95-2114. Improved Flammability Standards for Materials Used in the Interiors of Transport Category Airplane Cabins  

  • [Federal Register Volume 60, Number 22 (Thursday, February 2, 1995)]
    [Rules and Regulations]
    [Pages 6616-6629]
    From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
    [FR Doc No: 95-2114]
    
    
    
    
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    Part V
    
    
    
    
    
    Department of Transportation
    
    
    
    
    
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    Federal Aviation Administration
    
    
    
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    14 CFR Part 25 et al.
    
    
    
    Improved Flammability Standards for Materials Used in the Interiors of 
    Transport Category Airplane Cabins; Final Rule
    
    Federal Register / Vol. 60, No. 22 / Thursday, February 2, 1995 / 
    Rules and Regulations
    
    [[Page 6616]]
    
    
    DEPARTMENT OF TRANSPORTATION
    
    Federal Aviation Administration
    
    14 CFR Parts 25, 121, and 135
    
    [Docket No. 26192, Amendments Nos. 25-83, 121-247 and 135-55]
    RIN 2120-AD28
    
    
    Improved Flammability Standards for Materials Used in the 
    Interiors of Transport Category Airplane Cabins
    
    AGENCY: Federal Aviation Administration (FAA), DOT.
    
    ACTION: Final rule.
    
    -----------------------------------------------------------------------
    
    SUMMARY: These amendments clarify standards adopted in 1986 concerning 
    the flammability of components used in the cabins of certain transport 
    category airplanes. This action is being taken to preclude costly, 
    unintended changes to airplane interiors. The clarifications, which are 
    applicable to air carriers, air taxi operators and commercial 
    operators, as well as manufacturers of such airplanes, will result in 
    more appropriate, consistent application of those standards.
    
    EFFECTIVE DATE: March 6, 1995.
    
    FOR FURTHER INFORMATION CONTACT: Gary L. Killion, Manager, Regulations 
    Branch, ANM-114, Transport Airplane Directorate, Aircraft Certification 
    Service, FAA, 1601 Lind Avenue Southwest, Renton, Washington 98055-
    4056; telephone (206) 227-2114.
    
    SUPPLEMENTARY INFORMATION: 
    
    Background
    
        These amendments are based on Notice of Proposed Rulemaking (NPRM) 
    90-12, that was published in the Federal Register on April 12, 1990 (55 
    FR 13886).
        As discussed in the notice, Amendments 25-61 and 121-189 (51 FR 
    26206, July 26, 1986) were adopted to upgrade the flammability 
    standards for materials used in the interiors of transport category 
    airplanes. The improved flammability standards were developed following 
    a research and development program managed and conducted primarily at 
    the FAA Technical Center in Atlantic City, New Jersey, to study 
    aircraft fire characteristics and develop practical test methods. Among 
    the tests conducted at the Technical Center were full-scale fire tests 
    using the fuselage of a military C-133 configured to represent a wide-
    body jet transport airplane. The test conditions simulated 
    representative post-crash external fuel-fed fires. Numerous laboratory 
    tests were also conducted to correlate possible material qualification 
    test methods with the full-scale tests. As a result of those tests, the 
    Ohio State University (OSU) radiant rate-of-heat-release apparatus was 
    determined to be the most suitable for material qualification. These 
    tests led to the adoption of Amendment 25-61.
        Amendment 25-61 established flammability standards for transport 
    category airplanes with passenger seating capacities of 20 or more and 
    specified the test method and apparatus to be used in showing 
    compliance with those standards. It specified that interior ceiling and 
    wall panels (other than lighting lenses), partitions, and the outer 
    surfaces of galleys, large cabinets and stowage compartments (other 
    than underseat stowage compartments and compartments for stowing small 
    items such as magazines and maps) must meet the new standards. As 
    outlined in the amendment, an average of three or more test specimens 
    must not exceed 65 kilowatts per square meter peak heat release nor 65 
    kilowatt minutes per square meter total heat release during the first 
    two minutes of sample exposure time (65/65) when tested using the OSU 
    test apparatus. These acceptance criteria were chosen in order to 
    produce a significant retardation of the flashover event which controls 
    occupant survivability, as experienced in the full-scale testing. 
    (Burning cabin materials give off unburned gases that collect in the 
    upper portions of the cabin. After a very short time, these unburned 
    gases are heated to the point where they ignite and burn 
    instantaneously. When this occurs, the temperature in the whole cabin 
    becomes so hot that survival is impossible for anyone remaining in the 
    cabin. This phenomenon, known as flashover, also makes further survival 
    impossible by consuming the oxygen in the cabin.)
        Because Amendment 25-61 applies explicitly only to airplanes for 
    which an application for type certificate is made after August 20, 
    1986, Amendment 121-189 to Part 121 of the FAR was also adopted to 
    require operators of certain other airplanes used in air carrier or 
    commercial service to meet the new 65/65 standards. Those airplanes 
    must meet the new standards if they were newly manufactured after 
    August 19, 1990. Airplanes type certificated on or after January 1, 
    1958, and manufactured prior to August 20, 1990, must also comply with 
    the new standards upon the first substantially complete replacement of 
    the specified cabin interior components on or after the latter date.
        Although Part 135 was not amended at that time, air taxi and 
    commercial operators of large airplanes are required to comply as well 
    because Sec. 135.169 incorporated the newly adopted provisions of Part 
    121 by reference.
        At the time the amendments were adopted, the FAA understood that 
    some persons were planning to install components which, even though 
    they would meet the previously existing requirements of Part 25 for 
    flammability, were more flammable than the components that were in 
    general use at that time. In order to preclude a possible degradation 
    in the flammability characteristics of the cabin interiors, Amendment 
    121-189 also established interim standards of 100 kilowatts per square 
    meter peak heat release and 100 kilowatt minutes per square meter total 
    heat release (100/100). The interim standards are applicable to 
    airplanes manufactured during the two-year period prior to August 20, 
    1990; and, unless there is a substantially complete replacement of the 
    specified cabin interior components after August 19, 1990, they will 
    remain applicable to those airplanes as long as they are operated under 
    the provisions of Part 121 or Part 135. (If there is a substantially 
    complete replacement on or after August 19, 1990, the definitive 65/65 
    standards would be applicable.) In addition, the interim standards are 
    also applicable to airplanes in which there is a substantially complete 
    replacement of the specified interior components during that two-year 
    period.
        Prior to the adoption of Amendment 121-189, Sec. 121.312 required 
    certain airplanes to meet earlier flammability standards upon the first 
    substantially complete replacement of the cabin interior. (Note that 
    this earlier rulemaking refers to a substantially complete replacement 
    of all cabin interior components, while the later rulemaking refers to 
    a substantially complete replacement of the specified interior 
    components. Whether certain other interior components, e.g., seat 
    cushions and flooring, are replaced is not relevant to whether there is 
    a substantially complete replacement in the latter case. Also, the 
    earlier rulemaking applies to all airplanes while the later rulemaking 
    applies only to airplanes with 20 or more passengers.) This earlier 
    requirement is partially superseded if there is a substantially 
    complete replacement of the interior components specified in 
    Sec. 25.853 (a-l) after August 19, 1988. It does, however, remain 
    applicable insofar as interior components not specified in 
    Sec. 25.853(a-l) are concerned. The earlier requirement also remains 
    applicable to airplanes in which there has not been a substantially 
    complete 
    
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    replacement of the cabin interior since August 19, 1988, and to 
    airplanes with 19 or fewer passengers.
        The date of manufacture, as used in Sec. 121.312, is the date on 
    which inspection records show that an airplane is in a condition for 
    safe flight. This is not necessarily the date on which the airplane is 
    in conformity to the approved type design, or the date on which a 
    certificate of airworthiness is issued, since some items not relevant 
    to safe flight, such as passenger seats, may not be installed at that 
    time. It could be earlier, but would be no later than the date on which 
    the first flight of the airplane occurs.
        For reasons discussed in the preamble to that amendment, Amendment 
    25-66 was adopted (53 FR 37542, September 27, 1988) to make minor 
    refinements in the test procedures and apparatus required to show 
    compliance with the standards adopted by Amendment 25-61 and to add a 
    requirement for smoke testing. Amendment 121-198, which was adopted at 
    the same time, added a provision allowing deviations to be granted for 
    certain components.
        In the preamble to Amendment 25-61, the FAA noted that the new heat 
    release standards apply to all large-surface cabin interior components, 
    such as sidewalls, ceilings, bins and partitions, and galley 
    structures. It was also noted that the new standards do not apply to 
    smaller items because their small masses would preclude significant 
    contributions to the total heat release in the cabin area. The FAA has 
    received a number of requests for clarification as to the maximum size 
    a component may be without having to comply with the new heat release 
    standards.
        The distinction between parts with large surface areas, which must 
    meet the new standards, and those with smaller surface areas is very 
    difficult because of the size of the cabin and other factors that may 
    vary from one airplane to another. For example, a specific component 
    might be insignificant when installed in a large wide-body airplane 
    because it would make a minor contribution to the overall flammability 
    of the area of the cabin in which it is installed. On the other hand, 
    it might represent a major contribution when installed in a smaller 
    transport category airplane. The proximity of the component to a 
    potential source of fire, such as an exit or galley, is also a 
    consideration. It is not possible to cite a specific size that will 
    apply in all installations; however, as a general rule, components with 
    exposed-surface areas of one square foot or less may be considered 
    small enough that they do not have to meet the new standards. 
    Components with exposed-surface areas greater than two square feet may 
    be considered large enough that they do have to meet the new standards. 
    Those with exposed-surface areas greater than one square foot, but less 
    than two square feet, must be considered in conjunction with the areas 
    of the cabin in which they are installed before a determination could 
    be made.
    
