title-14-part-25-sec25-1187

334

14 CFR Ch. I (1–1–24 Edition)

§ 25.1182

(7) Combustor, turbine, and tailpipe

sections of turbine engine installations
that contain lines or components car-
rying flammable fluids or gases.

(b) Each designated fire zone must

meet the requirements of §§ 25.863,
25.865, 25.867, 25.869, and 25.1185 through
25.1203.

[Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as
amended by Amdt. 25–11, 32 FR 6913, May 5,
1967; Amdt. 25–23, 35 FR 5677, Apr. 8, 1970;
Amdt. 25–72, 55 FR 29785, July 20, 1990; Amdt.
25–115, 69 FR 40527, July 2, 2004]

§ 25.1182

Nacelle areas behind fire-

walls, and engine pod attaching
structures containing flammable
fluid lines.

(a) Each nacelle area immediately

behind the firewall, and each portion of
any engine pod attaching structure
containing flammable fluid lines, must
meet each requirement of §§ 25.1103(b),
25.1165 (d) and (e), 25.1183, 25.1185(c),
25.1187, 25.1189, and 25.1195 through
25.1203, including those concerning des-
ignated fire zones. However, engine pod
attaching structures need not contain
fire detection or extinguishing means.

(b) For each area covered by para-

graph (a) of this section that contains
a retractable landing gear, compliance
with that paragraph need only be
shown with the landing gear retracted.

[Amdt. 25–11, 32 FR 6913, May 5, 1967]

§ 25.1183

Flammable fluid-carrying

components.

(a) Except as provided in paragraph

(b) of this section, each line, fitting,
and other component carrying flam-
mable fluid in any area subject to en-
gine fire conditions, and each compo-
nent which conveys or contains flam-
mable fluid in a designated fire zone
must be fire resistant, except that
flammable fluid tanks and supports in
a designated fire zone must be fireproof
or be enclosed by a fireproof shield un-
less damage by fire to any non-fire-
proof part will not cause leakage or
spillage of flammable fluid. Compo-
nents must be shielded or located to
safeguard against the ignition of leak-
ing flammable fluid. An integral oil
sump of less than 25-quart capacity on
a reciprocating engine need not be fire-
proof nor be enclosed by a fireproof
shield.

(b) Paragraph (a) of this section does

not apply to—

(1) Lines, fittings, and components

which are already approved as part of a
type certificated engine; and

(2) Vent and drain lines, and their fit-

tings, whose failure will not result in,
or add to, a fire hazard.

within a designated fire zone must be
fireproof if, when exposed to or dam-
aged by fire, they could—

(1) Result in fire spreading to other

regions of the airplane; or

(2) Cause unintentional operation of,

or inability to operate, essential serv-
ices or equipment.

[Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as
amended by Amdt. 25–11, 32 FR 6913, May 5,
1967; Amdt. 25–36, 39 FR 35461, Oct. 1, 1974;
Amdt. 25–57, 49 FR 6849, Feb. 23, 1984; Amdt.
25–101, 65 FR 79710, Dec. 19, 2000]

§ 25.1185

Flammable fluids.

(a) Except for the integral oil sumps

specified in § 25.1183(a), no tank or res-
ervoir that is a part of a system con-
taining flammable fluids or gases may
be in a designated fire zone unless the
fluid contained, the design of the sys-
tem, the materials used in the tank,
the shut-off means, and all connec-
tions, lines, and control provide a de-
gree of safety equal to that which
would exist if the tank or reservoir
were outside such a zone.

(b) There must be at least one-half

inch of clear airspace between each
tank or reservoir and each firewall or
shroud isolating a designated fire zone.

flammable fluid system components
that might leak must be covered or
treated to prevent the absorption of
hazardous quantities of fluids.

[Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as
amended by Amdt. 25–19, 33 FR 15410, Oct. 17,
1968; Amdt. 25–94, 63 FR 8848, Feb. 23, 1998]

§ 25.1187

Drainage and ventilation of

fire zones.

(a) There must be complete drainage

of each part of each designated fire
zone to minimize the hazards resulting
from failure or malfunctioning of any
component containing flammable
fluids. The drainage means must be—

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§ 25.1193

(1) Effective under conditions ex-

pected to prevail when drainage is
needed; and

(2) Arranged so that no discharged

fluid will cause an additional fire haz-
ard.

(b) Each designated fire zone must be

ventilated to prevent the accumulation
of flammable vapors.

where it would allow the entry of flam-
mable fluids, vapors, or flame from
other zones.

(d) Each ventilation means must be

arranged so that no discharged vapors
will cause an additional fire hazard.

(e) Unless the extinguishing agent ca-

pacity and rate of discharge are based
on maximum air flow through a zone,
there must be means to allow the crew
to shut off sources of forced ventilation
to any fire zone except the engine
power section of the nacelle and the
combustion heater ventilating air
ducts.

§ 25.1189

Shutoff means.

(a) Each engine installation and each

fire zone specified in § 25.1181(a)(4) and
(5) must have a means to shut off or
otherwise prevent hazardous quantities
of fuel, oil, deicer, and other flammable
fluids, from flowing into, within, or
through any designated fire zone, ex-
cept that shutoff means are not re-
quired for—

(1) Lines, fittings, and components

forming an integral part of an engine;
and

(2) Oil systems for turbine engine in-

stallations in which all components of
the system in a designated fire zone,
including oil tanks, are fireproof or lo-
cated in areas not subject to engine
fire conditions.

(b) The closing of any fuel shutoff

valve for any engine may not make
fuel unavailable to the remaining en-
gines.

interfere with the later emergency op-
eration of other equipment, such as the
means for feathering the propeller.

(d) Each flammable fluid shutoff

means and control must be fireproof or
must be located and protected so that
any fire in a fire zone will not affect its
operation.

(e) No hazardous quantity of flam-

mable fluid may drain into any des-
ignated fire zone after shutoff.

(f) There must be means to guard

against inadvertent operation of the
shutoff means and to make it possible
for the crew to reopen the shutoff
means in flight after it has been closed.

(g) Each tank-to-engine shutoff valve

must be located so that the operation
of the valve will not be affected by
powerplant or engine mount structural
failure.

(h) Each shutoff valve must have a

means to relieve excessive pressure ac-
cumulation unless a means for pressure
relief is otherwise provided in the sys-
tem.

[Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as
amended by Amdt. 25–23, 35 FR 5677, Apr. 8,
1970; Amdt. 25–57, 49 FR 6849, Feb. 23, 1984]

§ 25.1191

Firewalls.

(a) Each engine, auxiliary power

unit, fuel-burning heater, other com-
bustion equipment intended for oper-
ation in flight, and the combustion,
turbine, and tailpipe sections of tur-
bine engines, must be isolated from the
rest of the airplane by firewalls,
shrouds, or equivalent means.

(b) Each firewall and shroud must

be—

(1) Fireproof;
(2) Constructed so that no hazardous

quantity of air, fluid, or flame can pass
from the compartment to other parts
of the airplane;

(3) Constructed so that each opening

is sealed with close fitting fireproof
grommets, bushings, or firewall fit-
tings; and

(4) Protected against corrosion.

§ 25.1192

Engine accessory section dia-

phragm.

For reciprocating engines, the engine

power section and all portions of the
exhaust system must be isolated from
the engine accessory compartment by a
diaphragm that complies with the fire-
wall requirements of § 25.1191.

[Amdt. 25–23, 35 FR 5678, Apr. 8, 1970]