The success of the Jungmann led Bucker to open a second factory where a single-seat derivative could be produced in parallel with the original two-seater. The single-seater was the Jungmeister (young champion) advanced trainer, essentially a scaled-down Jungmann. First introduced in 1935, quickly developed an international reputation for its outstanding aerobatic capabilities.
The initial Bu 133A had the 101-kW (135-hp) Hirth HM 6 inline but better performance than the higher-powered Bu 131. Quantity production was undertaken for the Luftwaffe, though precise details are lacking. The Bu 133B export version was produced to the extent of some 100 aircraft by Dornier in Switzerland and CASA in Spain with the 119-kW (160-hp) Hirth HM 506 inline. The definitive version, however, was the Bu 133C with a radial engine: this had excellent agility and performance, and was used as a fighter lead-in trainer as well as for advanced flying training. This model too was built in Switzerland and Spain.
Bu 133C Jungmeister
The Bu 133 was built be Construcciones Aeronauticas S.A. in Spain for the Spanish Air Force under the designation ES-1, and 47 were built in Switzerland by the former Dornier-Werke for the Swiss Air Force.
In 1968, the Aero Technik Canary in Munich, Germany, began production of the BU-133 D-1, also called the Jungmeister. Its engine is a remanufactured Siemens-Halske Sh-14A4; however, due to this engine’s limited availability and demand for more power, a new version, the BU-133F, was built by Wolf Hirth GmbH with a 220 hp Franklin engine.
The Bu-133D-1 is basically as the Bu-133C but engine, optimised for constant inverted flight, Goodyear tyres, wheels and brakes, and US instruments.
Bucker Prado Sl offered kits to build the former German Jungmann two-seat aerobatic biplane using original Bucker/CASA Bu 131 jigs, plus Jungmeister single-seat aerobatic biplane.
Bu 133A Engine: Hirth HM 6 inline, 101-kW (135-hp)
Bu 133B Engine: Hirth HM 506 inline, 119-kW (160-hp)
Bu 133C Jungmeister Engine: l x Siemens Sh 14A-4, 119kW (160hp) Span: 6.6m (21 ft 7.75in) Length: 6m (l9ft 8.25 in) Empty weight: 420 kg / 925 lb Max T/O weight: 585 kg (1,290 lb) Max speed: 134 mph / 116 kt / 215 kph at sea level Max cruise: 108 kt / 124 mph / 200 kph Climb to 3300 ft / 1000m: 2 min 50 sec Service ceiling: 19,685 ft / 6000 m Operational range: 311 mi / 269 nm / 500 km Optional fuel: 8.6 ImpGal / 39 lt
Bu 133 D-1 Engine: Siemens Sh-14A-4 Bramo, 158 hp Length: 19.751 ft / 6.02 m Height: 7.71 ft / 2.35 m Wingspan: 21.654 ft / 6.6 m Wing area: 129.168 sq.ft / 12.0 sq.m Max take off weight: 1411.2 lb / 640.0 kg Weight empty: 992.3 lb / 450.0 kg Max. weight carried: 419.0 lb / 190.0 kg Max. speed: 113 kts / 210 km/h Initial climb rate: 1082.68 ft/min / 5.5 m/s Service ceiling: 12467 ft / 3800 m Wing load: 10.87 lb/sq.ft / 53.00 kg/sq.m Range: 205 nm / 380 km Endurance: 2 h Crew: 1
Bücker Flugzeugbau first design, designed by Anders Andersson, was the Bü.131A Jungmann powered by a 4 cylinder Hirth in line engine. A light two-seat biplane trainer specially developed for school and other training purposes, the prototype “D-3150” flew first 27 April 1934 with a 60-kW (80-hp) Hirth HM 6CR inline engine. The Jungmann was ordered by the Deutsche Luftsport Verband (The German Air-Sports Association). In 1936, the Luftwaffe adopted the Jungmann as one of its primary trainers.
Power was provided by a 60kW Hirth H.M.60R engine in the Bü.131A and a 78kW Hirth H.M.504A inverted engine in the Bü.131B.
