Armstrong Siddeley Adder

Adder
Type	Turbojet
Manufacturer	Armstrong Siddeley
First run	November 1948
Developed from	Armstrong Siddeley Mamba
Developed into	Armstrong Siddeley Viper

The Armstrong Siddeley Adder was an early British turbojet engine developed by the Armstrong Siddeley company and first run in November 1948.

The Adder, a pure-jet derivative of the Armstrong Siddeley Mamba, was originally developed as an expendable engine to power the Jindivik 1 target drone. The engine 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.

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