A window unit from a Trident HS121 airplane. This plane was designed by de Havilland in the 1950s and made by Hawker Siddley Aviation. It made its maiden flight in 1962 and continued in production until 1978, a total of 117 planes being manufactured. It was in service with British European Airways, British Airways, Civil Aviationn Administration of China, and Cyprus airways. This window unit has a curved profile and is fitted with a textile pull-down blind. The unit has metal fixings and window frame and it is fitted with a textile insulation sheet.