Section 1 – requirements

(a) General. For the tests prescribed in

JAR 27.1041 (b), the following apply:

(1) If the tests are conducted under

conditions deviating from the maximum

ambient atmospheric temperature specified in

sub-paragraph (b) of this paragraph, the

recorded powerplant temperatures must be

corrected under sub-paragraphs (c) and (d) of

this paragraph unless a more rational

correction method is applicable.

(2) No corrected temperature

determined under sub-paragraph (a) (1) of

this paragraph 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 JAR 27.1045.

(b) Maximum ambient atmospheric

temperature. A maximum ambient atmospheric

temperature corresponding to sea-level

conditions of at least 38°C (100°F) must be

established. The assumed temperature lapse rate

is 1.98°C (3.6°F) per thousand feet of altitude

above sea-level until a temperature of –56.5°C

(–69.7°F) is reached, above which altitude the

temperature is considered constant at –56.5°C

(–69.7°F). However, for winterization

installations, the applicant may select a

maximum ambient atmospheric temperature

corresponding to sea-level conditions of less

than 38°C (100°F).

(c) Correction factor (except cylinder

applies, temperatures of engine fluids and

powerplant 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.

(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 stabilisation. For the

purpose of the cooling tests, a temperature is

‘stabilised’ when its rate of change is less than

1°C (2°F) per minute. The following component

and engine fluid temperature stabilisation rules

apply:

stage of flight –

(i) The temperatures must be

stabilised 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

stabilise, 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

take-off stage of flight the climb at take-off

power must be preceded by a period of hover

during which the temperatures are stabilised.

(c) Duration of test. For each stage of

flight the tests must be continued until –

(1) The temperatures stabilise 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.

(a) The air induction system for each

engine must supply the air required by that

engine under the operating conditions and

manoeuvres 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 from

entering the engine intake system; and

(2) The air inlet ducts must be located

or protected so as to minimise the ingestion of

foreign matter during take-off, landing, and

taxying.