Avro 552 
At least two Avro 552 floatplane biplanes delivered from the manufacturer in 1923. The Avro 552 was a conversion of the Avro 504K using the Wolseley Viper in-line engine from the wartime S.E.5A fighter and mounted on twin wooden floats. Used on the Black Sea coast for advanced pilot training. Date withdrawn from service not known.

Serial	c/no.	Prev. Identity	Delivered	Fate/Notes
B-BAHA	?		1923
B-BBAH	?		1923

References:

• Avro Aircraft Since 1908 pp203

Armstrong Whitworth F.K.3 
One Armstrong Whitworth F.K.3 biplane damaged in dogfight on 8 July 1917 when flown by Captain O'Dwyer of 17 Sqn RFC and crash-landed near Petrich. Transferred to Belica airfield and taken on strength by 1 Aeroplane Otdelenie. Well liked by Bulgarian pilots and actively used by bombing and reconnaissance missions. Still used January 1918 and retained until about April 1918. (Referred to as an F.K.8 in the reference below but the serial shows it is an F.K.3).

Serial	c/no.	Prev. Identity	Delivered	Fate/Notes
6219			July 1917	ex-RFC 17 Sqn

References:

• Air Power of the Kingdom of Bulgaria Part II by Dimitar Nedialkov, 2001