Bücker Bü 181
|Bü 181 Bestmann|
|D-EKYF, a Swedish-built Sk 25 (Bücker Bü 181 B-1)|
|First flight||February 1939|
The Bücker Bü 181 Bestmann was a two-seater, single-engine aerobatic monoplane aircraft built by Bücker Flugzeugbau GmbH in Rangsdorf, near Berlin and extensively used by the Luftwaffe in World War II.
The Bücker Bü 181 was named Bestmann after a German maritime term designating a member of the deck crew on coastal or fishing vessels. The prototype Bü 181 (D-ERBV) made its maiden flight in February 1939 with Chief Pilot Arthur Benitz at the controls. After thorough works and official flight testing by the Reichsluftfahrtministerium (RLM) the Bü 181 was nominated to be the standard primary trainer for the Luftwaffe. Series production of the Bü 181 commenced in 1940. The production types were designated B to C with only slight variations between each, and could be powered by the Hirth HM 500 A or B.
The Bü 181 aircraft was a single-engine low-wing monoplane with fixed undercarriage, split flap, twin controls and two adjustable seats arranged side-by-side. The cabin section of the fuselage was of a tubular steel frame construction whereas the rear of the fuselage had a wooden shell. The wing assembly and tail unit were also of wooden shell construction. All the rudders, elevators and ailerons had wooden ribs and are covered in fabric. The flaps were metallic on the B types and wood on the C types. The Bü 181 Bestmann was powered by a 105 hp four-cylinder Hirth HM 500A or B piston engine. The aircraft was designed for training flights, pleasure trips and aerobatics. Its strength corresponded to Stress Group 5 with a limited load (single occupancy) and Stress Group 4 fully laden
The Bücker factory at Rangsdorf built most of the Bü 181's, but because of demand was forced to license the design to the Fokker Company in the Netherlands, who subsequently built 373 of the type for the Luftwaffe all of which were delivered by the end of 1943. Production of both the Bü 181B and the slightly modified Bü 181C was begun by Fokker in Amsterdam in 1942 and its total wartime production was 708 aircraft.
The Bü 181 was also built by Zliner Flugzeugwerke AG plant at Zlin, in the Bohemia & Moravia Protectorate and after the German withdrawal the production continued after the war in the same Zlin works, now denominated as the C.6 and C.106 for the Czechoslovak Air Force and as the Zlín Z.281 and Z.381 in various versions for civil use. 783 aircraft were built. Between 1943 and 1945, Hägglund & Söner AB in Sweden built 120 Bü 181's under license with the Swedish military designation Sk 25.
During the 1950s the Heliopolis Aircraft Works of Egypt acquired a Czechoslovakian licence to produce the Zlín Z-381 with a 105 hp Walter-Minor engine. It was produced for the Egyptian Air Force as the Heliopolis Gomhouria (meaning "Republic") and subsequent versions were supplied to other Arab air forces. At least 300 Gomhourias were built. In all, 3,400 aircraft were built but only a handful survives today.
Although built primarily as a trainer for the Luftwaffe, the type also performed other duties such as courier & liaison. From March 1945 an order was issued to concentrate all the available Bü 181s to be converted either to the "tank busting" role carrying four Panzerfaust anti-tank grenade launchers from wing-mounted launchers (C-3 subtype) or to the night harassment role carrying three 50 kg bombs (B-3 subtype), most likely inspired by the Soviet female nocturnal Nochnye Vedmy units' campaigns from 1942 to V-E Day. These units saw very limited use in the final days of the war due to the war situation. However, some missions were carried out, achieving moderate success but at the price of severe losses. One restored Bestmann on the tank buster configuration is on display at the Deutsches Technikmuseum Berlin.
The Bü 181 evolved very little during the war, the differences between the B type and the C types were minimal, the most important being the increased autonomy of the C types. The main difference between the B-1 & C-1 and the B-2 and C-2 sub-types was the presence of pitot heating and position & cabin lights while the B-2 and C-2 types lacked any electrical system.
Bu 181V Prototype.
Bü 181 B-0 Pre-production series with Hirth HM 504 A-2 engine
Bü 181 B-1 With Hirth HM 500 A engine
Bü 181 B-2 As B-1 but no electrics
Bü 181 B-3 (Schlachtflugzeug): Night harassment version made from converted B-1s and C-1s carrying improved instrumentation, Revi gunsights and three ETC 50 bomb racks. Bomb loads; either three SC50 or three SD50 or three SD70 or three AB70 droppable clusters. Max. Bomb load 210 kg.
Bü 181 C-1 Increased range and Hirth HM 500B engine.
Bü 181 C-2 As C-1 but no electrics
Bü 181 C-3 (Panzerjäger): B-2 or C-2 subtypes modified for the antitank role carrying four wing mounted Panzerfaust 100 single-use antitank grenade launchers in pairs, two on each wing.
Post war license built & developments
- Zlín Z.181
- Two-seat primary trainer aircraft. Czech production version of the Bu 181, built by Zlín in Czechoslovakia after the war.
