The Narrow Margin of Criticality: The Question of the Supply of 100-Octane Fuel in the Battle of Britain

Abstract

Aviation historians have advanced the supply of 100-octane aviation fuel as a critical and recognisably American contribution to the Battle of Britain during the critical events of 1940. A study of the contemporary Air Ministry records in the Public Record Office indicates that this assertion can be challenged. This challenge can be made both on the grounds of the aircraft performance benefit involved, as indicated by contemporary RAF testing, and on the national origin attributed to 100-octane fuel supplies. These records demonstrate that, contrary to the assertions of aviation history, the supply of 100-octane fuel to the RAF in time for use in the Battle of Britain must be attributed to pre-war British planning and investment during the rearmament period of the late nineteen- thirties.