This ballot is being proposed to clarify that the requirements for high temperature thermal stability testing of synthetic blending components is applicable only at the point of manufacture. The requirement for elevated thermal stability testing temperature is necessary when producing a synthetic blending component to assure quality of manufacture of the product. However, when a synthetic blending component is moved through the distribution system it will be challenging to keep the elevated thermal stability as it is likely to come in contact with residues of conventional aviation turbine fuel that will not have as high a thermal stability.
As currently written, if the synthetic blending component’s thermal stability drops slightly in the distribution system due to contact with lower thermal stability conventional aviation fuel residues, the synthetic blending component would no longer be eligible for blending with conventional aviation fuel due to it no longer meeting the elevated thermal stability requirements of the respective Annex.
In accordance with standard industry practice, quality assurance requirements for synthetic blend components in the distribution system are covered in other documents such as EI 1533 (to be published shortly), EI/JIG 1530, ATA103, JIG 2, API 1595, etc. The thermal stability testing temperature requirements for the final finished blend of synthetic blending component with conventional aviation turbine fuel (Table 1 of the main body of D7566) remains unchanged.