title-14-part-27-sec27-1021

539

Federal Aviation Administration, DOT

§ 27.1021

below the maximum established value.
This must be shown by flight tests.

[Doc. No. 5074, 29 FR 15695, Nov. 24, 1964, as
amended by Amdt. 27–23, 53 FR 34213, Sept. 2,
1988]

§ 27.1013

Oil tanks.

Each oil tank must be designed and

installed so that—

(a) It can withstand, without failure,

each vibration, inertia, fluid, and
structural load expected in operation;

(b) [Reserved]
(c) Where used with a reciprocating

engine, it has an expansion space of not
less than the greater of 10 percent of
the tank capacity or 0.5 gallon, and
where used with a turbine engine, it
has an expansion space of not less than
10 percent of the tank capacity.

(d) It is impossible to fill the tank

expansion space inadvertently with the
rotorcraft in the normal ground atti-
tude;

(e) Adequate venting is provided; and
(f) There are means in the filler open-

ing to prevent oil overflow from enter-
ing the oil tank compartment.

[Doc. No. 5074, 29 FR 15695, Nov. 24, 1964, as
amended by Amdt. 27–9, 39 FR 35461, Oct. 1,
1974]

§ 27.1015

Oil tank tests.

Each oil tank must be designed and

installed so that it can withstand,
without leakage, an internal pressure
of 5 p.s.i., except that each pressurized
oil tank used with a turbine engine
must be designed and installed so that
it can withstand, without leakage, an
internal pressure of 5 p.s.i., plus the
maximum operating pressure of the
tank.

[Amdt. 27–9, 39 FR 35462, Oct. 1, 1974]

§ 27.1017

Oil lines and fittings.

(a) Each oil line must be supported to

prevent excessive vibration.

(b) Each oil line connected to compo-

nents of the rotorcraft between which
relative motion could exist must have
provisions for flexibility.

diameter of not less than the inside di-
ameter of the engine inlet or outlet. No
line may have splices between connec-
tions.

§ 27.1019

Oil strainer or filter.

(a) Each turbine engine installation

must incorporate an oil strainer or fil-
ter through which all of the engine oil
flows and which meets the following re-
quirements:

(1) Each oil strainer or filter that has

a bypass must be constructed and in-
stalled so that oil will flow at the nor-
mal rate through the rest of the sys-
tem with the strainer or filter com-
pletely blocked.

(2) The oil strainer or filter must

have the capacity (with respect to op-
erating limitations established for the
engine) to ensure that engine oil sys-
tem functioning is not impaired when
the oil is contaminated to a degree
(with respect to particle size and den-
sity) that is greater than that estab-
lished for the engine under Part 33 of
this chapter.

(3) The oil strainer or filter, unless it

is installed at an oil tank outlet, must
incorporate a means to indicate con-
tamination before it reaches the capac-
ity established in accordance with
paragraph (a)(2) of this section.

(4) The bypass of a strainer or filter

must be constructed and installed so
that the release of collected contami-
nants is minimized by appropriate lo-
cation of the bypass to ensure that col-
lected contaminants are not in the by-
pass flow path.

(5) An oil strainer or filter that has

no bypass, except one that is installed
at an oil tank outlet, must have a
means to connect it to the warning
system required in § 27.1305(r).

(b) Each oil strainer or filter in a

powerplant installation using recipro-
cating engines must be constructed and
installed so that oil will flow at the
normal rate through the rest of the
system with the strainer or filter ele-
ment completely blocked.

[Amdt. 27–9, 39 FR 35462, Oct. 1, 1974, as
amended by Amdt. 27–20, 49 FR 6849, Feb. 23,
1984; Amdt. 27–23, 53 FR 34213, Sept. 2, 1988]

§ 27.1021

Oil system drains.

A drain (or drains) must be provided

to allow safe drainage of the oil sys-
tem. Each drain must—

(a) Be accessible; and

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14 CFR Ch. I (1–1–24 Edition)

§ 27.1027

(b) Have manual or automatic means

for positive locking in the closed posi-
tion.

[Amdt. 27–20, 49 FR 6849, Feb. 23, 1984]

§ 27.1027

Transmissions and gear-

boxes: General.

(a) The lubrication system for com-

ponents of the rotor drive system that
require continuous lubrication must be
sufficiently independent of the lubrica-
tion systems of the engine(s) to ensure
lubrication during autorotation.

(b) Pressure lubrication systems for

transmissions and gearboxes must
comply with the engine oil system re-
quirements of §§ 27.1013 (except para-
graph (c)), 27.1015, 27.1017, 27.1021, and
27.1337(d).

must have an oil strainer or filter
through which all of the lubricant
flows and must—

(1) Be designed to remove from the

lubricant any contaminant which may
damage transmission and drive system
components or impede the flow of lu-
bricant to a hazardous degree;

(2) Be equipped with a means to indi-

cate collection of contaminants on the
filter or strainer at or before opening
of the bypass required by paragraph
(c)(3) of this section; and

(3) Be equipped with a bypass con-

structed and installed so that—

(i) The lubricant will flow at the nor-

mal rate through the rest of the sys-
tem with the strainer or filter com-
pletely blocked; and

(ii) The release of collected contami-

nants is minimized by appropriate lo-
cation of the bypass to ensure that col-
lected contaminants are not in the by-
pass flowpath.

(d) For each lubricant tank or sump

outlet supplying lubrication to rotor
drive systems and rotor drive system
components, a screen must be provided
to prevent entrance into the lubrica-
tion system of any object that might
obstruct the flow of lubricant from the
outlet to the filter required by para-
graph (c) of this section. The require-
ments of paragraph (c) do not apply to
screens installed at lubricant tank or
sump outlets.

(e) Splash-type lubrication systems

for rotor drive system gearboxes must
comply with §§ 27.1021 and 27.1337(d).

[Amdt. 27–23, 53 FR 34213, Sept. 2, 1988, as
amended by Amdt. 27–37, 64 FR 45095, Aug. 18,
1999]

OOLING

§ 27.1041

General.

(a) Each powerplant cooling system

must be able to maintain the tempera-
tures of powerplant components within
the limits established for these compo-
nents under critical surface (ground or
water) and flight operating conditions
for which certification is required and
after normal shutdown. Powerplant
components to be considered include
but may not be limited to engines,
rotor drive system components, auxil-
iary power units, and the cooling or lu-
bricating fluids used with these compo-
nents.

(b) Compliance with paragraph (a) of

this section must be shown in tests
conducted under the conditions pre-
scribed in that paragraph.

[Doc. No. 5074, 29 FR 15695, Nov. 24, 1964, as
amended by Amdt. 27–23, 53 FR 34213, Sept. 2,
1988]

§ 27.1043

Cooling tests.

(a)

General. For the tests prescribed

in § 27.1041(b), the following apply:

(1) If the tests are conducted under

conditions deviating from the max-
imum ambient atmospheric tempera-
ture specified in paragraph (b) of this
section, the recorded powerplant tem-
peratures must be corrected under
paragraphs (c) and (d) of this section
unless a more rational correction
method is applicable.

(2) No corrected temperature deter-

mined under paragraph (a)(1) of this
section may exceed established limits.

(3) For reciprocating engines, the fuel

used during the cooling tests must be
of the minimum grade approved for the
engines, and the mixture settings must
be those normally used in the flight
stages for which the cooling tests are
conducted.

(4) The test procedures must be as

prescribed in § 27.1045.

(b)

Maximum ambient atmospheric tem-

perature. A maximum ambient atmos-
pheric temperature corresponding to