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Discussion
This AD supersedes EAD 2010-25-51, issued November 24, 2010 (EAD 2010-25-51), which superseded EAD 2010-24-52, issued November 19, 2010 (EAD 2010-24-52). EAD 2010-24-52 superseded EAD 2010-24-51, issued November 12, 2010 (EAD 2010-24-51). EAD 2010-24-51, EAD 2010-24-52, and EAD 2010-25-51 were all issued for the Bell Model 212 helicopters with a certain fitting installed.
EAD 2010-24-51, the initial EAD, was issued for all Bell Model 212 helicopters with a fitting, part number (P/N) 212-010-103-007, S/Ns 9956 through 10005 with a prefix of ``A''. That EAD required, before further flight, removing any affected fitting and replacing it with an airworthy fitting. That EAD also prohibited installing any affected fitting on any helicopter. That EAD was prompted by an accident that resulted in several fatalities. During the investigation of the accident, a crack was found on a fitting. Subsequently, four additional fittings from the same manufacturing lot were inspected, and two were found to exhibit the same type of cracking. We issued EAD 2010-24-51 to remove this lot from service to prevent failure of a fitting, loss of a main rotor blade, and subsequent loss of control of the helicopter.
After we issued EAD 2010-24-51, additional fittings from a different manufacturing lot were found to have the same type of crack as that found on the fitting involved in the accident. Therefore, we issued superseding EAD 2010-24-52 to require the same actions as EAD 2010-24-51, and to expand the applicability to include additional fittings. In addition to S/Ns 9956 through 10005 with a prefix of ``A'', EAD 2010-24-52 added S/Ns 52, 54, 55, 57 through 65, 67, 69, 70, 71, 73, 103, 112, 113, 137, and 139 with a prefix of ``SH'' to the applicability. EADs 2010-24-51 and 2010-24-52 were issued as interim actions to address a known unsafe condition, and Bell continued to investigate the cause of the cracking.
Because the root cause of the cracking had not been determined, and due to the severity of a fitting failure, we issued superseding EAD 2010-25-51 to require the same action as EAD 2010-24-52 and to also require performing an MPI on fittings with S/Ns 9911 through 9955, 10006 through 10049, 10075 through 10174, 10455 through 10460, 10581 through 10655, 10742 through 10791, and 10862 through 10946 with a prefix of ``A'' to detect a crack on those fittings. If you find a crack, you are required to replace the cracked fitting with an airworthy fitting, and within 24 hours, report the information specified in Appendix 1 of the EAD to the Manager, Rotorcraft Certification Office. If you do not find a crack, you are required to reidentify and refinish the fitting in accordance with the specified portion of Alert Service Bulletin (ASB) 212-10-142, dated November 24, 2010 (ASB 212-10-142).
Actions Since AD Was Issued
Since we issued EAD 2010-25-51, additional fittings with cracks were found using the MPI process. In response to these findings, Bell issued ASB 212-10-142, Revision A, dated March 21, 2011, that specifies performing an MPI for a crack on all serial-numbered fittings with the same part number in stock or in service. We have determined that certain fittings were not manufactured in accordance with the approved manufacturing processes and controls. Due to the severity of a fitting failure, this superseding AD is being issued to continue to require replacing certain serial-numbered fittings, and to expand the applicability to require performing an MPI for a crack on the remaining serial numbers of the fittings with the same part number. Serial- numbered fittings affected by this superseding AD are listed in Table 1 of the Applicability section of this AD. This superseding AD is being issued to prevent failure of a fitting, loss of a main rotor blade, and subsequent loss of control of the helicopter.
Relevant Service Information
We reviewed Bell Alert Service bulletin (ASB) No. 212-10-141, dated November 11, 2010 (ASB-212-10-141), which specified the immediate removal of the affected fittings, S/Ns A-9956 through A-10005, from service. We also reviewed ASB No. 212-10-141, Revision A, dated November 18, 2010 (ASB 212-10-141 Rev. A), which incorporates additional S/Ns of the affected fittings and specifies removing the affected serial-numbered fittings from service. In ASB 212-10-141, Bell states that they have determined that the fittings may not have been manufactured in accordance with the engineering design requirements and may fracture as a result of the nonconformance.
We have also reviewed Bell ASB 212-10-142, initial release, dated November 24, 2010 (ASB 212-10-142) which specifies performing an MPI on fittings with certain S/Ns to detect a crack on those fittings.
Finally, we have reviewed Bell ASB 212-10-142, Revision A, dated March 21, 2011 (ASB 212-10-142 Rev. A), which includes all serial- numbered fittings except those already inspected and marked with ``FM''. ASB 212-10-142 Rev. A specifies 1) within 25 hours time-in- service (TIS) or 15 days, whichever comes first, for all fittings with less than 400 hours TIS; or 2) within 100 hours TIS or 30 days, whichever comes first, for all fittings with 400 or more hours but less than 800 hours TIS; or 3) at the next main rotor teardown inspection or next tension-torsion strap replacement, whichever comes first, for all fittings with more than 800 hours TIS, performing a one-time MPI of the fitting, P/N 212-010-103-007, with all S/Ns in stock or in service. Finally, ASB 212-10-142 Rev. A states that all fittings, S/Ns A-11021 and subsequent, SH-053, SH-066, SH-072, SH-074 through SH-102, SH-104 through SH-111, SH-114 through SH-136, SH-138, and SH-140 and subsequent are not affected by ASB 212-10-142 Rev. A. Bell states that a one-time MPI of the affected fittings is required to ensure continued airworthiness of the fittings.