    Discussion
    
        Since the time Amendments 25-61 and 121-189 were adopted, the FAA 
    became aware of four areas in which the wording of the new rules does 
    not clearly reflect the intent of the agency as discussed in the 
    preamble to those amendments. Because the new rules do not clearly 
    reflect the intent in those areas and because the comments that were 
    received may have been based on the intent, as expressed in the 
    preambles, rather than the literal wording of the rules, the following 
    clarifications were proposed in Notice 90-12.
        Cabin windows and clear vision panels in cabin partitions: The 
    preamble to Amendments 25-61 and 121-189 states, ``The new flammability 
    standards do not apply to transparent or translucent components such as 
    lenses used in interior lights and illuminated signs, and window anti-
    scratch panels, because of the lack of materials which will meet the 
    flammability standards and still have the light transmissibility 
    characteristics which are vital in emergency situations.'' Although not 
    specifically mentioned in the earlier rulemaking, transparent panels 
    are sometimes inserted in cabin partitions to enhance cabin safety. For 
    example, they are sometimes used to provide seated flight attendants a 
    clear, unobstructed view of the cabin or to provide passengers a view 
    of an exit as an aid to an emergency evacuation. As in the case of 
    lighting lenses and windows, the need for transparent partition panels 
    that enhance cabin safety outweighs the increased safety provided by 
    components that meet the new flammability standards considering the 
    small area such transparencies would involve. In order to preclude 
    confusion concerning the applicability of the standards to such 
    transparent or translucent panels, Sec. 25.853(a-l) (1) and (2) were 
    proposed to read, ``Interior ceiling and wall panels, other than 
    lighting lenses and windows,'' and, ``Partitions, other than 
    transparent panels needed to enhance cabin safety,'' respectively. The 
    maximum size of a transparent panel would, of course, be limited to 
    that which is actually needed to enhance cabin safety.
        It was noted that the FAA would consider further rulemaking to 
    require those components to meet the new flammability standards should 
    materials capable of meeting the new flammability standards and having 
    the necessary light transmissibility characteristics for use as 
    windows, etc., be developed later.
        Galleys: As currently worded, Sec. 25.853(a-1) states that the new 
    flammability standards apply to the ``outer surfaces of galleys.'' This 
    phrase was intended to make an exception for the interior surfaces of 
    galley cabinets, etc., that would not be exposed to a cabin fire. It is 
    ambiguous, however, because most galleys are not isolated from the main 
    cabin by a door. While one might consider the surfaces of a galley 
    working are to be ``inner surfaces,'' they are actually outer surfaces 
    in most installations in the sense that they could be exposed to a 
    cabin fire. In addition, the inner walls of the galley cart cavity or 
    standard container cavity may also be exposed on some lightly loaded 
    flights when there is not a full complement of carts or containers on 
    board. In order to preclude any confusion in this regard, it was 
    proposed that Sec. 25.853(a-1) would be amended to clarify that any 
    galley surface exposed to the passenger cabin must meet the new 
    standards.
        Isolated compartments: Unlike previously existing paragraphs (a) 
    and (b) of Sec. 25.853, the new flammability standards of paragraph (a-
    1) were intended to apply only to the passenger cabin and not to 
    compartments that are isolated from the passenger cabin. Due, however, 
    to the organization of Sec. 25.853(a-1), if taken literally, the new 
    standards also pertain to each compartment occupied by crew (including 
    one occupied only on a temporary basis) or passengers regardless of 
    whether the particular compartment is isolated from the passenger 
    cabin.
        Neither the research and development program nor the regulatory 
    evaluations on which the new flammability standards were based 
    considered that compartments isolated from the passenger cabin (or 
    cabins in the case of airplanes with passenger cabins located on two 
    different decks) would have to comply with the new standards. Unlike 
    most galleys located in the main cabin, remote galleys and other 
    compartments, such as lavatories, pilot compartments and crew rest or 
    sleeping areas, are generally isolated from the passenger cabin by at 
    least a door. In some instances, they are located on separate decks. 
    They would, therefore, not be exposed to a cabin fire until well after 
    
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    flashover had occurred in the cabin and egress was no longer possible. 
    Should an external fire enter the airplane at one of those 
    compartments, the flammability of the materials used in them would not 
    directly affect the cabin due to their isolation. As stated in the 
    earlier rulemaking, the new standards address a post-crash, external 
    fuel-fed fire situation. With the exception of the pilot compartment, 
    it can be assumed that such compartments would not be occupied by 
    passengers or crewmembers during a post-crash situation.
        Although the rulemaking was undertaken to address a post-crash 
    scenario, there is also the question of whether or not requiring the 
    lavatories to meet the new flammability standards would enhance safety 
    significantly in the event a fire originated in a lavatory during 
    flight. This question is particularly pertinent in light of the 
    recently adopted ban on smoking on domestic airline flights. Although 
    some persons might be more tempted to smoke illicitly in a lavatory 
    during such flights, the lavatory smoke detector required by recently 
    adopted Amendment 121-185 (50 FR 12726, March 29, 1985) serves as a 
    deterrent and provides warning of illicit smoking to the crew. In 
    addition, the new standards would not apply to many of the components 
    in a lavatory due to their small size. The doors and most sidewalls 
    have to meet the new standards regardless of whether the new standards 
    are applicable to lavatories because their outer sides also form 
    surfaces of the passenger cabin. Some portions of the lavatory are 
    generally constructed of fireproof stainless steel due to functional 
    considerations. Requiring the few remaining large components to meet 
    the new standards would have very little impact on the overall 
    flammability of the lavatory and would not significantly enhance safety 
    in the event of an inflight fire.
        Pilot compartments are generally isolated from the passenger cabin 
    by a bulkhead and door. Although they are obviously occupied full-time, 
    requiring them to meet the new standards would not significantly 
    enhance safety in the event of an inflight fire for essentially the 
    same reasons. Pilot compartments are generally constructed of many 
    small components which would not have to meet the new standards due to 
    their small size. The bulkhead and entry door have to meet the new 
    standards regardless of whether they are applicable to the pilot 
    compartment because the aft sides of those components also form 
    surfaces of the passenger cabin. As in the case of the lavatories, 
    requiring the few remaining large components to meet the new standards 
    would have very little impact on the overall flammability of the pilot 
    compartment. Although there is no smoke detector required, a fire would 
    be detected immediately by the flight crewmembers. In addition, at 
    least one hand fire extinguisher must be conveniently located in the 
    pilot compartment in accordance with Sec. 25.851.(a)(6).
        In view of these considerations, it was proposed that Sec. 25.853 
    would be amended to clarify that compartments that are isolated from 
    the cabin need not meet the standards. Sidewalls, doors etc., that 
    separate such compartments from the passenger cabin would, of course, 
    have to meet the new standards because their outer sides also form 
    surfaces of the passenger cabin.
        Galley carts and other rotatable galley equipment: The earlier 
    rulemaking contained the statement, ``Service items, such as pillows or 
    blankets, magazines, food, and alcoholic beverages, are not part of the 
    certification process and would not have to meet the new flammability 
    standard.'' Galley carts are considered to be service items; however, 
    unlike the items cited in the preamble statement, they are generally 
    approved as part of the airplane type design. Although the new 
    flammability standards do not apply expressly to galley carts, it was 
    intended that they would apply implicitly to the extent that, when 
    stowed, the galley carts form exterior surfaces of the galley. 
    Typically, at least one end of each cart remains exposed and forms a 
    galley surface while the cart is stowed. In addition to galley carts, 
    these are galley standard containers used for various meal courses, 
    beverages, plates, etc., that also form galley surfaces when stowed.
        Operators have pointed out that galley carts are removable items 
    that are rotated from one airplane to another with each flight. In this 
    regard, they note that their fleets will include older airplanes that 
    are not required to meet the new standards, as well as new airplanes 
    (or airplanes in which the interiors have been replaced) that will be 
    required to meet the new standards. They further note that the carts 
    are loaded before a flight by persons, usually independent caterers, 
    who have no way of knowing whether or not the airplane that will be 
    used on a particular flight is required to meet the new standards. 
    Unless all existing noncomplying galley carts are replaced with galley 
    carts that meet the new standards, there is no practical means to 
    ensure that galley carts meeting the new standards will be loaded on 
    the airplanes that are required to have them. It is estimated that 
    there are now approximately 125,000 galley carts in use with the U.S. 
    air carrier fleet. Typically, the cost per cart ranges from $800 to 
    $3,500; and the service life is about eight to ten years. While it is 
    feasible to replace the existing carts on an attrition basis, it would 
    be impractical to produce enough galley carts meeting the new standards 
    in time to meet the established deadlines. In addition, such immediate 
    replacement would be very costly. The operators note that they would 
    have commented accordingly had they not believed that, as service 
    items, galley carts did not have to meet the new standards.
        The galley standard containers are also rotated from airplane to 
    airplane; and they, too, are filled prior to the flight by persons who 
    have no way of knowing whether the airplane that will be used on the 
    flight is one required to meet the new standards. While the cost of 
    each galley standard container would be less than that of a beverage 
    cart, replacing the entire inventory of containers would be very 
    costly.
        Although it was intended that the exposed surfaces of stowed galley 
    carts and standard containers should meet the new standards, the FAA 
    has concluded, upon further review, that it was not clearly stated that 
    the galley carts and containers would be required to comply. The FAA 
    does, however, consider that the exposed surfaces of stowed galley 
    carts and standard containers must ultimately meet the new flammability 
    standards. It was, therefore, proposed that Sec. 25.853(a-1) would be 
    amended to specifically require the exposed surfaces of those 
    components to meet the new standards.
        The FAA concurs that unless all carts and containers are replaced, 
    it would be extremely difficult to ensure that galley carts and 
    standard containers meeting the new standards are loaded on the 
    airplanes that are required to meet them. Furthermore, the immediate 
    replacement of all galley carts and standard containers would be 
    logistically impossible and would present an unreasonable economic 
    burden. If, on the other hand, galley carts and standard containers 
    that meet the new standards are acquired at a rate commensurate with 
    the rate at which new airplanes are acquired (and interiors of older 
    airplanes are replaced), it can be assumed that the overall level of 
    safety of the air carrier fleet will not be adversely affected by 
    intermixing carts and containers complying with the new standards with 
    those that do not. The small decrement of safety that would be suffered 
    due to 
    
