Sunday, 14 February 2016

Horten Ho229 - a brief outline of the story. Part 1. Compiled by Cesar Winklemann

A Ho IX under construction. This document depicts the wood
construction of this flying wing. (The clamps are aligned on the left).
The jet engines are fictitious.
Horten logo
Almost unknown today, all wing twin-jet Go 229 was probably the most startling and unconventional warplane built during the WWII. It stemmed from the belief of the brothers Walter and Reimar Horten that a flying wing was the most efficient form of the heavier-than-air flying machines.They set out to prove this with a series of gliders, beginning with the Horten O in 1931. From 1936 Hortens brothers were officers in the Luftwaffe, but continued their work, wich in 1942 lead to studies for a flying-wing jet fighter.

Walter Horten testing flying model 1929
The first major step was to build a trainer to familiarise Luftwaffe pilots; this, the Horten VII, flew in 1943. It had tandem dual controls and two 179-KW (9240-hp) As 10C pusher engines their inventions. The Ho VII was described as for aerodynamic research and communications.Meanwhile , the Brothers' Sonderkommando 9 at Göttingen had already begun construction of the definitive twin-jet fighter,the Ho IX.None of this had any official sanction by the Reichsflugfarthministerium, but the brothers had a good political connections.Once Reichsmeschall Göring had seen the drawings, he instead that this futuristic machine should fly as soon as possible.
        Accordingly, work was hastened on two prototypes, wich was all the small team could contemplate. The Ho IX V1 was to fly as glider , subsequently being modified to intall teo BMW 003A turbojet. Gliding trials at Orannienburg began in about may 1944, and from the start the handling characteristics were outstandingly good. The
Horten IX V1 in flight, most likely with Heinz Scheidhauer as pilot
Ho IX comprised a center section and others panels. The center section was thick enough to house the pilots, engines, guns , tricycle landing gear and nearly all the fuel. It was made of welded steel tube witch plywood skin, except near the engines where it was aluminium or steel.The slender sweptback outer wings where all wood,some of it beging Fonnholz  composite made of wood shavings bonded with resin adhesive and moulded to shape under high pressure. The structure was stressed to 7G, strong enough to out-turn virtually any other aircraft.
Reimar Horten
A Ho IX V1, prototype for the Go 229s. It represents the philosophy
 of the Horten Brothers
 a flying wing glider in its purest form that would be eventually motorized.
Tests with the fully instrument V1 glider suggested that a production Ho IX would do just this, but the V1 was wrecked later in 1944 when the pilot forgot to retract a long incidence pole before landing. By may 1944 the outstanding potential of the aircraft had led to full RLM blessing, with control passed to Gotha Waggonfabrik, the new designation being Go 229 in addition to V1 and V2 seven more prototypes were ordered, plus 20 production fighters. These were to have a span of 16.75m, two Jumo Junkers 004B of four 30 mm guns. The pilot was to have a simple ejection seat.The go 229 V2 began its flight test programme at Oranienburg in January 1945 . Take off required less than 450 m and handling was superb. By early March the landing gear was being retract and speeds had reached 800 Km/h, when the aircraft crashed on approach because of sudden failure of one of engines. The pilot was Erwin Ziller and he die 2 months after became the first pilot in the world to fly a all-wing-twin-jet.
      The programme advanced no further.The Gotha factory at Friedrichsroda had virtually completed the production  prototype V3 , and had many others Go 229 in an advanced state of assembly.

Erwin Ziller's death

Erwin Ziller
After repairs of the plane , there was the order that no new starts without an Horten brother would be allowed. Ziller started again! No one really knows the reason for Zillers start without permission, maybe the Sowiets near the area or/and the try to finish the testflights as fast as possible were his thoughts....
After 45 minutes in the air Ziller gets problems.
From 800 meter high he pushed the Horton to ca. 400 meters and pulled out his landing gear. One turbine is trashed !
Suddenly Zillers Horten flipped upside down and was going into a right 20 degrees full circle.
The Horten gets faster and faster, another two full circles, and at the beginn of the 4th the Horten crashed outside the airfield hard on the ground. Ziller flew out of the cockpit and hit a fruit tree, he died after two weeks in the hospital as a result of damage. Before Ziller started, a tech ground member witnessed problems with the right turbine, but no spare part was available. Ziller don't ejected or used his radio, maybe he gets unconscious by the burning oil ? But Walter Horten said:

" Zillers state of mind was at zero , the he started to his last flight . Just before he take off , he get the message quer his wife and children are refugees of the Russians . "