143. AMENDMENT 25-72, Effective August 20, 1990.
a. Regulation.
Passenger information signs [and placards.] [(a) If smoking is to be prohibited, there must be at least one placard so stating that is legible to each person seated in the cabin. If smoking is to be allowed, and if the crew compartment is separated from the passenger compartment, there must be at least one sign notifying when smoking is prohibited. Signs which notify when smoking is prohibited must be operable by a member of the flightcrew and, when illuminated, must be legible under all probable conditions of cabin illumination to each person seated in the cabin.
(b) Signs that notify when seat belts should be fastened and that are installed to comply with the operating rules of this chapter must be operable by a member of the flightcrew and, when illuminated, must be legible under all probable conditions of cabin illumination to each person seated in the cabin.
(c) A placard must be located on or adjacent to the door of each receptacle used for the disposal of flammable waste materials to indicate that use of the receptacle for disposal of cigarettes, etc., is prohibited.
(d) Lavatories must have "No Smoking" or "No Smoking in Lavatory" placards conspicuously located on or adjacent to each side of the entry door.
(e) Symbols that clearly express the intent of the sign or placard may be used in lieu of letters.]
b. Guidance.
(1) Paragraph (a). In compartments where smoking is not allowed, it may be necessary to hardwire ON any lighted NO SMOKING signs to avoid confusing occupants. Note: this may affect an operator’s ability to comply with § 121.317(a). The FAA issued a policy memorandum ANM-03-115-05, dated July 7, 2003, titled “Policy Statement and Equivalent Safety Finding on No Smoking Placards and Signs” that addresses this subject. Refer to related guidance in § 25.853, which includes portions of the policy memorandum ANM-03-115-05. (Amendment 25-32)
(2) Paragraph (a) and (b). Each cabin occupant, including flight attendants but not pilot compartment occupants, should be able to Refer to a passenger information sign when seated in a seat occupiable for taxi, takeoff, and landing and for in-flight only seats. This should be accomplished for any seat position such as upright, reclined, swiveled, or tracked. The sign should be readable by a person with 20/20 vision. To read the sign, the head may be moved about to normal positions, but not rotated backwards (tilted). This evaluation should be conducted with 5th percentile female to 95th percentile male occupants. (Amendment 25-32)
(3) Paragraph (a) and (b). The words "FASTEN SEAT BELT" and "NO SMOKING" are acceptable. In remote areas, such as the lavatory or lower lobe galley, a sign with the words "RETURN TO SEAT" is acceptable. This sign should be operated by the same switch as the "FASTEN SEAT BELT" sign switch. (Amendment 25-32)
(4) Paragraph (e). Refer to Appendix 2 for acceptable symbols for these signs.
(Amendment 25-32) 144 -160. [RESERVED]
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165 SECTION 25.793 FLOOR SURFACES
161. Section 25.793 Did Not Exist Prior to Amendment 25-51.
162. AMENDMENT 25-51, Effective March 6, 1980.
a. Regulation.
The floor surface of all areas which are likely to become wet in service must have slip resistant properties.
b. Guidance. Military Specifications Mil-W-5044B and Mil-W-5044C, titled "Walkway Compound, Nonslip and Walkway Matting, Nonslip,” measure dynamic coefficient of friction and provide an acceptable standard for the slip resistant properties when a minimum dynamic coefficient of friction of 0.45 is measured. This is an acceptable measure for this section and for § 25.803. (Amendment 25-51) 163 - 210. [RESERVED]
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167 SECTION 25.795 SECURITY CONSIDERATIONS
211. Section 25.795 Did Not Exist Prior to Amendment 25-106.
212. AMENDMENT 25-106, Effective January 15, 2002.
a. Regulation.
[(a) Protection of flightdeck. If a flightdeck door is required by operating rules, the door installation must be designed to:
(1) Resist forcible intrusion by unauthorized persons and be capable of withstanding impacts of 300 Joules (221.3 foot-pounds) at the critical locations on the door, as well as a 250 pound (1113 Newtons) constant tensile load on the knob or handle, and
(2) Resist penetration by small arms fire and fragmentation devices to a level equivalent to level IIIa of the National Institute of Justice Standard (NIJ) 0101.04.
(b) [Reserved]]
b. Guidance.
(1) Paragraph (a)(1). Refer to AC 25.795-1A, “Flightdeck Intrusion Resistance.”
(Amendment 25-106)
(2) Paragraph (a)(1). Refer to Appendix 11, FAA Memorandum, 01-115-11, Original Release: dated November 6, 2001, Revision dated December 3, 2002, “Subject: Certification of Strengthened Flightdeck Doors on Transport Category Airplanes.” This memorandum outlines acceptable means of compliance with this paragraph and many other regulatory requirements that were affected by Amendment 25-106. (Amendment 25-106)
(3) Paragraph (a)(2). Refer to AC 25.795-2A, “Flightdeck Penetration Resistance.”
