Comments Invited
This AD is a final rule that involves requirements affecting flight safety, and we did not provide you with notice and an opportunity to provide your comments prior to it becoming effective. However, we invite you to participate in this rulemaking by submitting written comments, data, or views. We also invite comments relating to the economic, environmental, energy, or federalism impacts that resulted from adopting this AD. The most helpful comments reference a specific portion of the AD, explain the reason for any recommended change, and include supporting data. To ensure the docket does not contain duplicate comments, commenters should send only one copy of written comments, or if comments are filed electronically, commenters should submit them only one time. We will file in the docket all comments that we receive, as well as a report summarizing each substantive public contact with FAA personnel concerning this rulemaking duringthe comment period. We will consider all the comments we receive and may conduct additional rulemaking based on those comments.
Discussion
We are adopting a new AD for Sikorsky Model S-92A helicopters. This AD requires, initially and each time the clamps are removed, inspecting for chafing between the electrical wires and the hydraulic lines and, if there is chafing between the wires and lines, before further flight, replacing the unairworthy wires or lines with airworthy wires or lines. Also, this AD requires inspecting each clamp for correct installation, and if a clamp is incorrectly installed or missing, before further flight, correctly installing the clamps.
This AD is prompted by chafing between high voltage electrical wires and hydraulic lines that led to two fires in the top deck of the helicopter, which does not have fire detection nor extinguishing capability. The chafing occurred because of improper clamp installation after maintenance was performed in the topdeck. A redesign eliminated the need for clamping in newer Model S-92A helicopters. However, because of the high volume of maintenance performed in the area where the fire occurred immediately following maintenance involving
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removing and installing the clamps, more detailed instructions are necessary for correct installation of the clamps in the older model helicopters. The actions specified by this AD are intended to detect any chafing between the electrical wires and the hydraulic lines that could result in a fire and subsequent loss of control of the helicopter.
FAA's Determination
We are issuing this AD because we evaluated all the relevant information and determined the unsafe condition described previously is likely to exist or develop in other helicopters of the same type design.
Related Service Information
Sikorsky has issued Alert Service Bulletin No. 92-20-001, dated October 27, 2005 (ASB) to specify a one-time installation of clamps to provide additional clearance between the electrical harnesses on the upper deck and the hydraulic lines.
AD Requirements
This AD requires:
Within 5 hours time-in-service (TIS), inspecting the electrical wires and the hydraulic lines in the affected area for evidence of chafing. If there is chafing between electrical wires and the hydraulic lines, this AD requires, before further flight, replacing unairworthy wires or lines with airworthy wires or lines.
Within 5 hours TIS, inspecting each clamp for correct installation. If clamps are incorrectly installed or missing, before further flight, install clamps by following the Accomplishment Instructions of the ASB.
After each maintenance that requires removing clamps, this AD requires repeating the previous inspections.
Differences Between This AD and the Service Information
The service information specifies a one-time installation of the clamps between the electrical harnesses on the upper deck and thehydraulic lines within 30 days. This AD requires, within 5 hours TIS, inspecting each clamp for correct installation, and within 5 hours TIS and after each maintenance that requires removing clamps, inspecting the electrical wires and the hydraulic lines for chafing. This AD applies to S/N 920006 through 920084, and the service bulletin applies to S/N 920006 through 920022.
Interim Action
We consider this AD interim action. The design approval holder is currently developing a modification that will address the unsafe condition identified in this AD. Once this modification is developed, approved, and available, we might consider additional rulemaking.
Costs of Compliance
We estimate that this AD will affect 20 helicopters of U.S. Registry.
We estimate that operators may incur the following costs in order to comply with this AD. Labor costs are estimated at $85 per work hour. An initial inspection of the clamps will take .5 work hour. Inspecting and reclamping will take 2 work hours at a parts cost of $25 per helicopter. Inspecting and replacing the electrical wires will take 2 work hours at a parts cost of $7,500 per helicopter. Inspecting and replacing the hydraulic lines will take 3 work hours at a parts cost of $500 per helicopter. Based on these estimates, the total cost per helicopter is $8,663, and the total cost of compliance for the U.S. fleet is $173,250, assuming the clamps, electrical wires, and hydraulic lines are replaced.
According to Sikorsky's service information, the costs of this AD may be covered under warranty thereby reducing the cost impact on affected individuals. We do not control warranty coverage by Sikorsky. Accordingly, we have included all costs in our cost estimate.
FAA's Justification and Determination of the Effective Date
Providing an opportunity for public comments before adopting these AD requirements would delay implementing the safety actions needed to correct this known unsafe condition. Therefore, we find that the risk to the flying public justifies waiving notice and comment before adopting this rule because the required corrective actions must be done within 5 hours TIS, a very short time period based on the average flight-hour utilization rate of these helicopters.
Since an unsafe condition exists that requires the immediate adoption of this AD, we determined that notice and opportunity for public comment before issuing this AD are impracticable and that good cause exists for making this amendment effective in less than 30 days.
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, I certify that this AD:
1. Is not a ``significant regulatory action'' under Executive Order 12866;
2. Is not a ``significant rule'' under DOT Regulatory Policies and Procedures (44 FR11034, February 26, 1979);
3. Will not affect intrastate aviation in Alaska to the extent that it justifies making a regulatory distinction; and
4. 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 an economic evaluation of the estimated costs to comply with this AD and placed it in the AD docket.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.