Sec. 25.807 - Emergency exits.
(a) Type. For the purpose of this
part, the types of exits are defined as follows:
(1) Type I. This type is a
floor-level exit with a rectangular opening of not less than 24 inches
wide by 48 inches high, with corner radii not greater than eight inches.
(2) Type II. This type is a
rectangular opening of not less than 20 inches wide by 44 inches high,
with corner radii not greater than seven inches. Type II exits must be
floor-level exits unless located over the wing, in which case they must
not have a step-up inside the airplane of more than 10 inches nor a
step-down outside the airplane of more than 17 inches.
(3) Type III. This type is a
rectangular opening of not less than 20 inches wide by 36 inches high with
corner radii not greater than seven inches, and with a step-up inside the
airplane of not more than 20 inches. If the exit is located over the wing,
the step-down outside the airplane may not exceed 27 inches.
(4) Type IV. This type is a
rectangular opening of not less than 19 inches wide by 26 inches high,
with corner radii not greater than 6.3 inches, located over the wing, with
a step-up inside the airplane of not more than 29 inches and a step-down
outside the airplane of not more than 36 inches.
(5) Ventral. This type is an exit
from the passenger compartment through the pressure shell and the bottom
fuselage skin. The dimensions and physical configuration of this type of
exit must allow at least the same rate of egress as a Type I exit with the
airplane in the normal ground attitude, with landing gear extended.
(6) Tailcone. This type is an aft
exit from the passenger compartment through the pressure shell and through
an openable cone of the fuselage aft of the pressure shell. The means of
opening the tailcone must be simple and obvious and must employ a single
operation.
(7) Type A. This type is a
floor-level exit with a rectangular opening of not less than 42 inches
wide by 72 inches high, with corner radii not greater than seven inches.
(8) Type B. This type is a
floor-level exit with a rectangular opening of not less than 32 inches
wide by 72 inches high, with corner radii not greater than six inches.
(9) Type C. This type is a
floor-level exit with a rectangular opening of not less than 30 inches
wide by 48 inches high, with corner radii not greater than 10 inches.
(b) Step down distance. Step down
distance, as used in this section, means the actual distance between the
bottom of the required opening and a usable foot hold, extending out from
the fuselage, that is large enough to be effective without searching by
sight or feel.
(c) Over-sized exits. Openings
larger than those specified in this section, whether or not of rectangular
shape, may be used if the specified rectangular opening can be inscribed
within the opening and the base of the inscribed rectangular opening meets
the specified step-up and step-down heights.
(d) Asymmetry. Exits of an exit
pair need not be diametrically opposite each other nor of the same size;
however, the number of passenger seats permitted under paragraph (g) of
this section is based on the smaller of the two exits.
(e) Uniformity. Exits must be
distributed as uniformly as practical, taking into account passenger seat
distribution.
(f) Location. (1) Each required
passenger emergency exit must be accessible to the passengers and located
where it will afford the most effective means of passenger evacuation.
(2) If only one floor-level exit per
side is prescribed, and the airplane does not have a tailcone or ventral
emergency exit, the floor-level exits must be in the rearward part of the
passenger compartment unless another location affords a more effective
means of passenger evacuation.
(3) If more than one floor-level exit
per side is prescribed, and the airplane does not have a combination cargo
and passenger configuration, at least one floor-level exit must be located
in each side near each end of the cabin.
(4) For an airplane that is required to
have more than one passenger emergency exit for each side of the fuselage,
no passenger emergency exit shall be more than 60 feet from any adjacent
passenger emergency exit on the same side of the same deck of the
fuselage, as measured parallel to the airplane's longitudinal axis between
the nearest exit edges.
(g) Type and number required. The
maximum number of passenger seats permitted depends on the type and number
of exits installed in each side of the fuselage. Except as further
restricted in paragraphs (g)(1) through (g)(9) of this section, the
maximum number of passenger seats permitted for each exit of a specific
type installed in each side of the fuselage is as follows:
Type A 110
Type B 75
Type C 55
Type I 45
Type II 40
Type III 35
Type IV 9
(1) For a passenger seating
configuration of 1 to 9 seats, there must be at least one Type IV or
larger overwing exit in each side of the fuselage or, if overwing exits
are not provided, at least one exit in each side that meets the minimum
dimensions of a Type III exit.
