CS 25.807 Emergency exits

• ED Decision 2020/024/R found in: CS-25 Amdt 27 - Large Aeroplanes (Jan 2023)

CS 25.807 Emergency exits ED Decision 2020/024/R (See AMC 25.807) (a) Type. For the purpose of this CS-25, 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 61 cm (24 inches) wide by 121.9 cm (48 inches) high, with corner radii not greater than 20.3 cm (8 inches). (2) Type II. This type is a rectangular opening of not less than 50.8 cm (20 inches) wide by 111.8 cm (44 inches) high, with corner radii not greater than 17.8 cm (7 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 aeroplane of more than 25.4 cm (10 inches) nor a step-down outside the aeroplane of more than 43.2 cm (17 inches). (3) Type III. This type is a rectangular opening of not less than 50.8 cm (20 inches) wide by 91.4 cm (36 inches) high, with corner radii not greater than 17.8 cm (7 inches), and with a step-up inside the aeroplane of not more than 50.8 cm (20 inches). If the exit is located over the wing, the step-down outside the aeroplane may not exceed 68.6 cm (27 inches). (4) Type IV. This type is a rectangular opening of not less than 48.3 cm (19 inches) wide by 66.0 cm (26 inches) high, with corner radii not greater than 16.0 cm (6.3 inches), located over the wing, with a step-up inside the aeroplane of not more than 73.7 cm (29 inches) and a step-down outside the aeroplane of not more than 91.4 cm (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 aeroplane in the normal ground attitude, with landing gear extended. (6) *Tail cone*. 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 tail cone 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 106.7 cm (42 inches) wide by 182.9 cm (72 inches) high, with corner radii not greater than 17.8 cm (7 inches). (8) *Type B*. This type is a floor-level exit with a rectangular opening of not less than 81.3 cm (32 inches) wide by 182.9 cm (72 inches) high, with corner radii not greater than 15.3 cm (6 inches). (9) *Type C*. This type is a floor-level exit with a rectangular opening of not less than 76.2 cm (30 inches) wide by 121.9 cm (48 inches) high, with corner radii not greater than 25.4 cm (10 inches). (b) *Step down distance*. Step down distance, as used in this paragraph, 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 paragraph, 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 subparagraph (g) of this paragraph 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. (See AMC 25.807(e)) (f) Location. (See AMC 25.807(f)) (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 aeroplane does not have a tail cone 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 aeroplane does not have a combination cargo and passenger configuration, at least one floor-level exit must be located on each side near each end of the cabin. (4) For an aeroplane that is required to have more than one passenger emergency exits for each side of the fuselage, no passenger emergency exit shall be more than 18.3 m (60 feet) from any adjacent passenger emergency exit on the same side of the same deck of the fuselage, as measured parallel to the aeroplane’s longitudinal axis between the nearest edges. (g) Type and number required. The maximum number of passenger seats permitted depends on the type and number of exits installed on each side of the fuselage. Except as further restricted in subparagraphs (g)(1) through (g)(9) of this paragraph, the maximum number of passenger seats permitted for each exit of a specific type installed on each side of the fuselage is as follows: <table border="1" cellpadding="0" cellspacing="0" width="94%"><tr><td valign="top" width="50%"><p>Type A</p></td><td valign="top" width="50%"><p>110</p></td></tr><tr><td valign="top" width="50%"><p>Type B</p></td><td valign="top" width="50%"><p>75</p></td></tr><tr><td valign="top" width="50%"><p>Type C</p></td><td valign="top" width="50%"><p>55</p></td></tr><tr><td valign="top" width="50%"><p>Type I</p></td><td valign="top" width="50%"><p>45</p></td></tr><tr><td valign="top" width="50%"><p>Type II</p></td><td valign="top" width="50%"><p>40</p></td></tr><tr><td valign="top" width="50%"><p>Type III</p></td><td valign="top" width="50%"><p>35</p></td></tr><tr><td valign="top" width="50%"><p>Type IV</p></td><td valign="top" width="50%"><p>9</p></td></tr></table> (1) For a passenger seating configuration of 1 to 9 seats, there must be at least one Type IV or larger over-wing exit on each side of the fuselage or, if over-wing exits are not provided, at least one exit on 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 on 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, on 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, on each side of the fuselage. (6) For a passenger seating configuration of more than 110 seats, the emergency exits on 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 on 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 on each side of the fuselage. (9) If a passenger ventral or tail cone exit is installed and that exit provides at least the same rate of egress as a Type III exit with the aeroplane 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 tail cone exit incorporating a floor-level opening of not less than 50.8 cm (20 inches) wide by 152.4 cm (60 inches) high, with corner radii not greater than 17.8 cm (7 inches), in the pressure shell and incorporating an approved assisting means in accordance with CS 25.810(a), 25 additional passenger seats. (iii) For a tail cone 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 142.2 cm (56 inches) from the passenger compartment floor, 15 additional passenger seats. (h) Other exits. The following exits must also meet the applicable emergency exit requirements of [CS 25.809](#_DxCrossRefBm1709821205) through [25.812](#_DxCrossRefBm1709821204), and must be readily accessible: (1) Each emergency exit in the passenger compartment in excess of the minimum number of required emergency exits. (2) Any other floor-level door or exit that is accessible from the passenger compartment and is as large or larger than a Type II exit, but less than 116.8 cm (46 inches) wide. (3) Any other ventral or tail cone passenger exit. (i) Ditching emergency exits for passengers. Whether or not ditching certification is requested, ditching emergency exits must be provided in accordance with the following conditions, unless the emergency exits required by subparagraph (g) of this paragraph already meet them: (1) For aeroplanes that have a passenger seating configuration of nine seats or less, excluding pilot seats, one exit above the waterline in each side of the aeroplane, meeting at least the dimensions of a Type IV exit. (2) For aeroplanes that have a passenger seating configuration of 10 seats or more, excluding pilot seats, one exit above the waterline in a side of the aeroplane, 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 aeroplane. 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 aeroplanes with a passenger configuration of 35 seats or less, excluding pilot seats, the two required Type III side exits need to be replaced by only one overhead hatch. (j) Flight crew emergency exits. For aeroplanes in which the proximity of passenger emergency exits to the flight crew area does not offer a convenient and readily accessible means of evacuation of the flight crew, and for all aeroplanes having a passenger seating capacity greater than 20, flight crew exits must be located in the flight crew area. Such exits must be of sufficient size and so located as to permit rapid evacuation by the crew. One exit must be provided on each side of the aeroplane; or, alternatively, a top hatch must be provided. Each exit must encompass an unobstructed rectangular opening of at least 48.3 cm by 50.8 cm (19 by 20 inches) unless satisfactory exit utility can be demonstrated by a typical crew member. [Amdt 25/4] [Amdt 25/5] [Amdt 25/6] [Amdt 25/12] [Amdt 25/18] [Amdt 25/19] [Amdt 25/26]