Name	Explanation	Examples
OBP	Opticheskij Bombardirivichnyj Pritsel , Optical Bomb Sight
OELID	Otdel Eksperimentalno Letnyh Ispytanij i Dovodki , Section for Experiemntal Flight Tests and Final Tuning
OFAB	High explosive / incendiary aiva bomb, Oskolochno-Fugasnaja Aviabomba
OGPU	Osoboe Gosudarstvennoe Politicheskoe Upravlenie , Special Governmental Political Management, Political police, to became KGB
OIIMF	Special Design Bureau, Osoboe Konstructorskoe Buro
OKA	Early designation for aircraft by Oleg Konstantinovich Antonov;	OKA-33
OKB	Odessa Engineering Institute of the Open-sea Fleet, Odesskij Institute Inzhenerov Morskogo Flota
OKO	Special Design Section , Osobyj Konstructorskij Otdel	OKO-6
OMOS	Department for experimental naval aircraft construction , Otdel Morskogo Opytnogo Samoliotostroenija	see OMOS page
OOS	Department for experimental aircraft construction , Otdel Opytnogo Samoliotostroenija
OP	Optical Gunsight, Opticheskij Pritsel
OPB	Single-seat dive bomber , Odnomestnyj Pikorujuschij Bombardirovschik	OPB-5
OPB	Optical Gunsight version, Opticheskij Pritsel B?
OPO	Experimental department, OPpytnij Otdel
ORA	Special Reconnaissance Air Detachment, Osobyj Razvedovatelnyj Aviaotryad
OSGA	Department for glisser and airsled construction, Otdel Stroitelstva Glisserov i Aerosanej
OSGA	Department for glisser and airsled construction, Otdel Stroitelstva Glisserov i Aerosanej
Osoaviakhim	The All-Union Voluntary Society for Support of the Air Force, ObscheSouznoe Obschestvo Aviatsii and Chimii
OSK	Department for Special Constructions, Otdel Spetsialnykh Konstruktsij
OSKBES	The Sectoral Special Design Bureau for Experimental Aircraft Construction, Otraslevoe Spetsialnoe Konstruktorskoe Buro Experimentalnogo Samoletodtroenija	see OSKBES MAI
OTB	Special Technical Bureau, Osoboe Tekhnicheskoe Buro. Very special because within NKVD system.	See OTB page