Text in force at 27-51: from 27-0, effective 1 Feb 1965.
Each item of installed equipment must--
(a) Be of a kind and design appropriate to its intended function;
(b) Be labeled as to its identification, function, or operating limitations, or any applicable combination of these factors;
(c) Be installed according to limitations specified for that equipment; and
(d) Function properly when installed.
29 FR 15695 · Source