If an auxiliary power unit that meets the requirements of TSO-C77 is installed in the rotorcraft, the limitations established for that auxiliary power unit under the TSO including the categories of operation must be specified as operating limitations for the rotorcraft. (Secs. 313(a), 601, 603, 604, Federal Aviation Act of 1958 (49 U.S.C. 1354(a), 1421, 1423), sec. 6(c), Dept. of Transportation Act (49 U.S.C. 1655(c))) [Amdt. 29-17, 43 FR 50602, Oct. 30, 1978]