(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 or 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.]
b. Guidance.
Note: At this amendment level of the regulation, the maximum distance between exits of 60 feet was inadvertently dropped from the regulation. Previously it was contained in § 25.807 (c)(7) at Amendment 25-67. However, this requirement is addressed in § 25.2 where compliance is required regardless of certification basis. The regulation was reintroduced at Amendment 25-94.
Note: At this amendment level of the regulations, the flightcrew exit requirement was inadvertently dropped from the regulation. Previously it was contained in § 25.807(f) at Amendment 25-72. The regulation was reintroduced at Amendment 25-94.
(1) The equivalency to that required by the regulations of nonstandard exits or arrangements may be determined by use of the Latin-Square test procedure. Refer to Appendix 4 which was derived from Notice FS 8110.12, Test Procedure for Evaluating Non-Standard Exits for Transport Category Airplanes, dated May 21, 1964. (Amendment 25-0)
(2) An “exit pair” consists of two exits of the same type, one in each side of the fuselage. The exits need not be the same size, nor do they have to be directly opposite each
274 other. As long as the exits on both sides of the fuselage are uniformly distributed with respect to the passenger seating arrangement, a pair need not be the two exits that are physically closest to each other. Refer to figure 329-1. (Amendment 25-0) FIGURE 329-1 AIRPLANE CONFIGURATION
(3) Paragraph (a)(3). Type III exits were not restricted to overwing locations. Further, Type IV exits were restricted to airplanes that have a passenger seating capacity of nine or less, as reflected in the § 25.807(c)(l) table. (Amendment 25-32)
(4) Paragraph (a). Exits may be “derated” in accordance with the requirements of a smaller type; that is, exits may not only be oversized, the interior may be reconfigured to specifically derate an exit that has previously been qualified as a larger type. In order to preclude the appearance of the exit being unusable, the following additional considerations have been found acceptable: (Amendment 25-15)
(i) Type A to Type I: Only seats may encroach into the projected exit opening, no more than 12-inch cumulative. A 24-inch passageway should be provided, and seats may not breakover into this passageway or into the assist space. The operating handle should be visible from the aisle. (Amendment 25-15)
(ii) Type A to Type III: A 24-inch passageway should be provided, and seats may not breakover into this passageway. The operating handle should be visible from the aisle.
(Amendment 25-15)
(iii) Type I to Type III: A 13-inch passageway is required when the passageway is bordered by seats, or by a seat and a wall. A 20-inch passageway should be provided when the passageway is bordered by walls and should be within the projected opening of the exit. The required Type III opening should be unobstructed inboard for the width of one passenger seat place. The operating handle should be visible from the aisle. (Amendment 25-15)
(5) Paragraph (e). It should be noted that this requirement also affects supplemental type certificates for airplanes manufactured after October 16, 1987. Also refer to § 25.2(b) at this amendment. Refer to AC 25.807-1, “Uniform Distribution of Exits,” dated 8/13/90 for additional guidance on this subject. (Amendment 25-67)
(6) Paragraph (g). An airplane with a Type I sized exit located in the forward left-hand side of the fuselage, a pair of Type III exits in the middle, and a Type I sized exit located in the aft right-hand side of the fuselage should be limited to a maximum passenger seating capacity of 70, because of concerns with oversized dead-end zones if either the left- or right-side exits are unusable. (Amendment 25-0)
(7) Paragraph (g). An airplane with a pair of exits forward in the fuselage with the left one Type I sized and the right one Type III sized, and a pair of exits in the aft end of the fuselage with the left one Type III sized and the right one Type I sized may be approved for passenger seating capacities up to 79. If an emergency evacuation demonstration is required, then either the left-side or right-side exits should be selected so as not to unduly penalize this well-balanced arrangement or to make a radical departure from all previous demonstrations. Refer to figure 329-1. (Amendment 25-0)
(8) Paragraph (g). Flight attendants are considered part of the crew and are not included in the passenger seating capacity mentioned in § 25.807(g). (Amendment 25-0)
(9) Paragraphs (g) and (i). When establishing the maximum capacity to be listed on the type data sheet, consideration should be given to all relevant parameters. For example, if the exit-limited passenger capacity as defined in § 25.807(g) has not been substantiated by compliance with the evacuation demonstration requirements of § 25.803, the data sheet should reflect the evacuation limit and not the exit limit. Other limiting factors include, but are not limited to, structural capability, seating density (uniform distribution of exits), or ditching exits.
