Discussion
On May 29, 2015, we issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to remove AD 2000-05-17 (65 FR 13875, March 15, 2000) and AD 2001-04-12 (66 FR 13232, March 5, 2001) and add a new AD. AD 2000-05-17 applied to Model EC120B helicopters with engine coupling tube part number (P/N) C631A1002101 and required recurring inspections of each coupling tube for a crack and replacing any cracked coupling tube with a reinforced coupling tube P/N C631A1101101. AD 2001-04-12 applied to Model EC120B helicopters with engine coupling tube P/N C631A1101101 and required repetitive visual checks of each coupling tube for a crack. AD 2000-05-17 and AD 2001-04-12 were prompted by reports of cracks on the reinforced coupling tube and were intended to prevent coupling tube failure, loss of engine drive, and a subsequent forced landing.
The NPRM published in the Federal Register on June 16, 2015 (80 FR 34335). The NPRM was prompted by reports of additional cracks in coupling tubes. Eurocopter France (now Airbus Helicopters) determined that the washer-type engine mount may, in certain cases, induce excessive loading on the coupling tube, which results in binding that increases component wear of the inner diameter of the mounting base. Because of this, the DGAC, on behalf of the European Aviation Safety Agency (EASA), issued AD No. F-2003-325 R1, dated May 12, 2004, for Model EC120B helicopters with engine coupling tube, P/N C631A1101101, and with an engine mount containing certain parts listed in Eurocopter Alert Service Bulletin (ASB) No. 04A005, dated July 16, 2003. DGAC AD No. F-2003-325 R1 requires inspections for helicopters with an engine mount block modified in accordance with Eurocopter Service Bulletin (SB) No. 71-003, Revision 1, dated July 18, 2002; replacing any coupling tube that has a crack; and increasing the life limit of the coupling tube from 1,000 flight hours to 20,000 flight hours. Also, DGAC AD No. F-2003-325 R1 requires, for helicopters with a new spring- loaded engine suspension modification in accordance with Eurocopter SB No. 71-005, Revision 0, dated May 14, 2004, increasing the life limit of the coupling tube to 20,000 flight hours and canceling the repetitive inspections of the coupling tube.
The NPRM proposed to require, for helicopters with certain engine mounts, before further flight, removing from service certain engine mount parts and measuring the height of the engine mounting base. If the height is more than 10.5 millimeters, the NPRM proposed replacing the engine mount with an engine mount that does not have the affected parts. For certain other helicopters, the NPRM proposed to require within 25 hours time-in-serice (TIS) replacing the spring-type engine suspension system, dye-penetrant inspecting the flared coupling for a crack, and replacing any cracked flared coupling. The NPRM also proposed removing coupling tube P/N C631A1002101 from service and prohibiting installation of that coupling tube on any helicopter.
Since the NPRM was issued, the FAA Southwest Regional Office has relocated and a group email address has been established for requesting an FAA alternative method of compliance for a helicopter of foreign design. We have revised the contact information throughout this final rule to reflect the new address and new email address.
Comments
After our NPRM (80 FR 34335, June 16, 2015) was published, we received comments from one commenter.
Request
Airbus Helicopters disagrees with the proposed requirement to replace the spring-type engine suspension system in accordance with Eurocopter SB No. 71-005 for helicopters with an improved engine mount under Eurocopter SB No. 71-003. Airbus Helicopters states there have been no coupling tube failures since incorporation of Eurocopter SB No. 71-003, and therefore the proposed requirement would not increase safety levels.
We disagree. Installing the improved enginemount specified in Eurocopter SB No. 71-003 extends the compliance time for a recurring visual inspection of the coupling tube from 5 hours TIS to 25 hours TIS. When issued, that recurring inspection was considered a short-term interim action until an effective modification or action was developed, approved, and available. Eurocopter SB No. 71-005 contained such an effective action to cancel that interim action and was developed and approved in May 2004.