(Amendment 25-106)
(4) Paragraph (a)(2). Refer to Appendix 11, FAA Memorandum, 01-115-11, Original Release: dated November 6, 2001, Revision dated December 3, 2002, “Subject: Certification of Strengthened Flightdeck Doors on Transport Category Airplanes.” This memorandum outlines acceptable means of compliance with this paragraph and many other regulatory requirements that were affected by Amendment 25-106. (Amendment 25-106) 213 - 250. [RESERVED]
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169 SECTION 25.801 DITCHING
251. REGULATION IN EFFECT AT ADOPTION OF PART 25.
a. Regulation.
(a) If certification with ditching provisions is requested, the airplane must meet the requirements of this section and §§ 25.807(d), 25.1411, and 25.1415(a).
(b) Each practicable design measure, compatible with the general characteristics of the airplane, must be taken to minimize the probability that in an emergency landing on water, the behavior of the airplane would cause immediate injury to the occupants or would make it impossible for them to escape.
(c) The probable behavior of the airplane in a water landing must be investigated by model tests or by comparison with airplanes of similar configuration for which the ditching characteristics are known. Scoops, flaps, projections, and any other factor likely to affect the hydrodynamic characteristics of the airplane, must be considered.
(d) It must be shown that, under reasonably probable water conditions, the flotation time and trim of the airplane will allow the occupants to leave the airplane and enter the liferafts required by § 25.1415. If compliance with this provision is shown by buoyancy and trim computations, appropriate allowances must be made for probable structural damage and leakage. If the airplane has fuel tanks (with fuel jettisoning provisions) that can reasonably be expected to withstand a ditching without leakage, the jettisonable volume of fuel may be considered as buoyancy volume.
(e) Unless the effects of the collapse of external doors and windows are accounted for in the investigation of the probable behavior of the airplane in a water landing (as prescribed in paragraphs (c) and (d) of this section), the external doors and windows must be designed to withstand the probable maximum local pressures.
b. Guidance.
(l) Background Information. The expression "reasonably probable water conditions" is considered judgmental in application to compliance for ditching and has never been specifically defined as to sea state force or wave height. Early ditching investigations of dynamic models were conducted by the National Advisory Committee for Aeronautics (NACA) at Langley Field, Virginia, and NACA Report 1347, issued in 1958. A compilation of such test results, set the precedence for early and modern transport airplane designers in substantiating airplanes for ditching by analyses. Such early tests were based on calm-water landings with the supposition
170 that rough-water landings of particular models that were made parallel to waves or swells would exhibit the same general type of performance. Later rough-water ditching investigations of models were conducted and their results were compiled in documents such as Technical Note No. D-101, issued by the National Aeronautics and Space Administration (NASA) in 1959, and Also referred to by designers in respective ditching analyses. In addition to the reference to actual ditching incidents, it became an acceptable practice for designers to substantiate the ditching behavior of a proposed airplane design by comparisons in basic geometric configuration to airplane designs approved for ditching by the models tested at Langley Field. Parametric comparisons usually revealed some identicalness in geometric aspects and where obvious discrepancies in dimensional relationships were evident, predetermined correction factors were applied. (Amendment 25-0)
(2) Paragraph (b). Ditching load factors may be determined by model tests. Landing procedures or design measures must be established that limit the factors to those listed in § 25.561. Load factors above these are considered to expose occupants to injurious loads. In addition, standard parts such as seats, belts, and harnesses are designed to § 25.561 load factors.
Higher load factors in the downward direction may be acceptable provided the structural components are designed for the higher loads and also provided it can be shown that the occupants are protected from serious injury under these loads. (Amendment 25-0)
(3) Paragraph (d). A maximum permissible evacuation time for liferafts per the rule is also considered judgmental in scope for ditching compliance. During certification, it is usually shown by analysis that an airplane will float for a period of time exceeding the most conservative estimate of time required to completely evacuate the airplane. Evacuation times and rates for liferaft type devices are normally established by analysis and included in the particular airplane model ditching and flotation document presented for approval during type certification.
(Amendment 25-0)
(4) Paragraph (d). Prior to approval of any size or type of transport airplane for ditching approval under § 25.801, there must be evidence of an engineering evaluation of the provisions for installing the emergency equipment specified in § 25.1411. (Amendment 25-0)
(5) Paragraph (d). In approving an airplane for overwater flight certification, two ditching conditions are examined. The first condition is the "planned ditching" case in which there is sufficient time to prepare the airplane for ditching and adjustments have been made to airplane weight and c.g. to account for loss of such items as engines, nacelles, and trailing edge flaps on impact with the water. The other condition is the "unplanned ditching" (§ 25.807(d)) case in which the airplane enters the water with insufficient time to prepare for ditching. The most critical situation for this case is at maximum gross weight due to a failed or aborted takeoff.
No airplane damage is considered for the "unplanned ditching" case. (Amendment 25-0)
(6) Paragraph (d). As to ditching structural criteria, external pressures must be determined for the fuselage and all external doors and exits that are subject to hydrodynamic forces. This can be determined by measurements on ditching models or by analysis based on tests. Section 25.533, "Hull and Main Float Bottom Pressure Loads," may be a source of some pressure information if similarity can be shown. The use of pressure distribution data from similar model airplanes is acceptable and is preferred over purely analytical methods.
