- Arthur Sack A.S.6
The Arthur Sack A.S.6 was an experimental German aircraft tested during
World War II with an unusual circularplanform .Development
Arthur Sack was a
farmer and aero-model construction enthusiast. In June1939 inLeipzig-Mockau he attended the First National Contest of Aero-models with Combustion Engines, where he hand-launched his first aero model with a circular wing, theA.S.1 . It possessed rather poor flying qualities. Arthur Sack's aeromodel measured 125 cm and weighed just 4.5 kg, powered by a Kratmo-30 motor of 0.65 V and 4,500 RPM with apropeller measuring 600 mm in diameter. His "circular aircraft" was unable to lift off the ground by itself, and finally Sack had to throw it into the air in desperation. After this " assisted takeoff", the model managed to perform 100 meters of stable flight, just barely reaching the finish line. However, the odd-shaped model instantly caught the attention of Air Ministry's GeneralErnst Udet who was fascinated by the circular shape and gave Sack permission to proceed with his research with official backing.Sack immediately began construction of A.S. aero models of increasing size up to the
A.S.5 which was by far the largest flying model. With a wingspan of 125 cm, length of 159 cm, and height of 65.3 cm the two-bladed propeller model took to the air and proved the soundness of the basic design. From this point on Sack was determined to build a manned machine that would become the Arthur Sack A.S.6 V-1.The aircraft was built in
Leipzig starting in January1944 in the workshops of theMitteldeutsche Motorwerke company. Assembly and final tuning were performed at the Flugplatz-Werkstatt workshop atBrandis air base during the same month. The basic structure was made ofplywood while the cockpit, pilot seat, and landing gear all came from an old wreckedBf 109 B. The engine was taken from aBf 108 "Taifun", an Argus As 10C-3 of 240 hp working on an old wooden two-bladepropeller . Theempennage was based on theKlemm Kl 35 .Flight tests
In February
1944 , the A.S.6 V-1 taxi test started, piloted by Baltabol from the ATG/DFW ofLeipzig . The first test proved that the rudder was not strong enough and some structural damage resulted from the test.During the second test five separate take-off runs were attempted from the 1,200 meter landing strip at Brandis. It was soon discovered that the control surfaces failed to function properly because they were positioned in the vacuum area produced by the circular wing while taxiing. The right leg of the landing gear was damaged on the last run. Due to war restrictions more powerful engines than the low-hp Argus were not available so the incidence angle was increased. The
test pilot at this point proposed moving the landing gear back 20 cm, but due to structural reasons that could not be overcome, the modification was deemed too risky. Instead, brakes were installed from aJu 88 , 70 kg of ballast was added ahead of wing spar No.3 and the tail surfaces were increased by adding 20 mm of corrugated plates.The third test flight was performed over the 700 meter strip at Brandis on
April 16 ,1944 . There was no wind and the plane rolled 500 meters without lifting its tail. No aerodynamic control of the empennages was achieved. The plane made a brief hop but could not get into the air.During the fourth flight test the jump was a bit longer; however, the plane banked to the left because of torsion generated by the propeller, this being very difficult to balance in a small wingspan aircraft. After this Baltabol lost all hope and recommended the installation of a proper
Daimler-Benz engine from a current MeBf 109 and a complete study of the basic design in an aerodynamicwind tunnel . Sack went on trying to solve the problem by himself in the traditional manner until the end of the war.Luftwaffe flight attempt
The A.S.6V-1 would have sat for the duration of the war had it not been for the arrival of Gruppe I/JG 400 at Brandis in the summer of
1944 . These were the confident newMe 163 Komet pilots who had plenty of experience with difficult take-offs and landings with short wingspan aircraft. So, it was inevitable that one of them, Oberleutnant Franz Roszle, made an attempt to fly what the Gruppe named the "Bierdeckel" ("Beermat ").His attempt, like Baltabol before him, ended with a short hop and collapsed landing gear. The "Komet" pilot made the same suggestion to Sack about testing the design in a wind tunnel and then turning the aircraft over to
Messerschmitt for proper redesign with components of the latestMe Bf 109 fighter, including armaments. Sack refused to listen or ask any favors from theReich Air Ministry .Further design work/Messerschmitt 600 proposal
Messerschmitt got word of the A.S.6V-1 and actually proposed that a new A.S.7V-1 should be re-designated asMe 600 (the unofficial double zero designation intended to denote a round aircraft). The proposed Me 600 would have enlarged the circular wing considerably and featured a complete fuselage with the latestDB 605 ASCM/DCM of 2,000 hp with MW (Methanol-Water) injection and a four-bladed propeller, repositioned gear, improved control surfaces, redesigned tail unit, Galland hood, and sixMK 108 cannon buried in the reinforced circular wing. Withwind tunnel data corrections andMesserschmitt construction the projected Me 600 would have been a formidable 500 mph fighter. The odd circular wing already had the "Komet" pilots making suggestions for a new nickname. They would call any Sack aircraft that made it into combat the "Bussard" ("Hawk").Fate
Sack was never given the opportunity to redesign the A.S.6. In April
1945 it was destroyed to hide its existence fromUS Army troops advancing toBrandis . No trace of the aircraft remained, as its wooden construction was used forfuel .pecifications (A.S.6)
aircraft specifications
plane or copter?= plane
jet or prop?= prop
ref=
crew= one pilot
capacity=
length main= 6.4 m
length alt=21 ft 0 in
span main= 5 m
span alt= 16 ft 5 in
height main= 2.56 m
height alt=8 ft 5 in
area main= 19.62 m²
area alt= 211.11 ft²
airfoil=
empty weight main=
empty weight alt=
loaded weight main=
loaded weight alt=
useful load main=
useful load alt=
max takeoff weight main= 900 kg
max takeoff weight alt= 1,980 lb
more general=
* Propeller: Wooden, 2-bladed, of 2.5 m (8 ft 2 in) diameterengine (prop)=
Argus As 10 C-3
type of prop=air-cooled invertedV8 engine
number of props=1
power main= 179 kW
power alt= 240 hp
power original=max speed main=
max speed alt=
cruise speed main=
cruise speed alt=
never exceed speed main=
never exceed speed alt=
stall speed main=
stall speed alt=
range main=
range alt=
ceiling main=
ceiling alt=
climb rate main=
climb rate alt=
loading main= 45.87 kg/m²
loading alt= 9.38 lb/ft²
power/mass main=
power/mass alt=
more performance=
armament=
* None
avionics=References
* [http://www.luft46.com/misc/sackas6.html luft46 site]
* [http://www.unrealaircraft.com/wings/german_discs.php unrealaircraft.com]
* [http://www.geocities.com/INEXPLICATA2000/issue1/1.htm An Aeronautical History of Flying Saucers]
* [http://www.bibliotecapleyades.net/esp_ufoaleman_1.htm Disc Aircraft of the Third Reich]External links
* [http://www.lonlygunmen.de/ufo/weapons/sack/as6.html lonlygunmen.de] de icon
* [http://www.kheichhorn.de/html/body_as_6.html Das Rundflugzeug des Arthur Sack] de icon
* [http://www.luftarchiv.info/flugscheiben/sack.htm LuftArchiv.de] de iconee also
aircontent
related=similar aircraft=
sequence=A.S.1 - A.S.2 - A.S.3 - A.S.4 - A.S.5 - A.S.6
lists=
*List of military aircraft of Germany
*List of experimental aircraft
*List of WW2 Luftwaffe aircraft prototype projects
see also=
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