The present invention relates to hydrocarbons and particularly to the manufacture of hydrocarbon components suitable as aviation fuels or jet fuels and as blending stocks for aviation fuels. The process comprises the stages, wherein in the first stage an oil feed of biological origin and hydrogen gas are subjected to conditions sufficient to effect hydrodeoxygenation in the presence of a hydrodeoxygenation catalyst to yield n-paraffins;in the second stage the n-paraffins and hydrogen gas are subjected to conditions sufficient to effect isomerisation in the presence of an isomerisation catalyst to yield isoparaffins and separating fractions; and recycling the fraction boiling at a temperature above 200° C. under atmospheric pressure obtained from the second stage to reisomerisation, where isomerisation is effected in the presence of an isomerisation catalyst.