Rolls-Royce RB.106

The RB.106 was an advanced military turbojet engine design of the 1950s by Rolls Royce Ltd. The work was sponsored by the Ministry of Supply and if completed it would have been known as the Rolls-Royce Thames.

The RB.106 was a two-shaft design with two axial flow compressors each fed by its own single stage turbine and reheat. Although of similar size to the Rolls-Royce Avon, allowing it to be used as a drop-in replacement, it would have produced about twice the thrust at 21,750 lbf (96.7 kN). The two-stage layout was relatively advanced for the era; the single-stage de Havilland Gyron matched in in power terms, while the two-spool Bristol Olympus was much less powerful (at the time).

Apart from being expected to power British aircraft such as those competing for Operational Requirement F.155 it was selected to be the powerplant for the Canadian Avro Arrow project. However funding was cut with the 1957 Defence White Paper which terminated most aircraft development then under way. The Arrow moved to an indigenous two-spool design similar to the RB.106, the Orenda Iroquois.