Text in force at 23-63: from 23-13, effective 23 Oct 1972.
Removable ballast may be used in showing compliance with the flight requirements of this subpart, if--
(a) The place for carrying ballast is properly designed and installed, and is marked under Sec. 23.1557; and
[(b) Instructions are included in the Airplane Flight Manual, approved manual material, or markings and placards, for the proper placement of the removable ballast under each loading condition for which removable ballast is necessary.]
37 FR 20023 · Source