title-14-part-29-sec29-1043

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14 CFR Ch. I (1–1–24 Edition)

§ 29.1025

Oil valves.

(a) Each oil shutoff must meet the re-

quirements of § 29.1189.

(b) The closing of oil shutoffs may

not prevent autorotation.

stops or suitable index provisions in
the ‘‘on’’ and ‘‘off’’ positions and must
be supported so that no loads resulting
from its operation or from accelerated
flight conditions are transmitted to
the lines attached to the valve.

§ 29.1027

Transmission and gearboxes:

general.

(a) The oil system for components of

the rotor drive system that require
continuous lubrication must be suffi-
ciently independent of the lubrication
systems of the engine(s) to ensure—

(1) Operation with any engine inoper-

ative; and

(2) Safe autorotation.
(b) Pressure lubrication systems for

transmissions and gearboxes must
comply with the requirements of
§§ 29.1013, paragraphs (c), (d), and (f)
only, 29.1015, 29.1017, 29.1021, 29.1023, and
29.1337(d). In addition, the system must
have—

(1) An oil strainer or filter through

which all the lubricant flows, and
must—

(i) 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; and

(ii) Be equipped with a bypass con-

structed and installed so that—

(A) The lubricant will flow at the

normal rate through the rest of the
system with the strainer or filter com-
pletely blocked; and

(B) 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;

(iii) Be equipped with a means to in-

dicate collection of contaminants on
the filter or strainer at or before open-
ing of the bypass;

(2) For each lubricant tank or sump

outlet supplying lubrication to rotor
drive systems and rotor drive system
components, a screen to prevent en-
trance into the lubrication system of
any object that might obstruct the

flow of lubricant from the outlet to the
filter required by paragraph (b)(1) of
this section. The requirements of para-
graph (b)(1) of this section do not apply
to screens installed at lubricant tank
or sump outlets.

for rotor drive system gearboxes must
comply with §§ 29.1021 and 29.1337(d).

[Amdt. 29–26, 53 FR 34218, Sept. 2, 1988]

OOLING

§ 29.1041

General.

(a) The powerplant and auxiliary

power unit cooling provisions must be
able to maintain the temperatures of
powerplant components, engine fluids,
and auxiliary power unit components
and fluids within the temperature lim-
its established for these components
and fluids, under ground, water, and
flight operating conditions for which
certification is requested, and after
normal engine or auxiliary power unit
shutdown, or both.

(b) There must be cooling provisions

to maintain the fluid temperatures in
any power transmission within safe
values under any critical surface
(ground or water) and flight operating
conditions.

iary power units, compliance with
paragraphs (a) and (b) of this section
must be shown by flight tests in which
the temperatures of selected power-
plant component and auxiliary power
unit component, engine, and trans-
mission fluids are obtained under the
conditions prescribed in those para-
graphs.

[Doc. No. 5084, 29 FR 16150, Dec. 3, 1964, as
amended by Amdt. 29–26, 53 FR 34218, Sept. 2,
1988]

§ 29.1043

Cooling tests.

(a)

General. For the tests prescribed

in § 29.1041(c), 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.

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Federal Aviation Administration, DOT

§ 29.1045

(2) No corrected temperature deter-

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

(3) The fuel used during the cooling

tests must be of the minimum grade
approved for the engines, and the mix-
ture settings must be those used in
normal operation.

(4) The test procedures must be as

prescribed in §§ 29.1045 through 29.1049.

(5) For the purposes of the cooling

tests, a temperature is ‘‘stabilized’’
when its rate of change is less than 2

per minute.

(b)

Maximum ambient atmospheric tem-

perature. A maximum ambient atmos-
pheric temperature corresponding to
sea level conditions of at least 100 de-
grees F. must be established. The as-
sumed temperature lapse rate is 3.6 de-
grees F. per thousand feet of altitude
above sea level until a temperature of

69.7 degrees F. is reached, above

which altitude the temperature is con-
sidered constant at

69.7 degrees F.

However, for winterization installa-
tions, the applicant may select a max-
imum ambient atmospheric tempera-
ture corresponding to sea level condi-
tions of less than 100 degrees F.

(c)

Correction factor (except cylinder

barrels). Unless a more rational correc-
tion applies, temperatures of engine
fluids and powerplant components (ex-
cept cylinder barrels) for which tem-
perature limits are established, must
be corrected by adding to them the dif-
ference between the maximum ambient
atmospheric temperature and the tem-
perature of the ambient air at the time
of the first occurrence of the maximum
component or fluid temperature re-
corded during the cooling test.

(d)

Correction factor for cylinder barrel

temperatures. Cylinder barrel tempera-
tures must be corrected by adding to
them 0.7 times the difference between
the maximum ambient atmospheric
temperature and the temperature of
the ambient air at the time of the first
occurrence of the maximum cylinder

barrel temperature recorded during the
cooling test.

(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. 5084, 29 FR 16150, Dec. 3, 1964, as
amended by Amdt. 29–12, 41 FR 55473, Dec. 20,
1976; Amdt. 29–15, 43 FR 2327, Jan. 16, 1978;
Amdt. 29–26, 53 FR 34218, Sept. 2, 1988]

§ 29.1045

Climb cooling test proce-

dures.

(a) Climb cooling tests must be con-

ducted under this section for—

(1) Category A rotorcraft; and
(2) Multiengine category B rotorcraft

for which certification is requested
under the category A powerplant in-
stallation requirements, and under the
requirements of § 29.861(a) at the steady
rate of climb or descent established
under § 29.67(b).

(b) The climb or descent cooling tests

must be conducted with the engine in-
operative that produces the most ad-
verse cooling conditions for the re-
maining engines and powerplant com-
ponents.

of 30-minute OEI power is requested, be
at 30-minute OEI power for 30 minutes,
and then at maximum continuous
power (or at full throttle when above
the critical altitude);

(2) For helicopters for which the use

of continuous OEI power is requested,
be at continuous OEI power (or at full
throttle when above the critical alti-
tude); and

(3) For other rotorcraft, be at max-

imum continuous power (or at full
throttle when above the critical alti-
tude).

(d) After temperatures have sta-

bilized in flight, the climb must be—

(1) Begun from an altitude not great-

er than the lower of—

(i) 1,000 feet below the engine critcal

altitude; and

(ii) 1,000 feet below the maximum al-

titude at which the rate of climb is 150
f.p.m; and

(2) Continued for at least five min-

utes after the occurrence of the highest
temperature recorded, or until the