Airbus Helicopters requested that, if we mandate the proposed requirement to replace the spring-type engine suspension system in accordance with Eurocopter SB No. 71-005, we change the proposed compliance time from 25 hours TIS to 18 months to allow for availability of parts.
We disagree. Eurocopter SB No. 71-005 was approved May 13, 2004. The NPRM was published June 16, 2015. The substantial amount of time that has passed since the approval of the service information and publication of our NPRM provided operators with enough notice of our proposal to mandate that procedure such that availability of parts should not be an issue.
FAA's Determination
This helicopter has been approved by the aviation authority of France and is approved for operation in the United States. Pursuant to our bilateral agreement with France, the DGAC on behalf of EASA, has kept the FAA informed of the situation described above. We are issuing this AD because we evaluated all information provided by the DGAC, reviewed the relevant information, considered the comments received, and determined the unsafe condition exists and is likely to exist or develop on other helicopters of this same type design and that air safety and the public interest require adopting the AD requirements as proposed.
Related Service Information Under 1 CFR Part 51
Eurocopter issued ASB No. 04A005, Revision 0, dated July 16, 2003, which prohibits, after June 30, 2004, operating an engine mount made up of the following parts: Support arm, P/NC714A1107201; swaged support arm, P/N C714A1106201; left-hand support bracket, P/N C714A1101102; and right-
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hand support bracket, P/N C714A1101103. ASB No. 04A005 also specifies measuring the height of the engine mounting base and, if the height is more than 10.5 millimeters, replacing the engine mount with an engine mount that does not have the specified P/N. ASB No. 04A005 does not apply to helicopters modified with an improved engine mount in accordance with SB No. 71-003. ASB No. 04A005 also does not apply to helicopters with a serial number 1170 or larger, as the specified engine mounts are not installed on those helicopters.
Eurocopter also issued SB No. 71-005, Revision 0, dated May 14, 2004, which contains procedures to modify the spring-type engine suspension system and dye-penetrant inspect the flared coupling assembly.
This service information is reasonably available because the interested parties have access to it through their normal course ofbusiness or by the means identified in the ADDRESSES section.
Other Related Service Information
Eurocopter issued SB No. 71-003, Revision 1, dated July 18, 2002, which contains procedures to improve the engine mount. Eurocopter also issued ASB No. 05A003, Revision 2, dated July 16, 2003, for helicopters that have not been modified with an improved engine mount in accordance with SB No. 71-003, which specifies inspecting the coupling tube for a crack every 5 hours and establishing a coupling tube life limit of 1,000 hours. For helicopters that have been modified with an improved engine mount, ASB No. 05A003 specifies inspecting the coupling tube for a crack every 25 hours and increasing the coupling tube life limit to 20,000 hours. ASB No. 05A003 was revised to Revision 3, dated May 11, 2004, to specify an optional spring-type engine suspension modification and cancel the repetitive inspection for this modified configuration.
Differences Between This AD and the DGAC ADThis AD requires the installation of the spring-type engine suspension modification specified in Eurocopter SB No. 71-005 and does not require the repetitive inspection of the coupling tube and the engine mount base. This AD also does not require you to contact the manufacturer.
Costs of Compliance
We estimate that this AD will affect 23 helicopters of the 115 helicopters of U.S. Registry. At an average labor rate of $85 per work- hour, we estimate that operators may incur the following costs in order to comply with this AD.
Installing new mounting arms and brackets requires about 12 work- hours and required parts cost $9,194, for a total cost per helicopter of $10,214 and $234,922 for the U.S. fleet. Installing the mounting spring kit requires about 14 work-hours and required parts cost $14,621, for a total cost per helicopter of $15,811 and $363,653 for the U.S. fleet. Dye-penetrant inspecting the coupling tube requires about 1 work-hour for a cost per helicopter of $85 and $1,955 for the U.S. fleet.
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 have 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 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 a regulatory, 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.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.