65.73—Ratings.

(a) The following ratings are issued under this subpart:
(1) Airframe.
(2) Powerplant.
(b) A mechanic certificate with an aircraft or aircraft engine rating, or both, that was issued before, and was valid on, June 15, 1952, is equal to a mechanic certificate with an airframe or powerplant rating, or both, as the case may be, and may be exchanged for such a corresponding certificate and rating or ratings.