BFW M.20

M 20
M 20, with a picture of Pilot Erich Pust, killed with eight passengers on another M.20 (D-1930) near Dresden, on the Berlin-Vienna run.
Role	Passenger transport
Manufacturer	Bayerische Flugzeugwerke
Designer	Willy Messerschmitt
First flight	26 February 1928
Introduction	1929
Retired	1948
Primary user	Deutsche Luft Hansa
Number built	15

The BFW M.20 (also known as the Messerschmitt M 20 after the designer's surname) was a German single-engine, high-wing monoplane 10-seat passenger transport aircraft, developed in the late 1920s and early 1930s. Deutsche Luft Hansa used it throughout the 1930s on a variety of routes.

Design and development

The M 20^[1] was designed by Willy Messerschmitt at Bayerische Flugzeugwerke, primarily for use with Luft Hansa which had ordered two in advance of the first flight. It was a development of the BFW M.18d eight-seater equipped with a single 375 kW (500 hp) upright inline water-cooled BMW VIa engine. It had a high, cantilever wing based around a robust D-section box formed from a single dural spar and dural skin forward to the leading edge. The fuselage was all-metal, with a mostly dural frame covered with metal sheeting^[2] providing rectangular cross-section accommodation, with four square windows a side, for eight passengers. The single-axle main undercarriage was strutted vertically to the wing.

The aircraft made its maiden flight on 26 February 1928 but was lost when pilot Hans Hackmack bailed out at low altitude and was killed after the surface stripped from part of the wing. A second M.20 was flown on 3 August 1928, and became the first of two M.20a series to fly with Luft Hansa.

Encouraged by their performance, Luft Hansa ordered 12 more, enlarged, M.20b aircraft. These carried 10 passengers in a fuselage with five windows a side. It had dihedral on the wing and a more rounded vertical tail.

Operational history

M.20 (1934)

The Luft Hansa M.20s^[1] entered service in 1929 on routes that went from Switzerland via Germany to the Netherlands and from Stuttgart via Marseille to Barcelona.^[3] From the mid-1930s, they were operating German internal and holiday routes. Two were still flying such routes in 1942.

One former Luft Hansa airframe went to Brazil with Varig in 1937.^[1][4] It crashed in 1948,^[5] the only M 20 to survive the war.

The Messerschmitt-Milch relationship

Hans Hackmack, who died in the first flight of the M 20, was a close friend of Erhard Milch, the head of Luft Hansa and the German civil aviation authorities. Milch was upset by the lack of response from Messerschmitt and this led to a lifelong hatred towards him. Milch eventually cancelled all contracts with Messerschmitt and forced BFW into bankruptcy in 1931. However, the German re-armament programs and Messerschmitt's friendship with Hugo Junkers prevented a stagnation of the careers of him and BFW, which was started again in 1933. Milch still prevented Messerschmitt's takeover of the BFW until 1938, hence the designation "Bf" of early Messerschmitt designs.

Variants

M 20a

The first two eight-seater aircraft for Luft Hansa.^[3]

M 20b

Twelve 10-seaters built for Luft Hansa.^[3]

M 20b-2

Upgraded with a 480 kW (640 hp) BMW VIu engine.^[6]

Operators

 Germany

• Luft Hansa

 Brazil

• Varig

Specifications (M 20b)

Data from ^[1]

General characteristics

• Capacity: 10 passengers
• Length: 15.90 m (52 ft 2 in)
• Wingspan: 25.50 m (83 ft 8 in)
• Height: 4.20 m (13 ft 9¼ in)
• Wing area: ^[2] 65.0 m² (700 ft²)
• Empty weight: 2,700 kg (5,952 lb)
• Loaded weight: 4,600 kg (10,141 lb)
• Powerplant: 1 × BMW VIa water-cooled inline V-12, 373 kW (500 hp)

Performance

• Maximum speed: 175 km/h at sea level (109 mph)
• Cruise speed: ^[2] 154 km/h (96 mph)
• Range: 880 km (547 mi)
• Service ceiling: ^[2] 5,000 m (16,404 ft)
• Rate of climb: ^[2] 2.1 m/s (413 ft/min) to 1,000 m (3,281)

References

Wikimedia Commons has media related to Messerschmitt M 20.

• Stroud, John (1966). European Transport Aircraft since 1910. London: Putnam.