Discussion
We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that would apply to the specified products. That NPRM was published in the Federal Register on December 8, 2010 (75 FR 76317). That NPRM proposed to correct an unsafe condition for the specified products. The MCAI states:
Sponge rubber padding used to provide separation between wheel well fuel lines and electrical harnesses was discovered during fleet maintenance. Use of this type of padding for this purpose is not approved as it is liable to cause corrosion of the fuel lines. Unless steps are taken to remove this padding and install approved separation means, fuel lines may be damaged by corrosion and/or chafing resulting in an unsafe condition due to fuel leakage[, which could result in a fire] in the wheel well area.
Corrective actions include installing loop clamps to correct improper separation and removing sponge rubber padding, andrepair or replacement of any corroded or chafed fuel lines found after sponge rubber padding removal. You may obtain further information by examining the MCAI in the AD docket.
Comments
We gave the public the opportunity to participate in developing this AD. We have considered the comments received.
Requests To Include Additional Inspection Area
Gulfstream Aerospace Corporation (Gulfstream) requested that the inspection area be expanded to include tube assemblies outside of the wheel well area that have also been found to have sponge rubber padding and corrosion beneath the padding. Gulfstream stated that the padding with corrosion beneath has been found on four tube assemblies outside of the wheel well area specified in the NPRM (75 FR 76317, December 8, 2010) and Gulfstream Service Bulletin 100-28-297, dated January 21, 2010. These four tube assemblies are part of, or an extension of, the tube assemblies identified by part number in that service bulletin, and terminate in the wing root area.
John R. Dunn, a private citizen, stated that, upon further investigation after discovering instances of sponge rubber
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in the left wheel well, foam (sponge rubber padding) was found wrapped around tubes in the forward wing root areas of two airplanes along with wire harnesses alongside the affected tubes. Corrosion was also found on those tubes. John R. Dunn stated that neither of the affected wing root areas are mentioned in Gulfstream Service Bulletin 100-28-297, dated January 21, 2010.
We partially agree. We agree to investigate reports of sponge rubber padding use, and any subsequent corrosion, that occurs outside of the wheel well area specified in Gulfstream Service Bulletin 100-28- 297, dated January 21, 2010. Depending on the results of the investigation, we will work with the airplane manufacturer to develop appropriate service information and might consider additional rulemaking to address these areas. We do not agree to change this AD to include the additional areas outside of the wheel well areas, since that would expand the scope of this AD and therefore require additional public review. We do not yet have sufficient information to justify delaying this AD to include those tubes. We have not changed the AD in this regard.
Request To Revise Wording in Paragraph (g) of NPRM (75 FR 76317, December 8, 2010)
Gulfstream requested that the NPRM (75 FR 76317, December 8, 2010) be revised to state that ``all'' tubes in the wheel well areas be inspected for the sponge rubber padding and corrosion conditions. Gulfstream stated that it has received reports where tube part numbers other than those called out in the service information have sponge rubber padding.
We disagree to revise the wording in paragraph (g) of this AD to add the word ``all.'' Gulfstream Service Bulletin 100-28-297, dated January 21, 2010, already specifies a detailed inspection in the wheel well area for the presence of sponge rubber padding without specifying part numbers. As noted in paragraph 4.A. of the Accomplishment Instructions of that service bulletin, this inspection is not limited to the fuel line part numbers identified in that service bulletin. The Accomplishment Instructions of that service bulletin note that if fuel lines other than those with part numbers identified in that service bulletin are found to have sponge rubber padding, then the padding must be removed and those affected tubes must also be inspected for corrosion. We have not revised the AD in this regard.
Conclusion
We reviewed the available data, including the comments received, and determined that air safety and the public interest require adopting the AD as proposed, except for minor editorial changes. We have determined that these minor changes:
Are consistent with the intent that was proposed in the NPRM (75 FR 76317, December 8, 2010) for correcting the unsafe condition; and
Do not add any additional burden upon the public than was already proposed in the NPRM (75 FR 76317, December 8, 2010).
Differences Between This AD and the MCAI or Service Information
Where Gulfstream Service Bulletin 100-28-297, dated January 21, 2010, specifies to submit a photo of any sponge rubber padding that is found to the manufacturer, this AD does not require that action.
Gulfstream Service Bulletin 100-28-297, dated January 21, 2010, instructs operators to contact Gulfstream if technical assistance is required. However, any deviation from the instructions provided in that service bulletin and mandated by this AD must be approved as an alternative method of compliance (AMOC) under the provisions of paragraph (h)(1) of this AD.
Costs of Compliance
We estimate that this AD will affect 130 products of U.S. registry. We also estimate that it will take about 25 work-hours per product to comply with the basic requirements of this AD. The average labor rate is $85 per work-hour. Required parts will cost about $100 per product. Where the service information lists required parts costs that are covered under warranty, we have assumed that there will be no charge for these parts. As we do not control warranty coverage for affected parties, some parties may incur costs higher than estimated here. Based on these figures, we estimate the cost of this AD to the U.S. operators to be $289,250, or $2,225 per product.
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 rulemaking action.
Regulatory Findings
We 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:
1. Is not a ``significant regulatory action'' under Executive Order 12866;
2. Is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979);
3. Will not affect intrastate aviation in Alaska; and
4. Will not have a significanteconomic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.
We prepared a regulatory evaluation of the estimated costs to comply with this AD and placed it in the AD docket.
Examining the AD Docket
You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Operations office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains the NPRM (75 FR 76317, December 8, 2010), the regulatory evaluation, any comments received, and other information. The street address for the Docket Operations office (telephone (800) 647-5527) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.