CS-25 S25 Airworthiness requirements for non-commercially operated aeroplanes and low-occupancy aeroplanes

(See AMC to Appendix S) S25.1 General (a) Applicability: unless otherwise specified within, the requirements of this Appendix are applicable to the passenger or crew compartments (interiors) of: (1) non-commercially operated aeroplanes with a passenger seating configuration of: (i) up to and including 19 passengers; or (ii) up to and including one half of the maximum passenger seating capacity of the type-certified aeroplane as indicated in the aeroplane type certificate data sheet (TCDS), provided that: (A) the total number of passengers approved for occupancy during taxiing, take-off or landing does not exceed 150 per deck; and (B) the total number of passengers approved for occupancy during taxiing, take-off or landing on a deck does also not exceed one half of the maximum passenger seating capacity for that deck as indicated in the aeroplane TCDS. (2) low-occupancy aeroplanes irrespective of the type of operations (commercial or non-commercial). A low-occupancy aeroplane is defined as an aeroplane which has a passenger seating configuration of: (i) up to and including 19; or (ii) up to and including one third of the maximum passenger seating capacity of the type-certified aeroplane as indicated in the aeroplane TCDS, provided that: (A) the total number of passenger seats approved for occupancy during taxiing, take-off, or landing does not exceed 100 per deck; and (B) the total number of passenger seats approved for occupancy during taxiing, take-off, or landing in any individual zone between pairs of emergency exits (or any dead end zone) does also not exceed one-third of the sum of the passenger seat allowances for the emergency exit pairs bounding that zone, using the passenger seat allowance for each emergency exit pair as defined by the applicable certification basis of the aeroplane. For the purpose of determining compliance with this zonal limitation, in the case of an aeroplane which has deactivated emergency exits, it shall be assumed that all emergency exits are functional. (b) Aeroplane Flight Manual (AFM) Limitation: if compliance with any part of this Appendix limits the aeroplane to non-commercial operations, this limitation must be included in the ‘Limitations’ Section of the AFM. S25.10 General Cabin Arrangement (a) Interior Doors on Non-Commercially Operated Aeroplanes (See AMC to Appendix S, S25.10(a)): For a non-commercially operated aeroplane, installation of doors that results in non-compliance with CS 25.813(e) is acceptable provided that it is ensured by design and procedure that: (1) each door is open before entering any of the taxiing, take-off, and landing phases; (2) each door remains open during taxiing, take-off, and landing, and especially during and after a crash landing; and (3) in the case of any probable failure or jamming of a door in a position other than fully open, any occupant is able, from any compartment separated by that door, to restore in an easy and simple manner a sufficient opening to access the compartment on the other side of the door. (b) Interior Doors on Commercially Operated Aeroplanes (See AMC to Appendix S, S25.10(b)): For a low-occupancy aeroplane having a passenger seating configuration of 19 or less, installation of doors that results in non-compliance with CS 25.813(e) is acceptable provided that the conditions of S25.10(a)(1), S25.10(a)(2) and S25.10(a)(3) are complied with and the following additional requirements are met for each passenger compartment created by a door or doors: (1) Within the compartment, there is at least one emergency exit above the waterline on each side of the fuselage that meets at least the requirements of a type IV emergency exit for a compartment that has a passenger seating configuration of nine seats or less, or of a type III emergency exit otherwise; or (2) Within the compartment, there is at least one emergency exit above the waterline on one side of the fuselage that meets at least the requirements of a type IV emergency exit for a compartment that has a passenger seating configuration of nine seats or less, or of a type III emergency exit otherwise, and: (i) an occupant of the compartment would not need to go through more than one door to access an emergency exit above the waterline on the other side of the fuselage; and (ii) the demonstration of compliance with the provisions S25.10(a)(1) and (2) does not rely on any passenger action, nor involve any flight crew member leaving their position in the cockpit. (c) Isolated Compartments: each cabin compartment isolated from the rest of the cabin