title-14-part-25-sec25-1199

336

14 CFR Ch. I (1–1–24 Edition)

§ 25.1195

vibration, inertia, and air load to
which it may be subjected in operation.

(b) Cowling must meet the drainage

and ventilation requirements of
§ 25.1187.

isolating the engine power section from
the engine accessory section, each part
of the accessory section cowling sub-
ject to flame in case of fire in the en-
gine power section of the powerplant
must—

(1) Be fireproof; and
(2) Meet the requirements of § 25.1191.
(d) Each part of the cowling subject

to high temperatures due to its near-
ness to exhaust system parts or ex-
haust gas impingement must be fire-
proof.

(e) Each airplane must—
(1) Be designed and constructed so

that no fire originating in any fire zone
can enter, either through openings or
by burning through external skin, any
other zone or region where it would
create additional hazards;

(2) Meet paragraph (e)(1) of this sec-

tion with the landing gear retracted (if
applicable); and

(3) Have fireproof skin in areas sub-

ject to flame if a fire starts in the en-
gine power or accessory sections.

§ 25.1195

Fire extinguishing systems.

(a) Except for combustor, turbine,

and tail pipe sections of turbine engine
installations that contain lines or com-
ponents carrying flammable fluids or
gases for which it is shown that a fire
originating in these sections can be
controlled, there must be a fire extin-
guisher system serving each designated
fire zone.

(b) The fire extinguishing system, the

quantity of the extinguishing agent,
the rate of discharge, and the discharge
distribution must be adequate to extin-
guish fires. It must be shown by either
actual or simulated flights tests that
under critical airflow conditions in
flight the discharge of the extin-
guishing agent in each designated fire
zone specified in paragraph (a) of this
section will provide an agent con-
centration capable of extinguishing
fires in that zone and of minimizing
the probability of reignition. An indi-
vidual ‘‘one-shot’’ system may be used
for auxiliary power units, fuel burning

heaters, and other combustion equip-
ment. For each other designated fire
zone, two discharges must be provided
each of which produces adequate agent
concentration.

a nacelle must be able to simulta-
neously protect each zone of the na-
celle for which protection is provided.

[Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as
amended by Amdt. 25–46, 43 FR 50598, Oct. 30,
1978]

§ 25.1197

Fire extinguishing agents.

(a) Fire extinguishing agents must—
(1) Be capable of extinguishing

flames emanating from any burning of
fluids or other combustible materials
in the area protected by the fire extin-
guishing system; and

(2) Have thermal stability over the

temperature range likely to be experi-
enced in the compartment in which
they are stored.

(b) If any toxic extinguishing agent is

used, provisions must be made to pre-
vent harmful concentrations of fluid or
fluid vapors (from leakage during nor-
mal operation of the airplane or as a
result of discharging the fire extin-
guisher on the ground or in flight) from
entering any personnel compartment,
even though a defect may exist in the
extinguishing system. This must be
shown by test except for built-in car-
bon dioxide fuselage compartment fire
extinguishing systems for which—

(1) Five pounds or less of carbon diox-

ide will be discharged, under estab-
lished fire control procedures, into any
fuselage compartment; or

(2) There is protective breathing

equipment for each flight crewmember
on flight deck duty.

[Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as
amended by Amdt. 25–38, 41 FR 55467, Dec. 20,
1976; Amdt. 25–40, 42 FR 15044, Mar. 17, 1977]

§ 25.1199

Extinguishing agent con-

tainers.

(a) Each extinguishing agent con-

tainer must have a pressure relief to
prevent bursting of the container by
excessive internal pressures.

(b) The discharge end of each dis-

charge line from a pressure relief con-
nection must be located so that dis-
charge of the fire extinguishing agent
would not damage the airplane. The

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§ 25.1207

line must also be located or protected
to prevent clogging caused by ice or
other foreign matter.

fire extinguishing agent container to
indicate that the container has dis-
charged or that the charging pressure
is below the established minimum nec-
essary for proper functioning.

(d) The temperature of each con-

tainer must be maintained, under in-
tended operating conditions, to prevent
the pressure in the container from—

(1) Falling below that necessary to

provide an adequate rate of discharge;
or

(2) Rising high enough to cause pre-

mature discharge.

(e) If a pyrotechnic capsule is used to

discharge the extinguishing agent,
each container must be installed so
that temperature conditions will not
cause hazardous deterioration of the
pyrotechnic capsule.

[Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as
amended by Amdt. 25–23, 35 FR 5678, Apr. 8,
1970; Amdt. 25–40, 42 FR 15044, Mar. 17, 1977]

§ 25.1201

Fire extinguishing system

materials.

(a) No material in any fire extin-

guishing system may react chemically
with any extinguishing agent so as to
create a hazard.

(b) Each system component in an en-

gine compartment must be fireproof.

§ 25.1203

Fire detector system.

(a) There must be approved, quick

acting fire or overheat detectors in
each designated fire zone, and in the
combustion, turbine, and tailpipe sec-
tions of turbine engine installations, in
numbers and locations ensuring
prompt detection of fire in those zones.

(b) Each fire detector system must be

constructed and installed so that—

(1) It will withstand the vibration, in-

ertia, and other loads to which it may
be subjected in operation;

(2) There is a means to warn the crew

in the event that the sensor or associ-
ated wiring within a designated fire
zone is severed at one point, unless the
system continues to function as a sat-
isfactory detection system after the
severing; and

(3) There is a means to warn the crew

in the event of a short circuit in the

sensor or associated wiring within a
designated fire zone, unless the system
continues to function as a satisfactory
detection system after the short cir-
cuit.

be affected by any oil, water, other
fluids or fumes that might be present.

(d) There must be means to allow the

crew to check, in flight, the func-
tioning of each fire or overheat detec-
tor electric circuit.

(e) Components of each fire or over-

heat detector system in a fire zone
must be fire-resistant.

(f) No fire or overheat detector sys-

tem component for any fire zone may
pass through another fire zone, un-
less—

(1) It is protected against the possi-

bility of false warnings resulting from
fires in zones through which it passes;
or

(2) Each zone involved is simulta-

neously protected by the same detector
and extinguishing system.

(g) Each fire detector system must be

constructed so that when it is in the
configuration for installation it will
not exceed the alarm activation time
approved for the detectors using the re-
sponse time criteria specified in the ap-
propriate Technical Standard Order for
the detector.

(h) EWIS for each fire or overheat de-

tector system in a fire zone must meet
the requirements of § 25.1731.

[Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as
amended by Amdt. 25–23, 35 FR 5678, Apr. 8,
1970; Amdt. 25–26, 36 FR 5493, Mar. 24, 1971;
Amdt. 25–123, 72 FR 63405, Nov. 8, 2007]

§ 25.1207

Compliance.

Unless otherwise specified, compli-

ance with the requirements of §§ 25.1181
through 25.1203 must be shown by a full
scale fire test or by one or more of the
following methods:

(a) Tests of similar powerplant con-

figurations;

(b) Tests of components;
(c) Service experience of aircraft

with similar powerplant configura-
tions;

(d) Analysis.

[Amdt. 25–46, 43 FR 50598, Oct. 30, 1978]