It was the production version of the Avia B.35 developed shortly before the war, based on the B.35/3 prototype (with a retracting main undercarriage) but featuring a new all-metal wing.

The B.135/1 prototype attracted the attention of Bulgarian Air Force officers visiting the Avia plant, and a production contract for 12 aircraft and 62 engines was signed, as well as a license to allow an additional 50 airframes to be constructed by DAR as the DAR 11 Lyastovitsa (Bulgarian: "Лястовица"; "Swallow").

Plans for further production were stopped by the RLM, which also interrupted engine deliveries after 35 units, and the Bulgarian Air Force was encouraged to purchase the Messerschmitt Bf 109 instead.

Four aircraft did, however, see combat on 30 March 1944 when they intercepted USAAF bomber formations encroaching on Bulgarian airspace after attacking Ploieşti.

According to Bílý, all four Avias, led by Captain Atanasov, took part in the possible shooting down of a four-engined bomber that day.