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    the use of noncomplying carts and containers in an airplane that must 
    meet the new standards would be compensated by an increment of safety 
    enjoyed due to the use of complying carts and containers in another 
    airplane that is not required to meet them. It was, therefore, proposed 
    that Sec. 121.312 would be amended to allow such intermixing of galley 
    carts and standard containers, provided that all carts and containers 
    manufactured after a specified date meet the new standards.
        Other changes: Certain minor refinements in the test apparatus and 
    procedures were identified; and it was proposed that Appendix F of Part 
    25, including the associated figures, would be revised accordingly. The 
    proposed refinements would not preclude the use of materials previously 
    found to be acceptable under the new standards; nor enable the use of 
    materials previously found unacceptable; however, they would improve 
    the repeatability of test results from one test run to another and from 
    one laboratory to another. Other minor nonsubstantive editing changes 
    would be made for consistency in style. Nonsubstantive editing changes 
    would also be made to Sec. 25.853 for clarity.
        It was also proposed that the organization and language of 
    Sec. 121.312(a) would be revised for clarity.
        As noted above, Part 135 was not amended at the time the new 
    standards were adopted; however, they are equally applicable to Part 
    135 operators because Sec. 135.169(a) incorporates the provisions of 
    Sec. 121.312 by cross reference. Since that time, it has come to the 
    attention of the FAA that the practice of incorporating certain 
    provisions of Part 121 in Part 135 by cross reference may cause 
    confusion. In order to preclude any confusion in this regard, it was 
    proposed that Part 135 would be amended to include the new standards 
    explicitly rather than by reference. Because Part 135 operators are 
    already required to meet these standards due to the incorporation by 
    cross reference, this change would not place any additional burden on 
    any person.
        The reference to ``November 26, 1987'' in Sec. 121.312(b) is no 
    longer relevant because that date has already passed. It would, 
    therefore, be removed for simplification. The redundant reference to 
    Appendix F of Part 25 would also be removed from Sec. 121.312(b) for 
    simplification and consistency with the editorial style used in 
    Sec. 121.312(a). (Appendix F, Part II, is incorporated by cross 
    reference in Sec. 25.853(c); and Appendix F, Part IV, is incorporated 
    by cross reference in Sec. 25.853(a-1).)
        Since the time Notice 90-12 was issued, Amendment 25-72 was adopted 
    (55 FR 29756, July 20, 1990). Although no substantive changes to 
    Sec. 25.853 were adopted, the requirements of that section were 
    rearranged considerably for clarity, and the test acceptance criteria 
    formerly contained in that section were transferred to Part I of 
    Appendix F. It is, therefore, necessary to make a number of 
    nonsubstantive conforming changes for consistency with Sec. 25.853 in 
    its present format.
        Among the changes made to Sec. 25.853 as a result of the adoption 
    of Amendment 25-72 was the transfer of the seat cushion flammability 
    standards from former Sec. 25.853(c) to new Sec. 25.853(b). It has been 
    brought to the attention of the FAA that this change is causing 
    considerable confusion.
        Seats are frequently transferred from one airplane to another; 
    therefore, as a practical matter, they must be marked to show that 
    their cushions comply with the flammability standards. With the change 
    in section number, the previous markings indicating compliance with 
    Sec. 25.853(c) are no longer accurate. In order to eliminate further 
    confusion in that regard, Sec. 25.853(b) has been marked ``Reserved,'' 
    and the seat cushion flammability standards have been transferred back 
    to Sec. 25.853(c).
        For convenience, the proposed changes to Sec. 25.853 are discussed 
    below both in terms of their identity in Notice 90-12 and as rearranged 
    for conformity with the changes resulting from the adoption of 
    Amendment 25-72.
    
    Discussion of Comments
    
        Seven commenters responded to the request for comments contained in 
    Notice 90-12. These included manufacturers, a foreign airworthiness 
    authority, and organizations representing manufacturers, airlines, and 
    airline employees.
        One commenter notes that the restructuring and numbering of 
    Sec. 25.853 may have inadvertently excluded such items as lighting 
    lenses, windows, transparent panels needed to enhance cabin safety, 
    etc., from compliance with any of the flammability standards of 
    Sec. 25.853. The FAA concurs that the wording proposed in Notice 90-12 
    could have led to an incorrect interpretation of that nature. Section 
    25.853 is, therefore, changed by transferring the statement ``Except as 
    provided * * *'' to Sec. 25.853(d), which would have been 
    Sec. 25.853(a-1) as proposed in Notice 90-12.
        One commenter opposes the proposal to clarify that compartments 
    isolated from the cabin are not required to meet the heat release 
    standards of Sec. 25.853(a-l). The commenter states that all 
    compartment components should be of the same standard and that meeting 
    the same standard would ensure that the net amount of material 
    contributing to fire development and propagation is at the absolute 
    minimum. In that regard, the commenter cites the accident involving a 
    McDonnell Douglas DC-9 operated by Air Canada on June 2, 1983, at the 
    Greater Cincinnati Airport, Covington, Kentucky. The commenter notes 
    that, while the origin of the fire that destroyed the airplane could 
    not be identified, the lavatory compartment's interior material was the 
    primary source of fuel and that the fire burned undetected for almost 
    15 minutes before the smoke was first noticed. The commenter asserts 
    that requiring the compartment to meet the same low heat release 
    standards as the main cabin would significantly reduce the amount of 
    fuel available for such a fire.
        Contrary to the commenter's assertion, requiring all lavatory 
    components to meet the new standards for heat release would not 
    significantly reduce the amount of fuel available for a fire 
    originating in the lavatory. As noted above under Background, the heat 
    release standards do not apply to small surface-area components. As 
    further noted above under Discussion, many of the components in the 
    lavatory are small enough that they would not have to meet the new 
    standards in any event. The doors and most sidewalls have to meet the 
    new standards regardless of whether the new standards are applicable to 
    lavatories because their outer sides also form surfaces of the 
    passenger cabin. Some portions of the lavatory are generally 
    constructed of stainless steel due to functional considerations. 
    Stainless steel is, of course, fireproof. Requiring the few remaining 
    large components to meet the new standards would have very little 
    impact on the overall flammability of the lavatory and would not 
    significantly enhance safety in the event of an inflight fire.
        In the accident cited by the commenter, smoke was discovered coming 
    from the left-hand lavatory in the aft cabin while the airplane was 
    enroute from Dallas, Texas to Montreal, Quebec. An emergency landing 
    was not made until 17 minutes later. By that time, the fire and smoke 
    had grown in intensity to the point that only half of the 46 occupants 
    were able to escape. As noted in their official accident report, NTSB/
    AAR-86/02, the National Transportation Safety Board determined that the 
    probable causes of the accident were a fire of unknown origin, an 
    underestimate of the fire severity, and 
    