Bu.131B
Before the outbreak of World War II the trainer was being used in 21 countries and licence-built in Holland, Czechoslovakia, Spain and Switzerland.
Spain was one of the earliest customers. Over a hundred German-built Jungmanns were delivered to the Spanish Nationalist side in the civil war. A total of 500 Jungmanns were built by the Construcciones Aeronauticas S.A. (CASA) in Spain. The first 200 had German Hirth HM504 engines but the remainder were powered by versions of the Spanish ENMA Tigre G-IV. In Spain production started 1938 and the CASA I-131 remained in production until the end of the fifties. The CASA E3B is a licence-built example.
Some 1,254+ were built in Japan by Watanabe and Kyushu as the army’s Kokusai Ki-86A (1,037) and the navy’s K9W1 Momiji (Maple) (217+). Later models had 110 hp Hitahi Ha.47 engines. The code name was Cypress, applied to both the Navy Type 2 Momiji and Army Type 4.
The prototype was originally delivered to Japan in 1939, and Navy production began in August 1941.
K9W1 Cypress
Production figures have not survived, but some indication of scale is provided by the fact that Hungary took 100 and Romania 150, while Switzerland built 75. The Bucker Bü.131B Jungmann was also built under license pre-war in Switzerland by Dornier, and Czechoslovakia as the Tatra T.131. In Czechoslovakia the post-war version of the Bu.131B was the C.4. The C.104 was as the C.4 but with a 105 hp Walter Minor 4-III engine.
CASA 1-131E
Bucker Prado Sl offered kits to build the former German Jungmann two-seat aerobatic biplane using original Bucker/CASA Bu 131 jigs, plus Jungmeister single-seat aerobatic biplane.
Bu 131A Engine: 1 x Hirth HM60R, 59kW / 80 hp Max Take-off weight: 630 kg / 1389 lb Empty weight: 280 kg / 617 lb Wingspan: 7.4 m / 24 ft 3 in Length: 6.7 m / 21 ft 12 in Height: 2.3 m / 7 ft 7 in Wing area: 13.5 sq.m / 145.31 sq ft Max. speed: 170 km/h / 106 mph Cruise speed: 150 km/h / 93 mph Ceiling: 3500 m / 11500 ft Range w/max.fuel: 680 km / 423 miles Crew: 2
Bu 131B Engine: Hirth HM 504 A-2, 104 hp, 78kW Wingspan: 24 ft 3.25 in / 7.4 m Wing area: 145.314 sq.ft / 13.5 sq.m Length: 21 ft 8in / 6.62 m Height: 7.776 ft / 2.37 m Max take-off weight: 1477.4 lb / 670.0 kg Weight empty: 882.0 lb / 400.0 kg Max. weight carried: 595.4 lb / 270.0 kg Max. speed: 93 kts / 173 km/h / 114mph at sea level Initial climb rate: 748.03 ft/min / 3.8 m/s Service ceiling: 11483 ft / 3500 m Wing load: 10.25 lb/sq.ft / 50.0kg/sq.m Range: 216 nm / 400 km Endurance: 3 h Crew: 2
Brothers Wincent and Rudolf Schindler, wealthy millers from Kraków, built in 1908 a working model airplane and in 1910 they commissioned a talented engineer Henryk Brzeski to build a plane to their ideas, named Aquila (Latin for “eagle”). In August 1910 it was demonstrated on the ground to emperor Franz-Josef I, and several days later a test-flight attempt was made, during which it crashed into a fence at the outskirst of the airfield.
Initial configuration
Final configuration
Span: 32’10” Length: 32’10” Weight empty: 660 lb pilot and 2 passengers
The Hybrid is a fully enclosed, modified RAF 2000 using a Subaru fuel injected 120 hp EJ-20 SOHC engine with a Sub4 gearbox. Built as a one-off, it is fitted with a Motec ECU, 87 litre seat tank, two blade wooden prop, 30 foot Patroney rotors. The hub bar and windscreen are new. A Rosco rotor head has an RAF rotor brake and electric pre-rotator with soft start. It is fitted with carpet, heater, pitch and roll trims. It was registered in Australia with the ASRA registration of G-400.
