645 SECTION 25.1557 MISCELLANEOUS MARKINGS AND PLACARDS 1061. REGULATION IN EFFECT AT ADOPTION OF PART 25.
NOTE: This AC only addresses paragraphs (a), (c), and (d) of this section.
a. Regulation.
(a) Baggage and cargo compartments, and ballast location. Each baggage and cargo compartment, and each ballast location must have a placard stating any limitations on contents, including weight, that are necessary under the loading conditions.
(c) Emergency exit placards. Each emergency exit placard must meet the requirements of § 25.811.
(d) Doors. Each door that must be used in order to reach any required emergency exit must have a suitable placard stating that the door is to be latched in the open position during take off and landing.
b. Guidance. There is no guidance for this regulation.
1062. AMENDMENT 25-32, Effective May 1, 1972.
a. Regulation.
[(a) Baggage and cargo compartments and ballast location. Each baggage and cargo compartment, and each ballast location must have a placard stating any limitations on contents, including weight, that are necessary under the loading requirements. However, underseat compartments designed for the storage of carryon articles weighing not more than 20 pounds need not have a loading limitations placard.]
(c) Emergency exit placards. Each emergency exit placard must meet the requirements of § 25.811.
(d) Doors. Each door that must be used in order to reach any required emergency exit must have a suitable placard stating that the door is to be latched in the open position during takeoff and landing.
b. Guidance. There is no guidance for this amendment.
646 1063. AMENDMENT 25-38, Effective February 1, 1977.
a. Regulation. - Amendment 25-38 Did Not Change Paragraphs (a), (c), or (d).
(a) Baggage and cargo compartments and ballast location. Each baggage and cargo compartment, and each ballast location must have a placard stating any limitations contents, including weight, that are necessary under the loading requirements.
However, underseat compartments designed for the storage of carry-on articles weighing not more than 20 pounds need not have a loading limitation placard.
(c) Emergency exit placards. Each emergency exit placard must meet the requirements of § 25.811.
(d) Doors. Each door that must be used in order to reach any required emergency exit must have a suitable placard stating that the door is to be latched in the open position during takeoff and landing.
b. Guidance. There is no guidance for this amendment.
1064. AMENDMENT 25-72, Effective August 20, 1990.
NOTE: This AC only addresses paragraphs (a), (c), and (d) of this section.
a. Regulation.
(a) Baggage and cargo compartments and ballast location. Each baggage and cargo compartment, and each ballast location must have a placard stating any limitations on contents, including weight, that are necessary under the loading requirements. However, underseat compartments designed for the storage of carryon articles weighing not more than 20 pounds need not have a loading limitation placard.
(c) Emergency exit placards. Each emergency exit placard must meet the requirements of § 25.811.
(d) Doors. Each door that must be used in order to reach any required emergency exit must have a suitable placard stating that the door is to be latched in the open position during takeoff and landing.
b. Guidance. There is no additional guidance for this amendment.
1065 - 1100. [RESERVED]
647 SECTION 25.1561 SAFETY EQUIPMENT 1101. REGULATION IN EFFECT AT ADOPTION OF PART 25.
a. Regulation.
(a) Each safety equipment control to be operated by the crew in emergency, such as controls for automatic life raft releases, must be plainly marked as to its method of operation.
(b) Each location, such as a locker or compartment, that carries any fire extinguishing, signaling or other life saving equipment must be marked accordingly.
(c) Stowage provisions for required emergency equipment must be conspicuously marked to identify the contents and facilitate removal of the equipment.
(d) Each life raft must have obviously marked operating instructions.
(e) Approved survival equipment must be marked for identification and method of operation.
b. Guidance.
(1) Paragraph (b). Equipment such as fire extinguishers, located in clear view, need not have an arrow or other indicators pointing to location. However, the location should be clearly marked to indicate what equipment goes in that location should that equipment be removed.