    [[Page 6620]]
    misleading fire progress information provided to the captain. 
    Considering the few lavatory components that would be affected and the 
    time that the fire had been burning prior to the emergency landing, it 
    is unlikely that the outcome of the accident would have been more 
    favorable if the lavatory of that airplane had met the new heat release 
    standards.
        Subsequent to the accident, the FAA adopted Amendments 25-58 and 
    121-183 (49 FR 43182, October 26, 1984), and 25-59 and 121-184 (49 FR 
    43188, October 26, 1984), that require, respectively, low-level 
    lighting to enable occupants to locate emergency exits in smoke-filled 
    cabins and new flammability standards for seat cushions. Unlike the 
    heat release standards of Amendment 25-61, the new flammability 
    standards for seat cushions are designed to slow the progression of a 
    fire through the cabin. The standards of Amendment 25-61 are, on the 
    other hand, designed to reduce the overall release of heat into the 
    cabin during a post-crash fire situation and provide more time for 
    egress before flashover makes further escape impossible. Amendment 121-
    185 (50 FR 12726, March 29, 1985) was also adopted to require each 
    lavatory to be equipped with a smoke detection system, or equivalent, 
    and a fire extinguisher that discharges automatically upon the 
    occurrence of a fire in the trash receptacle. In addition, the 
    amendment requires the passenger cabins of certain airplanes to be 
    equipped with additional hand fire extinguishers, some of which must 
    contain the improved agent Halon 1211.
        The commenter also notes that all compartments with essential 
    systems adjacent to their surfaces should be required to meet the heat 
    release standards of Sec. 25.853(a-1) in order to protect the essential 
    conductors of those systems from the high heat releases of burning 
    interior materials.
        The commenter appears to be confusing the standards for heat 
    release with other standards for flame resistance. As noted above, the 
    heat release standards are designed to reduce the overall release of 
    heat into an area and thereby delay the time until flashover occurs. It 
    is assumed, on the other hand, that the insulation of electrical wiring 
    and cables could be enveloped by flame. They must, therefore, be tested 
    by actual application of flame to the insulation surface.
        The same commenter recommends that, if an isolated compartment does 
    not have to meet the heat release standards, the doors separating the 
    compartment from the main cabin should be able to contain the heat and 
    smoke in the isolated compartment for at least five minutes. (Such 
    doors would be `fire-resistant' as defined in Part 1 of the FAR.)
        The commenter's recommendation is apparently based on the 
    assumption that there will be an uncontrollable fire originating from 
    an isolated compartment. In view of the fire protection measures that 
    have been adopted for lavatories since the above noted accident, there 
    is no evident need for fire-resistant lavatory doors. Furthermore, 
    service history does not support a need for such doors to other 
    isolated compartments. The exception proposed as Sec. 25.853(a-2) is, 
    therefore, adopted as Sec. 25.853(e).
        One commenter recommends that Sec. 25.853(a-1)(1) be amended to 
    read, ``other than lighting lenses, illuminated signs and windows,'' 
    since illuminated signs are discussed in the preamble to Notice 90-12 
    as examples of excluded items. While it is true that the illuminated 
    portions of passenger information signs are not required to meet the 
    heat release standards of that section, it is not necessary to refer to 
    them specifically in Sec. 25.853(a-1)(1) because they are ``lighting 
    lenses.'' Proposed Sec. 25.853(a-1)(1) is adopted as Sec. 25.853(d)(1).
        The same commenter and one other recommend that Sec. 25.853(a-2) be 
    clarified by adding ``lavatories'' to the list of compartments whose 
    interiors are excluded. Unlike the illuminated signs discussed above, 
    it may not be as clear that lavatories are considered isolated 
    compartments and, as such, are already excluded. Proposed 
    Sec. 25.853(a-2) is, therefore, changed to read, ``* * * such as pilot 
    compartments, galleys, lavatories, crew rest quarters, cabinets and 
    stowage compartments, * * *,'' and adopted as Sec. 25.853(e).
        One commenter suggests that Sec. 25.853(a-2) should stipulate ``20 
    or more passengers.'' Since the only purpose of this paragraph, adopted 
    as paragraph (e), is to make an exception to paragraph (a-1), adopted 
    as paragraph (d), which is already so limited, there is no need to 
    repeat this limitation of applicability.
        Because the flammability standards of Sec. 25.853(d), formerly 
    Sec. 25.853(a-1), are applicable only to airplanes with 20 or more 
    passengers, some persons have mistakenly assumed that the seat cushion 
    standards of Sec. 25.853(c) are also applicable only to airplanes with 
    20 or more passengers. To preclude any confusion in this regard, the 
    phrase, ``regardless of the passenger capacity of the airplane,'' has 
    been added to Sec. 25.853 (a) and (c).
        Another commenter suggests that Part IV of Appendix F should be 
    amended to permit the use of the optional 14-hole upper pilot burner 
    that has been found satisfactory. Actually, the use of this optional 
    burner has already been accepted by the FAA under the equivalent safety 
    provisions of Sec. 21.21(b)(1). The FAA notes that test data obtained 
    during testing with the three-hole burner are sometimes invalidated 
    because the pilot burner would not remain lighted for the entire 5-
    minute duration of the test. With the optional 14-hole burner, there is 
    a greater probability of reigniting any flamelets that might extinguish 
    during a test. Because the 14-hole burner may be preferable in some 
    instances, Part IV is amended to describe the optional use of that 
    burner, as suggested by the commenter. Testing with this optional 
    burner is already permitted under the equivalent safety provisions of 
    Sec. 21.21(b)(1); therefore, this is a minor nonsubstantive change that 
    places no additional burden on any person.
        Paragraph (b)(8) states that the pilot burners must remain lighted 
    for the entire duration of the test. In regard to the difficulties 
    experienced in keeping the three-hole upper pilot burner lighted for 
    the entire duration of the test, the FAA proposed to add the statement, 
    ``Intermittent pilot flame extinguishment for more than 3 seconds would 
    invalidate the test results.'' The same commenter notes that further 
    clarification is required. According to the commenter, it is normal for 
    some of the upper pilot-burner flamelets to be extinguished for periods 
    that can exceed three seconds when samples containing flame retardants 
    are tested. The commenter notes that the results of such tests have 
    been considered acceptable provided some of the flamelets have remained 
    lighted.
        The FAA concurs that it is not necessary for each flamelet of the 
    three-hole upper pilot burner to remain lighted for the entire 5-minute 
    duration of the test; however, test results may be invalidated if two 
    flamelets are unlighted for more than 3 seconds. In order to preclude, 
    such intermittent flamelet extinguishment, the FAA has permitted 
    applicants to install an igniter. Intermittent flame extinguishment has 
    not posed a problem with the optional 14-hole upper pilot burner since 
    it was developed to preclude flame extinguishment. Paragraph (b)(8) is, 
    therefore, changed to read, ``Since intermittent pilot flame 
    extinguishment for more than 3 seconds would invalidate the test 
    results, a spark igniter may be installed to ensure that the burners 
    remain lighted.'' Paragraph 
    
    [[Page 6621]]
    (e)(8), which is considered a more appropriate location than paragraph 
    (b)(8), is amended to clarify the requirements for burners and 
    flamelets to remain lighted.
        Part IV, paragraph (e)(3) states that the proper air flow may be 
    set and monitored by either an orifice meter or a rotometer. Because of 
    difficulties experienced in setting and monitoring the air flow with a 
    rotometer, the FAA proposed in Notice 90-12 to amend that paragraph to 
    refer only to an orifice meter. The same commenter cited the successful 
    use of a rotometer by the National Research Council of Canada and 
    recommended that the reference to a rotormeter be retained in that 
    paragraph. While the use of a rotometer may be successful in some 
    instances, the FAA does not have sufficient information at this time to 
    conclude that a rotometer is acceptable on a general basis. It is, 
    therefore, not considered appropriate to specifically cite the 
    rotormeter in that paragraph as an acceptable alternative means of 
    setting and monitoring air flow. The FAA does recognize, however, that 
    rotometers, or any other devices for that matter, may be improved to 
    the point that their use is acceptable. In that event, those devices 
    could be used under the equivalent safety provisions of 
    Sec. 21.21(b)(1).
        The same commenter notes that the area of .02323 m2 specified 
    in the heat release equation of paragraph (f)(2) is based on a test 
    specimen size of 6 x 6 inches. Since the actual size of the sample is 
    150 x 150 mm, the commenter believes that an area factor of .0225 
    m2 should actually be used in the heat release equation.
        Although the commenter is technically correct, the definitive 65/65 
    and the interim 100/100 standards were established based on the use of 
    a factor of .02323 m2. Furthermore all testing completed to date 
    has been based on the use of the .02323 factor. Changing the factor to 
    .0225 at this late date would mean that the 65/65 and 100/100 standards 
    would have to be changed to 67/67 and 103/103, respectively, in order 
    to preclude a degradation of the components approved for use in 
    airplane cabins. This would no doubt cause considerable confusion, 
    particularly when test results obtained with the .0225 factor are 
    compared with earlier test results obtained with the original .02323 
    factor.
        The same commenter notes that considerable confusion is created by 
    the fact that dimensions of the the test apparatus are specified in 
    U.S. units in some instances and in metric units in others. The FAA 
    concurs. For clarity, part IV is revised to show dimensions in both 
    U.S. units and their metric equivalents. Other minor, nonsubstantive 
    changes are also made to Part IV for clarity.
        Section 121.312(a) incorporates the heat release standards of 
    Sec. 25.853(a-1) by cross reference. Since the latter section applies 
    only to airplanes with passenger capacities of 20 or more, 
    Sec. 121.312(a) requires compliance with these heat release standards 
    only for airplanes with passenger capacities of 20 or more. As one 
    commenter notes, Sec. 121.312(a) can be misinterpreted to require 
    compliance for all transport category airplanes regardless of their 
    passenger capacity. In order to preclude possible confusion in this 
    regard, both Sec. 121.312(a) and newly adopted Sec. 135.170(b)(1) state 
    specifically that compliance is required only for airplanes with 
    passenger capacities of 20 or more.
        Another commenter notes that Sec. 121.312(a) (1) through (6) and 
    the corresponding Sec. 135.170(b)(1) (i) through (vi) are complex and 
    difficult to understand. The FAA acknowledges that these sections are 
    very complex. This is due primarily to the fact that there are 
    differing requirements dependent on such factors as when the airplane 
    was type certificated, when it was manufactured, when there was a 
    substantially complete replacement of the cabin interior components, 
    etc. There is even a distinction between complete replacement of all 
    cabin interior components in one case and just those components 
    identified in Sec. 25.853(a-1) in another. The only way in which the 
    provisions of these sections could be significantly simplified would be 
    to require compliance for all airplanes at one time. While that would 
    simplify the regulatory language considerably, it would impose costly 
    additional burdens on some operators with no commensurate improvement 
    in safety. Nevertheless, minor nonsubstantive changes have been made 
    wherever possible to clarify these requirements.
        Proposed Sec. 121.312(a)(8) states, in part, that ``* * * galley 
    carts and galley standard containers that do not meet the heat release 
    rate testing requirements * * * may be used * * * provided the galley 
    carts or standard containers were manufactured prior to August 20, 
    1990.'' One commenter believes that this section should refer to galley 
    carts and standard containers manufactured prior to a date two years 
    after the effective date of this amendment.
        The FAA concurs that it is inappropriate to specify a date earlier 
    than the date on which this final rule becomes effective. The FAA does 
    not, however, agree that an additional two-year compliance time is 
    necessary. The amendment does not require galley carts and standard 
    containers manufactured after the specified date to comply. Instead, it 
    relieves operators of the burden of ensuring that only complying galley 
    carts and standard containers are loaded on airplanes that are required 
    to meet the new flammability standards provided the galley carts and 
    standard containers are manufactured prior to that date. Section 
    121.312(a)(8) and the corresponding Sec. 135.170(b)(viii) are, 
    therefore, changed to read, ``* * * provided the galley carts or 
    standard containers were manufactured prior to March 6, 1995.
        One commenter believes that there should be a specific definition 
    of what constitutes ``substantially complete replacement'' as stated in 
    Sec. 121.312. The commenter expresses concern that the definition 
    should allow for the individual replacement of cabin interior 
    components without the mandatory replacement of all components at the 
    same time.
        ``Complete replacement,'' as used in Sec. 121.312 and newly adopted 
    Sec. 135.170(b), means that all of the affected components in the cabin 
    are replaced. (As noted above under Background, whether the other 
    components that are not affected, e.g. seat cushions and flooring, are 
    replaced is not relevant.) The qualifying word ``substantially'' was 
    added simply to prevent operators from avoiding compliance by not 
    replacing a minor, inconsequential cabin component and claiming that 
    there had not been a ``complete replacement.'' Section 212.312 does, 
    therefore, permit individual replacement of cabin interior components 
    without the mandatory replacement of all components at the same time. 
    This, of course, assumes that the cabin components did not already have 
    to meet the heat release standards because of the date of manufacture 
    of the airplane or because they had been completely replaced 
    previously. It should also be noted that removing components for 
    refinishing and reinstalling them in the same airplane is considered 
    ``refurbishment,'' not ``replacement.''
        Proposed Sec. 135.170(b) states, ``No person may operate a large 
    airplane unless * * *'' Several commenters note that Part 23 commuter 
    category airplanes are ``large airplanes,'' as defined by Part 1 of the 
    FAR, and, as such, would be required to meet the new flammability 
    standards contained in that section. Another commenter has a similar 
    concern that proposed 
    