such that a fire starting in the compartment would not be directly and quickly detected by the occupants of another compartment, in an aeroplane that has a passenger seating configuration of 20 or more, or which has a cabin length of more than 18.29 m (60 ft), must be equipped with a smoke/fire detection system or equivalent which allows detection within one minute after the start of a fire and provides a visual indication in the cockpit, or a visual indication or audible warning in the passenger cabin that would be readily detected by a cabin crew member. However, if it can be demonstrated that a fire would be directly and quickly detected because the compartment is likely to be occupied for the majority of the flight time, such a system is not required (See AMC to Appendix S, S25.10(c)). (d) Deactivation of existing Emergency Exits: Deactivation of one of more emergency exits that results in non-compliance with CS 25.807(e) is acceptable, provided that compliance with the following requirements is shown (See AMC to Appendix S, S25.10(d) and (e)): (1) the number of passenger seats allowed in a zone between two remaining adjacent pairs of emergency exits is limited to one half of the combined rated capacity of the two pairs of emergency exits (rounded to the nearest whole number); (2) the number of passenger seats allowed in a zone with only one remaining pair of emergency exits at one end (a so called dead end zone) is limited to one half of the rated capacity of the pair of emergency exits (rounded to the nearest whole number); and (3) the distance from each passenger seat to at least one remaining emergency exit, on each side of the fuselage, remains compatible with easy egress from the aeroplane. (e) Distance between Emergency Exits: deactivation of emergency exits which results in non-compliance with CS 25.807(f)(4) is acceptable on non-commercially operated aeroplanes only, provided that: (1) compliance with S25.10(d) is shown; and (2) a distance of more than 18.29 m (60 ft) between adjacent remaining emergency exits is created only once per side of the fuselage on each deck (See AMC to Appendix S, S25.10(d) and (e)). S25.20 Emergency Evacuation (a) Flammability Requirements (1) Mattresses of permanent bed installations that are located in compartments isolated from the main passenger cabin by doors or equivalent means that would normally be closed during taxiing, take-off, and landing do not need to meet the ‘Oil Burner Test’ requirement of Appendix F, Part II as required by CS 25.853(c) (See AMC to Appendix S, S25.20(a)(1)). (2) On non-commercially operated aeroplanes only, compliance with CS 25.853(d) does not need to be demonstrated if it can be shown by test or a combination of test and analysis under the conditions specified in Appendix J that the maximum time for evacuation of all occupants does not exceed 45 sec. (b) Access to Type III and IV Emergency Exits: low-occupancy aeroplanes that have a passenger seating configuration of 19 or less and non-commercially operated aeroplanes may have an item deployable into the region defined by CS 25.813 (c)(4)(i) or CS 25.813 (c)(1), (2) or (3) which creates an obstruction and, therefore, leads to non-compliance with one or more of the aforementioned requirements, provided that: (1) it is ensured that the item will be safely stowed before entering any of the taxiing, take-off, approach, and landing phases, by means of a position monitoring and alerting system that, in a timely manner, notifies the flight crew and compels the passengers to stow the item if it is in a position that creates an obstruction (See AMC to Appendix S, S25.20(b)(1)). It must be substantiated that, with the item in its most adverse position(s), the remaining exit is at least as effective as a Type IV emergency exit, unless it can be shown that following any single failure, an exit at least as effective as a Type IV emergency exit can be obtained by simple and obvious means; or (2) the approved passenger configuration is such that this number of passengers can be evacuated through the exit in question, with the obstruction in its most adverse position and under the conditions of Appendix J, at least as quickly as the maximum number of passengers allowed by CS 25.807(g) without the obstruction. It must be substantiated that, with the obstruction in place, the remaining exit is at least as effective as a Type IV emergency exit; or (3) for aeroplanes required to have at least one cabin crew member on board, the item is intended for use only by a cabin crew member that has direct view of the deployable item and can confirm that it is correctly stowed and secured, while