Code of Federal Regulations - Title 14

287

Federal Aviation Administration, DOT

§ 23.1093

NDUCTION

YSTEM

§ 23.1091

Air induction system.

(a) The air induction system for each

engine and auxiliary power unit and
their accessories must supply the air
required by that engine and auxiliary
power unit and their accessories under
the operating conditions for which cer-
tification is requested.

(b) Each reciprocating engine instal-

lation must have at least two separate
air intake sources and must meet the
following:

(1) Primary air intakes may open

within the cowling if that part of the
cowling is isolated from the engine ac-
cessory section by a fire-resistant dia-
phragm or if there are means to pre-
vent the emergence of backfire flames.

(2) Each alternate air intake must be

located in a sheltered position and may
not open within the cowling if the
emergence of backfire flames will re-
sult in a hazard.

(3) The supplying of air to the engine

through the alternate air intake sys-
tem may not result in a loss of exces-
sive power in addition to the power loss
due to the rise in air temperature.

(4) Each automatic alternate air door

must have an override means acces-
sible to the flight crew.

(5) Each automatic alternate air door

must have a means to indicate to the
flight crew when it is not closed.

planes—

(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 sys-
tem; and

(2) The airplane must be designed to

prevent water or slush on the runway,
taxiway, or other airport operating
surfaces from being directed into the
engine or auxiliary power unit air in-
take ducts in hazardous quantities.
The air intake ducts must be located or
protected so as to minimize the hazard
of ingestion of foreign matter during
takeoff, landing, and taxiing.

[Doc. No. 4080, 29 FR 17955, Dec. 18, 1964, as
amended by Amdt. 23–7, 34 FR 13095, Aug. 13,
1969; Amdt. 23–43, 58 FR 18973, Apr. 9, 1993; 58
FR 27060, May 6, 1993; Amdt. 23–51, 61 FR 5137,
Feb. 9, 1996]

§ 23.1093

Induction system icing pro-

tection.

(a)

Reciprocating engines. Each recip-

rocating engine air induction system
must have means to prevent and elimi-
nate icing. Unless this is done by other
means, it must be shown that, in air
free of visible moisture at a tempera-
ture of 30

F—

(1) Each airplane with sea level en-

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

F. with the en-

gines at 75 percent of maximum contin-
uous power;

(2) Each airplane with altitude en-

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

F. with the en-

gines at 75 percent of maximum contin-
uous power;

(3) Each airplane with altitude en-

gines using fuel metering device tend-
ing to prevent icing has a preheater
that, with the engines at 60 percent of
maximum continuous power, can pro-
vide a heat rise of—

(i) 100

F.; or

(ii) 40

F., if a fluid deicing system

meeting the requirements of §§ 23.1095
through 23.1099 is installed;

(4) Each airplane with sea level en-

gine(s) using fuel metering device tend-
ing to prevent icing has a sheltered al-
ternate source of air with a preheat of
not less than 60

F with the engines at

75 percent of maximum continuous
power;

(5) Each airplane with sea level or al-

titude engine(s) using fuel injection
systems having metering components
on which impact ice may accumulate
has a preheater capable of providing a
heat rise of 75

F when the engine is op-

erating at 75 percent of its maximum
continuous power; and

(6) Each airplane with sea level or al-

titude engine(s) using fuel injection
systems not having fuel metering com-
ponents projecting into the airstream
on which ice may form, and intro-
ducing fuel into the air induction sys-
tem downstream of any components or
other obstruction on which ice pro-
duced by fuel evaporation may form,
has a sheltered alternate source of air
with a preheat of not less than 60

with the engines at 75 percent of its
maximum continuous power.

VerDate Mar<15>2010

10:12 Mar 18, 2014

Jkt 232046

PO 00000

Frm 00297

Fmt 8010

Sfmt 8010

Y:\SGML\232046.XXX

232046

pmangrum on DSK3VPTVN1PROD with CFR