???? Conventions ??????? essential ????? functioning ???????? ??? ????? ??????. Specifies ??? ????????? ?????????? ??? ??? ???? ????? maintenance equipment, ????????? schedules ???????. Aids ??? ????????? ?? minimizing disputes ??? parties making clear duties ?? ??? Aids ?? ensuring ???? ????????

??? ????? ?? ?????? ??? ???? ?????? ???? ??? ??????? ???????. ??? ???? ???? ?????? ??? ?????? ???????. ??? ??? ?????? ??? ????? ??? ??????? ???????, ??? ????? ?? ????? . ?????? ????? ?????? ? ?????? ???? ? ??? ??????. ??????? ??????? ?????? ???? ????? ????? ?????? ??????? ???? ???? ?? ?? ?????. ?