The Freedom 28 won Grand Champion Reserve at Oshkosh 1986 and was still available in 1996. The airframe is all aluminium sheet metal with a steel undercarriage.
Top speed: 86 mph Cruise: 76 mph Stall: 27 mph Range: 138 sm Rate of climb: 950 fpm Takeoff dist: 150 ft Landing dist: 150 ft Service ceiling: 20,500 ft Engine: Hirth 2702, 40 hp HP range: 28-42 hp Fuel capacity: 5 USG Empty weight: 310 lb Gross weight: 560 lb Height: 6 ft Length: 18 ft Wing span: 28 ft Wing area: 112 sq.ft Seats: 1 Landing gear: tailwheel
The LF-1 was designed by Prof. Dr.-Ing. Hermann Winter and some of his students from the Technische Universität Braunschweig (English:Technical University of Brunswick), Lower Saxony, Germany in 1939, as a fool-proof trainer for novice student pilots to experience solo flight. Winter was a former chief engineer at the Bulgarian company, DAR (Drzhavnata Aeroplanna Rabotilnitsa in cyrillic ДАР – Държавната аеропланна работилница).
The LF-1 is a parasol wing monoplane with a high-set tailplane, powered by a Zündapp Z 9-092 engine delivering 37 kW (50 hp), able to operate from a 100 m (330 ft) airstrip. The two-piece wings are set at 16° dihedral and are supported by a pair of v cabane struts and v-struts either side from approx half-span to the lower centre fuselage. Full span leading edge slats extend automatically and full span trailing edge flaps / drooping ailerons can be extended manually by the pilot. The fixed tailwheel undercarriage attaches to the fuselage with long struts and oleo pneumatic shock absorbers.
When the flaps were lowered (max. angle 40°), the ailerons also drooped. The Zündapp engine was an air-cooled 4-cylinder engine with single ignition, it produced 51 hp producing a max. airspeed of 87 m.p.h.
It was a proof-of-concept design for a ‘fool-proof’ trainer intended for novice pilots with only one hour of ground instruction, the hour being reduced to five-minutes for those who had already flown gliders, and was intended to be impossible to either stall or spin.
The first prototype, the LF-1 V1, was built in 1940 and made its maiden flight, piloted by Winter himself, on 17 December 1940 powered by a 51 hp Zündapp 9-092 engine. The flight characteristics revealed a good-natured behavior, while the flight performance confirmed the expectations with a stall speed of 29.2 mph (47 kmh) and a maximum speed in level flight of 87.6 mph (141 kmh). The aircraft was repaired and flown again on July 16, 1941, however, on September 11, 1942, during a flight to determine the roll speed of the aircraft, a second serious accident occurred. During the flight tests, performed by the assistant Franz Glatz, there was an overload of the lateral control system, which then failed. This led to the flapping of the wings and subsequently the loss of the right wing. The pilot managed to parachute to safety, the plane crashed onto a truck parked on the parade ground in Brunswick, and both the aircraft and the truck were a total loss.
In 1943 a second prototype, the V2, was built, again receiving the registration D-YBAR. The aircraft was tested for military applications and was once even armed with a Panzerfaust 100 recoilless anti-tank weapon.
The type was named Zaunkönig (Wren) on February 5, 1944.
The aircraft survived WW II, but shortly before the occupation of the Technische Hochschule Braunschweig by Allied troops in April 1945, all aircraft documentation was destroyed. In 1945 groups of specialist units were capturing German secrets and technology. Eric ‘Winkle’ Brown led a British aviation team and managed to fly most of the Luftwaffe’s aeroplanes, from the Messerschmitt 163 rocket fighter to the Blohm und Voss 222 6- engined flying boat. One less exotic type he encountered was the Zaunkönig (Wren). An example was brought back to England for thorough testing.
The Zaunkönig registration D-YBAR was taken to the Royal Aircraft Establishment (RAE) at Farnborough for slow flying tests; given the British serial VX190, where amongst others, it was flown by Eric “Winkle” Brown CO Aero Flight, the aircraft also being soloed by the then-head of the RAE Aerodynamics Section, Handel Davies, whose previous experience was as a pupil in a dual-control Miles Magister, after a half-hour of ground instruction.
