BFW M.21

Bayerische Flugzeug-Werke (BFW)
Industry	Aircraft manufacturing
Founded	1927; 99 years ago
Founder	Willy Messerschmitt
Headquarters	Germany
Products	Aircraft

Template:Infobox aircraft

The BFW M.21 was a single-engine biplane trainer crafted by Willy Messerschmitt under commission from the German Ministry of Transport. It represents one of only two biplane designs created by Messerschmitt, both of which did not enter mass production.

Design and development

In 1927, after the successful launch of his Messerschmitt M 18 airliner, Messerschmitt sought financial backing from the Bavarian government. Since Bayerische Flugzeug-Werke (BFW) was already receiving subsidies from the government, they proposed that Messerschmitt join BFW with the condition that the company would exclusively manufacture his designs. These discussions concluded on 8 September 1927. Concurrently, the Ministry of Transport urged Messerschmitt to develop military aircraft, which resulted in his only two biplane creations—the first being the BFW M.21, also referred to as the Messerschmitt M 21.

This model was a two-seat trainer featuring a single-bay biplane configuration powered by one engine. The wings were designed with parallel chords, minimal stagger, and no sweepback, and could be folded to facilitate transportation. Both upper and lower wings were equipped with ailerons. To enhance visibility from the rear cockpit, the upper wing had a rounded cutout; meanwhile, the front cockpit was positioned beneath the wing. The fuselage had a square cross-section with a triangular upper deck behind the open cockpits and tapered towards the tail, accentuating the size of the fin and rudder. The landing gear was conventional, consisting of a single axle with a tail skid.

The M.21 was driven by an uncowled radial engine—either a 96 hp (72 kW) Siemens Sh 11 in the M.21a variant or a more powerful 125 hp (93 kW) Siemens-Halske Sh 12 in the M.21b—both turning a two-bladed propeller. Its maiden flight occurred in 1928; however, it failed to secure production orders and only one unit was manufactured. Registered as D-1566 for civilian use, this aircraft remained operational until 1933 under DVS GmbH, the German sports flying organization.