b. Guidance.
(1) Advisory Circular 20-38A, “Measurement of Cabin Interior Emergency Illumination in Transport Airplanes,” dated 2/8/66, provides guidance material for the minimum measurements required by this paragraph. (Amendment 25-15)
(2) Paragraph (b)(1). 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)
(3) Paragraph (c). (Amendment 25-15)
(i) Required illumination levels for main aisles also apply to cross aisles that are required to meet § 25.807(a)(7)(v), Amendment 25-67 (§ 25.813(a), Amendment 25-72). Cross aisles that are in excess of those required need not be provided with emergency lighting.
(Amendment 25-15)
(ii) When measuring the illumination levels required by this paragraph, the interior color scheme (sidewalls, seat covers, floor covering, etc.) should be evaluated for its reflective contribution to the illumination level. This may be accomplished by negating the contribution of reflected light and demonstrating the minimum illumination levels independent of reflected light. If the reflective contribution is known, subsequent interiors of different reflectivity may be analyzed to show the effect on illumination levels is not detrimental. (Amendment 25-15)
(4) Paragraph (e). The floor proximity emergency escape path marking system is included as part of the emergency lighting system when determining compliance with the separation requirements of paragraph (l). (Amendment 25-58)
(5) Paragraph (e). Refer to AC 25.812-1A, “Floor Proximity Emergency Escape Path Marking,” dated 5/22/89 and AC 25.812-2, “Floor Proximity Emergency Escape Path Marking Systems Incorporating Photoluminescent Elements,” dated 7/24/97. (Amendment 25-58)
(6) Paragraph (f). Normal electrical power is interpreted to mean the engine driven generators. (Amendment 25-15)
(7) Paragraph (f)(1). The emergency lighting switch in the cabin cannot turn off the system once it is activated. This switch should activate the system, however, even if the switch in the cockpit is “off.” (Amendment 25-46)
(8) Paragraph (g)(1). The illumination level at an overwing escape route where the evacuee would take his first step outside the airplane may be measured with the exit
394 unobstructed. It is not necessary to consider an evacuee standing in the exit opening when measuring illumination levels. Transient blocking of the wing contact area illumination as an evacuee passes through the exit is acceptable provided no adverse effects are observed during the demonstration required by § 25.803(c). (Amendment 25-15)
(9) Paragraphs (h)(1) and (h)(2)(ii). With one or more landing gear legs collapsed, the resultant position of the assist means should be evaluated so that it does not obscure the illumination at the point of evacuees first ground contact. Under such conditions the likely point of contact may change, depending upon the specific collapsed landing gear case. The emergency lighting system must provide for these changes. (Amendment 25-32)
(10) Paragraph (h). Illumination of the overwing escape path or an assist means at any exit should be automatically activated as part of the airplane emergency lighting system, or by the action of opening the exit. The required exterior lighting at an exit may not be dependent on the operation of another exit. (Amendment 25-15)
(11) Paragraph (i). When the airplane is exposed to the critical minimum and maximum ambient temperatures such that the airplane is in equilibrium, the airplane environmental systems may be used to condition the airplane prior to boarding passengers. The temperature of the power supplies may be determined following a reasonable conditioning period to obtain operation voltage when the airplane is at the critical outside ambient temperature. The illumination may then be measured assuming ten-minute operation from these initial conditions. If an applicant is unable to furnish what initial conditions are, it is acceptable to use Radio Technical Commission for Aeronautics Document No. RTCA/DO-160B, titled "Environmental Conditions and Test Procedures for Airborne Equipment," for low and high temperature tests. An additional alternate set of satisfactory environmental conditions may be found in AC 25.812-1A, “Floor Proximity Emergency Escape Path Marking,” dated 5/22/89.
(Amendment 25-15)
(12) Paragraph (l). A transverse separation is considered to occur at any fuselage station, irrespective of the perceived likelihood that a separation could occur there. “Separation” in this context refers to all degrees of fuselage separation such that the emergency lighting system is interrupted, and not just separations that result in two distinct segments of fuselage.
