The
Rumpler and
Friedrichshafen aircraft used by the Germans and turned over to the Bulgarians mentioned by
agblume were based at Varna and consisted of:
1. Single-seat
Rumpler 6B1 types w/ 1 synchronized LMG 08 machine gun.
2. Two seater
Friedrichshafen FF33e (three-bay) w/ FT (transmitter) for observation
3. Two-seater
Friedrichshafen FF33h (two-bay) armed w/ rear gun and capable of dropping bombs.
As for Romania, the
Sopwith 1 1/2 Strutter was built in much larger numbers by the French and as such the Strutters supplied were most likely French-built variants for the most part. Photos would show the differences between them whether French licence-built or British built.
Also, in the Balkans photos show that German
Jasta 25 flew the
Fokker D.II,
Halberstadt D.II,
Roland D.II, and
Albatros D.III fighters over the course of late 1916/mid-1917. Some of the pilots that flew with this unit and on the Balkan front in Macedonia were: Hptm. Burkhard, Bodo
Freiherr von Lyncker,
Otto Brauneck,
Gerhard Fieseler,
Rudolf von Eschwege,
Otto Könnecke...
The Bulgarians units flew the following:
Two-seat reconnaisance/observation/bombing:
Albatros B.II, C.I, C.III, C.VI, C.VII,
LVG B.II
DFW C.V
Otto C.I
Armstrong-Whitworth FK3 (1 captured example)
Single-seat fighter aircraft:
Fokker E.III (three examples)
Roland D.II (Pfalz-built)
Roland D.III
Nieuport 24bis and 24/27 (three examples were captured through force landing and flown operationally before their engines wore out or they were lost in accidents.)