[Code of Federal Regulations] [Title 14, Volume 1] [Revised as of January 1, 2007] From the U.S. Government Printing Office via GPO Access [CITE: 14CFR27.161] [Page 578] TITLE 14--AERONAUTICS AND SPACE CHAPTER I--FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PART 27_AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT--Table of Contents Subpart B_Flight Sec. 27.161 Trim control. The trim control-- (a) Must trim any steady longitudinal, lateral, and collective control forces to zero in level flight at any appropriate speed; and (b) May not introduce any undesirable discontinuities in control force gradients. [Doc. No. 5074, 29 FR 15695, Nov. 24, 1964, as amended by Amdt. 27-21, 49 FR 44433, Nov. 6, 1984]