14 CFR 27.939 - Turbine engine operating characteristics.

prev | next
§ 27.939 Turbine engine operating characteristics.
(a) Turbine engine operating characteristics must be investigated in flight to determine that no adverse characteristics (such as stall, surge, or flameout) are present, to a hazardous degree, during normal and emergency operation within the range of operating limitations of the rotorcraft and of the engine.
(b) The turbine engine air inlet system may not, as a result of airflow distortion during normal operation, cause vibration harmful to the engine.
(c) For governor-controlled engines, it must be shown that there exists no hazardous torsional instability of the drive system associated with critical combinations of power, rotational speed, and control displacement.
[Amdt. 27-1, 32 FR 6914, May 5, 1967, as amended by Amdt. 27-11, 41 FR 55469, Dec. 20, 1976]

Title 14 published on 2014-01-01

no entries appear in the Federal Register after this date.

This is a list of United States Code sections, Statutes at Large, Public Laws, and Presidential Documents, which provide rulemaking authority for this CFR Part.

This list is taken from the Parallel Table of Authorities and Rules provided by GPO [Government Printing Office].

It is not guaranteed to be accurate or up-to-date, though we do refresh the database weekly. More limitations on accuracy are described at the GPO site.


United States Code

Title 14 published on 2014-01-01

The following are ALL rules, proposed rules, and notices (chronologically) published in the Federal Register relating to 14 CFR 27 after this date.

  • 2014-07-31; vol. 79 # 147 - Thursday, July 31, 2014
    1. 79 FR 44320 - Interest in Restructure of Rotorcraft Airworthiness Standards
      GPO FDSys XML | Text
      DEPARTMENT OF TRANSPORTATION, Federal Aviation Administration
      Notice of Disposition of Comments.
      The docket is terminated as of July 31, 2014.
      14 CFR Parts 27 and 29