HB 531-1974
rings (English Version)
- Standard No.
- HB 531-1974
- Language
- Chinese, Available in English version
- Published By
- Professional Standard - Aviation
- Status
- 1989-12
- Replace By
- HB 531-1989
- Latest
- HB 531-1989
HB 531-1974 history
- 1989 HB 531-1989 rings
- 1970 HB 531-1974 rings
