676
14 CFR Ch. I (1–1–14 Edition)
§ 27.871
combinations to be used for human ex-
ternal cargo, the fatigue evaluation of
§ 27.571 of this part applies to the entire
quick release and personnel carrying
device structural systems and their at-
tachments.
[Amdt. 27–11, 41 FR 55469, Dec. 20, 1976; as
amended by Amdt. 27–26, 55 FR 8001, Mar. 6,
1990; Amdt. 27–36, 64 FR 43019, Aug. 6, 1999]
M
ISCELLANEOUS
§ 27.871
Leveling marks.
There must be reference marks for
leveling the rotorcraft on the ground.
§ 27.873
Ballast provisions.
Ballast provisions must be designed
and constructed to prevent inadvertent
shifting of ballast in flight.
Subpart E—Powerplant
G
ENERAL
§ 27.901
Installation.
(a) For the purpose of this part, the
powerplant installation includes each
part of the rotorcraft (other than the
main and auxiliary rotor structures)
that—
(1) Is necessary for propulsion;
(2) Affects the control of the major
propulsive units; or
(3) Affects the safety of the major
propulsive units between normal in-
spections or overhauls.
(b) For each powerplant installa-
tion—
(1) Each component of the installa-
tion must be constructed, arranged,
and installed to ensure its continued
safe operation between normal inspec-
tions or overhauls for the range of tem-
perature and altitude for which ap-
proval is requested;
(2) Accessibility must be provided to
allow any inspection and maintenance
necessary for continued airworthiness;
(3) Electrical interconnections must
be provided to prevent differences of
potential between major components of
the installation and the rest of the
rotorcraft;
(4) Axial and radial expansion of tur-
bine engines may not affect the safety
of the installation; and
(5) Design precautions must be taken
to minimize the possibility of incorrect
assembly of components and equipment
essential to safe operation of the rotor-
craft, except where operation with the
incorrect assembly can be shown to be
extremely improbable.
(c) The installation must comply
with—
(1) The installation instructions pro-
vided under § 33.5 of this chapter; and
(2) The applicable provisions of this
subpart.
(Secs. 313(a), 601, and 603, 72 Stat. 752, 775, 49
U.S.C. 1354(a), 1421, and 1423; sec. 6(c), 49
U.S.C. 1655(c))
[Doc. No. 5074, 29 FR 15695, Nov. 24, 1964, as
amended by Amdt. 27–2, 33 FR 963, Jan. 26,
1968; Amdt. 27–12, 42 FR 15044, Mar. 17, 1977;
Amdt. 27–23, 53 FR 34211, Sept. 2, 1988]
§ 27.903
Engines.
(a)
Engine type certification. Each en-
gine must have an approved type cer-
tificate. Reciprocating engines for use
in helicopters must be qualified in ac-
cordance with § 33.49(d) of this chapter
or be otherwise approved for the in-
tended usage.
(b)
Engine or drive system cooling fan
blade protection. (1) If an engine or rotor
drive system cooling fan is installed,
there must be a means to protect the
rotorcraft and allow a safe landing if a
fan blade fails. This must be shown by
showing that—
(i) The fan blades are contained in
case of failure;
(ii) Each fan is located so that a fail-
ure will not jeopardize safety; or
(iii) Each fan blade can withstand an
ultimate load of 1.5 times the cen-
trifugal force resulting from operation
limited by the following:
(A) For fans driven directly by the
engine—
(
1) The terminal engine r.p.m. under
uncontrolled conditions; or
(
2) An overspeed limiting device.
(B) For fans driven by the rotor drive
system, the maximum rotor drive sys-
tem rotational speed to be expected in
service, including transients.
(2) Unless a fatigue evaluation under
§ 27.571 is conducted, it must be shown
that cooling fan blades are not oper-
ating at resonant conditions within the
operating limits of the rotorcraft.
(c)
Turbine engine installation. For
turbine engine installations, the pow-
erplant systems associated with engine
VerDate Mar<15>2010
10:12 Mar 18, 2014
Jkt 232046
PO 00000
Frm 00686
Fmt 8010
Sfmt 8010
Y:\SGML\232046.XXX
232046
pmangrum on DSK3VPTVN1PROD with CFR