2013 APRIL / Vol. 5 / No. 4 /
GA
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machine at this time, it made perfect
sense. With a wing full of wood,
this could potentially make the Ho
229 difficult 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
The Design Evolve
s
Work on the Ho IX began in
1942. The Ho IX V1 became the
first prototype constructed and
intended to fit the BMW 109-003-1
series turbojets. However, the radius
of the 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.
The Ho IXb was a planned two-
seat trainer whose airframe was also
considered for a nightfighter role.
Neither form was ever constructed.
Armament
The German Air Ministry required
the production version of the bomber
to also serve as a fighter. 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 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
MK108 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.
Walter Horten (13 November 1913 - 9 December 1998) and Reimar Horten (12 March 1915 - 14 March
1994), sometimes credited as the Horten Brothers, were German aircra pilots and enthusiasts, and mem-
bers of the Hitler Youth and Nazi party
Walter Horten (13 November 1913 - 9 December 1998) and Reimar Horten (12 March
1915 - 14 March 1994), sometimes credited as the Horten Brothers, were German
Aircraft pilots and enthusiasts, and members of the Hitler Youth and Nazi party.
As a bomber, the Ho IX could field
2 x 1,100lbs (envisioned as higher
in the final model), making for one
complete fighter-bomber system.
History
The Horten Ho IX maintains a certain
level of celebrity status in the world
of military aviation, essentially
becoming the first production-worthy
form of any aircraft categorized as
a true 'flying wing'. It also made
heavy use of swept-back wings
before they became the norm of the
jet age. Though a production order
was in the works by 1945 though the
end of World War 2 meant that this
machine never contributed to the
German war effort in any respect.
Flying Wings
The flying wing designs had been the
focus of man-a-aircraft engineer for
some time leading up to World War 2.
American Jack Northrop was one of
the big name pioneers in the realm,
working on his own flying wing
designs, while the Horten brothers
had been studying the capabilities
and possibilities for some time now
primarily in the field of unpowered
glider flight (a third brother, Wolfram,
would later die when his bomber
was downed over Dunkirk).
Flying wings featuring a lack
of vertical implements theoretically
offered som inherent advantages by
the deletion of such surfaces thus
reducing drag to an extent. In a
flying wing design, the fuselage was
generally integrated into the wing
roots for a very streamlined approach
adding to effective aerodynamic
principles. A larger wing surface
area also promoted a better rate-of-
climb, a larger fuel load (essentially
increasing range) and a larger bomb
load. However, the lack of vertical
flying surfaces also brought about
challenges in controlling such an
aircraft - an issue that Northrop dealt
with to a high degree in his XB-35
flying wing strategic bomber (finally
realized in the modern Northrop B-2
Spirit stealth bomber). Northrop's
attempt was in fact a commissioned
effort to develop a wing-only design
based on pictures received of the
Horten early 1930's glider attempts.
Despite their success with
early designs, the Horten brothers
destroyed their original Ho I and took
to building a more efficient design.
The second attempt was appropriately
designated as Ho II and featured
swept-back leading and trailing edge
wings, a prone glazed-over cockpit
and instantly set itself apart from
the preceding design attempt. Four
Ho II prototypes were produced to
test out further flying wing concepts
and while at least one of these was
powered through a single Hirth-brand
80 horsepower engine mounted to the
rear of the main body in a "pusher"
arrangement. The Ho IIs were
tested sometime in 1938, with one
such flight occurring at Darmstadt
in the capable hands of renowned
female test pilot Hanna Reitsch.
Such developments in wartime
Germany did not go unnoticed. And
the brothers received additional
funding moved into a more permanent
environment operating out of
Tempelhof Airport and set to work on
further developments of the aircraft.
Of note in the powered Ho III was
the inclusion of folding propeller
blades which could be collapsed in
flight to help reduce drag. While being
powered, the HoIII was still a glider
through and through. The design
made use of a wide span swept wing
approach with the pilot seated at the
center of the forward profile under
a forward-opening glazed cockpit
with the engine mounted to his rear.
The Ho IV & V followed and the
Ho V and Ho VI appeared as a "one-
off" prototype example following in
line with the Horten IV. This flying
wing offered up a greater span
than others before it but proved too
delicate for the rigors of even basic
ground operations. The similar Ho
VII followed suit but fitted 2 x Argus
As 10C engines of 240 horsepower
each. A single prototype was
constructed of this model and later
relocated to Oranienburg in March
of 1945. It is believed that the Ho
VII was tested there to some extent.
The Ho VIII proved the most
ambitious Horten flying wing attempt
to date - a six engine, 60-passenger
commercial endeavor. Power was
to be supplied by no fewer than 6 x
BMW 600 horsepower (each) engines
fitted into a pusher arrangement. The
wingspan of 262.5 feet alone made
this flying wing design easily the
largest Horten. Range estimations put
the Ho VIII at 3,725 miles at speeds
hitting over 200 miles per hour. The
collapse of Nazi Germany by mid-
1945 killed the project altogether.
The Ho XVIII bomber would
most likely have fitted an atomic
bomb should both projects
(the bomber and atom bomb)
have advanced in Germany
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.
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. ·