(Amendment 25-15)
(13) Paragraph (l)(1). This paragraph is based on the number of electrically illuminated lights required to meet the illumination levels of this section. Exit signs which are not used to contribute to cabin illumination and subsystems provided in accordance with paragraph (h)(2) do not apply to this paragraph. However, an applicant should not be penalized for providing lights in excess of the number required. (Amendment 25-15)
(14) Paragraph (l)(2). “Directly damaged,” as used in this paragraph, refers to a sign that is located at the same station as a transverse fuselage separation, or between the frames bounding the separation location, and therefore rendered inoperative. The sign is also considered inoperative if the separation occurs at the same station as any part of the power supply. The sign should remain operative unless it is “directly damaged” or the separation renders the exit
395 unopenable. Therefore, the power supply should be located at a station between the frames that make up the exit, or in the case of a sign beside the exit, the power supply may also be at the same fuselage station as any part of the sign. (Amendment 25-15) 398 - 410. [RESERVED]
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397 SECTION 25.813 EMERGENCY EXIT ACCESS
411. REGULATION IN EFFECT AT ADOPTION OF PART 25.
a. Regulation.
(a) Except as provided in § 25.803(c) with regard to passageways between individual compartments, each passageway between individual passenger areas, and passageways leading to Type I and Type II emergency exits, must be unobstructed and at least 20-inches wide.
(b) For each emergency exit covered by § 25.809(f), there must be enough space adjacent to that exit to allow a crewmember to assist in the evacuation of passengers without reducing the unobstructed width of the passageway below that required for that exit.
(c) There must be access from the main aisle to each Type III and Type IV exit. The access may not be obstructed by seats, berths, or other protrusions, to an extent that would reduce the effectiveness of the exit. However, there may be minor obstructions if there are compensating factors to maintain the effectiveness of the exit.
(d) If it is necessary to pass through a doorway to reach any required emergency exit from any seat in the passenger cabin, the door must have a means to latch it in the open position.
b. Guidance.
(1) Paragraph (a). Attendant seating facilities should not normally result in any reduction in required aisle widths, passageways between compartments, or the minimum 20-inch passageway leading to Type I, and Type II exits. Attendants seating facilities provided with any acceptable means of clearing the passageway immediately is not considered as being an obstruction to these passageways. An acceptable means of demonstrating compliance would be a spring loaded attendant seat which provides automatic retraction when the seat is vacated.
(Amendment 25-0)
(2) Paragraph (a). In determining the 20-inch passageway requirements leading to Type I and Type II exits: (Amendment 25-0)
(i) The presence of passenger feet need not be considered. (Amendment 25-0)
(ii) Curtain tie-backs with appropriate placards may be required to maintain an unobstructed passageway. (Amendment 25-0)
(iii) Seat backs of seats facing the passageway with breakover feature should remain clear of the required passageway when placed in breakover position. (Amendment 25-0)
(iv) Recline into the required passageway is permitted if the seatback does not preclude opening the exit and if the passageway is located between rows of seats. (Amendment 25-0)
(v) No seat cushion compression and no breakover from the upright position of a seat facing away from the passageway should be allowed to achieve the required passageway.
(Amendment 25-0)
(vi) The passageway may be offset from the projected exit opening if the effectiveness of the exit is not reduced. (Amendment 25-0)
(vii) Galley, lavatory or closet doors, drawers, shelves, etc., that obstruct the required passageway, should be placarded to be stowed and/or latched for taxi, takeoff, and landing or be spring-loaded closed. (Amendment 25-0)
(viii) Galley and stowage unit doors, drawers, etc., that interfere with the opening of an emergency exit should be spring-loaded closed. The evaluation for interference is made with the stowage unit door in any position and opening the emergency exit from either the inside or the outside. If it is not possible to spring-load the door, drawer, etc., there should be a special emphasis placard to close and latch for taxi, takeoff, and landing. (Refer to paragraph 1041b(6).)
