Code of Federal Regulations - Title 14

793

Federal Aviation Administration, DOT

§ 29.1103

free of visible moisture at a tempera-
ture of 30

F., and with the engines at

60 percent of maximum continuous
power—

(1) Each rotorcraft with sea level en-

gines using conventional venturi car-
buretors has a preheater that can pro-
vide a heat rise of 90

F.;

(2) Each rotorcraft with sea level en-

gines using carburetors tending to pre-
vent icing has a preheater that can
provide a heat rise of 70

F.;

(3) Each rotorcraft with altitude en-

gines using conventional venturi car-
buretors has a preheater that can pro-
vide a heat rise of 120

F.; and

(4) Each rotorcraft with altitude en-

gines using carburetors tending to pre-
vent icing has a preheater that can
provide a heat rise of 100

(b)

Turbine engines. (1) It must be

shown that each turbine engine and its
air inlet system can operate through-
out the flight power range of the en-
gine (including idling)—

(i) Without accumulating ice on en-

gine or inlet system components that
would adversely affect engine oper-
ation or cause a serious loss of power
under the icing conditions specified in
appendix C of this Part; and

(ii) In snow, both falling and blowing,

without adverse effect on engine oper-
ation, within the limitations estab-
lished for the rotorcraft.

(2) Each turbine engine must idle for

30 minutes on the ground, with the air
bleed available for engine icing protec-
tion at its critical condition, without
adverse effect, in an atmosphere that is
at a temperature between 15

and 30

(between ¥9

and ¥1

C) and has a liq-

uid water content not less than 0.3
grams per cubic meter in the form of
drops having a mean effective diameter
not less than 20 microns, followed by
momentary operation at takeoff 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 Administrator.

(c)

Supercharged reciprocating engines.

For each engine having a supercharger
to pressurize the air before it enters
the carburetor, the heat rise in the air
caused by that supercharging at any
altitude may be utilized in determining
compliance with paragraph (a) of this

section if the heat rise utilized is that
which will be available, automatically,
for the applicable altitude and oper-
ation condition because of super-
charging.

(Secs. 313(a), 601, and 603, 72 Stat. 752, 775, 49
U.S.C. 1354(a), 1421, and 1423; sec. 6(c), 49
U.S.C. 1655 (c))

[Amdt. 29–3, 33 FR 969, Jan. 26, 1968, as
amended by Amdt. 29–12, 41 FR 55473, Dec. 20,
1976; Amdt. 29–13, 42 FR 15046, Mar. 17, 1977;
Amdt. 29–22, 49 FR 6850, Feb. 23, 1984; Amdt.
29–26, 53 FR 34219, Sept. 2, 1988]

§ 29.1101

Carburetor air preheater de-

sign.

Each carburetor air preheater must

be designed and constructed to—

(a) Ensure ventilation of the pre-

heater when the engine is operated in
cold air;

(b) Allow inspection of the exhaust

manifold parts that it surrounds; and

of the preheater itself.

§ 29.1103

Induction systems ducts and

air duct systems.

(a) Each induction system duct up-

stream of the first stage of the engine
supercharger and of the auxiliary
power unit compressor must have a
drain to prevent the hazardous accu-
mulation of fuel and moisture in the
ground attitude. No drain may dis-
charge where it might cause a fire haz-
ard.

(b) Each duct must be strong enough

to prevent induction system failure
from normal backfire conditions.

nents between which relative motion
could exist must have means for flexi-
bility.

(d) Each duct within any fire zone for

which a fire-extinguishing system is re-
quired must be at least—

(1) Fireproof, if it passes through any

firewall; or

(2) Fire resistant, for other ducts, ex-

cept that ducts for auxiliary power
units must be fireproof within the aux-
iliary power unit fire zone.

(e) Each auxiliary power unit induc-

tion system duct must be fireproof for
a sufficient distance upstream of the
auxiliary power unit compartment to
prevent hot gas reverse flow from burn-
ing through auxiliary power unit ducts

VerDate Mar<15>2010

10:12 Mar 18, 2014

Jkt 232046

PO 00000

Frm 00803

Fmt 8010

Sfmt 8010

Y:\SGML\232046.XXX

232046

pmangrum on DSK3VPTVN1PROD with CFR