Federal Aviation Administration, DOT

Section 27.859

Section 27.831 Ventilation.
(a) The ventilating system for the
pilot and passenger compartments
must be designed to prevent the presence of excessive quantities of fuel
fumes and carbon monoxide.
(b) The concentration of carbon monoxide may not exceed one part in 20,000
parts of air during forward flight or
hovering in still air. If the concentration exceeds this value under other
conditions, there must be suitable operating restrictions.

(2) Fire resistant, in the case of other
compartments.
(b) No compartment may contain any
controls, wiring, lines, equipment, or
accessories whose damage or failure
would affect safe operation, unless
those items are protected so that - 
(1) They cannot be damaged by the
movement of cargo in the compartment; and
(2) Their breakage or failure will not
create a fire hazard.

Section 27.833 Heaters.
Each combustion heater must be approved.

(a) General. For each heating system
that involves the passage of cabin air
over, or close to, the exhaust manifold,
there must be means to prevent carbon
monoxide from entering any cabin or
pilot compartment.
(b) Heat exchangers. Each heat exchanger must be - 
(1) Of suitable materials;
(2) Adequately cooled under all conditions; and
(3) Easily disassembled for inspection.
(c) Combustion heater fire protection.
Except for heaters which incorporate
designs to prevent hazards in the event
of fuel leakage in the heater fuel system, fire within the ventilating air passage, or any other heater malfunction,
each heater zone must incorporate the
fire protection features of the applicable requirements of SectionSection 27.1183, 27.1185,
27.1189, 27.1191, and be provided with - 
(1) Approved, quick-acting fire detectors in numbers and locations ensuring
prompt detection of fire in the heater
region.
(2) Fire extinguisher systems that
provide at least one adequate discharge
to all areas of the heater region.
(3) Complete drainage of each part of
each zone to minimize the hazards resulting from failure or malfunction of
any component containing flammable
fluids. The drainage means must be - 
(i) Effective under conditions expected to prevail when drainage is
needed; and
(ii) Arranged so that no discharged
fluid will cause an additional fire hazard.
(4) Ventilation, arranged so that no
discharged vapors will cause an additional fire hazard.

[Amdt. 27-23, 53 FR 34210, Sept. 2, 1988]

FIRE PROTECTION
Section 27.853 Compartment interiors.
For each compartment to be used by
the crew or passengers - 
(a) The materials must be at least
flame-resistant;
(b) [Reserved]
(c) If smoking is to be prohibited,
there must be a placard so stating, and
if smoking is to be allowed - 
(1) There must be an adequate number of self-contained, removable ashtrays; and
(2) Where the crew compartment is
separated from the passenger compartment, there must be at least one illuminated sign (using either letters or
symbols) notifying all passengers when
smoking is prohibited. Signs which notify when smoking is prohibited must - 
(i) When illuminated, be legible to
each passenger seated in the passenger
cabin under all probable lighting conditions; and
(ii) Be so constructed that the crew
can turn the illumination on and off.

spaschal on DSK3GDR082PROD with CFR

[Amdt. 27-17, 45 FR 7755, Feb. 4, 1980, as
amended by Amdt. 27-37, 64 FR 45095, Aug. 18,
1999]

Section 27.855 Cargo and baggage compartments.
(a) Each cargo and baggage compartment must be constructed of, or lined
with, materials that are at least - 
(1) Flame resistant, in the case of
compartments that are readily accessible to a crewmember in flight; and

Section 27.859

Heating systems.

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