The maximum passenger capacity is also limited by the ditching requirements of § 25.807(i) whether certification for ditching is requested or not. In any case, the data sheet should not list a capacity for which the airplane is not capable. When the type data sheet limit is not the § 25.807(g) exit limit, an additional note, which briefly describes the reason for the limit, is appropriate. (Amendment 25-0)
(10) Paragraph (g) and (i). An airplane design is determined to be eligible for a certain passenger seating complement which is commensurate with meeting all of the relevant portions
276 of § 25.807. That is, in addition to meeting § 25.807(g), the eligibility complement is also governed by the ditching requirements of § 25.807(i), whether certification for ditching is requested or not. (Amendment 25-0)
(11) Paragraph (h). Seats that have dual approval for occupancy by either crew/observers and passengers will be included in the passenger seating configuration.
Regarding removal of excess exits, regardless of airplane certification basis, the following criteria applies: (Amendment 25-15)
(i) All interior and exterior exit signs, markings, and lighting pertaining to the deactivated exits must be removed. There must be no recognizable evidence of the deactivated exits, visible to occupants of the cabin. However, the exterior door outline and handle need not be obscured. (Amendment 25-15)
(ii) The modification which deactivates and obscures the exits must be approved through issuance of an amendment to the Type Certificate (TC) or Supplemental Type Certificate (STC) by the Manager, Aircraft Certification Office having jurisdiction over the project, and the airplane cabin, as modified, must remain in compliance with the certification basis of the model. (Amendment 25-15)
(iii) Also refer to AC 20-60, “Accessibility to Excess Emergency Exits,” dated 7/18/68. (Amendment 25-15)
(12) Paragraph (i). All transport category airplanes must have ditching exits whether or not ditching certification was requested. Actually, this guidance has been in effect since April 9, 1957, as reflected in Amendment 4b-5, "Emergency Evacuation Provisions," to CAR 4b.
(Amendment 25-0)
(13) Paragraph (i)(2). The wording “a passenger seating configuration, excluding pilot seats, of 10 seats or more,” which was promulgated with the intent of being consistent with Amendment 23-10 to part 23, does not directly address seats intended for use by observers or flight attendants. Seats approved for use by observers or flight attendants are not included in the passenger seating configuration. Seats that have dual approval for occupancy by either crew/observers or passengers will be included in the passenger seating configuration.
(Amendment 25-32)
(14) Paragraph (i)(3). The wording “a passenger seating configuration of 35 seats or less, excluding pilot seats,” which was promulgated with the intent of being consistent with Amendment 23-10 to part 23, does not directly address seats intended for use by observers or flight attendants. Seats approved for use by observers or flight attendants are not included in the passenger seating configuration. Seats that have dual approval for occupancy by either crew/observers or passengers will be included in the passenger seating configuration.
(Amendment 25-32)
330. AMENDMENT 25-94, Effective March 25, 1998.
a. Regulation.
(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 stepup 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 stepdown 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 of the 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 airplanes 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 A110
Type B75
Type C55
Type I45
Type II40
Type III35
Type IV9
(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 in 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 or 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.]
b. Guidance.
(1) The equivalency to that required by the regulations of nonstandard exits or arrangements may be determined by use of the Latin-Square test procedure. Refer to Appendix 4, which was derived from Notice FS 8110.12, “Test Procedure for Evaluating Non-Standard Exits for Transport Category Airplanes,” dated May 21, 1964. (Amendment 25-0)
(2) An “exit pair” consists of two exits of the same type, one in each side of the fuselage. The exits need not be the same size, nor do they have to be directly opposite each other. As long as the exits on both sides of the fuselage are uniformly distributed with respect to the passenger seating arrangement, a pair need not be the two exits that are physically closest to each other. Refer to figure 330-1. (Amendment 25-0) FIGURE 330-1 AIRPLANE CONFIGURATION
(3) Paragraph (a)(3). Type III exits were not restricted to overwing locations. Further, Type IV exits were restricted to airplanes that have a passenger seating capacity of nine or less, as reflected in the § 25.807(c)(l) table. (Amendment 25-32)
(4) Paragraph (a). Exits may be “derated” in accordance with the requirements of a smaller type; that is, exits may not only be oversized, the interior may be reconfigured to specifically derate an exit that has previously been qualified as a larger type. In order to preclude the appearance of the exit being unusable, the following additional considerations have been found acceptable: (Amendment 25-15)
(i) Type A to Type I: Only seats may encroach into the projected exit opening, no more than 12-inch cumulative. A 24-inch passageway should be provided, and seats may not breakover into this passageway or into the assist space. The operating handle should be visible from the aisle. (Amendment 25-15)
(ii) Type A to Type III: A 24-inch passageway should be provided, and seats may not breakover into this passageway. The operating handle should be visible from the aisle.