    [[Page 6622]]
    Sec. 135.170(b) would appear to add substantial requirements for 
    airplanes type certificated under the provisions of Part 23 and Special 
    Federal Aviation Regulations (SFAR) No. 41.
        Although commuter category airplanes may be large enough to be 
    ``large airplanes'' as defined by Part 1, they are not permitted to 
    carry more than 19 passengers. Since the flammability standards of 
    Sec. 135.170(b) apply only to airplanes with more than 19 passengers, 
    commuter category airplanes would not be required to comply even though 
    they may be ``large airplanes.'' SFAR No. 41 provides that, contrary 
    provisions of Part 1 notwithstanding, airplanes certificated under the 
    provisions of that SFAR are considered to be ``small airplanes'' in 
    regard to compliance with Part 135. Furthermore they, like commuter 
    category airplanes, are not permitted to carry more than 19 passengers.
        Since neither commuter category airplanes nor those type 
    certificated under the provisions of SFAR No. 41 are permitted to carry 
    more than 19 passengers, there is no need to amend Sec. 135.170(b) of 
    specifically exclude those airplanes. Specifically stating in 
    Secs. 121.312(a) and 135.170(b)(1) that only airplanes with 20 or more 
    passengers seats are required to comply, as discussed above, will 
    preclude confusion in this regard.
        One commenter reiterates a belief that the seat cushion 
    flammability standards of Sec. 25.853(c) are an unnecessary burden for 
    operators of small transport category airplanes with passenger seating 
    capacities of fewer than 19 passengers. The commenter is referring in 
    this regard to the provisions of Sec. 121.312 which were previously 
    incorporated by cross reference in Sec. 135.169 and now are stated 
    explicitly as new Sec. 135.170(b)(2). Section 121.312(b) and the new 
    Sec. 135.170(b)(2), in turn specify that the operator must have seat 
    cushions that meet the flammability standards of Sec. 25.853(c). That 
    issue has already been addressed by FAA in earlier rulemaking and is 
    not related, in any substantive manner, to the present rulemaking.
        Another commenter notes an inadvertent error in proposed 
    Sec. 135.169(a) in that it would incorporate Sec. 121.311 by cross 
    reference. The intent was to move the no longer needed reference to 
    Sec. 121.312, not to replace it with Sec. 121.311. Section 135.169(a) 
    is corrected accordingly.
    
    Regulatory Evaluation
    
    Regulatory Evaluation
    
        Exeuctive Order 12291, dated February 17, 1981, directs Federal 
    agencies to promulgate new regulations or modify existing regulations 
    only if potential benefits to society for each regulatory change 
    outweigh potential costs. This section summarizes the full regulatory 
    evaluation prepared by the FAA that provides more detailed estimates of 
    the economic consequences of this regulatory action.
        The evaluations prepared for Amendments 25-61 and 121-189, and 
    Amendments 25-66 and 121-198 remain unchanged by this rule with respect 
    to costs and benefits, regulatory flexibility determinations, and trade 
    impact assessment.
        None of the amendments in this rule will generate significant costs 
    or benefits. In part, the rule clarifies the original intent of the 
    earlier amendments. The changes to the test apparatus and procedures 
    for determining heat release rate are minor refinements that will 
    result only in negligible costs and benefits. The amendment to Part 135 
    is a nonsubstantive change that incorporates existing requirements 
    explicitly rather than by cross reference. The remaining changes are 
    editorial or conforming in nature.
    
    Regulatory Flexibility Determination
    
        The Regulatory Flexibility Act of 1989 (RFA) was enacted by 
    Congress to ensure that small entities are not unnecessarily or 
    disproportionately burdened by Government regulations. The RFA requires 
    a Regulatory Flexibility Analysis if a rule has a significant economic 
    impact, either detrimental or beneficial, on a substantial number of 
    small entities. FAA Order 2100.14A, Regulatory Flexibility Criteria and 
    Guidance, established threshold cost values and small entity size 
    standards for complying with RFA review requirements in FAA rulemaking 
    actions. The FAA has determined that this rule will not have a 
    significant economic impact on a substantial number of small entities.
    International Trade Impact Analysis
    
        This rule will not have an adverse impact either on the trade 
    opportunities of U.S. operators or manufacturers of transport category 
    airplanes doing business abroad, or on foreign operators or aircraft 
    manufacturers doing business in the United States.
    
    Federalism Implications
    
        The regulations adopted herein will not have substantial direct 
    effects on the States, on the relationship between the national 
    government and the States, or on the distribution of power and 
    responsibilities among the various levels of government. Therefore, in 
    accordance with Executive Order 12612, it is determined that this final 
    rule will not have sufficient federalism implications to warrant the 
    preparation of a Federalism Assessment.
        Conclusion: Because the regulations adopted herein are expected to 
    result only in negligible costs, the FAA has determined that this final 
    rule is not major as defined in Executive Order 12291. Because this is 
    an issue that has not prompted a great deal of public concern, this 
    final rule is not considered to be significant as defined in Department 
    of Transportation Regulatory Policies and Procedures (44 FR 11034, 
    February 26, 1979). In addition, since there are no small entities 
    affected by this rulemaking, it is certified, under the criteria of the 
    Regulatory Flexibility Act, that this final rule, at promulgation, will 
    not have a significant economic impact, positive or negative, on a 
    substantial number of small entities. The regulatory evaluation 
    prepared for Amendments 25-66 and 121-198 remains applicable and has 
    been placed on the docket. A copy of this evaluation may be obtained by 
    contacting the person identified under the caption FOR FURTHER 
    INFORMATION CONTACT.
    
    List of Subjects
    
    14 CFR Part 25
    
        Aircraft, Air transportation, Aviation safety, Safety.
    
    14 CFR Part 121
    
        Air carriers, Aircraft, Airplanes, Air transportation, Aviation 
    safety, Common carriers, Flammable materials, Safety, Transportation.
    
    14 CFR Part 135
    
        Air carriers, Aircraft, Airplanes, Air transportation, Aviation 
    safety, Cargo, Hazardous materials, Mail, Safety, Transportation.
    
    Adption of the Amendment
    
        Accordingly, 14 CFR Parts 25, 121 and 135 of the Federal Aviation 
    Regulations (FAR) are amended as follows:
    
    PART 25--AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES
    
        1. The authority citation for Part 25 is revised to read as 
    follows:
    
        Authority: 49 U.S.C. 106(g), 1344, 1354(a), 1355, 1421, 1423, 
    1424, 1425, 1428, 1429, 1430.
    
        2. By revising Sec. 25.853 to read as follows:
    
    [[Page 6623]]
    
    
    
    Sec. 25.853  Compartment interiors.
    