FAA's DeterminationWe 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 this same type design.
AD Requirements
This AD supersedes EAD 2010-25-51 and requires the following:
Before further flight, for any helicopter with a fitting, S/N 9956 through 10005, with a prefix of ``A'', and S/N 52, 54, 55, 57 through 65, 67, 69, 70, 71, 73, 103, 112, 113, 137, and 139 with a prefix of ``SH'', replace the fitting with an airworthy fitting. Any fitting with a S/N identified in this paragraph is no longer eligible for installation on any helicopter.
Before further flight, for any helicopter with a fitting, S/N 9911 through 9955, 10006 through 10049, 10075 through 10174, 10455 through 10460, 10581 through 10655, 10742 through 10791, and 10862 through 10946, with a prefix of ``A'', perform an MPI of each fitting for a crack. If the fitting is cracked, replace it with an airworthy fitting. If the fitting is not cracked, reidentify and refinish the fitting.
For any fitting with a serial number identified in paragraph (h) in the Compliance section of this AD, perform an MPI of each fitting for a crack:
[cir] For any fitting with 400 or less hours TIS, perform an MPI within 25
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hours TIS or 15 days, whichever comes first.
[cir] For any fitting with more than 400 hours but less than 800 hours TIS, perform an MPI within 100 hours TIS or 30 days, whichever comes first.
[cir] For fittings with 800 hours or more TIS, perfrom an MPI at the next main rotor hub teardown inspection or tension-torsion strap replacement, whichever comes first.
[cir] If a fitting is cracked, replace it with an airworthy fitting. If a fitting is not cracked, reidentify and refinish the fitting.
If a crack is found on any fitting, within 24 hours, report the information requested in Appendix 1 of this AD to the Manager, Rotorcraft Certification Office, FAA, 2601 Meacham Blvd, Fort Worth, Texas 76137, or e-mail 7-AVS-ASW-170@faa.gov.
Differences Between the AD and the Service Information
This AD differs from ASB 212-10-142 Rev. A as follows:
We do not require returning parts to Bell.
We require performing an MPI before further flight on certain S/N fittings included in the initial release of ASB 212-10-142.
We require sending information to the Rotorcraft Certification Office and not to Bell.
Bell uses the term ``total time-in-service'' to describe compliance times, and we use the term ``time-in-service.''
We specify S/Ns in our AD, and Bell does not specify S/Ns in ASB 212-10-142 Rev. A.
FAA's Justification and Determination of the Effective Date
An unsafe condition exists that requires the immediate adoption of this AD. The FAA finds that the risk to the flying public justifies waiving notice and comment prior to adoption of this rule because we evaluated all the available information and determined the unsafe condition described is likely to exist or develop in other helicopters of this same type design. Therefore, we find that notice and opportunity for prior public comment are impracticable because of the short compliance times, and that good cause exists for making this amendment effective in less than 30 days.
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 before it becomes effective. However, we invite you to send any written data, views, or arguments about this AD. Send your comments to an address listed under the ADDRESSES section. Include the Docket Number FAA-2011-0323 and ``Directorate Identifier 2011-SW- 005-AD'' at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this AD. We will consider all comments received by the closing date and may amend this AD because of those comments.
We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this AD.
Costs of Compliance
We estimate that this AD affects 84 helicopters of U.S. registry. We estimate the following costs to comply with this AD:
Estimated Costs ----------------------------------------------------------------------------------------------------------------
Cost per Cost on U.S.
Action Labor cost Parts cost helicopter operators ---------------------------------------------------------------------------------------------------------------- (a) For any fitting, S/N 9956 through 40 work-hours x $85 per $2,367 $5,767 $415,224
10005 and a prefix of ``A''; or a S/N hour = $3,400.
of 52, 54,55, 57 through 65, 67, 69,
70, 71, 73, 103, 112, 113, 137, 139
with a prefix of ``SH''; replace the
fitting with an airworthy fitting
(assumes action affects 72 fittings). (c) For any fitting affected by this 40 work-hours x $85 per 0 3,400 40,800
AD with a S/N not identified in hour = $3,400.
paragraph (a) of this table, perform
an MPI on each fitting for a crack
unless documentation exists of any
previous MPI performed during
regularly scheduled maintenance
(assumes action affects 12 fittings). ----------------------------------------------------------------------------------------------------------------
We estimate a total cost of $456,024 to do the actions required by this AD.
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
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 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,
(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.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
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