(Amendment 25-0)
(3) Paragraph (a). For excess Type I and Type II exits (Refer to AC 20-60, “Accessibility to Excess Emergency Exits,” dated 7/18/68), access shall be provided from the aisle by one of the following: (Amendment 25-0)
(i) By means of an unobstructed 20-inch passageway. (Amendment 25-0)
(ii) By means of an unobstructed passageway 20-inches wide at the outboard seat location and 15-inches wide at the inboard seat location. (Amendment 25-0)
(iii) By removing the outboard seat nearest the centerline of the exit and establishing two unobstructed 8-inch passageways. (Amendment 25-0)
(4) Paragraph (a) and (c). The FAA issued policy memorandum 02-115-20, dated November 21, 2002, titled “Policy Statement on Corded Electrical Devices Used in the Passenger Cabin.” The new policy may be used for demonstrating compliance with § 25.813(a) and (c), Amendment 25-0, and is provided below. (Amendment 25-0)
(i) The policy contained herein is intended to provide the applicant with various certification options, which will require little or no on-aircraft evaluation of cord devices, provided that these devices meet certain basic criteria. This policy is applicable to typical commercial air carrier passenger configurations, i.e., 14 CFR part 121 and part 135 operations.
(ii) The cordreels used for corded device installations must be of sufficient quality and design that they reliably retract. The reliability of the cord reels should be established by the
399 manufacturer, e.g., lifecycle testing, or analysis supported by testing. The data or analysis with supporting data should be made available upon request. The constant tension cordreel should be tested to show that it can be extended and retracted for its service life without a degradation in its performance. In addition to the extension testing, the ratcheting cordreel should also be tested to show that the ratcheting mechanism will perform reliably for its projected service life. The same basic philosophy applies to coiled cords as well.
(iii) The following guidelines apply: Refer to figure 411-1, Corded Devices.
(A) If the device is not intended for use during taxi, takeoff, and landing (TT&L), and is restricted accordingly, e.g., by appropriate placarding, then no cord length and no cord loop evaluations are required.
(B) If the device is intended for use during TT&L, and it has a constant tension cord, then no cord length and no cord loop evaluations are required.
(C) If the device is intended for use during TT&L, and it does not have a constant tension cord and it is not installed on an aisle, cross aisle or exit row, then no cord loop and length evaluation is required.
(D) If, however, the device is intended for use during TT&L, and does not have a constant tension cord, and is installed on an aisle armrest, a cross aisle armrest or aisle side seatback or in an exit row, then cord loop and length evaluations must be made to ensure that the corded device will not interfere with passenger emergency egress. These devices may include breakaway capabilities in the cord connections, or frangibility in the cord itself, that can act as compensating features during the evaluation.
(1) Cord Loop Evaluation. Loops created by mis-stowage of a corded device should be evaluated to determine if they pose an egress hazard. It should be shown that, with the handset stowed in its cradle, an unstowed cord does not become a hazard which can entrap or snag limbs or clothing during an emergency evacuation. Evaluations should be made with a 5th percentile female and a 95th percentile male, as follows:
(i) Any cord loop that can be formed by mis-stowing the handset using reasonable force should be evaluated to determine that the location of the loop does not pose an egress hazard. Loops formed below the level of the armrest and contained within the bounds of the seat bottom cushion should be acceptable.
(ii) Any loop that can be formed by mis-stowing the handset using reasonable force, which extends into an aisle, must be unable to encircle an appendage (limb or clothing) without significant manipulation or contrivance.
(iii) Any loop that can be formed by mis-stowing the handset using reasonable force, in a location where a limb may be encircled, must be easily escapable by
400 normal passenger movement, or the handset must be able to be pulled free with normal motion and strength.
(2) Cord Length. Applicants must demonstrate that their handset installation cord length will not permit the handset to lie flat on the floor when the handset is not properly stowed. Also, on seat back mounted handsets, the cord length must be restricted so that the device cannot be used by anyone seated across the aisle or by anyone seated in a row behind the row directly facing the unit. Note: This does not preclude the passing of the handset forward to the row on which the handset is mounted.