        For each compartment occupied by the crew or passengers, the 
    following apply:
        (a) Materials (including finishes or decorative surfaces applied to 
    the materials) must meet the applicable test criteria prescribed in 
    Part I of Appendix F of this Part, or other approved equivalent 
    methods, regardless of the passenger capacity of the airplane.
        (b) [Reserved]
        (c) In addition to meeting the requirements of paragraph (a) of 
    this section, seat cushions, except those on flight crewmember seats, 
    must meet the test requirements of part II of Appendix F of this Part, 
    or other equivalent methods, regardless of the passenger capacity of 
    the airplane.
        (d) Except as provided in paragraph (e) of this section, the 
    following interior components of airplanes with passenger capacities of 
    20 or more must also meet the test requirements of parts IV and V of 
    Appendix F of this Part, or other approved equivalent method, in 
    addition to the flammability requirements prescribed in paragraph (a) 
    of this section:
        (1) Interior ceiling and wall panels, other than lighting lenses 
    and windows;
        (2) Partitions, other than transparent panels needed to enhance 
    cabin safety;
        (3) Galley structure, including exposed surfaces of stowed carts 
    and standard containers and the cavity walls that are exposed when a 
    full complement of such carts or containers is not carried; and
        (4) Large cabinets and cabin stowage compartments, other than 
    underseat stowage compartments for stowing small items such as 
    magazines and maps.
        (e) The interiors of compartments, such as pilot compartments, 
    galleys, lavatories, crew rest quarters, cabinets and stowage 
    compartments, need not meet the standards of paragraph (d) of this 
    section, provided the interiors of such compartments are isolated from 
    the main passenger cabin by doors or equivalent means that would 
    normally be closed during an emergency landing condition.
        (f) Smoking is not to be allowed in lavatories. If smoking is to be 
    allowed in any other compartment occupied by the crew or passengers, an 
    adequate number of self-contained, removable ashtrays must be provided 
    for all seated occupants.
        (g) Regardless of whether smoking is allowed in any other part of 
    the airplane, lavatories must have self-contained, removable ashtrays 
    located conspicuously on or near the entry side of each lavatory door, 
    except that one ashtray may serve more than one lavatory door if the 
    ashtray can be seen readily from the cabin side of each lavatory 
    served.
        (h) Each receptacle used for the disposal of flammable waste 
    material must be fully enclosed, constructed of at least fire resistant 
    materials, and must contain fires likely to occur in it under normal 
    use. The capability of the receptacle to contain those fires under all 
    probable conditions of wear, misalignment, and ventilation expected in 
    service must be demonstrated by test.
        3. By amending part IV of Appendix F to Part 25 by revising 
    paragraphs (a), (b)(1) through (6), (b)(8), (c)(1), (d) heading and 
    (d)(1), (d)(3), (e)(1) through (5), (e)(8), (f)(2), and by adding 
    paragraph (c)(3); transferring Figures 1 through 5 at the end of 
    Appendix F to the end of part IV of Appendix F and adding a heading 
    preceding the figures, and by removing Figure 1 of part IV and adding 
    Figures 1A and 1B in its place to read as follows:
    
    Appendix F to Part 25
    
    * * * * *
        Part IV--Test Method to Determine the Heat Release Rate from Cabin 
    Materials Exposed to Radiant Heat.
        (a) Summary of Method. Three or more specimens representing the 
    completed aircraft component are tested. Each test specimen is injected 
    into an environmental chamber through which a constant flow of air 
    passes. The specimen's exposure is determined by a radiant heat source 
    adjusted to produce, on the specimen, the desired total heat flux of 
    3.5 W/cm2. The specimen is tested with the exposed surface 
    vertical. Combustion is initiated by piloted ignition. The combustion 
    products leaving the chamber are monitored in order to calculate the 
    release rate of heat.
        (b) * * *
        (1) This apparatus is shown in Figures 1A and 1B of this part IV. 
    All exterior surfaces of the apparatus, except the holding chamber, 
    must be insulated with 1 inch (25 mm) thick, low density, high 
    temperature, fiberglass board insulation. A gasketed door, through 
    which the sample injection rod slides, must be used to form an airtight 
    closure on the specimen hold chamber.
        (2) Thermopile. The temperature difference between the air entering 
    the environmental chamber and that leaving must be monitored by a 
    thermopile having five hot, and five cold, 24-guage Chromel-Alumel 
    junctions. The hot junctions must be spaced across the top of the 
    exhaust stack, .38 inches (10 mm) below the top of the chimney. The 
    thermocouples must have a .050  .010 inch (1.3  
    .3mm) diameter, ball-type, welded tip. One thermocouple must be located 
    in the geometric center, with the other four located 1.18 inch (30 mm) 
    from the center along the diagonal toward each of the corners (Figure 5 
    of this part IV). The cold junctions must be located in the pan below 
    the lower air distribution plate (see paragraph (b)(4) of this part 
    IV). Thermopile hot junctions must be cleared of soot deposits as 
    needed to maintain the calibrated sensitivity.
        (3) Radiation Source. A radiant heat source incorporating four Type 
    LL silicon carbide elements, 20 inches (508 mm) long by .63 inch (16 
    mm) O.D., must be used, as shown in Figures 2A and 2B of this part IV. 
    The heat source must have a nominal resistance of 1.4 ohms and be 
    capable of generating a flux up to 100 kW/m\2\. The silicone carbide 
    elements must be mounted in the stainless steel panel box by inserting 
    them through .63 inch (16 mm) holes in .03 inch (1 mm) thick ceramic 
    fiber or calcium-silicate millboard. Locations of the holes in the pads 
    and stainless steel cover plates are shown in Figure 2B of this part 
    IV. The truncated diamond-shaped mask of .042.002 inch 
    (1.07.05mm) stainless steel must be added to provide 
    uniform heat flux density over the area occupied by the vertical 
    sample.
        (4) Air Distribution System. The air entering the environmental 
    chamber must be distributed by a .25 inch (6.3 mm) thick aluminum plate 
    having eight No. 4 drill-holes, located 2 inches (51 mm) from sides on 
    4 inch (102 mm) centers, mounted at the base of the environmental 
    chamber. A second plate of 18 guage stainless steel having 120, evenly 
    spaced, No. 28 drill holes must be mounted 6 inches (152 mm) above the 
    aluminum plate. A well-regulated air supply is required. The air-supply 
    manifold at the base of the pyramidal section must have 48, evenly 
    spaced, No. 26 drill holes located .38 inch (10 mm) from the inner edge 
    of the manifold, resulting in an airflow split of approximately three 
    to one within the apparatus.
        (5) Exhaust Stack. An exhaust stack, 5.25 x 2.75 inches (133 x 70 
    mm) in cross section, and 10 inches (254 mm) long, fabricated from 28 
    guage stainless steel must be mounted on the outlet of the pyramidal 
    section. A. 1.0 x 3.0 inch (25 x 76 mm) baffle plate of 
    0.18.002 inch (.50.05 mm) stainless steel must 
    be centered inside the stack, perpendicular to the air flow, 3 inches 
    (76 mm) above the base of the stack.
        (6) Specimen Holders. (i) The specimen must be tested in a vertical 
    
    
    [[Page 6624]]
    orientation. The specimen holder (Figure 3 of this part IV) must 
    incorporate a frame that touches the specimen (which is wrapped with 
    aluminum foil as required by paragraph (d)(3) of this Part) along only 
    the .25 inch (6 mm) perimeter. A ``V'' shaped spring is used to hold 
    the assembly together. A detachable .50 x .50 x 5.91 inch 
    (12 x 12 x 150 mm) drip pan and two .020 inch (.5 mm) stainless steel 
    wires (as shown in Figure 3 of this part IV) must be used for testing 
    materials prone to melting and dripping. The positioning of the spring 
    and frame may be changed to accommodate different specimen thicknesses 
    by inserting the retaining rod in different holes on the specimen 
    holder.
        (ii) Since the radiation shield described in ASTM E-906 is not 
    used, a guide pin must be added to the injection mechanism. This fits 
    into a slotted metal plate on the injection mechanism outside of the 
    holding chamber. It can be used to provide accurate positioning of the 
    specimen face after injection. The front surface of the specimen must 
    be 3.9 inches (100 mm) from the closed radiation doors after injection.
        (iii) The specimen holder clips onto the mounted bracket (Figure 3 
    of this part IV). The mounting bracket must be attached to the 
    injection rod by three screws that pass through a wide-area washer 
    welded onto a \1/2\-inch (13 mm) nut. The end of the injection rod must 
    be threaded to screw into the nut, and a .020 inch (5.1 mm) thick wide 
    area washer must be held between two \1/2\-inch (13 mm) nuts that are 
    adjusted to tightly cover the hole in the radiation doors through which 
    the injection rod or calibration calorimeter pass.
        (7) * * *
        (8) Pilot-Flame Positions. Pilot ignition of the specimen must be 
    accomplished by simultaneously exposing the specimen to a lower pilot 
    burner and an upper pilot burner, as described in paragraph (b)(8)(i) 
    and (b)(8)(ii) or (b)(8)(iii) of this part IV, respectively. Since 
    intermittent pilot flame extinguishment for more than 3 seconds would 
    invalidate the test results, a spark ignitor may be installed to ensure 
    that the lower pilot burner remains lighted.
        (i) Lower Pilot Burner. The pilot-flame tubing must be .25 inch 
    (6.3 mm) O.D., .03 inch (0.8mm) wall, stainless steel tubing. A mixture 
    of 120 cm3/min. of methane and 850 cm3/min. of air must be 
    fed to the lower pilot flame burner. The normal position of the end of 
    the pilot burner tubing is .40 inch (10 mm) from and perpendicular to 
    the exposed vertical surface of the specimen. The centerline at the 
    outlet of the burner tubing must intersect the vertical centerline of 
    the sample at a point .20 inch (5 mm) above the lower exposed edge of 
    the specimen.
        (ii) Standard Three-Hole Upper Burner. The pilot burner must be a 
    straight length of .25 inch (6.3 mm) O.D., .03 inch (0.8 mm) wall, 
    stainless steel tubing that is 14 inches (360 mm) long. One end of the 
    tubing must be closed, and three No. 40 drill holes must be drilled 
    into the tubing, 2.38 inch (60 mm) apart, for gas ports, all radiating 
    in the same direction. The first hole must be .19 inch (5 mm) from the 
    closed end of the tubing. The tube must be positioned .75 inch (19 mm) 
    above and .75 inch (19 mm) behind the exposed upper edge of the 
    specimen. The middle hole must be in the vertical plane perpendicular 
    to the exposed surface of the specimen which passes through its 
    vertical centerline and must be pointed toward the radiation source. 
    The gas supplied to the burner must be methane and must be adjusted to 
    produce flame lengths of 1 inch (25 mm).
        (iii) Optional Fourteen-Hole Upper Pilot Burner. This burner may be 
    used in lieu of the standard three-hole burner described in paragraph 
    (b)(8)(ii) of this part IV. The pilot burner must be a straight length 
    of .25 inch (6.3 mm) O.D., .03 inch (0.8 mm) wall, stainless steel 
    tubing that is 15.75 inches (400 mm) long. One end of the tubing must 
    be closed, and 14 No. 59 drill holes must be drilled into the tubing, 
    .50 inch (13 mm) apart, for gas ports, all radiating in the same 
    direction. The first hole must be .50 inch (13 mm) from the closed end 
    of the tubing. The tube must be positioned above the specimen holder so 
    that the holes are placed above the specimen as shown in Figure 1B of 
    this part IV. The fuel supplied to the burner must be methane mixed 
    with air in a ratio of approximately 50/50 by volume. The total gas 
    flow must be adjusted to produce flame lengths of 1 inch (25 mm). When 
    the gas/air ratio and the flow rate are properly adjusted, 
    approximately .25 inch (6 mm) of the flame length appears yellow in 
    color.
        (c) * * * (1) Heat Release Rate. A calibration burner, as shown in 
    Figure 4, must be placed over the end of the lower pilot flame tubing 
    using a gas tight connection. The flow of gas to the pilot flame must 
    be at least 99 percent methane and must be accurately metered. Prior to 
    usage, the wet test meter must be properly leveled and filled with 
    distilled water to the tip of the internal pointer while no gas is 
    flowing. Ambient temperature and pressure of the water are based on the 
    internal wet test meter temperature. A baseline flow rate of 
    approximately 1 liter/min. must be set and increased to higher preset 
    flows of 4, 6, 8, 6 and 4 liters/min. Immediately prior to recording 
    methane flow rates, a flow rate of 8 liters/min. must be used for 2 
    minutes to precondition the chamber. This is not recorded as part of 
    calibration. The rate must be determined by using a stopwatch to time a 
    complete revolution of the wet test meter for both the baseline and 
    higher flow, with the flow returned to baseline before changing to the 
    next higher flow. The thermopile baseline voltage must be measured. The 
    gas flow to the burner must be increased to the higher preset flow and 
    allowed to burn for 2.0 minutes, and the thermopile voltage must be 
    measured. The sequence must be repeated until all five values have been 
    determined. The average of the five values must be used as the 
    calibration factor. The procedure must be repeated if the percent 
    relative standard deviation is greater than 5 percent. Calculations are 
    shown in paragraph (f) of this part IV.
        (2) * * *
        (3) As noted in paragraph (b)(2) of this part IV, thermopile hot 
    junctions must be cleared of soot deposits as needed to maintain the 
    calibrated sensitivity.
        (d) Preparation of Test Specimens. (1) The test specimens must be 
    representative of the aircraft component in regard to materials and 
    construction methods. The standard size for the test specimens is 5.91 
     .03  x  5.91  .03 inches (149  1 
    x  149  1 mm). The thickness of the specimen must be the 
    same as that of the aircraft component it represents up to a maximum 
    thickness of 1.75 inches (45 mm). Test specimens representing thicker 
    components must be 1.75 inches (45 mm).
        (2) * * *
        (3) Mounting. Each test specimen must be wrapped tightly on all 
    sides of the specimen, except for the one surface that is exposed with 
    a single layer of .001 inch (.025 mm) aluminum foil.
        (e) Procedure. (1) The power supply to the radiant panel must be 
    set to produce a radiant flux of 3.5  .05 W/cm2, as 
    measured at the point the center of the specimen surface will occupy 
    when positioned for the test. The radiant flux must be measured after 
    the air flow through the equipment is adjusted to the desired rate.
        (2) After the pilot flames are lighted, their position must be 
    checked as described in paragraph (b)(8) of this part IV.
        (3) Air flow through the apparatus must be controlled by a circular 
    plate orifice located in a 1.5 inch (38.1 mm) I.D. pipe with two 
    pressure measuring 
    
    [[Page 6625]]
    points, located 1.5 inches (38 mm) upstream and .75 inches (19 mm) 
    downstream of the orifice plate. The pipe must be connected to a 
    manometer set at a pressure differential of 7.87 inches (200 mm) of Hg. 
    (See Figure 1B of this part IV.) The total air flow to the equipment is 
    approximately .04 m3/seconds. The stop on the vertical specimen 
    holder rod must be adjusted so that the exposed surface of the specimen 
    is positioned 3.9 inches (100 mm) from the entrance when injected into 
    the environmental chamber.
        (4) The specimen must be placed in the hold chamber with the 
    radiation doors closed. The airtight outer door must be secured, and 
    the recording devices must be started. The specimen must be retained in 
    the hold chamber for 60 seconds, plus or minus 10 seconds, before 
    injection. The thermopile ``zero'' value must be determined during the 
    last 20 seconds of the hold period. The sample must not be injected 
    before completion of the ``Zero'' value determination.
        (5) When the specimen is to be injected, the radiation doors must 
    be opened. After the specimen is injected into the environmental 
    chamber, the radiation doors must be closed behind the specimen.
        (6) * * *
        (7) * * *
        (8) The test duration is five minutes. The lower pilot burner and 
    the upper pilot burner must remain lighted for the entire duration of 
    the test, except that there may be intermittent flame extinguishment 
    for periods that do not exceed 3 seconds. Furthermore, if the optional 
    three-hole upper burner is used, at least two flamelets must remain 
    lighted for the entire duration of the test, except that there may be 
    intermittent flame extinguishment of all three flamelets for periods 
    that do not exceed 3 seconds.
        (9) * * *
        (f) * * *
        (2) Heat release rates may be calculated from the reading of the 
    thermopile output voltage at any instant of time as:
    [GRAPHIC][TIFF OMITTED]TR02FE95.006
    
    HRR=heat release rate (kw/m\2\)
    Vb=baseline voltage (mv)
    Vm=measured thermopile voltage (mv)
    Kh=calibration factor (kw/mv)
    * * * * *
    Figures to Part IV of Appendix F
    BILLING CODE 4910-13-M
    
    [[Page 6626]]
    [GRAPHIC][TIFF OMITTED]TR02FE95.004
    
    
    
    [[Page 6627]]
    [GRAPHIC][TIFF OMITTED]TR02FE95.005
    
    
    BILLING CODE 4910-13-C
    
    [[Page 6628]]
    
    * * * * *
    
    PART 121--CERTIFICATION AND OPERATIONS: DOMESTIC, FLAG, AND 
    SUPPLEMENTAL AIR CARRIERS AND COMMERCIAL OPERATORS OF LARGE 
    AIRCRAFT
    
        4. The authority citation for Part 121 continues to read as 
    follows:
    
        Authority: 49 U.S.C. 1354(a), 1355, 1356, 1357, 1401, 1421-1430, 
    1472, 1485, and 1502; 49 U.S.C. 106(g); 49 CFR 1.47(a).
    
        5. By amending Sec. 121.312 by revising paragraphs (a)(1) through 
    (a)(6), adding a new paragraph (a)(8), and revising paragraph (b) to 
    read as follows:
    
    
    Sec. 121.312  Materials for compartment interiors.
    
