[Federal Register Volume 71, Number 171 (Tuesday, September 5, 2006)]
[Rules and Regulations]
[Pages 52287-52288]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-14632]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Parts 91, 121, 125 and 135

[Docket No. 2005-23462]
RIN 2120-AI64


Thermal/Acoustic Insulation Installed on Transport Category 
Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Disposition of comments on final rule.

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SUMMARY: On December 30, 2005, the FAA published a final rule; request 
for comments (Amendment Nos. 91-290, 121-320, 125-50, and 135-103), on 
the requirements for thermal/acoustic insulation flammability (70 FR 
77748). We sought public comments on those amendments, but they became 
effective on February 28, 2006. This action responds to the comments 
received on that final rule; request for comments.

ADDRESSES: You may review the public docket (Docket No. 2005-23462) in 
the Docket Management Facility between 9 a.m. and 5 p.m., Monday 
through Friday, except Federal holidays. The Docket Management Facility 
is on the plaza level of the Nassif Building at the Department of 
Transportation, Room Plaza 401, 400 Seventh Street, SW., Washington, DC 
20590-0001. Also you may review the public docket on the Internet at 
http://dms.dot.gov.

FOR FURTHER INFORMATION CONTACT: Jeff Gardlin, Airframe and Cabin 
Safety Branch (ANM-115), Transport Airplane Directorate, Aircraft 
Certification Service, Federal Aviation Administration, 1601 Lind 
Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2136, 
facsimile (425) 227-1149, e-mail: [email protected].

SUPPLEMENTARY INFORMATION:

Background

    On September 20, 2000, the FAA published Notice No. 00-09, which 
proposed to upgrade the flammability and fire protection standards for 
thermal/acoustic insulation installed in transport category airplanes 
(65 FR 56992). The notice contained a provision that would require 
thermal/acoustic insulation to comply with the proposed new standards 
when used as replacements on airplanes already in service, as well as 
requirements about newly manufactured airplanes. The requirement was 
adopted in the final rule, published on July 31, 2003, in Sec. Sec.  
91.613(b)(1), 121.312(e)(1), 125.113(c)(1), and 135.170(c)(1) (68 FR 
45046). These rules required operators to use replacement insulation 
materials meeting the requirements of Sec.  25.856 after September 2, 
2005.
    For reasons discussed in the preamble, we published Amendment Nos. 
91-290, 121-320, 125-50, and 135-103 on December 30, 2005, to refocus 
the requirements for replacement materials (70 FR 77748). Because of 
these amendments, only certain types of thermal/acoustic insulation are 
required to comply with the upgraded standards when replaced. As noted 
in the preamble, the revised requirements align the regulatory language 
more closely with the intent of the provision.
    Although the immediately adopted rule revised the replacement 
provisions, we requested comments on the provisions. Six commenters 
responded to the request for comments.

Discussion of Comments

    The General Aviation Manufacturers Association and Continental 
Airlines support the rule as written. AMIS International provided 
comments that were not directed at the substance of the amendments. 
Airbus, Boeing and the National Air Transport Association (NATA) 
support the rule, but suggest further changes as well.
    Boeing suggests we further amend the rules so the requirements of 
14 CFR part 25 match the revised requirements for replacement 
materials. The FAA does not agree. The intent of the part 25 rule is to 
upgrade the standards for thermal/acoustic insulation in the fuselage 
of transport category airplanes. Advisory Circular 25.856-1, Thermal/
Acoustic Insulation Flame Propagation Test Method Details, dated 6/24/
05, provides discussion and methods of compliance for specific 
installations that simplify the compliance demonstration. Conversely, 
the provision on replacement thermal/acoustic insulation is intended to 
address insulation that is often replaced. The objective of that 
requirement is to encourage production only of materials that comply 
with the new standards, as well as to purge inventories of materials 
that do not comply. Thus, the two provisions are complementary, and 
need not be the same. Since manufacturers are producing airplanes that 
comply with the existing requirements of Sec.  25.856(a), the 
requirements are clearly feasible. Changing part 25 as requested would 
reduce the level of safety already achieved.
    Boeing further suggests the definition of insulation provided in 
the final rule be included in Advisory Circular 25.856-1 and possibly 
Sec.  25.856(a) to be consistent. The FAA does not agree. Amendment 91-
290 et al., does not ``define'' insulation. These amendments modify the 
applicability of requirements for insulation. That is, they specify the 
conditions under which we require compliance with Sec.  25.856(a) for 
replacement thermal/acoustic insulation. Thus, we require no changes to 
the advisory circular since it pertains to compliance with Sec.  
25.856(a), and does not apply if compliance with Sec.  25.856(a) is not 
required.
    Boeing also suggests we change the rule to exclude blanket type 
insulation installed inside galley inserts or other components. These 
components can be replaced and it is not obvious the replacement 
includes insulation. The FAA does not agree. Advisory Circular 25.856-1 
already addresses these components, and describes a means of compliance 
that does not necessitate testing in most cases. Since compliant 
materials are available for those cases when testing is required, the 
rule should remain as is.
    Airbus similarly suggests we change the replacement provision to 
exclude blanket type insulation when bonded to interior panels, such as 
sidewalls or floors. Airbus notes that these are infrequently replaced 
and it would be difficult to change the insulation. The FAA does not 
agree. Although the insulation is bonded to these panels, if it is in 
blanket form, there are available substitutes that comply. As long as 
operators are aware of the particular parts that are affected, they can 
accommodate the upgraded materials into their maintenance plan.
    Airbus also notes that it used many resources to modify its 
affected parts and drawings before the compliance date, and now some of 
that effort appears wasted. Because the issues with replacement 
insulation were identified very late in the process, the FAA 
acknowledges that Airbus' proactive

[[Page 52288]]

approach probably did result in changes that ultimately were not 
strictly required for compliance. However, these changes do improve the 
overall flammability of the materials and are not wasted effort.
    The NATA concurred with the rule, but was concerned the now 
outdated part numbers associated with non-complying parts have not been 
purged from parts catalogs. The NATA requests the FAA help industry 
deal with the issue of out of date parts catalogs. Parts catalogs are 
not directly regulated documents, and the FAA does not typically 
maintain oversight of them. However, the FAA will work with operators 
and airframe manufacturers to help facilitate updating of the parts 
catalogs.
    Boeing suggested a rewording of the preamble discussion of 
insulation that is the subject of airworthiness directives as follows: 
``Insulation that is the subject of airworthiness directives (even if 
that insulation is bonded to the surface of the duct and would 
otherwise be excluded by this rule) must still be replaced in 
accordance with those airworthiness directives.''
    While the FAA acknowledges the suggested rewording is more 
explicit, the intent is the same. This discussion in the preamble was 
purely a reminder, and does not introduce a requirement or deviate in 
any way from standard procedure. No change to the rule is required.

Conclusion

    After consideration of the comments submitted in response to the 
final rule; request for comments, the FAA has determined that no 
further rulemaking action is necessary and Amendments Nos. 91-290, 121-
320, 125-50, and 135-103 remain in effect as adopted.

    Issued in Washington, DC, on August 25, 2006.
John J. Hickey,
Director, Aircraft Certification Service.
 [FR Doc. E6-14632 Filed 9-1-06; 8:45 am]
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