G-AWZO Hawker Siddeley DH121/HS121 Trident 3B
of British European Airways - Oct 1972
The Trident version with three and a half engines: Three Rolls Royce Spey 512 and an the tiny RB162 as an additional take-off thrust engine in the tail.
Due to the decision by BEA to downsize the originally proposed DH 121 Design, leading to the adoption of Spey Engines, meant that development of the Trident was now defined by its engines As the Spey 512m was the limit of that engines civilian development potential, also meant that the 3B (and the extended range Super 3B) was the end of the development path for the Aircraft.
British European Airways - Wikipedia Entry
Hawker Siddeley Trident - The Wikipedia Entry
Trident Preservation Society