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
The European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Union, has issued EASA Emergency AD No. 2012-0207-E, dated October 5, 2012 (EAD 2012-0207-E), to correct an unsafe condition for Eurocopter Model AS 350 B3 helicopters modified by Modification (MOD) 07 5601. MOD 07 5601 is an integral part of a specific Model AS350B3 configuration, commercially identified as ``AS350B3e'' and is not fitted on Model AS350B3 helicopters of other configurations. EASA advises that premature failures of bearings, P/N 704A33-633-261, installed in combination with T/R blades P/N 355A12.0055.00 or 355A12.0055.01, have recently been detected on AS 350 B3 helicopters in ``AS350B3e'' configuration. Three cases of vibrations originating from the T/R, caused by failure of the bearings, were reported, which were detected in flight. Subsequently, an accident occurred in which the pilot felt strong vibrations from the T/R before losing control of the helicopter. An investigation revealed that prior to the accident, the bearings had been replaced twice on the helicopter due to deterioration. EASA EAD 2012-0207-E requires installing placards and changing the RFM to limit the flight envelope by reducing the Velocity Never Exceed (VNE) true airspeed (TAS) limitation to reduce the dynamic loads on the T/R, a one-time pre-flight inspection and repetitive post-flight inspections of the bearings to detect damage, a one-time ``After Last Flight of the day'' (ALF) inspection (including T/R disassembly), and replacing all bearings if any bearing is damaged.
On October 17, 2012, we issued EAD No. 2012-21-51 for Eurocopter Model AS350B3 helicopters with MOD 07 5601, with bearing P/N 704A33- 633-261 in combination with tail rotor blade P/N 355A12.0055.00 or 355A12.0055.01, installed. We sent that EAD toall known U.S. owners and operators of these helicopters. That EAD requires, before further flight, installing two placards on the instrument panel and revising the RFM to reduce the VNE indicated airspeed (IAS) limitation. It also requires, before further flight and thereafter after each flight, visually checking all visible faces of the bearings for separation, a crack, or an extrusion, and replacing the four bearings if there is an extrusion or if there is a separation or a crack on the pressure side bearing greater than 5 millimeters (.196 inches). Lastly, the EAD requires, after the last flight of the day, performing a one-time
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inspection of the bearings for a separation, a crack, or an extrusion, and replacing the four bearings if there is a separation, crack, or extrusion. Our EAD differed from EASA EAD 2012-0207-E in that the EASA EAD placard limited TAS, while the placard in our EAD limited IAS.
Actions Since Existing EAD Was Issued
Since weissued EAD 2012-21-51, EASA issued EAD No. 2012-0217-E, dated October 19, 2012 (EAD 2012-0217-E), which superseded EASA EAD 2012-0207-E. EAD 2012-0217-E retains some of the requirements of EAD 2012-207-E, changes the airspeed limitation from TAS to IAS, and requires inserting a temporary engine health check procedure into the RFM. We are not issuing this superseding AD to adopt the revised EASA requirements, because the airspeed limitations in EAD 2012-21-51 currently use IAS, and the revised engine health check procedure does not correct the unsafe condition.
In addition, we have been informed by EASA that newly-designed T/R blades with a P/N not listed in EAD 2012-21-51 have been developed and may be installed on these model helicopters, but will also be affected by the unsafe condition. Additionally, the compliance interval for the bearing removal and inspection required in EAD 2012-21-51 did not allow an operator to perform the inspection prior to the last flight of the day, ifdesired, and would have required the bearing removal and inspection after the last flight of the day following any bearing replacement, which was not intended when we issued the EAD. Therefore, we are issuing this AD to remove the laminated half-bearing and T/R blade P/Ns from the applicability and revise the language of the removal and inspection paragraph to clarify when that inspection is required.
FAA's Determination
These helicopters have been approved by the aviation authority of France and are approved for operation in the United States. Pursuant to our bilateral agreement with France, EASA, its technical representative, has notified us of the unsafe condition described in the EASA AD. We are issuing this AD because we evaluated all information provided by EASA and determined the unsafe condition exists and is likely to exist or develop on other helicopters of the same type design.
Related Service Information
We reviewed Eurocopter Emergency Alert Service Bulletin (EASB) with two numbers, No. 01.00.65 for the Model AS350B3 helicopters and No. 01.00.24 for the non-FAA type certificated Model AS550C3 helicopters, both Revision 0, and both dated October 4, 2012. The EASB specifies installing two placards on the instrument panel and revising the RFM to limit airspeed to both 100 knots IAS and TAS, on-aircraft checking of the bearings after each flight, and performing a one-time removal and inspection of the bearings. The EASB also defines an RFM procedure in case of in-flight vibrations originating in the tail rotor. Revision 1 of the EASB, dated October 18, 2012, which Eurocopter issued after we issued EAD 2012-21-51, introduced a new procedure for the periodic ``Engine Health Check'' procedure, and specified to remove the placard and RFM changes with the VNE TAS limitation. Revision 2 of the EASB, dated November 2, 2012, accounted for newly designed T/R blades by removing specific part-numbered T/R blades from the Effectivity section of the EASB.
AD Requirements
This AD retains the requirements of EAD 2012-21-51, expands the applicability by removing the half-bearing and the T/R blade P/Ns from the applicability paragraph, clarifies that the removal and inspection of the bearings is not a daily inspection, and clarifies that the inspection of the bearings may be performed prior to the last flight of the day (not after the last flight of the day).
Differences Between This AD and the EASA AD
The EASA AD requires removing the placard and RFM changes with the TAS limitation and replacing it with an IAS limitation. Since the FAA EAD did not include the TAS limitation, this AD does not need to require removing it. This AD does not require inserting the temporary engine health check procedure in the RFM.
Interim Action
We consider this AD interim action. The design approval holder is currently developing a modification that will address the unsafe condition specified 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 18 helicopters of U.S. Registry.
We estimate that operators may incur the following costs in order to comply with this AD. Installing a placard and revising the RFM will require about .5 work-hour, at an average labor rate of $85 per hour, for a cost per helicopter of $43 and a total cost to U.S. operators of $774. Disassembling and inspecting the bearings will require about 6 work-hours, at an average labor rate of $85 per hour, for a cost per helicopter of $510 and a total cost to U.S. operators of $9,180.
If necessary, replacing the bearings installed on the aircraft will require about 6 work-hours, at an average labor rate of $85, and required parts will cost $2,415, for a cost per helicopter of $2,925.
FAA's Justification and Determination of the Effective Date
The short compliance time involved is required because the previously described unsafe condition can adversely affect both the structural integrity and controllability of the helicopter. Therefore, because several of the corrective actions are required before further flight, this AD must be issued immediately.
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.
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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.