(Amendment 25-0)
(2) Paragraph (c). If the slide, slide/raft and/or locator transmitter is installed in a container on the exit, the container should be marked "SLIDE," "SLIDE/RAFT," and/or "LOCATOR TRANSMITTER," as applicable. (Refer to paragraphs 101b(1), 801b(1)(ii), and 1041b(5).) (Amendment 25-0) 1102. AMENDMENT 25-46, Effective December 1, 1978.
a. Regulation.
(a) Each safety equipment control to be operated by the crew in emergency, such as controls for automatic liferaft releases, must be plainly marked as to its method of operation.
(b) Each location, such as a locker or compartment, that carries any fire extinguishing, signaling, or other lifesaving equipment must be marked accordingly.
(c) Stowage provisions for required emergency equipment must be conspicuously marked to identify the contents and facilitate [the easy] removal of the equipment.
(d) Each liferaft must have obviously marked operating instructions.
(e) Approved survival equipment must be marked for identification and method of operation.
b. Guidance.
(1) Paragraph (b). Equipment such as fire extinguishers, located in clear view, need not have an arrow or other indicators pointing to location. However, the location should be clearly marked to indicate what equipment goes in that location should that equipment be removed.
(Amendment 25-0)
(2) Paragraph (c). If the slide, slide/raft and/or locator transmitter is installed in a container on the exit, the container should be marked "SLIDE," "SLIDE/RAFT," and/or "LOCATOR TRANSMITTER," as applicable. (Refer to paragraphs 101b(1), 801b(1)(ii), and 1041b(5).) (Amendment 25-0) 1103 - 1150. [RESERVED]
649 APPENDIX F TO PART 25
ACCEPTABLE PROCEDURES FOR SHOWING COMPLIANCE WITH §§ 25.853, 25.855, and 25.1359 1151. APPENDIX F Did Not Exist Prior to Amendment 25-15.
1152. APPENDIX F, AMENDMENT 25-15, Effective October 24, 1967.
AN ACCEPTABLE TEST PROCEDURE FOR SHOWING COMPLIANCE WITH § 25.853.
(a) Conditioning. Specimens must be conditioned at 70±5 degrees F., and at 50±5 percent plus or minus 5 percent relative humidity until moisture equilibrium is reached. Only one specimen at a time may be removed from the conditioned environment immediately before subjecting it to the flame.
(b) Specimen configuration. The specimen must be no thicker than the minimum thickness to be qualified for use in the airplane. Rigid and flexible specimens, 4-l/2-inches by 12- 1/2-inches, or the actual size used in the airplane must be clamped in a metal frame so that the two long edges and one end are held securely. The frame must be such that the exposed area is at least 2-inches wide and 11-l/2-inches long unless the actual size used in the airplane is smaller. In the case of fabrics, the direction of the weave corresponding to the most critical burn rate must be parallel to the longest dimension.
(c) Apparatus. The tests must be conducted in a sheet metal cabinet of approximate size provided with a door containing a glass insert for observing the burning specimen. The cabinet top must contain a baffled vent. There must be baffled holes or similar means of ventilation near the bottom of the cabinet. Larger panels need not be tested in this apparatus but must be tested in similar draft free conditions.
(d) Horizontal test. A minimum of three specimens must be tested and the results averaged.
Each specimen must be supported horizontally. The surface exposed to the air when installed in the aircraft must be face down for the test. The specimen must be ignited by a Bunsen burner or Tirrill burner with a nominal three-eighths-inch internal diameter (I.D.)
tube adjusted to give a flame of 1-1/2-inches in height with the air completely shutoff. The specimen must be positioned so that the edge being tested is three-fourths-inch above the top of, and on the center line of, the burner. The flame must be applied for 15 seconds and then removed. Char length must be noted when testing for compliance with § 25.853(a). To determine burn rate for compliance with § 25.853(b), a minimum of 10- inches of the specimen must be used for timing purposes, approximately 1-1/2-inches must burn before the burning front reaches the timing zone, and the average burn rate must not exceed 4-inches per minute. If, in testing for compliance with § 25.853(b), the specimens do not support combustion after the ignition flame is applied for 15 seconds, or if the flame extinguishes itself and subsequent burning without a flame does not extend into the undamaged areas, the material is also acceptable.
