Avia B-135

The Avia B-135 was a Czechoslovak cantilever monoplane fighter. It was based on the third prototype of the Avia B-35 redesigned with a new all-metal wing.

• Czechoslovakia: As the B-135 was developed after Germany occupied Czechoslovakia, the drawing depicted below is speculative of how it would've looked like if it served with the Czechoslovak Air Force.
• Germany: As it was developed mainly during 1939, it was presented officialy in the Brussels Air Saloon of 1939 under German colours. However, as Germany wasn't interested on it, they sold all of them to Bulgaria.
• Japan: Apparently, at least one airplane was sold to the Imperial Japanese Army Air Service to evaluate it. It did even got a nickname from the Americans which nicknamed it as "Alex".

Sources:
1. https://en.wikipedia.org/wiki/Avia_B-135
2. Salamander Books - The Complete Book of Fighters
3. http://www.wardrawings.be/WW2/Files/2-Airplanes/Axis/3-Japan/01-Fighters/B-135/B-135-105.htm

Avia B-135, Bulgarian Users

The Avia B-135 was a Czechoslovak monoplane fighter that was used by Bulgaria.

Back in the late 1930s, the Bulgarian DAR company bought a license to locally build the Avia B-135, which was to be known as the DAR 11 Lyastovitsa (Bulgarian word for "Swallow") but the DAR factories proved to be unsuitable for producing the airplane and only the 12 Czechoslovak made fighters ended serving in the Bulgarian Air Force.

As they were giving engine problems, they were mainly used on training duties. However, four of them were used in combat on 30th March 1944 when they intercepted some USAAC bombers returning from a bombing mission in Ploesti, Romania. Apparently an Avia B-135 piloted by Yordan Ferdinandov managed to shot down a B-24 bomber which crashed into Bulgarian soil that day.

Sources:
1. https://en.wikipedia.org/wiki/Avia_B-135
2. Salamander Books - The Complete Book of Fighters