The standard is intended to be applied for the production or repair of aerospace components by thermal spraying at plants manufacturing parts in conformity with this standard.; The layers obtained by thermal spraying are subdivided into three safety classes according to their function and the effects of failures on aircraft safety.; The conditions required for thermal spraying to this standard are only given when the plant has a responsible specialist assigned and thermal spraying is carried out with appropriate spraying equipment and facilities tested in accordance with DIN 23521 and operated by a qualified personnel.