(e) Vertical test. A minimum of three specimens must be tested and the results averaged.
Each specimen must be supported vertically. Ceiling or floor panels may be tested with any edge down. Rigid specimens of materials mounted vertically in the airplane must be oriented for the test in the same manner as oriented in the airplane. The specimen must be ignited by a Bunsen or Tirrill burner with a nominal 3/8-inch I.D. tube adjusted to give a flame of 1-1/2-inches in height with the air completely shut off. The center line of the burner must be in line with a surface of the material being tested or, in the case of fabricated units, must be in line with the surface exposed to the air in the airplane. The lower edge of the specimen being tested must be three-fourths-inch above the top of the burner. The flame must be applied for 12 seconds and then removed. Char length must be noted.
(f) Char length. Char length for fabrics and coated fabrics is the distance from the specimen end that was exposed to the flame to the end of a tear made lengthwise on the specimen through the center of the charred area. The test must be made as follows: A hook must be inserted in the specimen at one side of the charred areas one-fourth-inch from the adjacent outside edge and one-fourth-inch in from the charred end of the specimen. A weight of sufficient size such that the weight and hook together equal the total tearing load specified below must be applied gently to the specimen by grasping the corner of the cloth at the opposite edge of the char from the load and raising the specimen and weight clear of the support. The total tearing load for various weights per square yard of test cloth is as follows:
Weight per square yard of test cloth (ounces) Total tearing load (pounds) 2 to 6 0.25 Over 6 to 15 0.5 Over 15 to 23 0.75 Over 23 l.0 On materials other than fabrics, the char length is the total length of the specimen consumed or charred by burning. The length is measured from the ignition edge to a point that is not punctured by a ballpoint pen (or equivalent) when progressively moved from unburned to burned areas.
1153. APPENDIX F, AMENDMENT 25-32, Effective May 1, 1972.
AN ACCEPTABLE TEST PROCEDURE FOR SHOWING COMPLIANCE WITH §§ 25.853, 25.855 AND 25.1359
(a) Conditioning. Specimens must be conditioned 70±5 degrees F., and at 50±5 percent relative humidity until moisture equilibrium is reached or for 24 hours. Only one
651 specimen at a time may be removed from the conditioning environment immediately before subjecting it to the flame.
(b) Specimen configuration. Except as provided for materials used in electrical wire and cable insulation and in small parts, materials must be tested either as a section cut from a fabricated part as installed in the airplane or as a specimen simulating a cut section, such as: a specimen cut from a flat sheet of the material or a model of the fabricated part. The specimen may be cut from any location in a fabricated part; however, fabricated units, such as sandwich panels, may not be separated for test. The specimen thickness must be no thicker than the minimum thickness to be qualified for use in the airplane, except that:
(1) thick foam parts, such as seat cushions, must be tested in 1/2-inch thickness; (2) when showing compliance with § 25.853(b-3) for materials used in small parts that must be tested, the materials must be tested in no more than 1/8-inch thickness; (3) when showing compliance with § 25.1359(d) for materials used in electrical wire and cable insulation, the wire and cable specimens must be the same size as used in the airplane. In the case of fabrics, both the warp and fill direction of the weave must be tested to determine the most critical flammability condition. When performing the tests prescribed in paragraphs (d) through (e) of this Appendix, the specimen must be mounted in a metal frame so that: (1) in the vertical tests of paragraph (d), the two long edges and the upper edge are held securely; (2) in the horizontal test of paragraph (e), the two long edges and the edge away from the flame are held securely; (3) the exposed area of the specimen is at least 2-inches wide and 12-inches long, unless the actual size used in the airplane is smaller; and (4) the edge to which the burner flame is applied must not consist of the finished or protected edge of the specimen but must be representative of the actual cross-section of the material or part installed in the airplane. When performing the test prescribed in paragraph (f) of this Appendix, the specimen must be mounted in a metal frame so that all four edges are held securely and the exposed area of the specimen is at least 8-inches by 8-inches.
