Central sales tax amendment adds Aviation Turbine Fuel supply to Turbo Prop Aircraft and expands iron classification. Amendment inserts a new clause identifying Aviation Turbine Fuel sold to a Turbo Prop Aircraft as a specified commodity and defines Turbo Prop Aircraft as an aircraft deriving thrust mainly from a propeller driven by either turbine or piston engine; it also substitutes 'pig iron and' with 'pig iron, sponge iron and' in an existing clause to include sponge iron in that category.