they are seated during taxiing, take-off, and landing. S25.30 Circulation Inside Cabin During Flight (a) Width of Aisle: for low-occupancy aeroplanes that have a passenger seating configuration of 19 or less, and for non-commercially operated aeroplanes, the design must be such that the dimensional requirements of CS 25.815 can be achieved during all flight phases, except that the width of aisle may be reduced to 0 m during in-flight operations provided that compliance with the following additional requirements is shown (See AMC to Appendix S, S25.30(a)): (1) all areas of the cabin must be easily accessible by passengers or crew in the event of an emergency situation (e.g. in-flight fire, depressurisation); (2) placard instructions for restoring the aisle to the taxiing, take-off, and landing configuration must be provided at the locations where the width of the cabin aisle is reduced; and (3) procedures must be established and documented in the AFM for restoring the aisle width for taxiing, take-off, and landing. (b) Firm Handholds: in lieu of the requirements of CS 25.785(j), if the seat backs do not provide a firm handhold, there must be an acceptable means to enable persons to steady themselves while using the aisles in moderately rough air (See AMC to Appendix S, S25.30(b)). S25.40 Markings and Placards (a) ‘No Smoking’ Placards and Lavatory Ashtrays: if smoking is to be prohibited, in lieu of the requirements of CS 25.791(a) and CS 25.791(d), a reduced number of ‘No smoking’ placards may be provided and lavatory ashtrays do not need to be provided in accordance with the following: (1) a ‘No smoking’ placard must be conspicuously located inside the passenger compartment in the immediate vicinity of each door that can be used as a passenger boarding door. Each placard must be clearly legible for passengers entering the aeroplane; (2) compliance with CS 25.853(g) is not required; and (3) the indication that smoking is prohibited must be the subject of a passenger briefing, and the requirement for this briefing must be part of the AFM. (b) Briefing Card Placard: for non-commercially operated aeroplanes, the instructions required by CS 25.1541 for properly setting the cabin in its configuration approved for taxiing, take-off, and landing may alternatively be provided by a reduced number of placards, each one referring to a briefing card. In that case (See AMC to Appendix S, S25.40(b)): (1) the detailed minimum instructions to be included in the briefing card must be part of the type design and referred to in the ‘Limitations’ section of the AFM; and (2) the briefing card must be easily accessible from each passenger seat. A dedicated stowage must be provided to stow the briefing card within easy reach of each seated passenger with their seat belts fastened. (c) Seats in Excess (See AMC to Appendix S, S25.40(c)) (1) If the total number of seats that are approved for occupancy during taxiing, take-off, and landing is greater than the approved passenger seating configuration, the difference between these two quantities is deemed to be seats in excess. If seats in excess exist, a placard indicating the approved passenger seating configuration must be installed adjacent to each door that can be used as a passenger boarding door. This placard must be clearly legible for passengers entering the aeroplane. Additionally, a note must be included in the ‘Limitations’ section of the AFM stating that there are excess seats installed, and indicating the maximum number of passengers that may be transported. (2) For each seating location available for in-flight use only (including in-flight-only seats, beds, berths, and divans), a placard indicating that the location is not to be occupied during taxiing, take-off, and landing must be installed such that the placard is legible to the seated occupant. S25.50 Cabin Attendant Direct View In lieu of the requirements of CS 25.785(h)(2), compliance with the following cabin attendant direct view requirements may be shown: (a) For non-commercially operated aeroplanes, at least half of the installed cabin crew member seats must face the passenger cabin. (b) For low-occupancy aeroplanes, cabin crew member seats must be, to the extent possible, without compromising proximity to a required floor level emergency exit, located to provide direct view of the cabin area for which the cabin crew member is responsible (See AMC to Appendix S, S25.50(b)). S25.60 Security Non-commercially operated aeroplanes do not need to comply with the security specifications of CS 25.795(b), (c) and (d). GENERAL ACCEPTABLE MEANS OF COMPLIANCE (AMC) GENERAL ACCEPTABLE MEANS OF COMPLIANCE (AMC)