- Zlín Z.281
- Two-seat primary trainer aircraft, powered by a Toma 4 piston engine.
- Zlín Z.381
- Two-seat primary trainer aircraft, powered by a 105 hp (78 kW) Walter Minor piston engine. Czech Air Force designation C-106.
- Gomhouria Mk 1
- Two-seat primary trainer aircraft, powered by a Walter Minor piston engine. Egyptian production version of the Zlín 381, built under licence in Egypt by the Heliopolis Aircraft Works.
- Gomhouria Mk 2
- Two-seat primary trainer aircraft, powered by a 145 hp (108 kW) Continental C-145 piston engine.
- Gomhouria Mk 3
- As Mk. 2, but with improved undercarriage.
- Gomhouria Mk 4
- Increased fuel capacity.
- Gomhouria Mk 5
- Similar to Mk 1, powered by Walter Minor, but with different engine mounting.
- Sk 25
- Swedish Air Force designation of the license-built Bestmann.
Of the over 4,000 Bü 181s originally built, only about 10 examples remain, none is in flying condition. However a good number of license-built Sk 25s fly still today, as well as some Zlin examples and an increasing number of Egyptian Gomhourias.
- Algerian Air Force – Gomhouria
- Czechoslovak Air Force – Post War
- Czechoslovakian National Security Guard – Post War
- Hungarian Air Force – Postwar.
- Royal Jordanian Air Force – Gomhouria
- Libyan Air Force (1951-2011) – Gomhouia
- – Postwar.
- Sudanese Air Force – Gomhouia
- Swiss Air Force – 1 + 6 Bü-181B-1 from German Luftwaffe landed and were interned in 1944.
- SFR Yugoslav Air Force – Postwar
Data from The Concise Guide to Axis Aircraft of World War II 
- Crew: Two
- Length: 7.85 m (25.7 ft)
- Wingspan: 10.6 m (34.71 ft)
- Height: 2.05 m (6.7 ft)
- Wing area: 13.5 m² (145.3 ft²)
- Empty weight: 480 kg (1,058 lb)
- Max. takeoff weight: 750 kg (1,653 lb)
- Powerplant: 1 × Hirth HM 500A or B 4-cyl. inverted air-cooled in-line piston engine, 78 kW (105 hp)
- Never exceed speed: 440 km/h
- Maximum speed: 116 knots (134 mph, 215 km/h) at sea level
- Cruise speed: 105 knots (121 mph, 195 km/h)
- Range: 800 km (497 mi, 432 nm)
- Service ceiling: 5,000 m (16,405 ft)
- Related development
- Related lists
- The few B-0 pre-series subtypes built carried still the old Hirth HM 504 engine
- Christian Möller: Das letzte Aufgebot der deutschen Luftwaffe Helios Verlag 2010 ISBN 978-3-86933-030-3
- info taken from book by Gerhard Bracke, "Melitta Gräfin Stauffenberg, das Leben einer Fliegerin'
- Based on the Bü 181 B & C parts list of April 1944 and other primary sources
- Taylor 1965, p.29.
- "Trade Registers". Armstrade.sipri.org. Retrieved 2013-06-20.
- Mondey 1996, p.30.
- Donald, David and Lake, Jon. (editors). Encyclopedia of World Military Aircraft. London: Aerospace Publishing, Single volume edition, 1996. ISBN 1-874023-95-6.
- König, Erwin. Bücker Bü 181 "Bestmann" (Flugzeug Profile 30) (in German). D-86669 Stengelheim, Germany: Unitec Medienvertrieb e.K.
- König, Erwin. Die Bücker-Flugzeuge (The Bücker Aircraft) (bilingual German/English). Martinsried, Germany: Nara Verlag, 1987. ISBN 3-925671-00-5.
- König, Erwin. Die Bückers, Die Geschichte der ehemaligen Bücker-Flugzeugbau-GmbH und ihrer Flugzeuge (in German). (1979)
- Mondey, David. The Hamlyn Concise Guide to Axis Aircraft of World War II. London: Chancellor Press Ltd, 1996. ISBN 1-85152-966-7.
- Smith, J.Richard and Kay, Antony L. German Aircraft of the Second World War. London: Putnam and Company Ltd., 3rd impression 1978, p. 94–96. ISBN 0-370-00024-2.
- Taylor, John W. R. Jane's All The World's Aircraft 1965–66. London: Samson Low, Marston, 1965.
- Wietstruk, Siegfried. Bücker-Flugzeugbau, Die Geschichte eines Flugzeugwerkes (in German). D-82041 Oberhaching, Germany: Aviatik Verlag, 1999. ISBN 3-925505-28-8.
- Wood, Tony and Gunston, Bill. Hitler's Luftwaffe: A pictorial history and technical encyclopedia of Hitlers air power in World War II. London: Salamander Books Ltd., 1977, p. 140. ISBN 0-86101-005-1.
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