(Amendment 25-0)
252. AMENDMENT 25-72, Effective August 20, 1990.
a. Regulation.
(a) If certification with ditching provisions is requested, the airplane must meet the requirements of this section and §§ 25.807[(e)], 25.1411, and 25.1415(a).
(b) Each practicable design measure, compatible with the general characteristics of the airplane, must be taken to minimize the probability that in an emergency landing on water, the behavior of the airplane would cause immediate injury to the occupants or would make it impossible for them to escape.
(c) The probable behavior of the airplane in a water landing must be investigated by model tests or by comparison with airplanes of similar configuration for which the ditching characteristics are known. Scoops, flaps, projections, and any other factor likely to affect the hydrodynamic characteristics of the airplane, must be considered.
(d) It must be shown that, under reasonably probable water conditions, the flotation time and trim of the airplane will allow the occupants to leave the airplane and enter the liferafts required by § 25.1415. If compliance with this provision is shown by buoyancy and trim computations, appropriate allowances must be made for probable structural damage and leakage. If the airplane has fuel tanks (with fuel jettisoning provisions) that can reasonably be expected to withstand a ditching without leakage, the jettisonable volume of fuel may be considered as buoyancy volume.
(e) Unless the effects of the collapse of external doors and windows are accounted for in the investigation of the probable behavior of the airplane in a water landing (as prescribed in paragraphs (c) and (d) of this section), the external doors and windows must be designed to withstand the probable maximum local pressures.
b. Guidance.
(l) Background Information. The expression "reasonably probable water conditions" is considered judgmental in application to compliance for ditching and has never been specifically defined as to sea state force or wave height. Early ditching investigations of dynamic models were conducted by the National Advisory Committee for Aeronautics (NACA) at Langley Field, Virginia, and NACA Report 1347, issued in 1958. A compilation of such test results, set the
172 precedence for early and modern transport airplane designers in substantiating airplanes for ditching by analyses. Such early tests were based on calm-water landings with the supposition that rough-water landings of particular models that were made parallel to waves or swells would exhibit the same general type of performance. Later rough-water ditching investigations of models were conducted and their results were compiled in documents such as Technical Note No. D-101, issued by the National Aeronautics and Space Administration (NASA) in 1959, and Also referred to by designers in respective ditching analyses. In addition to the reference to actual ditching incidents, it became an acceptable practice for designers to substantiate the ditching behavior of a proposed airplane design by comparisons in basic geometric configuration to airplane designs approved for ditching by the models tested at Langley Field. Parametric comparisons usually revealed some identicalness in geometric aspects and where obvious discrepancies in dimensional relationships were evident, predetermined correction factors were applied. (Amendment 25-0)
(2) Paragraph (b). Ditching load factors may be determined by model tests. Landing procedures or design measures must be established that limit the factors to those listed in § 25.561. Load factors above these are considered to expose occupants to injurious loads. In addition, standard parts such as seats, belts, and harnesses are designed to § 25.561 load factors.
Higher load factors in the downward direction may be acceptable provided the structural components are designed for the higher loads and also provided it can be shown that the occupants are protected from serious injury under these loads. (Amendment 25-0)
(3) Paragraph (d). A maximum permissible evacuation time for liferafts per the rule is also considered judgmental in scope for ditching compliance. During certification, it is usually shown by analysis that an airplane will float for a period of time exceeding the most conservative estimate of time required to completely evacuate the airplane. Evacuation times and rates for liferaft type devices are normally established by analysis and included in the particular airplane model ditching and flotation document presented for approval during type certification.
(Amendment 25-0)
(4) Paragraph (d). Prior to approval of any size or type of transport airplane for ditching approval under § 25.801, there must be evidence of an engineering evaluation of the provisions for installing the emergency equipment specified in § 25.1411. (Amendment 25-0)
(5) Paragraph (d). In approving an airplane for overwater flight certification, two ditching conditions are examined. The first condition is the "planned ditching" case in which there is sufficient time to prepare the airplane for ditching and adjustments have been made to airplane weight and c.g. to account for loss of such items as engines, nacelles, and trailing edge flaps on impact with the water. The other condition is the "unplanned ditching" (§ 25.807(e)) case in which the airplane enters the water with insufficient time to prepare for ditching. The most critical situation for this case is at maximum gross weight due to a failed or aborted takeoff.
No airplane damage is considered for the "unplanned ditching" case. (Amendment 25-0)
(6) Paragraph (d). As to ditching structural criteria, external pressures must be determined for the fuselage and all external doors and exits that are subject to hydrodynamic forces. This can be determined by measurements on ditching models or by analysis based on
173 tests. Section 25.533, "Hull and Main Float Bottom Pressure Loads," may be a source of some pressure information if similarity can be shown. The use of pressure distribution data from similar model airplanes is acceptable and is preferred over purely analytical methods.
(Amendment 25-0) 253 - 270. [RESERVED]