(c) Apparatus. Except as provided in paragraph (g) of this Appendix, tests must be conducted in a draft-free cabinet in accordance with Federal Test Method Standard 191 Method 5903 (revised Method 5902) for the vertical test, or Method 5906 for horizontal test (available from the General Services Administration, Business Service Center, Region 3, Seventh & D Streets, SW., Washington, D.C., 20407) or other approved equivalent methods. Specimens which are too large for the cabinet must be tested in similar draftfree conditions.
(d) Vertical test in compliance with § 25.853(a) and (b). A minimum of three specimens must be tested and the results averaged. For fabrics, the direction of weave corresponding to the most critical flammability conditions must be parallel to the longest dimension.
Each specimen must be supported vertically. The specimen must be exposed to a Bunsen or Tirrill burner with a nominal 3/8-inch I.D. tube adjusted to give a flame of 1-1/2-inches in height. The minimum flame temperature measured by a calibrated thermocouple pyrometer in the center of the flame must be 1550 degrees F. The lower edge of the specimen must be three-fourths-inch above the top edge of the burner. The flame must be applied to the center line of the lower edge of the specimen. For materials covered by § 25.853(a), the flame must be applied for 60 seconds and then removed. For materials
652 covered by § 25.853(b), the flame must be applied for 12 seconds and then removed.
Flame time, burn length, and flaming time of drippings, if any, must be recorded. The burn length determined in accordance with paragraph (h) of this Appendix must be measured to the nearest 1/10-inch.
(e) Horizontal test in compliance with § 25.853(b-2) and (b-3). A minimum of three specimens must be tested and the results averaged. Each specimen must be supported horizontally. The exposed surface when installed in the aircraft must be face down for the test. The specimen must be exposed to a Bunsen burner or Tirrill burner with a nominal 3/8-inch I.D. tube adjusted to give a flame of 1-1/2-inches in height. The minimum flame temperature measured by a calibrated thermocouple pyrometer in the center of the flame must be 1550 degrees F. The specimen must be positioned so that the edge being tested is three-fourths of an-inch above the top of, and on the center line of, the burner. The flame must be applied for 15 seconds and then removed. A minimum of 10-inches of the specimen must be used for timing purposes, approximately 1-1/2-inches must burn before the burning front reaches the timing zone, and the average burn rate must be recorded.
(f) Forty-five degree test in compliance with § 25.855(a-1). A minimum of three specimens must be tested and the results averaged. The specimens must be supported at an angle of 45 degrees to a horizontal surface. The exposed surface when installed in the aircraft must be face down for the test. The specimens must be exposed to a Bunsen or Tirrill burner with a nominal 3/8-inch I.D. tube adjusted to give a flame of 1-1/2-inches in height. The minimum flame temperature measured by a calibrated thermocouple pyrometer in the center of the flame must be 1550 degrees F. Suitable precautions must be taken to avoid drafts. One-third of the flame must contact the material at the center of the specimen and must be applied for 30 seconds and then removed. Flame time, glow time, and whether the flame penetrates (passes through) the specimen must be recorded.
(g) Sixty degree test in compliance with § 25.1359(d). A minimum of three specimens of each wire specification (make and size) must be tested. The specimen of wire or cable (including insulation) must be placed at an angle of 60 degrees with the horizontal in the cabinet specified in paragraph (c) of this Appendix with the cabinet door open during the test or must be placed within a chamber approximately 2 feet high x 1 foot x 1 foot, open at the top and at one vertical side (front), and which allows sufficient flow of air for complete combustion, but which is free from drafts. The specimen must be parallel to and approximately 6-inches from the front of the chamber. The lower end of the specimen must be held rigidly clamped. The upper end of the specimen must pass over a pulley or rod and must have an appropriate weight attached to it so that the specimen is held tautly throughout the flammability test. The test specimen span between lower clamp and upper pulley or rod must be 24-inches and must be marked 8-inches from the lower end to indicate the central point for flame application. A flame from a Bunsen or Tirrill burner must be applied for 30 seconds at the test mark. The burner must be mounted underneath the test mark on the specimen, perpendicular to the specimen and at an angle of 30 degrees to the vertical plane of the specimen. The burner must have a nominal bore of three-eighths-inch, and must be adjusted to provide a 3-inch high flame with an inner cone approximately one third of the flame height. The minimum temperature of the hottest
653 portion of the flame, as measured with a calibrated thermocouple pyrometer, may not be less than 1750 degrees F. The burner must be positioned so that the hottest portion of the flame is applied to the test mark on the wire. Flame time, burn length, and flaming time of drippings, if any, must be recorded. The burn length determined in accordance with paragraph (h) of this Appendix must be measured to the nearest one-tenth-inch. Breaking of the wire specimens is not considered a failure.
(h) Burn length. Burn length is the distance from the original edge to the farthest evidence of damage to the test specimen due to flame impingement, including areas of partial or complete consumption, charring, or embrittlement, but not including areas sooted stained, warped, or discolored, nor areas where material has shrunk or melted away from the heat source.
1154. APPENDIX F, AMENDMENT 25-55, Effective April 26, 1982. References to paragraphs (g) and (h) from Amendment 25-32 were corrected by this amendment. The typing errors are shown corrected in Amendment 25-32 above.
(a) Conditioning. Specimens must be conditioned to 70° F., plus or minus 5°[,] and at 50 percent plus or minus 5 percent relative humidity until moisture equilibrium is reached or for 24 hours. Only one specimen at a time may be removed from the conditioning environment immediately before subjecting it to the flame.
(b) Specimen configuration. Except as provided for materials used in electrical wire and cable insulation and in small parts, materials must be tested either as a section cut from a fabricated part as installed in the airplane or as a specimen simulating a cut section, such as: a specimen cut from a flat sheet of the material or a model of the fabricated part. The specimen may be cut from any location in a fabricated part; however, fabricated units, such as sandwich panels, may not be separated for test. The specimen thickness must be no thicker than the minimum thickness to be qualified for use in the airplane, except that:
(1) thick foam parts, such as seat cushions, must be tested in ½-inch thickness; (2) when showing compliance with § 25.835(b-3) for materials used in small parts that must be tested, the materials must be tested in no more than ⅛-inch thickness; (3) when showing compliance with § 25.1359(d) for materials used in electrical wire and cable insulation, the wire and cable specimens must be the same size as used in the airplane. In the case of fabrics, both the warp and fill direction of the weave must be tested to determine the most critical flammability condition[.] When performing the tests prescribed in paragraphs (d) through (e) of this Appendix, the specimen must be mounted in a metal frame so that; (1) in the vertical tests of paragraph (d), the two long edges and the upper edge are held securely; (2) in the horizontal test of paragraph (e), the two long edges and the edge away from the flame are held securely; (3) the exposed area of the specimen is at least 2-inches wide and 12-inches long, unless the actual size used in the airplane is smaller; and (4) the edge to which the burner flame is applied must not consist of the finished or protected edge of the specimen but must be representative of the actual cross-section of the material or part installed in the airplane. When performing the test prescribed in paragraph (f) of
654 this Appendix, the specimen must be mounted in a metal frame so that all four edges are held securely and the exposed area of the specimen is at least 8-inches by 8-inches.
(c) Apparatus. Except as provided in paragraph [(g)] of this Appendix, tests must be conducted in a draft-free cabinet in accordance with Federal Test Method Standard 191 Method 5903 (revised Method 5902) for the vertical test, or Method 5906 for horizontal test (available from the General Services Administration, Business Service Center, Region 3, Seventh & D Streets, S.W., Washington, D.C., 20407) or other approved equivalent methods. Specimens which are too large for the cabinet must be tested in similar draftfree conditions.
