Federal Aviation Administration, DOT

Section 27.903

Subpart E - Powerplant

Section 27.903

GENERAL
Section 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 inspections or overhauls.
(b) For each powerplant installation - 
(1) Each component of the installation must be constructed, arranged,
and installed to ensure its continued
safe operation between normal inspections or overhauls for the range of temperature and altitude for which approval 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 turbine 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 rotorcraft, except where operation with the
incorrect assembly can be shown to be
extremely improbable.
(c) The installation must comply
with - 
(1) The installation instructions provided under Section 33.5 of this chapter; and
(2) The applicable provisions of this
subpart.

spaschal on DSK3GDR082PROD with CFR

(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]

Engines.

(a) Engine type certification. Each engine must have an approved type certificate. Reciprocating engines for use
in helicopters must be qualified in accordance with Section 33.49(d) of this chapter
or be otherwise approved for the intended 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 failure will not jeopardize safety; or
(iii) Each fan blade can withstand an
ultimate load of 1.5 times the centrifugal 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 system rotational speed to be expected in
service, including transients.
(2) Unless a fatigue evaluation under
Section 27.571 is conducted, it must be shown
that cooling fan blades are not operating at resonant conditions within the
operating limits of the rotorcraft.
(c) Turbine engine installation. For
turbine engine installations, the powerplant systems associated with engine
control devices, systems, and instrumentation must be designed to give
reasonable assurance that those engine
operating limitations that adversely
affect turbine rotor structural integrity will not be exceeded in service.
(d) Restart capability: A means to restart any engine in flight must be provided.
(1) Except for the in-flight shutdown
of all engines, engine restart capability
must be demonstrated throughout a
flight envelope for the rotorcraft.

527

VerDate Sep<11>2014

12:50 Apr 30, 2019

Jkt 247046

PO 00000

Frm 00537

Fmt 8010

Sfmt 8010

Y:\SGML\247046.XXX

247046