Federal Aviation Administration, DOT
Section 27.1519
(b) The operating limitations and
other information necessary for safe
operation must be made available to
the crewmembers as prescribed in
SectionSection 27.1541 through 27.1589.
(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 2325, Jan. 16, 1978]
OPERATING LIMITATIONS
Section 27.1503
Airspeed limitations: general.
(a) An operating speed range must be
established.
(b) When airspeed limitations are a
function of weight, weight distribution,
altitude, rotor speed, power, or other
factors,
airspeed
limitations
corresponding with the critical combinations of these factors must be established.
nshattuck on DSK9F9SC42PROD with CFR
Section 27.1505
Never-exceed speed.
VNE and the speed used in meeting the
requirements of -
(i) Section 27.65(b) for single engine helicopters; and
(ii) Section 27.67 for multiengine helicopters.
(2) VNE (power-off) is -
(i) A constant airspeed;
(ii) A constant amount less than
power-on VNE; or
(iii) A constant airspeed for a portion
of the altitude range for which certification is requested, and a constant
amount less than power-on VNE for the
remainder of the altitude range.
(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. 27-2, 33 FR 964, Jan. 26, 1968, and
Amdt. 27-14, 43 FR 2325, Jan. 16, 1978; Amdt.
27-21, 49 FR 44435, Nov. 6, 1984]
Section 27.1509
(a) The never-exceed speed, VNE, must
be established so that it is -
(1) Not less than 40 knots (CAS); and
(2) Not more than the lesser of -
(i) 0.9 times the maximum forward
speeds established under Section 27.309;
(ii) 0.9 times the maximum speed
shown under SectionSection 27.251 and 27.629; or
(iii) 0.9 times the maximum speed
substantiated for advancing blade tip
mach number effects.
(b) VNE may vary with altitude,
r.p.m., temperature, and weight, if -
(1) No more than two of these variables (or no more than two instruments integrating more than one of
these variables) are used at one time;
and
(2) The ranges of these variables (or
of the indications on instruments integrating more than one of these variables) are large enough to allow an
operationally practical and safe variation of VNE.
(c) For helicopters, a stabilized
power-off VNE denoted as VNE (poweroff) may be established at a speed less
than VNE established pursuant to paragraph (a) of this section, if the following conditions are met:
(1) VNE (power-off) is not less than a
speed midway between the power-on
Rotor speed.
(a) Maximum power-off (autorotation).
The maximum power-off rotor speed
must be established so that it does not
exceed 95 percent of the lesser of -
(1) The maximum design r.p.m. determined under Section 27.309(b); and
(2) The maximum r.p.m. shown during the type tests.
(b) Minimum power off. The minimum
power-off rotor speed must be established so that it is not less than 105
percent of the greater of -
(1) The minimum shown during the
type tests; and
(2) The minimum determined by design substantiation.
(c) Minimum power on. The minimum
power-on rotor speed must be established so that it is -
(1) Not less than the greater of -
(i) The minimum shown during the
type tests; and
(ii) The minimum determined by design substantiation; and
(2) Not more than a value determined
under Section 27.33(a)(1) and (b)(1).
Section 27.1519
Weight and center of gravity.
The weight and center of gravity limitations determined under SectionSection 27.25 and
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