British Aircrew 626-Type Socket /
"NATO" Socket
Stores Ref: 10H/18574 or 10H/9491940 | NSN: 5935-99-949-1940
The most standard conenctor used in the RAF and RN since the second world war for aircraft to interface with headsets and helmets. It mates with the NATO plug 671-Type. I am still very unsure as to why they get called NATO plugs and sockets, as they are not standard across NATO, only used in Britain and France.
The "NATO" plug and socket came about as a means of quick headset disconnection from an ejection seat. This requirement also saw much shorter helmet cables in use (Type-C*, Type-D*, and Type-E* helmets), and the mating 626-Type "NATO" socket located on the ejection seat closer to the occupant.
Service Photographs
Martin Baker Video, September 1947
This Martin Baker video clip (click here) and the below images taken from the video shows a 626-Type "NATO" socket during early ejection seat development, fitted to the seat.
The "NATO" plug and socket are referred to in the video as a "quick release device", this GIF created from the video shows why:
