Discussion
What events have caused this AD? The Federal Office for Civil Aviation (FOCA), which is the airworthiness authority for Switzerland, recently notified FAA that an unsafe condition may exist on certain Pilatus Models PC-12 and PC-12/45 airplanes. The FOCA reports part number (P/N) 532.10.12.077 bolts that do not have white primed and painted heads are subject to corrosion. These bolts attach the hydraulic actuators to the left and right main landing gear (MLG) assemblies. The FOCA further reports the separation of a bolt head in an MLG assembly has occurred due to corrosion. The corrosion occurred because the bolt head was not primed and painted.
Pilatus has designed and produced a new bolt (P/N 532.10.12.077F) as part of Modification Kit No. 500.50.12.299 to replace the subject bolt. Pilatus recommends the replacement of bolts in pairs.
What is the potential impact if FAA took no action? Corrosion of the bolt could lead to MLG collapse during airplane landing and take- off operations with consequent loss of airplane control.
Has FAA taken any action to this point? 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 Pilatus Aircraft Ltd. (Pilatus) Models PC-12 and PC-12/45 airplanes. This proposal was published in the Federal Register as a notice of proposed rulemaking (NPRM) on August 2, 2005 (70 FR 44297). The NPRM proposed to require you to inspect the left and right main landing gear (MLG) assemblies for any part number (P/N) 532.10.12.077 bolts that do not have white primed and painted heads; and replace any bolt found with new P/N 532.10.12.077F bolts in all MLG assemblies.
Comments
Was the public invited to comment? We provided the public the opportunity to participate in developing this AD. The following presents the comments received on the proposal and FAA's response to each comment:
Comment Issue: Include Parts Manufacture Approval (PMA) Parts Approved by Identicality in Both the Parts Replaced and the Replacement Parts
What is the commenters' concern? Two commenters specifically ask that the FAA address PMA parts approved by identicality in both the parts replaced (unsafe condition) and the replacement parts (correction of condition). Specifically, the commenters state:
1. One commenter believes FAA should add the phrase "or FAA- approved equivalent part number" to the replacement part as it did with the parts replaced; and
2. Another commenter states that restricting parts to be replaced and parts installed to just those cited in the manufacturer service bulletin is not good form and might establish a dangerous precedent. The commenter believes that installed PMA parts could have the same unsafe condition and that the owner/operator should have the option of installing equivalent parts without applying for an alternative method of compliance (AMOC). The commenteralso believes that the phrase "or FAA-approved equivalent part number" is inadequate for replacement parts and proposes language to clarify that phrase.
What is FAA's response to the concern? The FAA concurs with all the comments above. The FAA will add information to further clarify the phrase "or FAA-approved equivalent part number", and add the phrase to cover the PMA replacement parts.
Conclusion
What is FAA's final determination on this issue? We have carefully reviewed the available data and determined that air safety and the public interest require adopting the AD as proposed except for the changes discussed above and minor editorial corrections. We have determined that these changes and 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.
Docket Information
Where can I go to view the docket information? You may view the AD docket that contains information relating to this subject in person at the DMS Docket Offices between 9:00 a.m. and 5:00 p.m. (eastern time), Monday through Friday, except Federal holidays. The Docket Office (telephone 1-800-647-5227) is located on the plaza level of the Department of Transportation NASSIF Building at the street address stated in ADDRESSES. You may also view the AD docket on the Internet at http://dms.dot.gov.
Changes to 14 CFR Part 39--Effect on the AD
How does the revision to 14 CFR part 39 affect this AD? On July 10, 2002, the FAA published a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which governs the FAA's AD system. This regulation now includes material that relates to altered products, special flight permits, and alternative methods of compliance. This material previously was included in each individual AD. Since this material is included in 14 CFR part 39, we will not include it in future AD actions.Costs of Compliance
How many airplanes does this AD impact? We estimate that this AD affects 350 airplanes in the U.S. registry.
What is the cost impact of this AD on owners/operators of the affected airplanes? 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 $65 per hour = $65
Not applicable
$65
$22,750
We estimate the following costs to do any necessary single bolt replacement (using Modification Kit No. 500.50.12.299) that would be required based on the results of this inspection. We have no way of determining the number of airplanes that may need this bolt replacement:
Labor cost
Parts cost
Total cost per airplane
3 work hours $65 per hour = $195
$1,000 estimate for each Modification Kit No. 500.50.12.299
$1,195
Pilatus will provide warranty credit for inspecting and replacing the specified bolts to the extent stated in the service information.
Authority for This Rulemaking
What authority does FAA have for issuing this rulemaking action? 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
Will this AD impact various entities? Wehave 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.
Will this AD involve a significant rule or regulatory action? 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); and
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 ofthis summary by sending a request to us at the address listed under ADDRESSES. Include "Docket No. FAA-2005-21835; Directorate Identifier 2005-CE-35-AD" in your request.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
Adoption of the Amendment
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:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. FAA amends Sec. 39.13 by adding a new AD to read as follows: