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
In June 2017, we received a report of an incident involving an Airbus Helicopters Model AS350B3 helicopter fitted with an IBF. The helicopter took off in heavy rain and experienced an engine flameout as the pilot increased power. The helicopter was less than 10 feet off the ground when the pilot was forced to land immediately. An inspection showed that violent water ingestion damaged six axial compressor blades. During our investigation, the FAA received additional reports of previous incidents of helicopters equipped with IBFs or induction filter installations experiencing abnormal engine operations during heavy precipitation.
The FAA issued Special Airworthiness Information Bulletin SW-17-30, dated October 13, 2017 \1\ (SAIB), to warn operators that persistent or heavy rains may result in the inlet barrier filter media collecting and retaining water. The SAIB recommended the following to affected owners and operators: ---------------------------------------------------------------------------
\1\ SAIB SW-17-30, dated October 13, 2017, may be viewed online at http://rgl/faa/gov. ---------------------------------------------------------------------------
Use IBF covers when the rotorcraft is parked or towed outside, particularly when precipitation is reported in the area;
During the helicopter preflight inspection, visually inspect the inlet and filter to verify that the inlet and filter medium are dry and free of accumulated moisture;
If the filter medium has moisture during the preflight inspection, or if the rotorcraft is operating in heavy precipitation, open the bypass doors if equipped; and
When operating in precipitation, sudden and rapid power transients should be avoided whenever practical.
Action Since the SAIB Was Issued
After the SAIB was issued, we continued to investigate this issue and determined that AD action was necessary for certain Pall Corporation IBF dry-media filter elements. Filters that have a hydrophobic coating resist water accumulation, while the dry-media filters that are the subject of this AD accumulate water. The risk of engine failure caused by the ingestion of an excessive amount of water through the IBF element results in an unsafe condition that requires AD action.
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 products of these same type designs.
Related Service Information
We reviewed Pall Corporation Service Information Letter CE01301F2SINFOL, Revision A, dated July 15, 2015, which recommends covering the engine inlet if the helicopter is outside while not operating. The letter also recommends conducting pre-flight inspections to ensure the engine inlet is clearof water.
AD Requirements
This AD requires, within 30 days, revising the rotorcraft flight manual supplement by inserting Appendix A of this AD into the limitations section.
Differences Between This AD and the Service Information
The service information allows for removing water and reinstalling the IBF element if there is standing water on the engine inlet. This AD prohibits operation unless the IBF element is dry.
Interim Action
We consider this AD to be an 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.
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Costs of Compliance
We estimate that this AD will affect 81 helicopters of U.S. Registry and that labor costs average $85 per work-hour. Based on these estimates, we expect the following costs:
Incorporating Appendix A of this AD into the rotorcraft flight manual requires 1 work-hour and no parts for a cost of $85 per helicopter and $6,885 for the U.S. fleet.
Replacing the inlet barrier filter, if required, requires 2 work-hours and parts cost $3,995 for a cost of $4,165 per filter replacement.
FAA's Justification and Determination of the Effective Date
An unsafe condition exists that requires the immediate adoption of this AD without providing an opportunity for public comments prior to adoption. The FAA has found that the risk to the flying public justifies waiving notice and comment prior to adoption of this rule because the unsafe condition requires corrective action within 30 days. Therefore, we find good cause that notice and opportunity for prior public comment are impracticable. In addition, for the reason stated above, we find that good cause exists for making this amendment effective in less than 30 days.
Authority for This Rulemaking
Title 49 of the United States Codespecifies 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 FR 11034, 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.