engines as pushers. The undercarriage was a tricycle arrangement and fully retractable. Seating was for two and the cargo bay took up a portion of the main body and wings, fitting some 13,448lbs of cargo and accessed via a rear door. Production was handled by DINFIA of Argentina. The single prototype became a permanent fixture at the Aeronautical School until destroyed by fire (suspected arson).
Performance estimates for the I.A.38 included a top speed of 155 miles per hour, a range of 777 miles and a service ceiling of 14,765 feet.
Raiders of the Lost Farce
The "flying wing" found in the motion picture "Raiders of the Lost Ark" is a fictional aircraft. The aircraft was specifically hand-picked by director Steven Spielberg and incorporated into the movie to showcase the technological advancements of German aircraft of the time. Designers used Northrop's B-36 flying wing bomber as the basis and construction of the aircraft was undertaken by Vickers Aircraft Company. It was shipped in pieces and assembled for filming in Tunisia.
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