This Standard specifies the requirements for a homogeneous mixture of an AL-61 Fuel Soluble Lubricity Improving Additive (LIA) and AL-41 Fuel System Icing Inhibitor (FSII) for addition to AVTUR F-35 (Def Stan 91-91) to prepare fuel meeting the requirements of AVTUR F-34 (Def Stan 91-87). The mixture may also be added to other aviation turbine fuels where the relevant standard requires the presence of AL-41 and AL-61 in the fuel. Material provided to this standard shall possess satisfactory performance and properties when used in appropriate vehicles and/or gas turbines or engines operated by the Ministry of Defence, or for which the Civil Aviation Authority is the certificating agency.