        (a) * * *
        (1) Except as provided in paragraph (a)(6) of this section, each 
    airplane with a passenger capacity of 20 or more and manufactured after 
    August 19, 1988, but prior to August 20, 1990, must comply with the 
    heat release rate testing provisions of Sec. 25.853(d) in effect March 
    6, 1995 (formerly Sec. 25.853(a-1) in effect on August 20, 1986), 
    except that the total heat release over the first 2 minutes of sample 
    exposure must not exceed 100 kilowatt minutes per square meter and the 
    peak heat release rate must not exceed 100 kilowatts per square meter.
        (2) Each airplane with a passenger capacity of 20 or more and 
    manufactured after August 19, 1990, must comply with the heat release 
    rate and smoke testing provisions of Sec. 25.853(d) in effect March 6, 
    1995 (formerly Sec. 25.853(a-1) in effect on September 26, 1988).
        (3) Except as provided in paragraph (a)(5) or (a)(6) of this 
    section, each airplane for which the application for type certificate 
    was filed prior to May 1, 1972, must comply with the provisions of 
    Sec. 25.853 in effect on April 30, 1972, regardless of the passenger 
    capacity if there is a substantially complete replacement of the cabin 
    interior after April 30, 1972.
        (4) Except as provided in paragraph (a)(5) or (a)(6) of this 
    section, each airplane for which the application for type certificate 
    was filed after May 1, 1972, must comply with the material requirements 
    under which the airplane was type certificated regardless of the 
    passenger capacity if there is a substantially complete replacement of 
    the cabin interior after that date.
        (5) Except as provided in paragraph (a)(6) of this section, each 
    airplane that was type certificated after January 1, 1958, and has a 
    passenger capacity of 20 or more, must comply with the heat release 
    rate testing provisions of Sec. 25.853(d) in effect March 6, 1995 
    (formerly Sec. 25.853(a-1) in effect on August 20, 1986), if there is 
    substantially complete replacement of the cabin interior components 
    identified in Sec. 25.853(d) on or after that date, except that the 
    total heat release over the first 2 minutes of sample exposure shall 
    not exceed 100 killowatt-minutes per square meter and the peak heat 
    release rate shall not exceed 100 kilowatts per square meter.
        (6) Each airplane that was type certificated after January 1, 1958, 
    and has a passenger capacity of 20 or more, must comply with the heat 
    release rate and smoke testing provisions of Sec. 25.853(d) in effect 
    March 6, 1995 (formerly Sec. 25.853(a-1) in effect on September 26, 
    1988), if there is a substantially complete replacement of the cabin 
    interior components identified in Sec. 25.853(d) on or after August 20, 
    1990.
    * * * * *
        (8) Contrary provisions of this section notwithstanding, galley 
    carts and galley standard containers that do not meet the flammability 
    and smoke emission requirements of Sec. 25.853(d) in effect March 6, 
    1995 (formerly Sec. 25.853(a-1)) may be used in airplanes that must 
    meet the requirements of paragraph (a-1), (a)(2), (a)(5) or (a)(6) of 
    this section, provided the galley carts or standard containers were 
    manufactured prior to March 6, 1995.
        (b) For airplanes type certificated after January 1, 1958, seat 
    cushions, except those on flight crewmember seats, in any compartment 
    occupied by crew or passengers must comply with the requirements 
    pertaining to fire protection of seat cushions in Sec. 25.853(c) 
    effective on November 26, 1984.
    
    PART 135--AIR TAXI OPERATORS AND COMMERCIAL OPERATORS
    
        6. The authority citation for Part 135 continues to read as 
    follows:
    
        Authority: 49 U.S.C. 1354(a), 1355(a), 1421-1431, and 1502; 49 
    U.S.C. 106(g); 49 CFR 1.47(a).
    
        7. By amending Sec. 135.169 by revising paragraph (a) to read as 
    follows:
    
    
    Sec. 135.169  Additional airworthiness requirements.
    
        (a) Except for commuter category airplanes, no person may operate a 
    large airplane unless it meets the additional airworthiness 
    requirements of Secs. 121.213 through 121.283 and 121.307 of this 
    chapter.
    * * * * *
        8. By revising Sec. 135.170 to read as follows:
    
    
    Sec. 135.170  Materials for compartment interiors.
    
        (a) No person may operate an airplane that conforms to an amended 
    or supplemental type certificate issued in accordance with SFAR No. 41 
    for a maximum certificated takeoff weight in excess of 12,500 pounds 
    unless within one year after issuance of the initial airworthiness 
    certificate under that SFAR, the airplane meets the compartment 
    interior requirements set forth in Sec. 25.853(a) in effect March 6, 
    1995 (formerly Sec. 25.853 (a), (b), (b-1), (b-2), and (b-3) of this 
    chapter in effect on September 26, 1978).
        (b) No person may operate a large airplane unless it meets the 
    following additional airworthiness requirements:
        (1) Except for those materials covered by paragraph (b)(2) of this 
    section, all materials in each compartment used by the crewmembers or 
    passengers must meet the requirements of Sec. 25.853 of this chapter in 
    effect as follows or later amendment thereto:
        (i) Except as provided in paragraph (b)(1)(iv) of this section, 
    each airplane with a passenger capacity of 20 or more and manufactured 
    after August 19, 1988, but prior to August 20, 1990, must comply with 
    the heat release rate testing provisions of Sec. 25.853(d) in effect 
    March 6, 1995 (formerly Sec. 25.853(a-1) in effect on August 20, 1986), 
    except that the total heat release over the first 2 minutes of sample 
    exposure rate must not exceed 100 kilowatt minutes per square meter and 
    the peak heat release rate must not exceed 100 kilowatts per square 
    meter.
        (ii) Each airplane with a passenger capacity of 20 or more and 
    manufactured after August 19, 1990, must comply with the heat release 
    rate and smoke testing provisions of Sec. 25.853(d) in effect March 6, 
    1995 (formerly Sec. 25.83(a-1) in effect on September 26, 1988).
        (iii) Except as provided in paragraph (b)(1) (v) or (vi) of this 
    section, each airplane for which the application for type certificate 
    was filed prior to May 1, 1972, must comply with the provisions of 
    Sec. 25.853 in effect on April 30, 1972, regardless of the passenger 
    capacity, if there is a substantially complete replacement of the cabin 
    interior after April 30, 1972.
        (iv) Except as provided in paragraph (b)(1) (v) or (vi) of this 
    section, each airplane for which the application for type certificate 
    was filed after May 1, 1972, must comply with the material requirements 
    under which the airplane was type certificated regardless of the 
    passenger capacity if there is a substantially complete replacement of 
    the cabin interior after that date.
    
    [[Page 6629]]
    
        (v) Except as provided in paragraph (b)(1)(vi) of this section, 
    each airplane that was type certificated after January 1, 1958, must 
    comply with the heat release testing provisions of Sec. 25.853(d) in 
    effect March 6, 1995 (formerly Sec. 25.853(a-1) in effect on August 20, 
    1986), if there is a substantially complete replacement of the cabin 
    interior components identified in that paragraph on or after that date, 
    except that the total heat release over the first 2 minutes of sample 
    exposure shall not exceed 100 kilowatt-minutes per square meter and the 
    peak heat release rate shall not exceed 100 kilowatts per square meter.
        (vi) Each airplane that was type certificated after January 1, 
    1958, must comply with the heat release rate and smoke testing 
    provisions of Sec. 25.853(d) in effect March 6, 1995 (formerly 
    Sec. 25.853(a-1) in effect on August 20, 1986), if there is a 
    substantially complete replacement of the cabin interior components 
    identified in that paragraph after August 19, 1990.
        (vii) Contrary provisions of this section notwithstanding, the 
    Manager of the Transport Airplane Directorate, Aircraft Certification 
    Service, Federal Aviation Administration, may authorize deviation from 
    the requirements of paragraph (b)(1)(i), (b)(1)(ii), (b)(1)(v), or 
    (b)(1)(vi) of this section for specific components of the cabin 
    interior that do not meet applicable flammability and smoke emission 
    requirements, if the determination is made that special circumstances 
    exist that make compliance impractical. Such grants of deviation will 
    be limited to those airplanes manufactured within 1 year after the 
    applicable date specified in this section and those airplanes in which 
    the interior is replaced within 1 year of that date. A request for such 
    grant of deviation must include a thorough and accurate analysis of 
    each component subject to Sec. 25.853(d) in effect March 6, 1995 
    (formerly Sec. 25.853(a-1) in effect on August 20, 1986), the steps 
    being taken to achieve compliance, and for the few components for which 
    timely compliance will not be achieved, credible reasons for such 
    noncompliance.
        (viii) Contrary provisions of this section notwithstanding, galley 
    carts and standard galley containers that do not meet the flammability 
    and smoke emission requirements of Sec. 25.853(d) in effect March 6, 
    1995 (formerly Sec. 25.853(a-1) in effect on August 20, 1986), may be 
    used in airplanes that must meet the requirements of paragraph 
    (b)(1)(i), (b)(1)(ii), (b)(1)(iv) or (b)(1)(vi) of this section 
    provided the galley carts or standard containers were manufactured 
    prior to March 6, 1995.
        (2) For airplanes type certificated after January 1, 1958, seat 
    cushions, except those on flight crewmember seats, in any compartment 
    occupied by crew or passengers must comply with the requirements 
    pertaining to fire protection of seat cushions in Sec. 25.853(c) 
    effective November 26, 1984.
        Issued in Washington, D.C., on January 24, 1995.
    David R. Hinson,
    Administrator.
    [FR Doc. 95-2114 Filed 2-1-95; 8:45 am]
    BILLING CODE 4910-13-M
    
    

Document Information

Effective Date:
3/6/1995
Published:
02/02/1995
Department:
Federal Aviation Administration
Entry Type:
Rule
Action:
Final rule.
Document Number:
95-2114
Dates:
March 6, 1995.
Pages:
6616-6629 (14 pages)
Docket Numbers:
Docket No. 26192, Amendments Nos. 25-83, 121-247 and 135-55
RINs:
2120-AD28
PDF File:
95-2114.pdf
CFR: (7)
14 CFR 25.853(a-1)
14 CFR 25.853
14 CFR 25.853
14 CFR 121.312
14 CFR 25.853
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