[Code of Federal Regulations]
[Title 14, Volume 1]
[Revised as of January 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 14CFR27.45]

[Page 538-539]
 
                     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. 27.45  General.

    (a) Unless otherwise prescribed, the performance requirements of 
this subpart must be met for still air and a standard atmosphere.
    (b) The performance must correspond to the engine power available 
under the particular ambient atmospheric conditions, the particular 
flight condition, and the relative humidity specified in paragraphs (d) 
or (e) of this section, as appropriate.
    (c) The available power must correspond to engine power, not 
exceeding the approved power, less--
    (1) Installation losses; and

[[Page 539]]

    (2) The power absorbed by the accessories and services appropriate 
to the particular ambient atmopheric conditions and the particular 
flight condition.
    (d) For reciprocating engine-powered rotorcraft, the performance, as 
affected by engine power, must be based on a relative humidity of 80 
percent in a standard atmosphere.
    (e) For turbine engine-powered rotorcraft, the performance, as 
affected by engine power, must be based on a relative humidity of--
    (1) 80 percent, at and below standard temperature; and
    (2) 34 percent, at and above standard temperature plus 50 degrees F. 
Between these two temperatures, the relative humidity must vary 
linearly.
    (f) For turbine-engine-powered rotorcraft, a means must be provided 
to permit the pilot to determine prior to takeoff that each engine is 
capable of developing the power necessary to achieve the applicable 
rotorcraft performance prescribed in this subpart.

(Secs. 313(a), 601, 603, 604, and 605 of the Federal Aviation Act of 
1958 (49 U.S.C. 1354(a), 1421, 1423, 1424, and 1425); and sec. 6(c) of 
the Dept. of Transportation Act (49 U.S.C. 1655(c)))

[Amdt. 27-14, 43 FR 2324, Jan. 16, 1978, as amended by Amdt. 27-21, 49 
FR 44432, Nov. 6, 1984]