The German aircraft manufacturer Klemm developed a successful low-powered light aeroplane, the Klemm L.25, which first flew in 1927, of which over 600 were produced.
 Several were sold to British owners, where they proved popular, so the British dealer for the L.25, Major E.F Stephen, set up the "British Klemm Aeroplane Company" at London Air Park, Hanworth, Middlesex to produce a version of the L.25 under license.

The prototype of the licensed version, known as the B.K. Swallow, first flew at Hanworth in November 1933.
 It was an all-wooden cantilever monoplane, with tandem cockpits accommodating two persons, and was powered by a 75 hp (56 kW) Salmson 9 or 85 hp (63 kW) Pobjoy Cataract radial engine.
 It differed from the German original with its more powerful engines and local strengthening to meet British airworthiness requirements.

In 1935 a revised version of the Swallow was introduced, with the curved wing tips, rudder and tailplane inherited from the Klemm original being made straight and with revised fuselage top decking.
 At this time the company changed its name to the British Aircraft Manufacturing Co., so the revised version was known as the B.A Swallow II.
 Swallow IIs were produced powered either by the Cataract or the Cirrus Minor inline engine, production continuing until 1938, with a total of 107 Swallow IIs produced, following on from the 28 Swallows I.
The German aircraft manufacturer Klemm developed a successful low-powered light aeroplane, the Klemm L.25, which first flew in 1927, of which over 600 were produced.  Several were sold to British owners, where they proved popular, so the British dealer for the L.25, Major E.F Stephen, set up the "British Klemm Aeroplane Company" at London Air Park, Hanworth, Middlesex to produce a version of the L.25 under license.
The prototype of the licensed version, known as the B.K. Swallow, first flew at Hanworth in November 1933.  It was an all-wooden cantilever monoplane, with tandem cockpits accommodating two persons, and was powered by a 75 hp (56 kW) Salmson 9 or 85 hp (63 kW) Pobjoy Cataract radial engine.  It differed from the German original with its more powerful engines and local strengthening to meet British airworthiness requirements.
In 1935 a revised version of the Swallow was introduced, with the curved wing tips, rudder and tailplane inherited from the Klemm original being made straight and with revised fuselage top decking.  At this time the company changed its name to the British Aircraft Manufacturing Co., so the revised version was known as the B.A Swallow II.  Swallow IIs were produced powered either by the Cataract or the Cirrus Minor inline engine, production continuing until 1938, with a total of 107 Swallow IIs produced, following on from the 28 Swallows I.
British Aircraft Swallow