(1) They cannot be damaged by the movement of cargo in the compartment, and
(2) Their breakage or failure will not create a fire hazard.
(f) There must be means to prevent cargo or baggage from interfering with the functioning of the fire protective features of the compartment.
(g) Sources of heat within the compartment must be shielded and insulated to prevent igniting the cargo or baggage.
(h) Flight tests must be conducted to show compliance with the provisions of § 25.857 concerning-
(1) Compartment accessibility,
(2) The entries of hazardous quantities of smoke or extinguishing agent into compartments occupied by the crew or passengers, and
(3) The dissipation of the extinguishing agent in Class C compartments.
(i) During the above tests, it must be shown that no inadvertent operation of smoke or fire detectors in any compartment would occur as a result of fire contained in any other compartment, either during or after extinguishment, unless the extinguishing system floods each such compartment simultaneously.]
b. Guidance.
(1) Paragraph (c). Material constructions (panels) which meet the ceiling liner test requirements are also acceptable for use as sidewall panels. The converse is not true.
(Amendment 25-60)
(2) Paragraph (c). The following is recommended when testing design features found in ceiling or sidewall panels: (Amendment 25-60)
(i) When testing joints and seams, position them longitudinally in the ceiling sample holder centered over the burner cone. If the seam or joint is in the sidewall, test it in the longitudinal position of the sidewall sample holder 2-inches below the sidewall top. All fastening systems should be tested similarly. (Amendment 25-60)
(ii) When testing corners, the corner should be positioned in the test fixture as it normally is in service. The test fixture may be altered slightly to accommodate this corner design feature. This will require the removal of the angle iron on the back corner of the fixture.
(Amendment 25-60)
(iii) When testing lighting fixtures or pressure-relief valves, any material forming the fire barrier should be tested as a flat sheet in the ceiling or sidewall position (depending on actual location in the cargo compartment) and treated as a liner. (Amendment 25-60)
(3) Paragraph (c). Holes in ceiling panels used to provide access for smoke detector sampling ports should not be larger than 3/8-inch in diameter. (Amendment 25-60)
(4) Paragraph (h). Refer to AC 25-9A, “Smoke Detection, Penetration, and Evacuation Test, and Related Flight Manual Emergency Procedures,” dated 1/6/94. (Amendment 25-0)
(5) Note: The FAA Memorandum 00-115-16, dated September 12, 2000, titled, “Use of the Aircraft Fire Test Handbook” provides guidance for the use of the Report # DOT/FAA/CT-99/15 titled, “Aircraft Fire Test Handbook” that may be used to show compliance with, or demonstrate an equivalent level of safety to, the applicable regulations. The test methods described in the handbook are intended to be adopted in total, if they are used. That is, use of a portion of a test method from the handbook, and another portion of the test method from Appendix F, is not automatically acceptable. (Amendment 25-0)
656. AMENDMENT 25-93, Effective March 19, 1998.
a. Regulation.
Cargo or baggage compartments.
For each cargo and baggage compartment not occupied by crew or passengers, the following apply:
(a) The compartment must meet one of the class requirements of § 25.857.
(b) Class B through E cargo or baggage compartments, as defined in § 25.857, must have a liner, and the liner must be separate from (but may be attached to) the airplane structure.
[(c) Ceiling and sidewall liner panels of Class C compartments must meet the test requirements of Part III of Appendix F of this part or other approved equivalent methods.]
(d) All other materials used in the construction of the cargo or baggage compartment must meet the applicable test criteria prescribed in Part I of Appendix F of this part or other approved equivalent methods.
(e) No compartment may contain any controls, wiring, lines, equipment, or accessories whose damage or failure would affect safe operation, unless those items are protected so that-
(1) They cannot be damaged by the movement of cargo in the compartment, and
(2) Their breakage or failure will not create a fire hazard.
(f) There must be means to prevent cargo or baggage from interfering with the functioning of the fire protective features of the compartment.
(g) Sources of heat within the compartment must be shielded and insulated to prevent igniting the cargo or baggage.
(h) Flight tests must be conducted to show compliance with the provisions of § 25.857 concerning-
(1) Compartment accessibility,
(2) The entries of hazardous quantities of smoke or extinguishing agent into compartments occupied by the crew or passengers, and
(3) The dissipation of the extinguishing agent in Class C compartments.