(2) For a passenger seating
configuration of more than 9 seats, each exit must be a Type III or larger
exit.
(3) For a passenger seating
configuration of 10 to 19 seats, there must be at least one Type III or
larger exit in each side of the fuselage.
(4) For a passenger seating
configuration of 20 to 40 seats, there must be at least two exits, one of
which must be a Type II or larger exit, in each side of the fuselage.
(5) For a passenger seating
configuration of 41 to 110 seats, there must be at least two exits, one of
which must be a Type I or larger exit, in each side of the fuselage.
(6) For a passenger seating
configuration of more than 110 seats, the emergency exits in each side of
the fuselage must include at least two Type I or larger exits.
(7) The combined maximum number of
passenger seats permitted for all Type III exits is 70, and the combined
maximum number of passenger seats permitted for two Type III exits in each
side of the fuselage that are separated by fewer than three passenger seat
rows is 65.
(8) If a Type A, Type B, or Type C exit
is installed, there must be at least two Type C or larger exits in each
side of the fuselage.
(9) If a passenger ventral or tailcone
exit is installed and that exit provides at least the same rate of egress
as a Type III exit with the airplane in the most adverse exit opening
condition that would result from the collapse of one or more legs of the
landing gear, an increase in the passenger seating configuration is
permitted as follows:
(i) For a ventral exit, 12 additional
passenger seats.
(ii) For a tailcone exit incorporating a
floor level opening of not less than 20 inches wide by 60 inches high,
with corner radii not greater than seven inches, in the pressure shell and
incorporating an approved assist means in accordance with §25.810(a), 25
additional passenger seats.
(iii) For a tailcone exit incorporating
an opening in the pressure shell which is at least equivalent to a Type
III emergency exit with respect to dimensions, step-up and step-down
distance, and with the top of the opening not less than 56 inches from the
passenger compartment floor, 15 additional passenger seats.
(h) Excess exits. Each emergency
exit in the passenger compartment in excess of the minimum number of
required emergency exits must meet the applicable requirements of §25.809
through §25.812, and must be readily accessible.
(i) Ditching emergency exits for
passengers. Whether or not ditching certification is requested,
ditching emergency exits must be provided in accordance with the following
requirements, unless the emergency exits required by paragraph (g) of this
section already meet them:
(1) For airplanes that have a passenger
seating configuration of nine or fewer seats, excluding pilot seats, one
exit above the waterline in each side of the airplane, meeting at least
the dimensions of a Type IV exit.
(2) For airplanes that have a passenger
seating configuration of 10 of more seats, excluding pilot seats, one exit
above the waterline in a side of the airplane, meeting at least the
dimensions of a Type III exit for each unit (or part of a unit) of 35
passenger seats, but no less than two such exits in the passenger cabin,
with one on each side of the airplane. The passenger seat/ exit ratio may
be increased through the use of larger exits, or other means, provided it
is shown that the evacuation capability during ditching has been improved
accordingly.
(3) If it is impractical to locate side
exits above the waterline, the side exits must be replaced by an equal
number of readily accessible overhead hatches of not less than the
dimensions of a Type III exit, except that for airplanes with a passenger
configuration of 35 or fewer seats, excluding pilot seats, the two
required Type III side exits need be replaced by only one overhead hatch.
(j) Flightcrew emergency exits.
For airplanes in which the proximity of passenger emergency exits to the
flightcrew area does not offer a convenient and readily accessible means
of evacuation of the flightcrew, and for all airplanes having a passenger
seating capacity greater than 20, flightcrew exits shall be located in the
flightcrew area. Such exits shall be of sufficient size and so located as
to permit rapid evacuation by the crew. One exit shall be provided on each
side of the airplane; or, alternatively, a top hatch shall be provided.
Each exit must encompass an unobstructed rectangular opening of at least
19 by 20 inches unless satisfactory exit utility can be demonstrated by a
typical crewmember.
[Amdt. 25-72, 55 FR 29781, July 20, 1990, as
amended by Amdt. 25-88, 61 FR 57956, Nov. 8, 1996; 62 FR 1817, Jan. 13,
1997; Amdt. 25-94, 63 FR 8848, Feb. 23, 1998; 63 FR 12862, Mar. 16, 1998]