(E) Associated Placards: If placards are installed which state when a handset may (or may not) be used, at least one placard should be in plain sight of the occupant of any position from which the handset is likely to be used, whether or not the handset is stowed.
These, and any other safety related placards, should be of sufficient size and color contrast (lettering to background) so as to be easily visible to all expected users under normal cabin lighting conditions. Visibility during low light level conditions, which are often encountered during night flights, is desirable, but not mandatory.
(iv) Finally, this guidance material covers compliance for cabin safety issues only.
All other applicable certification regulations still apply.
FIGURE 411-1 CORDED DEVICES Yes Corded Device No intended for use during TT&L Constant Tension No Located in air Exit Row or Aisle* or No Cord Cross Aisle Yes Yes Cord Creates Redesign Loop Impeding Evac Yes No Cord Length Redesign Creates a Barrier to Evac Yes Redesign No Head Strike Yes Located in the Found Acceptable Head Strike Zone Yes No Corded Device meets Cabin → Safety Requirements for * Aisle location - mounted on either the seatback or the armrest Installation ** ** This process only covers compliance for Cabin Safety regulations, all other applicable regulations still apply.
(5) Paragraph (b). When it is required that there be an area adjacent to an exit to permit a crewmember to assist passengers in the use of escape devices, a 12 x 20-inch assist space with the long dimension parallel to and clear of the required 20-inch exit approach passageway or equivalent facility should be provided. The area should be adequate to permit an attendant to stand erect and to perform needed assist services in the evacuation of passengers. Minor deviations from the 12 X 20-inch assist space are permitted if an evaluation is made that the effectiveness of the exit is not reduced. A demonstration may be necessary to show that passengers can be effectively evacuated. (Amendment 25-0)
(6) Paragraph (b). Seat breakover should not be used to clear the assist space. Recline into the assist space and cushion compression are permitted, if the seat is easily pushed forward, and the cushion readily compressible. (Amendment 25-0)
(7) Paragraph (b). If the assist space is under the overhead bins such that the attendant cannot stand erect, additional space, such as removal of the outboard seat, is required. The effectiveness of the assist space must be demonstrated. (Amendment 25-0)
(8) Paragraph (b). The assist space need not be directly adjacent to the exit. In some cases the assist space could be inboard a short distance from the exit but outboard of the main aisle. (Amendment 25-0)
(9) Paragraph (b). Assist handles are often provided at floor level emergency exits to provide stability for the flight attendant during an emergency evacuation. There is no specific requirement to provide an assist handle however, where an assist handle has been utilized for an evacuation demonstration used to show compliance with the regulations, production airplanes should also have an assist handle. The assist handle should be located at the assist space, even if the location of the assist space is not the same as the location on the airplane used for the evacuation demonstration. (Amendment 25-0)
(10) Paragraph (c). Projection of the seat backs into the minimum required exit opening should be permitted only if the seat back can be pushed forward or aft to clear the opening with the seat occupied. The force required to push the seat back away from the opening should be as low as practicable and should not exceed a maximum of 35 lbs with the seat unoccupied. The action should not require operation of any mechanical release. (Refer to paragraph 81b(11) for minimum breakover force.) A clear opening should permit the required minimum exit shape to be projected inward past the seat bottom and back cushion. Minor protrusion of the seat upholstery is acceptable if it does not interfere with exit removal and if it could be compressed without special effort by the person(s) using the exit. (Amendment 25-0)
(11) Paragraph (c). Armrests, curtains, or other protuberances which are removed simultaneously with opening of the exit are not considered to restrict the required minimum opening. (Amendment 25-0)
(12) Paragraph (c). Berth installations, whether or not made up, should not decrease the accessibility and utility of emergency exits. (Amendment 25-0)
(13) Paragraph (c). Seat back recline or breakover should not render the exit unopenable from either inside or outside. (Amendment 25-0)
(14) Paragraph (c). An armrest should not protrude into the projected opening of the required exit, even if it could be rotated out of the projected exit opening. (Amendment 25-0)
(15) Paragraph (c). A minor protrusion, not to exceed two-inches, of the outboard seat cushion into the required exit opening is permitted, if the cushion is easily compressed. A force of 170 lbs distributed over 40 square-inches has been found acceptable to determine if the cushion is easily compressed. (Amendment 25-0)
412. AMENDMENT 25-1, Effective June 7, 1965.
a. Regulation.