(d) Vertical test in compliance with § 25.853(a) and (b). A minimum of three specimens must be tested and the results averaged. For fabrics, the direction of weave corresponding to the most critical flammability conditions must be parallel to the longest dimension. Each specimen must be supported vertically. The specimen must be exposed to a Bunsen or Tirrill burner with a nominal 3/8-inch I.D. tube adjusted to give a flame of 1½-inches in height. The minimum flame temperature measured by a calibrated thermocouple pyrometer in the center of the flame must be 1550° F. The lower edge of the specimen must be three-fourths-inch above the top edge of the burner. The flame must be applied to the center line of the lower edge of the specimen. For materials covered by § 25.853(a), the flame must be applied for 60 seconds and then removed. For materials covered by § 25.853(b), the flame must be applied for 12 seconds and then removed.
Flame time, burn length, and flaming time of drippings, if any, must be recorded. The burn length determined in accordance with paragraph [(h)] for this Appendix must be measured to the nearest one-tenth-inch.
(e) Horizontal test in compliance with § 25.853(b-2) and (b-3). A minimum of three specimens must be tested and the results averaged. Each specimen must be supported horizontally. The exposed surface when installed in the aircraft must be face down for the test. The specimen must be exposed to a Bunsen burner or Tirrill burner with a nominal three-eighths-inch I.D. tube adjusted to give a flame of 1½-inches in height. The minimum flame temperature measured by a calibrated thermocouple pyrometer in the center of the flame must be 1550° F. The specimen must be positioned so that the edge being tested in three-fourths of an-inch above the top of, and on the center line of, the burner. The flame must be applied for 15 seconds and then removed. A minimum of 10-inches of the specimen must be used for timing purposes, approximately 1½-inches must burn before the burning front reaches the timing zone, and the average burn rate must be recorded.
(f) Forty-five degree test in compliance with § 25.855(a-1). A minimum of three specimens must be tested and the results averaged. The specimens must be supported at an angle of 45° to a horizontal surface. The exposed surface when installed in the aircraft must be face down for the test. The specimens must be exposed to a Bunsen or Tirrill burner with a normal three-eighths-inch I.D. tube adjusted to give a flame of 1½-inches in height. The minimum flame temperature measured by a calibrated thermocouple pyrometer in the center of the flame must be 1550° F. Suitable precautions must be taken to avoid drafts. One-third of the flame must contact the material at the center of the
655 specimen and must be applied for 30 seconds and then removed. Flame time, glow time, and whether the flame penetrates (passes through) the specimen must be recorded.
(g) Sixty degree test in compliance with § 25.1359(d). A minimum of three specimens of each wire specification (make and size) must be tested. The specimen of wire or cable (including insulation) must be placed at an angle of 60° with the horizontal in the cabinet specified in paragraph (c) of this Appendix with the cabinet door open during the test or must be place within a chamber approximately 2 feet high x 1 foot x 1 foot, open at the tope and at one vertical side (front), and which allows sufficient flow of air for complete combustion, but which is free from drafts. The specimen must be parallel to and approximately 6-inches from the front of the chamber. The lower end of the specimen must be held rigidly clamped. The upper end of the specimen must pass over a pulley or rod and must have an appropriate weight attached to it so that the specimen is held tautly throughout the flammability test. The test specimen span between lower clamp and upper pulley or rod must be 24-inches and must be marked 8-inches from the lower end to indicate the central point for flame application. A flame from a Bunsen or Tirrill burner must be applied for 30 seconds at the test mark. The burner must be mounted underneath the test mark on the specimen, perpendicular to the specimen and at an angle of 30° to the vertical plane of the specimen. The burner must be adjusted to provide a 3-inch high flame with an inner cone approximately one-third of the flame height. The minimum temperature of the hottest portion of the flame, as measured with a calibrated thermocouple pyrometer, may not be less than 1750° F. The burner must be positioned so that the hottest portion of the flame is applied to the test mark on the wire. Flame time, burn length, and flaming time of drippings, if any, must be recorded. The burn length determined in accordance with paragraph [(h)] of this Appendix must be measured to the nearest 1/10-inch. Breaking of the wire specimens is not considered failure.
