| Name | Explanation | Examples |
|---|---|---|
| K | Initials of Kalinin Design Bureau | K-5, K-7, K-12 |
| Ka | Initials of Kamov | Ka-8, Ka-50 and more; |
| KAI | Kazanskij Aviatsionnij Institut , Kazan Aviation Institute | |
| KAPO | Kazanskoe Aviatsionno-Promizvodstvennoe Ob'edinenie, Kazan Aircraft Production Association named for S P Gorbunov | |
| KASKR | Initials of Kamov and Skrzhinskij | KASKR-1, KASKR-2 |
| KB | Design bureau, Konstructorskoe Bureau | See KB-102 |
| KGB | Commetee on State Security, Komitet Gosudarstvennoj Bezopasnosti | |
| KhAI | Kharkovskij Aviatsionnij Institut , Kharkov Aviation Institute | KhAI-5 |
| KhAZ | Kharkovskij Aviatsionnij Zavod , Kharkov Aircraft Factory | |
| KMB | Kasseta Melkih Bomb, Small Bomb Canister | see PTAB bomb page |
| Kolchugaluminij | First mass produced aluminum alloy in the USSR. It's composition differed from German duralumin. Production started in 1922 at Kolchugino factory, and lasted for 15 years. Soviet industry switched to duralumin at the same time when smooth aircraft skin replaced corrugated one. | |
| Komsevmorput | Kommunisticheskij severnyj morskoj put' , Communist Northern Sea Route | |
| KOMTA | Heavy Aviation Commission, KOMissia po Tiazholoj Aviatsii | See TsAGI Facts and KOMTA page; |
| KOR | Ship-borne, Korablemij | KOR-1 |
| KOSOS | Design Department of the SOS TsAGI , Konstruktorskij Odel SOS TsAGI | |
| KOZOK | Design Department of the ZOK TsAGI , Konstruktorskij Odel ZOK TsAGI | |
| KnAAPO | Komsomolsk-on-Amur Aircraft Production Association, Komsomolsk-na-Amure Aviatsionnoe Proizvodstvennoe Objedinenie |
|
| KPB | Bolshevik Communist Party , Kommunisticheskaya Partia Bolshevikov | |
| KR | Ship-borne recce, Korablemij Razvedchik | KR-1 |
| KR | Artillery Spotter Reconnaissater, Korrektirovschik-Razvedchik | Il-2KR |
| KR | Cruiser (Kreiser) used for sometime to designate a heavy long-range fighter. Generally - conversion of a bomber aircraft. | KR-6 |
| KR | Counter-revolutioner, KontrRevolutsioner
Term used to label anti-bolshevik (later - anti-Stalin) opposition. Also - abbreviation for corresponding article in prosecution code | |
| KT | Winged Tank, Krilatij Tank | KT, KT-40 |
| KuAI | Kujbyshev (today - Samara) Aviation Institute, Kuibushevskij Aviatsionnyj Institut | KuAI |