[(a) Each passageway between individual passenger areas, or leading to a Type I or Type II emergency exit, must be unobstructed and at least 20-inches wide.
(b) There must be enough space next to each Type I or Type II emergency exit to allow a crewmember to assist in the evacuation of passengers without reducing the unobstructed width of the passageway to the exit below that required by paragraph
(a) of this section.
(c) There must be access from the main aisle to each Type III or Type IV exit. The access may not be obstructed by seats, berths, or other protrusions to an extent that would reduce the effectiveness of the exit. However, there may be minor obstructions if there are compensatory factors to maintain the effectiveness of the exit.
(d) If it is necessary to pass through a passageway between passenger compartments to reach any required emergency exit from any seat in the passenger cabin, the passageway must be unobstructed. However, curtains may be used if they allow free entry through the passageway.
(e) No door may be installed in any partition between passenger compartments.
(f) If it is necessary to pass through a doorway separating the passenger cabin from other areas to reach any required emergency exit from any passenger seat, the door must have a means to latch it in open position. The latching means must be able to withstand the loads imposed upon it when the door is subjected to the ultimate inertia forces, relative to the surrounding structure, listed in § 25.561(b).]
b. Guidance.
(1) Paragraph (a). Attendant seating facilities should not normally result in any reduction in required aisle widths, passageways between compartments, or the minimum 20-inch passageway leading to Type I, and Type II exits. Attendants seating facilities provided with any acceptable means of clearing the passageway immediately is not considered as being an obstruction to these passageways. An acceptable means of demonstrating compliance would be a spring loaded attendant seat which provides automatic retraction when the seat is vacated.
(Amendment 25-0)
(2) Paragraph (a). In determining the 20-inch passageway requirements leading to Type I and Type II exits: (Amendment 25-0)
(i) The presence of passenger feet need not be considered. (Amendment 25-0)
(ii) Curtain tie-backs with appropriate placards may be required to maintain an unobstructed passageway. (Amendment 25-0)
(iii) Seat backs of seats facing the passageway with breakover feature should remain clear of the required passageway when placed in breakover position. (Amendment 25-0)
(iv) Recline into the required passageway is permitted if the seatback does not preclude opening the exit and if the passageway is located between rows of seats. (Amendment 25-0)
(v) No seat cushion compression and no breakover from the upright position of a seat facing away from the passageway should be allowed to achieve the required passageway.
(Amendment 25-0)
(vi) The passageway may be offset from the projected exit opening if the effectiveness of the exit is not reduced. (Amendment 25-0)
(vii) Galley, lavatory or closet doors, drawers, shelves, etc., that obstruct the required passageway, should be placarded to be stowed and/or latched for taxi, takeoff, and landing or be spring-loaded closed. (Amendment 25-0)
(viii) Galley and stowage unit doors, drawers, etc., that interfere with the opening of an emergency exit should be spring-loaded closed. The evaluation for interference is made with the stowage unit door in any position and opening the emergency exit from either the inside or the outside. If it is not possible to spring-load the door, drawer, etc., there should be a special emphasis placard to close and latch for taxi, takeoff, and landing. (Refer to paragraph 1041b(6).)
(Amendment 25-0)
(3) Paragraph (a). For excess Type I and Type II exits (Refer to AC 20-60, “Accessibility to Excess Emergency Exits,” dated 7/18/68), access shall be provided from the aisle by one of the following: (Amendment 25-0)