(Amendment 25-15)
(iii) Type I to Type III: A 13-inch passageway is required when the passageway is bordered by seats, or by a seat and a wall. A 20-inch passageway should be provided when the passageway is bordered by walls and should be within the projected opening of the exit. The required Type III opening should be unobstructed inboard for the width of one passenger seat place. The operating handle should be visible from the aisle. (Amendment 25-15)
(5) Paragraph (e). It should be noted that this requirement also affects supplemental type certificates for airplanes manufactured after October 16, 1987. Also refer to § 25.2(b) at this amendment. Refer to AC 25.807-1, “Uniform Distribution of Exits,” dated 8/13/90 for additional guidance on this subject. (Amendment 25-67)
(6) Paragraph (g). An airplane with a Type I sized exit located in the forward left-hand side of the fuselage, a pair of Type III exits in the middle, and a Type I sized exit located in the aft right-hand side of the fuselage should be limited to a maximum passenger seating capacity of 70, because of concerns with oversized dead-end zones if either the left- or right-side exits are unusable. (Amendment 25-0)
(7) Paragraph (g). An airplane with a pair of exits forward in the fuselage with the left one Type I sized and the right one Type III sized, and a pair of exits in the aft end of the fuselage with the left one Type III sized and the right one Type I sized may be approved for passenger seating capacities up to 79. If an emergency evacuation demonstration is required, then either the left-side or right-side exits should be selected so as not to unduly penalize this well-balanced arrangement or to make a radical departure from all previous demonstrations. Refer to figure 330-1. (Amendment 25-0)
(8) Paragraph (g). Flight attendants are considered part of the crew and are not included in the passenger seating capacity mentioned in § 25.807(g). (Amendment 25-0)
(9) Paragraphs (g) and (i). When establishing the maximum capacity to be listed on the type data sheet, consideration should be given to all relevant parameters. For example, if the exit-limited passenger capacity as defined in § 25.807(g) has not been substantiated by
283 compliance with the evacuation demonstration requirements of § 25.803, the data sheet should reflect the evacuation limit and not the exit limit. Other limiting factors include, but are not limited to, structural capability, seating density (uniform distribution of exits), or ditching exits.
The maximum passenger capacity is also limited by the ditching requirements of § 25.807(i) whether certification for ditching is requested or not. In any case, the data sheet should not list a capacity for which the airplane is not capable. When the type data sheet limit is not the § 25.807(g) exit limit, an additional note, which briefly describes the reason for the limit, is appropriate. (Amendment 25-0)
(10) Paragraph (g) and (i). An airplane design is determined to be eligible for a certain passenger seating complement which is commensurate with meeting all of the relevant portions of § 25.807. That is, in addition to meeting § 25.807(g), the eligibility complement is also governed by the ditching requirements of § 25.807(i), whether certification for ditching is requested or not. (Amendment 25-0)
(11) Paragraph (h). Seats that have dual approval for occupancy by either crew/observers and passengers will be included in the passenger seating configuration.
Regarding removal of excess exits, regardless of airplane certification basis, the following criteria applies: (Amendment 25-15)
(i) All interior and exterior exit signs, markings, and lighting pertaining to the deactivated exits must be removed. There must be no recognizable evidence of the deactivated exits, visible to occupants of the cabin. However, the exterior door outline and handle need not be obscured. (Amendment 25-15)
(ii) The modification which deactivates and obscures the exits must be approved through issuance of an amendment to the Type Certificate (TC) or Supplemental Type Certificate (STC) by the Manager, Aircraft Certification Office having jurisdiction over the project, and the airplane cabin, as modified, must remain in compliance with the certification basis of the model. (Amendment 25-15)
(iii) Also refer to AC 20-60, “Accessibility to Excess Emergency Exits,” dated 7/18/68. (Amendment 25-15)
(12) Paragraph (i). All transport category airplanes must have ditching exits whether or not ditching certification was requested. Actually, this guidance has been in effect since April 9, 1957, as reflected in Amendment 4b-5, "Emergency Evacuation Provisions," to CAR 4b.
(Amendment 25-0)
(13) Paragraph (i)(2). The wording “a passenger seating configuration, excluding pilot seats, of 10 seats or more,” which was promulgated with the intent of being consistent with Amendment 23-10 to part 23, does not directly address seats intended for use by observers or flight attendants. Seats approved for use by observers or flight attendants are not included in the passenger seating configuration. Seats that have dual approval for occupancy by either crew/observers or passengers will be included in the passenger seating configuration.
(Amendment 25-32)
(14) Paragraph (i)(3). The wording “a passenger configuration of 35 seats or less, excluding pilot seats,” which was promulgated with the intent of being consistent with Amendment 23-10 to part 23, does not directly address seats intended for use by observers or flight attendants. Seats approved for use by observers or flight attendants are not included in the passenger seating configuration. Seats that have dual approval for occupancy by either crew/observers or passengers will be included in the passenger seating configuration.
(Amendment 25-32) 331 - 350. [RESERVED]