Section 27.49

14 CFR Ch. I (1-1-19 Edition)

(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
(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)))

spaschal on DSK3GDR082PROD with CFR

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

Section 27.49 Performance at minimum operating speed.
(a) For helicopters - 
(1) The hovering ceiling must be determined over the ranges of weight, altitude, and temperature for which certification is requested, with - 
(i) Takeoff power;
(ii) The landing gear extended; and
(iii) The helicopter in-ground effect
at a height consistent with normal
takeoff procedures; and

(2) The hovering ceiling determined
under paragraph (a)(1) of this section
must be at least - 
(i) For reciprocating engine powered
helicopters, 4,000 feet at maximum
weight with a standard atmosphere;
(ii) For turbine engine powered helicopters, 2,500 feet pressure altitude at
maximum weight at a temperature of
standard plus 22 SectionC (standard plus 40
SectionF).
(3) The out-of-ground effect hovering
performance must be determined over
the ranges of weight, altitude, and
temperature for which certification is
requested, using takeoff power.
(b) For rotorcraft other than helicopters, the steady rate of climb at the
minimum operating speed must be determined over the ranges of weight, altitude, and temperature for which certification is requested, with - 
(1) Takeoff power; and
(2) The landing gear extended.
[Amdt. 27-44, 73 FR 10998, Feb. 29, 2008]

Section 27.51 Takeoff.
The takeoff, with takeoff power and
r.p.m. at the most critical center of
gravity, and with weight from the maximum weight at sea level to the weight
for which takeoff certification is requested for each altitude covered by
this section - 
(a) May not require exceptional piloting skill or exceptionally favorable
conditions throughout the ranges of altitude from standard sea level conditions to the maximum altitude for
which takeoff and landing certification
is requested, and
(b) Must be made in such a manner
that a landing can be made safely at
any point along the flight path if an
engine fails. This must be demonstrated up to the maximum altitude
for which takeoff and landing certification is requested or 7,000 feet density
altitude, whichever is less.
[Amdt. 27-44, 73 FR 10999, Feb. 29, 2008]

Section 27.65 Climb: all engines operating.
(a) For rotorcraft other than helicopters - 
(1) The steady rate of climb, at VY,
must be determined - 
(i) With maximum continuous power
on each engine;

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