Fuel system icing inhibitor (FSII) is an additive to aviation fuels that acts to prevent the formation of ice crystals, providing relevant security in event of free water contamination in aviation fuel. Due to restrictive weight requirements military air crafts require them as part of additional security. It is a mandatory additive in many military aviation fuel specifications.
We at Spare Parts Pakistan, have this additive available which is suitable for use in either aviation turbine fuel (jet fuel) or aviation gasoline, subject to specification requirements and approvals.