This SAE Aerospace Standard (AS) establishes the aerodynamic flow-off requirements and test procedures for AMS1424 Type I and AMS1428 Type II@ III and IV fluids used to deice and/or anti-ice aircraft. The objective of this standard is to ensure acceptable aerodynamic characteristics of the deicing/anti-icing fluids as they flow off of aircraft lifting and control surfaces during the takeoff ground acceleration and climb. Aerodynamic acceptance of an aircraft ground deicing/anti-icing fluid is based upon the fluid??s boundary layer displacement thickness (BLDT) on a flat plate@ measured after experiencing the free stream velocity time history of a representative aircraft takeoff. Acceptability of the fluid is determined by comparing BLDT measurements of the candidate fluid with a datum established from the values of a reference fluid BLDT and the BLDT over the dry (clean) test plate. Testing is carried out in the temperature range at which the fluid@ undiluted and diluted@ is to be used in airline service. NOTE: No additional testing is required for non-glycol fluids at this time. For more information about non-glycol fluids please refer to AMS1424.