Section 27.1045

14 CFR Ch. I (1-1-19 Edition)

sea level conditions of at least 100 degrees F. must be established. The assumed temperature lapse rate is 3.6 degrees F. per thousand feet of altitude
above sea level until a temperature of
Section69.7 degrees F. is reached, above
which altitude the temperature is considered constant at Section69.7 degrees F.
However, for winterization installations, the applicant may select a maximum ambient atmospheric temperature corresponding to sea level conditions of less than 100 degrees F.
(c) Correction factor (except cylinder
barrels). Unless a more rational correction applies, temperatures of engine
fluids and power-plant components (except cylinder barrels) for which temperature limits are established, must
be corrected by adding to them 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
component or fluid temperature recorded during the cooling test.
(d) Correction factor for cylinder barrel
temperatures. Cylinder barrel temperatures 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.

engine fluid temperature stabilization
rules apply:
(1) For each rotorcraft, and for each
stage of flight - 
(i) The temperatures must be stabilized under the conditions from
which entry is made into the stage of
flight being investigated; or
(ii) If the entry condition normally
does not allow temperatures to stabilize, operation through the full entry
condition must be conducted before
entry into the stage of flight being investigated in order to allow the temperatures to attain their natural levels
at the time of entry.
(2) For each helicopter during the
takeoff stage of flight, the climb at
takeoff power must be preceded by a
period of hover during which the temperatures are stabilized.
(c) Duration of test. For each stage of
flight the tests must be continued
until - 
(1) The temperatures stabilize or 5
minutes after the occurrence of the
highest temperature recorded, as appropriate to the test condition;
(2) That stage of flight is completed;
or
(3) An operating limitation is
reached.

(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)))

INDUCTION SYSTEM

[Doc. No. 5074, 29 FR 15695, Nov. 24, 1964, as
amended by Amdt. 27-11, 41 FR 55470, Dec. 20,
1976; Amdt. 27-14, 43 FR 2325, Jan. 16, 1978]

spaschal on DSK3GDR082PROD with CFR

Section 27.1045

Cooling test procedures.

(a) General. For each stage of flight,
the cooling tests must be conducted
with the rotorcraft - 
(1) In the configuration most critical
for cooling; and
(2) Under the conditions most critical
for cooling.
(b) Temperature stabilization. For the
purpose of the cooling tests, a temperature is  - stabilized -  when its rate of
change is less than two degrees F. per
minute. The following component and

[Doc. No. 5074, 29 FR 15695, Nov. 24, 1964, as
amended by Amdt. 27-23, 53 FR 34214, Sept. 2,
1988]

Section 27.1091

Air induction.

(a) The air induction system for each
engine must supply the air required by
that engine under the operating conditions and maneuvers for which certification is requested.
(b) Each cold air induction system
opening must be outside the cowling if
backfire flames can emerge.
(c) If fuel can accumulate in any air
induction system, that system must
have drains that discharge fuel - 
(1) Clear of the rotorcraft; and
(2) Out of the path of exhaust flames.
(d) For turbine engine powered rotorcraft - 
(1) There must be means to prevent
hazardous quantities of fuel leakage or
overflow from drains, vents, or other
components of flammable fluid systems

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