The MBB Bo 209 Monsun (originally the Bolkow MHK-101) is a two-seat light aircraft that was developed in West Germany in the late 1960s.
Design and development
The Monsun was designed by three
Bölkow
Bölkow was a West German aircraft manufacturer based in Stuttgart, Germany, and later Ottobrunn.
History
The company was founded in 1948 by Ludwig Bölkow, who since 1955 with Emil Weiland had developed helicopters for Bölkow Entwicklungen KG.
...
engineers, led by Bölkow's technical director Dr
Hermann Mylius Hermann or Herrmann may refer to:
* Hermann (name), list of people with this name
* Arminius, chieftain of the Germanic Cherusci tribe in the 1st century, known as Hermann in the German language
* Éditions Hermann, French publisher
* Hermann, M ...
, in their spare time with the intention of creating a more versatile aircraft than the
Bölkow Bo 208
Bölkow was a West German aircraft manufacturer based in Stuttgart, Germany, and later Ottobrunn.
History
The company was founded in 1948 by Ludwig Bölkow, who since 1955 with Emil Weiland had developed helicopters for Bölkow Entwicklungen K ...
, with design work beginning in 1965. The new aircraft, designated the MHK-101, was a low-wing monoplane of all-metal construction with a
tricycle undercarriage
Tricycle gear is a type of aircraft undercarriage, or ''landing gear'', arranged in a tricycle fashion. The tricycle arrangement has a single nose wheel in the front, and two or more main wheels slightly aft of the center of gravity. Tricycle ...
, which had fixed mainwheels, with the option for the nosewheel to be fixed or retractable. While the MHK-101 used some components of the Bo-208, it had a larger and more comfortable cockpit, and an entirely new wing, which could be folded for towing and storage (the Bo 208 was a high-wing aircraft).
The first prototype MHK-101, powered by a
Lycoming O-235
The Lycoming O-235 is a family of four-cylinder, air-cooled, horizontally opposed piston aircraft engines that produce , derived from the earlier O-233 engine.Textron Lycoming: ''Operator's Manual, Textron Lycoming Aircraft Engines, Series O-23 ...
engine driving a fixed-pitch propeller and with a retractable nosewheel, flew on 22 December 1967. In April 1969, Bölkow selected the MK-101 to replace the Bo 208 in production, with the type becoming the "Bölkow Bo 209 Monson". A second prototype flew in May 1969. That year, Messerschmitt-Bölkow merged with Messerschmitt-Bölkow to become
Messerschmitt-Bölkow-Blohm
Messerschmitt-Bölkow-Blohm (MBB) was a West German aerospace manufacturer. It was formed during the late 1960s as the result of efforts to consolidate the West German aerospace industry; aircraft manufacturer Messerschmitt AG merged with the civ ...
, with the aircraft becoming the MBB Bo 209. The aircraft, which was offered with a variety of engines, a choice of fixed or variable pitch propellers and fixed or retractable nosewheels, entered production at MBB's
Laupheim
Laupheim (; Swabian: ''Laoba'') is a major district town in southern Germany in the state of Baden-Württemberg. Laupheim was first mentioned in 778 and gained city rights in 1869. One of the main trading routes, from Ulm to Ravensburg and then ...
factory early in 1970 and received its
type certificate
A type certificate signifies the airworthiness of a particular category of aircraft, according to its manufacturing design (''type design''). It confirms that the aircraft of a new type intended for serial production, is in compliance with applic ...
on 9 April 1970.
With this broad array of equipment options Bölkow displayed the aircraft at the Air Show in
Hanover
Hanover (; german: Hannover ; nds, Hannober) is the capital and largest city of the German state of Lower Saxony. Its 535,932 (2021) inhabitants make it the 13th-largest city in Germany as well as the fourth-largest city in Northern Germany ...
1970: 57 orders of the new type were drawn in advance and commercial success of the project seemed secured. In March 1972, however, MBB stopped production of the Bo 209 in order to concentrate on the
MBB Bo 105
The Messerschmitt-Bölkow-Blohm Bo 105 is a light, twin-engine, multi-purpose helicopter developed by Bölkow of Ottobrunn, West Germany. It was the first light twin-engine helicopter in the world, and the first rotorcraft that could perform ae ...
helicopter., after production of 100 Bo 209s in addition to the two prototypes. Rights to the Bo 208 were purchased by Pneuma-Technik E. Ficht who planned to build the Monsun at
Weiden,
Bavaria
Bavaria ( ; ), officially the Free State of Bavaria (german: Freistaat Bayern, link=no ), is a state in the south-east of Germany. With an area of , Bavaria is the largest German state by land area, comprising roughly a fifth of the total l ...
, setting up Monson Gmbh in November 1973, but only two aircraft were built before production ended in June 1974. A United States businessman invested in the model, secured funding, and started shipping factory equipment to
Georgia
Georgia most commonly refers to:
* Georgia (country), a country in the Caucasus region of Eurasia
* Georgia (U.S. state), a state in the Southeast United States
Georgia may also refer to:
Places
Historical states and entities
* Related to t ...
. Before completion of the transition, the investor committed suicide after losses in stock market speculation.
In the late 1990s Dr. Mylius's son, Albert Mylius, completed a totally revised version of his father's design under a new company,
Mylius Flugzeugwerk GmbH & Co KG, based in Bitburg. Two models were produced: a single seat developed as a low cost aerobatic airplane (My-102), and the two-seat
Mylius My-103 Mistral, which has some variations over the original Bo 209 design, like wider cockpit, better handling characteristics and improved overall performance (including aerobatic rating) with a more powerful 200 hp engine.
Variants

* MHK-101 prototype
* Bo 209-125 - proposed production version with
Lycoming O-235
The Lycoming O-235 is a family of four-cylinder, air-cooled, horizontally opposed piston aircraft engines that produce , derived from the earlier O-233 engine.Textron Lycoming: ''Operator's Manual, Textron Lycoming Aircraft Engines, Series O-23 ...
engine. No production.
* Bo 209-150 - production version with
Lycoming O-320
The Lycoming O-320 is a large family of naturally aspirated, air-cooled, four-cylinder, direct-drive engines produced by Lycoming Engines. They are commonly used on light aircraft such as the Cessna 172 and Piper Cherokee. Different variants ...
-E1C engine.
* Bo 209-160 - production version with
Lycoming IO-320-D1A engine.
* Bo 209S - trainer version with dual controls, non-retracting nosewheel, and non-folding wings, powered by
Rolls-Royce Continental O-240-A.
Specifications (Bo 209-160)
See also
Notes
References
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{{MBB aircraft
1960s German civil utility aircraft
Bo 209
Single-engined tractor aircraft
Low-wing aircraft
Aircraft first flown in 1967