(i) During the above tests, it must be shown that no inadvertent operation of smoke or fire detectors in any compartment would occur as a result of fire contained in any other compartment, either during or after extinguishment, unless the extinguishing system floods each such compartment simultaneously.
b. Guidance.
(1) Paragraph (c). Material constructions (panels) which meet the ceiling liner test requirements are also acceptable for use as sidewall panels. The converse is not true.
(Amendment 25-60)
(2) Paragraph (c). The following is recommended when testing design features found in ceiling or sidewall panels: (Amendment 25-60)
(i) When testing joints and seams, position them longitudinally in the ceiling sample holder centered over the burner cone. If the seam or joint is in the sidewall, test it in the longitudinal position of the sidewall sample holder 2-inches below the sidewall top. All fastening systems should be tested similarly. (Amendment 25-60)
(ii) When testing corners, the corner should be positioned in the test fixture as it normally is in service. The test fixture may be altered slightly to accommodate this corner design feature. This will require the removal of the angle iron on the back corner of the fixture.
(Amendment 25-60)
(iii) When testing lighting fixtures or pressure-relief valves, any material forming the fire barrier should be tested as a flat sheet in the ceiling or sidewall position (depending on actual location in the cargo compartment) and treated as a liner. (Amendment 25-60)
(3) Paragraph (c). Holes in ceiling panels used to provide access for smoke detector sampling ports should not be larger than 3/8-inch in diameter. (Amendment 25-60)
(4) Paragraph (h). Refer to AC 25-9A, “Smoke Detection, Penetration, and Evacuation Test, and Related Flight Manual Emergency Procedures,” dated 1/6/94. (Amendment 25-0)
(5) Note: The FAA Memorandum 00-115-16, dated September 12, 2000, titled, “Use of the Aircraft Fire Test Handbook” provides guidance for the use of the Report # DOT/FAA/CT-99/15 titled, “Aircraft Fire Test Handbook” that may be used to show compliance with, or demonstrate an equivalent level of safety to, the applicable regulations. The test methods described in the handbook are intended to be adopted in total, if they are used. That is, use of a portion of a test method from the handbook, and another portion of the test method from Appendix F, is not automatically acceptable. (Amendment 25-0) 657 - 660. [RESERVED]
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571 SECTION 25.856 THERMAL/ACOUSTIC INSULATION MATERIALS
661. Section 25.856 Did Not Exist Prior to Amendment 25-111.
662. AMENDMENT 25-111, Effective September 2, 2003.
a. Regulation.
[Thermal/Acoustic Insulation materials.] [(a) Thermal/acoustic insulation material installed in the fuselage must meet the flame propagation test requirements of part VI of Appendix F to this part, or other approved equivalent test requirements. This requirement does not apply to "small parts," as defined in part I of Appendix F of this part.
(b) For airplanes with a passenger capacity of 20 or greater, thermal/acoustic insulation materials (including the means of fastening the materials to the fuselage) installed in the lower half of the airplane fuselage must meet the flame penetration resistance test requirements of part VII of Appendix F to this part, or other approved equivalent test requirements. This requirement does not apply to thermal/acoustic insulation installations that the FAA finds would not contribute to fire penetration resistance.]
b. Guidance.
(1) Paragraph (a). Refer to AC 25.856-1, “Thermal/Acoustic insulation flame propagation test method details” dated 6/24/05 for guidance.
(2) Paragraph (b). Refer to AC 25.856-2, “Installation of thermal/acoustic insulation for burnthrough protection” dated 1/17/06 for guidance.
663-670. [RESERVED]
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573 SECTION 25.857 CARGO COMPARTMENT CLASSIFICATION
671. REGULATION IN EFFECT AT ADOPTION OF PART 25.
a. Regulation.
(a) Class A. A Class A cargo or baggage compartment is one in which-
(1) The presence of a fire would be easily discovered by a crewmember while at his station; and
(2) Each part of the compartment is easily accessible in flight.
(b) Class B. A Class B cargo or baggage compartment is one in which-
(1) There is sufficient access in flight to enable a crewmember to effectively reach any part of the compartment with the contents of a hand fire extinguisher;
(2) When the access provisions are being used, no hazardous quantity of smoke, flames or extinguishing agent, will enter any compartment occupied by the crew or passengers;
(3) There is a separate approved smoke detector or fire detector system to give warning at the pilot or flight engineer station; and
(4) There is a fire-resistant lining.
