This site displays a prototype of a “Web 2.0” version of the daily
Federal Register. It is not an official legal edition of the Federal
Register, and does not replace the official print version or the official
electronic version on GPO’s govinfo.gov.
The documents posted on this site are XML renditions of published Federal
Register documents. Each document posted on the site includes a link to the
corresponding official PDF file on govinfo.gov. This prototype edition of the
daily Federal Register on FederalRegister.gov will remain an unofficial
informational resource until the Administrative Committee of the Federal
Register (ACFR) issues a regulation granting it official legal status.
For complete information about, and access to, our official publications
and services, go to
About the Federal Register
on NARA's archives.gov.
The OFR/GPO partnership is committed to presenting accurate and reliable
regulatory information on FederalRegister.gov with the objective of
establishing the XML-based Federal Register as an ACFR-sanctioned
publication in the future. While every effort has been made to ensure that
the material on FederalRegister.gov is accurately displayed, consistent with
the official SGML-based PDF version on govinfo.gov, those relying on it for
legal research should verify their results against an official edition of
the Federal Register. Until the ACFR grants it official status, the XML
rendition of the daily Federal Register on FederalRegister.gov does not
provide legal notice to the public or judicial notice to the courts.
Rule
Enter a search term or FR citation e.g.
88 FR 38230 FR 78782024-13208USDA09/05/24RULE0503-AA39SORN
Choosing an item from
full text search results
will bring you to those results. Pressing enter in the search box
will also bring you to search results.
Choosing an item from
suggestions
will bring you directly to the content.
This table of contents is a navigational tool, processed from the
headings within the legal text of Federal Register documents.
This repetition of headings to form internal navigation links
has no substantive legal effect.
Document page views are updated periodically throughout the day and are
cumulative counts for this document. Counts are subject to sampling,
reprocessing and revision (up or down) throughout the day.
Page views
25
as of
08/19/2026 at 8:15 am EDT
Other Formats
Enhanced Content - Other Formats
This document is also available in the following formats:
This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.
AGENCY:
Federal Aviation Administration (FAA), Department of Transportation (DOT).
ACTION:
Final rule.
SUMMARY:
We are adopting a new airworthiness directive (AD) for certain Cessna Aircraft Company (Cessna) Model 525 airplanes. This AD requires you to inspect for missing firewall sealant between the aft firewall assembly and seal assembly; and, if you find that firewall sealant is missing, seal with firewall sealant between the aft firewall assembly and seal assembly. This AD results from a report that firewall sealant may not have been applied between the aft firewall assembly and seal assembly during manufacture of certain Model 525 airplanes. We are issuing this AD to detect and correct missing firewall sealant between the aft firewall assembly and seal assembly, which could result in failure of the fire extinguishing system to prevent the spread of fire through the firewall gap. This failure could lead to an uncontrolled fire.
DATES:
This AD becomes effective on July 16, 2008.
On July 16, 2008, the Director of the Federal Register approved the incorporation by reference of certain publications listed in this AD.
ADDRESSES:
For service information identified in this AD, contact Cessna Aircraft Company, Product Support, P.O. Box 7706, Wichita, Kansas 67277; telephone: (316) 517-5800; fax: (316) 942-9006.
To view the AD docket, go to U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590, or on the Internet at
http://www.regulations.gov.
The docket number is FAA-2008-0306; Directorate Identifier 2008-CE-014-AD.
On March 7, 2008, we issued a proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that would apply to certain Cessna Model 525 airplanes. This proposal was published in the
Federal Register
as a notice of proposed rulemaking (NPRM) on March 13, 2008 (73 FR 13486). The NPRM proposed to require you to inspect for missing firewall sealant between the aft firewall assembly and seal assembly; and, if you find that firewall sealant is missing, seal with firewall sealant between the aft firewall assembly and seal assembly.
Comments
We provided the public the opportunity to participate in developing this AD. We received no comments on the proposal or on the determination of the cost to the public.