Most of the pilots found flying the Zaunkönig ‘an interesting experience’. Getting into the small cockpit close under the wing was quite a gymnastic manoeuvre. The engine started easily and with no ignition check or elevator trimmer it was soon time for take-off. The briefing was that flap position was ‘anywhere you like’ and on opening the throttle the aircraft ‘cannot fail to fly itself away’. It left the ground at 44 m.p.h. flaps up or 31 m.p.h. flaps down. The lack of trimmer was not a problem as all three controls were light and pleasantly balanced. Approach to land was at 45 m.p.h. flaps up or 40 m.p.h. flaps down. There was no need to flatten out. The aircraft approached in a three point attitude and the pilot could be told to ‘wait until the ground hits the aircraft’. The undercarriage was strengthened to allow it to absorb the shock of the widest range of landing techniques – or should that be lack of technique.
‘Stalling’ tests were carried out with wool tufts attached to the upper surface of the wing. These were filmed from a following helicopter and showed that, at about 30 m.p.h., engine off or engine on, the centre section of the wing stalled but the outer section went on flying and the ailerons continued to give full lateral control. The Zaunkönig effectively ‘turned into a parachute’.
After being wrung out at Farnborough, there seemed to be no useful military function for the Zaunkönig and it was tested by the Civil Aviation Flying Unit of the Ministry of Civil Aviation at Gatwick. There were ideas of using it to promote the expected surge in private flying so it was sold to a British private owner in June 1949 as G-ALUA, and then to the Experimental Flying Group and to the Ultra Light Aircraft Association.
It toured the flying clubs whose members could fly it for £1 per hour. However, it caused little excitement and passed through the hands of several private owners including one in Ireland. At one stage, it was rebuilt by John Isaacs (noted for his own designs of a mini Hawker Fury biplane and mini Spitfire).
It was subsequently sold in 1974 to an Irish owner, being registered EI-AYU, returning to Germany, in 1976, as D-EBCQ. As of 2008, it was preserved in the Deutsches Museum collection at Oberschleissheim near Munich.
The second Zaunkönig D-EBCQ preserved in the Deutsches Museum, Oberschleissheim, in July 2008
Encouraged by the positive British reviews Prof. Ing. Hermann Winter decided to build a third LF-1. The construction started in 1954 and it was the first new aircraft in Germany after the war to receive a certificate by the Luftfahrt-Bundesamt (LBA) in Braunschweig and the registration D-EBAR. Winter envisioned the Zaunkönig as a People’s Aircraft affordable for all (for a price of around DM 6,000). On 28 April 1957, the wartime Luftwaffe fighter ace Heinrich Bär was conducting a routine flight check in the D-EBAR. Bär put the aircraft into a flat spin, the final manoeuvre in the test process at Braunschweig-Waggum. The aircraft spun down to 50 m (160 ft) then, unable to regain control, it crashed and Bär received fatal head injuries. The aircraft was damaged beyond repair and written off.
At the time a fourth LF-1 V4 was already under construction and it flew a few months after the fatal accident with the V3, in the summer of 1957. It received its certificate in 1958, it expired on October 8, 1964, when the aircraft was grounded, and the code D-ECER. This aircraft flew for some years in Germany until grounded after the death of Prof. Ing. Winter in 1968. In November 1979 it was registered again, this time as D-EBCG, restored in 1980 and flew until 1999 as D-EBCG. The registration was cancelled on October 15, 1999. As of 2008 it was preserved in the collection of the Internationals Luftfahrtmuseum Manfred Pflumm near Villingen-Schwenningen.
This machine was built for the inventor, Erhard Brunsmann of Berlin-Eichwalde, Germany, by Edmund Rumpler in Berlin-Johannisthal. The tandem wings were driven by a complex patented crank mechanism and it was intended that control would be achieved by differential flapping of the wings, rather than by separate control surfaces. Lange dismisses it in little more than two lines as a “Fehlkonstruktion”.