(c) Class C. A Class C cargo or baggage compartment is one not meeting the requirements for either a Class A or B compartment but in which-
(1) There is a separate approved smoke detector or fire detector system to give warning at the pilot or flight engineer station;
(2) There is an approved built-in fire-extinguishing system controllable from the pilot or flight engineer stations;
(3) There are means to exclude hazardous quantities of smoke, flames, or extinguishing agent, from any compartment occupied by the crew or passengers;
(4) There are means to control ventilation and drafts within the compartment so that the extinguishing agent used can control any fire that may start within the compartment; and
(5) There is a fire-resistant lining.
(d) Class D. A Class D cargo or baggage compartment is one in which-
(1) A fire occurring in it will be completely confined without endangering the safety of the airplane or the occupants;
(2) There are means to exclude hazardous quantities of smoke, flames, or other noxious gases, from any compartment occupied by the crew or passengers;
(3) Ventilation and drafts are controlled within each compartment so that any fire likely to occur in the compartment will not progress beyond safe limits;
(4) There is a fire-resistant lining; and
(5) Consideration is given to the effect of heat within the compartment on adjacent critical parts of the airplane.
For compartments of 500 cubic feet or less, an airflow of 1500 cubic feet per hour is acceptable.
(e) Class E. A Class E cargo compartment is one on airplanes used only for the carriage of cargo and in which-
(1) There is a fire-resistant lining;
(2) There is a separate approved smoke or fire detector system to give warning at the pilot or flight engineer station;
(3) There are means to shut off the ventilating airflow to, or within, the compartment, and the controls for these means are accessible to the flightcrew in the crew compartment;
(4) There are means to exclude hazardous quantities of smoke, flames, or noxious gases, from the flightcrew compartment; and
(5) The required crew emergency exits are accessible under any cargo loading condition.
b. Guidance.
(1) Paragraphs (a), (b), and (c). In the interest of fire protection, classification of cargo compartments on transport category airplanes was developed and incorporated into a rule with CAR Amendment 04-1 on November 1, 1946. Class A, B, and C categories were established, and two basic factors of fire protection were envisioned: (Amendment 25-0)
(i) Detection of a fire by a crewmember while at his station. (Amendment 25-0)
(ii) Extinguishment or suppression of the fire when detected. (Amendment 25-0)
(2) Paragraphs (d) and (e). Later, a Class D compartment was developed and incorporated into a rule with CAR Amendment 4b-6 on July 20, 1950. Further, when a need developed for bulk loading cargo into the main cabin in which the fire protection provision of the Class A, B, C, and D did not suffice, a Class E category was established. The Class E was incorporated into a rule with CAR Amendment 4b-10 on April 23, 1959. The basic category provisions are essentially the same to date in current part 25 requirements. The main differences in classification are: (Amendment 25-0)
(i) Accessibility. (Amendment 25-0)
(ii) Means of detection of fire or smoke. (Amendment 25-0)
(iii) Method of extinguishment or suppression of fire. (Amendment 25-0)
(iv) Protection for structural members. (Amendment 25-0)
(3) Paragraphs (a), (b), (c), (d) and (e). As prescribed in CAR 4b and part 25, the Class A requires that the presence of a fire be readily discernible to a crewmember at his station and that all parts be easily accessible. The Class B must also be accessible, but detection is by smoke/fire detectors. The Class C, D, and E are generally not accessible and detection in the C and E are by smoke/fire detectors. Extinguishment in the Class C is by flooding, in the Class D by suppressing oxygen, and in the Class E by shutting off the ventilating airflow. Fire resistant liners were required in the Class B, C, D, and E for protection of structural members.