(h) Burn length. Burn length is the distance from the original edge to the farthest evidence of damage to the test specimen due to flame impingement, including areas of partial or complete consumption, charring, or embrittlement, but not discolored, nor areas where material has shrunk or melted away from the heat source.
1155. APPENDIX F, [PART I] AMENDMENT 25-59, Effective November 26, 1984.
(a) Conditioning. Specimens must be conditioned to 70° F., plus or minus 5°, and at 50 percent plus or minus 5 percent relative humidity until moisture equilibrium is reached or for 24 hours. Only one specimen at a time may be removed from the conditioning environment immediately before subjecting it to the flame.
(b) Specimen configuration. Except as provided for materials used in electrical wire and cable insulation and in small parts, materials must be tested either as a section cut from a fabricated part as installed in the airplane or as a specimen simulating a cut section, such as: a specimen cut from a flat sheet of the material or a model of the fabricated part. The specimen may be cut from any location in a fabricated part; however, fabricated units, such as sandwich panels, may not be separated for test. The specimen thickness must be
656 no thicker than the minimum thickness to be qualified for use in the airplane, except that:
(1) thick foam parts, such as seat cushions, must be tested in ½-inch thickness; (2) when showing compliance with § 25.835(b-3) for materials used in small parts that must be tested, the materials must be tested in no more than ⅛-inch thickness; (3) when showing compliance with § 25.1359(d) for materials used in electrical wire and cable insulation, the wire and cable specimens must be the same size as used in the airplane. In the case of fabrics, both the warp and fill direction of the weave must be tested to determine the most critical flammability condition. When performing the tests prescribed in paragraphs (d) through (e) of [Part I of this Appendix,] the specimen must be mounted in a metal frame so that; (1) in the vertical tests of paragraph (d), the two long edges and the upper edge are held securely; (2) in the horizontal test of paragraph (e), the two long edges and the edge away from the flame are held securely; (3) the exposed area of the specimen is at least 2- inches wide and 12-inches long, unless the actual size used in the airplane is smaller; and
(4) the edge to which the burner flame is applied must not consist of the finished or protected edge of the specimen but must be representative of the actual cross-section of the material or part installed in the airplane. When performing the test prescribed in paragraph (f) of [Part I of this Appendix,] the specimen must be mounted in a metal frame so that all four edges are held securely and the exposed area of the specimen is at least 8- inches by 8-inches.
(c) Apparatus. Except as provided in paragraph (g) of [Part I of this Appendix,] tests must be conducted in a draft-free cabinet in accordance with Federal Test Method Standard 191 Method 5903 (revised Method 5902) for the vertical test, or Method 5906 for horizontal test (available from the General Services Administration, Business Service Center, Region 3, Seventh & D Streets, S.W., Washington, D.C., 20407) or other approved equivalent methods. Specimens which are too large for the cabinet must be tested in similar draft-free conditions.
(d) Vertical test in compliance with § 25.853(a) and (b). A minimum of three specimens must be tested and the results averaged. For fabrics, the direction of weave corresponding to the most critical flammability conditions must be parallel to the longest dimension. Each specimen must be supported vertically. The specimen must be exposed to a Bunsen or Tirrill burner with a nominal 3/8-inch I.D. tube adjusted to give a flame of 1½-inches in height. The minimum flame temperature measured by a calibrated thermocouple pyrometer in the center of the flame must be 1550° F. The lower edge of the specimen must be three-fourths-inch above the top edge of the burner. The flame must be applied to the center line of the lower edge of the specimen. For materials covered by § 25.853(a), the flame must be applied for 60 seconds and then removed. For materials covered by § 25.853(b), the flame must be applied for 12 seconds and then removed.
Flame time, burn length, and flaming time of drippings, if any, must be recorded. The burn length determined in accordance with paragraph (h) for [Part I of this Appendix] must be measured to the nearest one-tenth-inch.
(e) Horizontal test in compliance with § 25.853(b-2) and (b-3). A minimum of three specimens must be tested and the results averaged. Each specimen must be supported