Conclusion
We have carefully reviewed the available data and determined that air safety and the public interest require adopting the AD as proposed except for minor editorial corrections. We have determined that these minor corrections:
Are consistent with the intent that was proposed in the NPRM for correcting the unsafe condition; and
Do not add any additional burden upon the public than was already proposed in the NPRM.
Costs of Compliance
We estimate that this AD affects 45 airplanes in the U.S. registry.
We estimate the following costs to do the inspection:
Labor cost
Parts cost
Total cost per airplane
Total cost on U.S. operators
1 work-hour × $80 per hour = $80
Not Applicable
$80
$3,600
We estimate the following costs to do any necessary repairs that would be required based on the results of the inspection. We have no way of determining the number of airplanes that may need this repair:
Labor cost
Parts cost
Total cost per airplane
4 work-hours × $80 per hour = $320
$30
$350
Authority for This Rulemaking
Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, Section 106 describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the agency's authority.
We are issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701, “General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this AD.
Regulatory Findings
We have determined that this AD will not have federalism implications under Executive Order 13132. This AD will not have a substantial direct effect 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.
For the reasons discussed above, I certify that this AD:
2. Is not a “significant rule” under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and
( printed page 32988)
3. Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.
We prepared a summary of the costs to comply with this AD (and other information as included in the Regulatory Evaluation) and placed it in the AD Docket. You may get a copy of this summary by sending a request to us at the address listed under
ADDRESSES
. Include “Docket No. FAA-2008-0306; Directorate Identifier 2008-CE-014-AD” in your request.
Accordingly, under the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:
PART 39—AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
(c) This AD applies to Model 525 airplanes, serial numbers 525-0600 through 525-0662, that are certificated in any category.
Affected ADs
(b) None.
Unsafe Condition
(d) This AD results from a report that firewall sealant may not have been applied between the aft firewall assembly and seal assembly during manufacture of certain Model 525 airplanes. We are issuing this AD to detect and correct missing firewall sealant between the aft firewall assembly and seal assembly, which could result in failure of the fire extinguishing system to prevent the spread of fire through the firewall gap. This failure could lead to an uncontrolled fire.
Compliance
(e) To address this problem, you must do the following, unless already done:
Actions
Compliance
Procedures
(1) Inspect between the 6352225 aft firewall assembly and 6352226 seal assembly for missing firewall sealant
Within the next 60 hours time-in-service (TIS) after July 16, 2008 (the effective date of this AD) or within 60 days after July 16, 2008 (the effective date of this AD), whichever occurs first
Follow Cessna Aircraft Company Citation Service Letter SL525-71-05, Revision 1, dated February 6, 2008.
(2) If, as a result of the inspection required by paragraph (e)(1) of this AD, you find there is missing firewall sealant between the 6352225 aft firewall assembly and 6352226 seal assembly, seal with U000117S firewall sealant in the gap between the 6352225 aft firewall assembly and 6352226 seal assembly
Before further flight after the inspection required by paragraph (e)(1) of this AD
Follow Cessna Aircraft Company Citation Service Letter SL525-71-05, Revision 1, dated February 6, 2008.
Alternative Methods of Compliance (AMOCs)
(f) The Manager, Wichita Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to ATTN: James Galstad, Aerospace Engineer, Wichita ACO, 1801 Airport Road, Room 100, Wichita, Kansas 67209; telephone: (316) 946-4135; fax: (316) 946-4107. Before using any approved AMOC on any airplane to which the AMOC applies, notify your appropriate principal inspector (PI) in the FAA Flight Standards District Office (FSDO), or lacking a PI, your local FSDO.
Material Incorporated by Reference
(g) You must use Cessna Aircraft Company Citation Service Letter SL525-71-05, Revision 1, dated February 6, 2008, to do the actions required by this AD, unless the AD specifies otherwise.
(1) The Director of the Federal Register approved the incorporation by reference of this service information under 5 U.S.C. 552(a) and 1 CFR part 51.
(2) For service information identified in this AD, contact Cessna Aircraft Company, Product Support, P.O. Box 7706, Wichita, Kansas 67277; telephone: (316) 517-5800; fax: (316) 942-9006.