(Amendment 25-0)
(4) Paragraphs (a), (d), and (e). With the exception of the Class D, which is limited to 2000 cubic feet, and the Class E, which was designed to encompass the entire passenger cabin, no specific volume limits were prescribed for the other category compartments. Early regional guidance, however, envisioned the Class A compartment as a small open container for storage of crew luggage located in the pilot compartment where the presence of any fire could be rapidly detected by the crew. Refer to the guidance in paragraph 672.b.(2) below. (Amendment 25-0)
(5) Paragraph (b)(1). In order to demonstrate that any part of the compartment can be effectively reached, the following test may be conducted: (Amendment 25-0)
(i) The test may be conducted in an airplane sitting statically on the ground. The cargo compartment should be filled to that allowed by the type design with empty cardboard boxes and such as mailbags filled with crumpled newspapers. (Amendment 25-0)
(ii) The assigned flight crewmember should be seated at his station with his seat belt and shoulder harness engaged. (Amendment 25-0)
(iii) When the test begins, the crewmember should don the portable oxygen equipment, carry the fire extinguisher to the most remote part of the cargo compartment and
576 remove the necessary boxes and bags in order to touch the pre-assigned and/or identified most remote box or bag with his hand. This ends the test. (Amendment 25-0)
(iv) The test time should be no longer than 5 minutes. (Amendment 25-0)
(6) Paragraphs (b)(3), (c)(1) and (e)(2). An acceptable detection time for smoke detectors is 5 minutes. Use the smoke quantity and location criteria of AC 25-9A, “Smoke Detection, Penetration, and Evacuation Tests, and Related Flight Manual Emergency Procedures,” dated 1/6/94, for showing that the smoke detection system detects a fire in satisfactory time. The time for fire detection systems was changed to one minute by Amendment 25-54 in § 25.858. (Amendment 25-0)
(7) Paragraphs (b)(4), (c)(5), (d)(4), and (e)(1). Refer to paragraph 621b(2) for an acceptable test for fire resistance. (Amendment 25-0)
(8) Paragraphs (b), (c), (d), and (e). Refer to AC 25-9A, “Smoke Detection, Penetration, and Evacuation Test, and Related Flight Manual Emergency Procedures,” dated 1/6/94. (Amendment 25-0)
(9) Paragraphs (b), (c), (d), and (e). The lining discussed in the Class B, C, D, and E, compartments refers to the sidewalls, ceilings and forward and aft panels of the compartments.
(Amendment 25-0)
672. AMENDMENT 25-32, Effective May 1, 1972.
a. Regulation.
(a) Class A. A Class A cargo or baggage compartment is one in which-
(1) The presence of a fire would be easily discovered by a crewmember while at his station; and
(2) Each part of the compartment is easily accessible in flight.
(b) Class B. A Class B cargo or baggage compartment is one in which-
(1) There is sufficient access in flight to enable a crewmember to effectively reach any part of the compartment with the contents of a hand fire extinguisher;
(2) When the access provisions are being used, no hazardous quantity of smoke, flames, or extinguishing agent, will enter any compartment occupied by the crew or passengers;
(3) There is a separate approved smoke detector or fire detector system to give warning at the pilot or flight engineer station; and
577 [(4) [Reserved.]]
(c) Class C. A Class C cargo or baggage compartment is one not meeting the requirements for either a Class A or B compartment but in which-
(1) There is a separate approved smoke detector or fire detector system to give warning at the pilot or flight engineer station;
(2) There is an approved built-in fire-extinguishing system controllable from the pilot or flight engineer stations;
(3) There are means to exclude hazardous quantities of smoke, flames, or extinguishing agent, from any compartment occupied by the crew or passengers;
(4) There are means to control ventilation and drafts within the compartment so that the extinguishing agent used can control any fire that may start within the compartment; and [(5) [Reserved.]]
(d) Class D. A Class D cargo or baggage compartment is one in which-
(1) A fire occurring in it will be completely confined without endangering the safety of the airplane or the occupants;
(2) There are means to exclude hazardous quantities of smoke, flames, or other noxious gases, from any compartment occupied by the crew or passengers;
(3) Ventilation and drafts are controlled within each compartment so that any fire likely to occur in the compartment will not progress beyond safe limits;
[(4 ) [Reserved.]]
(5) Consideration is given to the effect of heat within the compartment on adjacent critical parts of the airplane.
For compartments of 500 cu. ft. or less, an airflow of 1500 cu. ft. per hour is acceptable.
(e) Class E. A Class E cargo compartment is one on airplanes used only for the carriage of cargo and in which- [(1) [Reserved.]]
(2) There is a separate approved smoke or fire detector system to give warning at the pilot or flight engineer station;