title-14-part-27-sec27-65

493

Federal Aviation Administration, DOT

§ 27.65

(b) The performance must correspond

to the engine power available under the
particular ambient atmospheric condi-
tions, the particular flight condition,
and the relative humidity specified in
paragraphs (d) or (e) of this section, as
appropriate.

respond to engine power, not exceeding
the approved power, less—

(1) Installation losses; and
(2) The power absorbed by the acces-

sories and services appropriate to the
particular ambient atmopheric condi-
tions and the particular flight condi-
tion.

(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 rotor-

craft, the performance, as affected by
engine power, must be based on a rel-
ative 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 rotor-

craft, a means must be provided to per-
mit the pilot to determine prior to
takeoff that each engine is capable of
developing the power necessary to
achieve the applicable rotorcraft per-
formance prescribed in this subpart.

(Secs. 313(a), 601, 603, 604, and 605 of the Fed-
eral 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]

§ 27.49

Performance at minimum oper-

ating speed.

(a) For helicopters—
(1) The hovering ceiling must be de-

termined over the ranges of weight, al-
titude, and temperature for which cer-
tification 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 heli-

copters, 2,500 feet pressure altitude at
maximum weight at a temperature of
standard plus 22

C (standard plus 40

F).

(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 heli-

copters, the steady rate of climb at the
minimum operating speed must be de-
termined over the ranges of weight, al-
titude, and temperature for which cer-
tification is requested, with—

(1) Takeoff power; and
(2) The landing gear extended.

[Amdt. 27–44, 73 FR 10998, Feb. 29, 2008]

§ 27.51

Takeoff.

The takeoff, with takeoff power and

r.p.m. at the most critical center of
gravity, and with weight from the max-
imum weight at sea level to the weight
for which takeoff certification is re-
quested for each altitude covered by
this section—

(a) May not require exceptional pilot-

ing skill or exceptionally favorable
conditions throughout the ranges of al-
titude from standard sea level condi-
tions 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 dem-
onstrated up to the maximum altitude
for which takeoff and landing certifi-
cation is requested or 7,000 feet density
altitude, whichever is less.

[Amdt. 27–44, 73 FR 10999, Feb. 29, 2008]

§ 27.65

Climb: all engines operating.

(a) For rotorcraft other than heli-

copters—

(1) The steady rate of climb, at

must be determined—

(i) With maximum continuous power

on each engine;

VerDate Sep<11>2014

09:06 Jun 28, 2024

Jkt 262046

PO 00000

Frm 00503

Fmt 8010

Sfmt 8010

Y:\SGML\262046.XXX

262046

jspears on DSK121TN23PROD with CFR

494

14 CFR Ch. I (1–1–24 Edition)

§ 27.67

(ii) With the landing gear retracted;

and

(iii) For the weights, altitudes, and

temperatures for which certification is
requested; and

(2) The climb gradient, at the rate of

climb determined in accordance with
paragraph (a)(1) of this section, must
be either—

(i) At least 1:10 if the horizontal dis-

tance required to take off and climb
over a 50-foot obstacle is determined
for each weight, altitude, and tempera-
ture within the range for which certifi-
cation is requested; or

(ii) At least 1:6 under standard sea

level conditions.

(b) Each helicopter must meet the

following requirements:

(1) V

must be determined—

(i) For standard sea level conditions;
(ii) At maximum weight; and
(iii) With maximum continuous

power on each engine.

(2) The steady rate of climb must be

determined—

(i) At the climb speed selected by the

applicant at or below V

;

(ii) Within the range from sea level

up to the maximum altitude for which
certification is requested;

(iii) For the weights and tempera-

tures that correspond to the altitude
range set forth in paragraph (b)(2)(ii) of
this section and for which certification
is requested; and

(iv) With maximum continuous power

on each engine.

(Secs. 313(a), 601, 603, 604, and 605 of the Fed-
eral 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)))

[Doc. No. 5074, 29 FR 15695, Nov. 24, 1964, as
amended by Amdt. 27–14, 43 FR 2324, Jan. 16,
1978; Amdt. 27–33, 61 FR 21907, May 10, 1996]

§ 27.67

Climb: one engine inoperative.

For multiengine helicopters, the

steady rate of climb (or descent), at

(or at the speed for minimum rate of
descent), must be determined with—

(a) Maximum weight;
(b) The critical engine inoperative

and the remaining engines at either—

(1) Maximum continuous power and,

for helicopters for which certification
for the use of 30-minute OEI power is
requested, at 30-minute OEI power; or

(2) Continuous OEI power for heli-

copters for which certification for the
use of continuous OEI power is re-
quested.

(Secs. 313(a), 601, 603, 604, and 605 of the Fed-
eral 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)))

[Doc. No. 5074, 29 FR 15695, Nov. 24, 1964, as
amended by Amdt. 27–23, 53 FR 34210, Sept. 2,
1988]

§ 27.71

Autorotation performance.

For single-engine helicopters and

multiengine helicopters that do not
meet the Category A engine isolation
requirements of Part 29 of this chapter,
the minimum rate of descent airspeed
and the best angle-of-glide airspeed
must be determined in autorotation
at—

(a) Maximum weight; and
(b) Rotor speed(s) selected by the ap-

plicant.

[Amdt. 27–21, 49 FR 44433, Nov. 6, 1984]

§ 27.75

Landing.

(a) The rotorcraft must be able to be

landed with no excessive vertical accel-
eration, no tendency to bounce, nose
over, ground loop, porpoise, or water
loop, and without exceptional piloting
skill or exceptionally favorable condi-
tions, with—

(1) Approach or autorotation speeds

appropriate to the type of rotorcraft
and selected by the applicant;

(2) The approach and landing made

with—

(i) Power off, for single engine rotor-

craft and entered from steady state
autorotation; or

(ii) One-engine inoperative (OEI) for

multiengine rotorcraft, with each oper-
ating engine within approved operating
limitations, and entered from an estab-
lished OEI approach.

(b) Multiengine rotorcraft must be

able to be landed safely after complete
power failure under normal operating
conditions.

[Doc. No. 5074, 29 FR 15695, Nov. 24, 1964, as
amended by Amdt. 27–14, 43 FR 2324, Jan. 16,
1978; Amdt. 27–44, 73 FR 10999, Feb. 29, 2008]

VerDate Sep<11>2014

09:06 Jun 28, 2024

Jkt 262046

PO 00000

Frm 00504

Fmt 8010

Sfmt 8010

Y:\SGML\262046.XXX

262046

jspears on DSK121TN23PROD with CFR