Section 1 – requirements

(a) Reciprocating engines. Each

reciprocating engine air induction system must

have means to prevent and eliminate icing.

Unless this is done by other means, it must be

shown that, in air free of visible moisture at a

temperature of –1°C (30°F) and with the engines

at 75% of maximum continuous power –

(1) Each rotorcraft with sea-level

engines using conventional venturi

carburettors has a preheater that can provide a

heat rise of 50°C (90°F);

(2) Each rotorcraft with sea-level

engines using carburettors tending to prevent

icing has a sheltered alternate source of air,

and that the preheat supplied to the alternate

air intake is not less than that provided by the

engine cooling air downstream of the

cylinders;

(3) Each rotorcraft with altitude

engines using conventional venturi

carburettors has a preheater capable of

providing a heat rise of 67°C (120°F); and

(4) Each rotorcraft with altitude

engines using carburettors tending to prevent

icing has a preheater that can provide a heat

rise of –

(i) 56°C (100°F); or

(ii) If a fluid de-icing system is

used, at least 22°C (40°F).

(b) Turbine engines

(1) It must be shown that each turbine

engine and its air inlet system can operate

throughout the flight power range of the

engine (including idling) –

(i) Without accumulating ice on

engine or inlet system components that

would adversely affect engine operation

or cause a serious loss of power under

the icing conditions specified in

Appendix C of JAR–29; and

(ii) In snow, both falling and

blowing, without adverse effect on

engine operation, within the limitations

established for the rotorcraft.

(2) Each turbine engine must idle for

30 minutes on the ground, with the air bleed

available for engine icing protection at its

critical condition, without adverse effect, in

an atmosphere that is at a temperature

between –9°C and –1°C (15° and 30°F) and

has a liquid water content not less than

0.3 grams per cubic metre in the form of

drops having a mean effective diameter of not

less than 20 microns, followed by momentary

operation at take-off power or thrust. During

the 30 minutes of idle operation, the engine

may be run up periodically to a moderate

power or thrust setting in a manner acceptable

to the Authority.

(c) Supercharged reciprocating engines.

For each engine having superchargers to

pressurise the air before it enters the carburettor,

the heat rise in the air caused by that

supercharging at any altitude may be utilised in

determining compliance with sub-paragraph (a)

of this paragraph if the heat rise utilised is that

which will be available, automatically, for the

applicable altitude and operating condition

because of supercharging.

For each exhaust system –

(a) There must be means for thermal

expansion of manifolds and pipes;

(b) There must be means to prevent local

hot spots;

(c) Exhaust gases must discharge clear of

the engine air intake, fuel system components,

and drains;

(d) Each exhaust system part with a surface

hot enough to ignite flammable fluids or vapours

must be located or shielded so that leakage from

any system carrying flammable fluids or vapours

will not result in a fire caused by impingement

of the fluids or vapours on any part of the

exhaust system including shields for the exhaust

system;

(e) Exhaust gases may not impair pilot

(f) If significant traps exist, each turbine

engine exhaust system must have drains

discharging clear of the rotorcraft, in any normal

ground and flight attitudes, to prevent fuel

accumulation after the failure of an attempted

engine start; and

(g) Each exhaust heat exchanger must

incorporate means to prevent blockage of the

exhaust port after any internal heat exchanger

failure.