Armstrong Siddeley Adder
The Adder, a pure-jet derivative of the Armstrong Siddeley Mamba ASM3 airscrew gas-turbine, was originally developed as an expendable engine to power the Jindivik 1 target drone. The engine, first run in November 1948, was then developed into a longer-life engine before evolving into the more-powerful Armstrong Siddeley Viper.
The ASA.1 Adder was flight tested in the rear-turret position of the Avro Lancaster III SW342, the aircraft also having been previously modified and used for icing trials of the Mamba by Armstrong Siddeley's Flight Test Department at Bitteswell.
Compressor: Axial Flow
Maximum thrust: 1,050 lb
Max continuous power: 900 lb / 409 kg
Diameter: 28 in / 71,12 cm
Length: 73.3 in / 1,84 m
Net dry Weight: 580 lb / 263 kg
Take-off power: 1,100 lb / 500 kg
Fuel burn max continuous: 1.2 lb/lb th/h