Discussion
On June 20, 2013 at 78 FR 37154, the Federal Register published our notice of proposed rulemaking (NPRM), which proposed to amend 14 CFR part 39 to add an AD that would apply to Eurocopter Model AS350B, AS350BA, AS350B1, AS350B2, AS350B3, AS350C, AS350D, AS350D1, AS355E, AS355F, AS355F1, AS355F2, AS355N, and AS355NP helicopters with sliding doors installed, except those with modification AL.4262. The NPRM proposed to require removing from service each nut, part number (P/N) ASN52320BH060N, and each washer, P/N 23111AG0LE, within 165 hours time- in-service (TIS) and replacing them with an airworthy nut and washer. The proposed requirements were intended to prevent loss of the lower ball-joint nut, which could lead to loss of the sliding door and damage to the helicopter.
The NPRM was prompted by AD No. 2012-0205, dated October 1, 2012, issued by the European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Union. EASA issued AD 2012-0205 to correct an unsafe condition for Eurocopter Model AS350B, AS350BA, AS350BB, AS350B1, AS350B2, AS350B3, AS350D, AS355E, AS355F, AS355F1, AS355F2, AS355N, and AS355NP helicopters with a sliding door installed, except those with modification AL. 4262. EASA advises that during a patrol flight with the doors open, the right-hand (RH) sliding door became detached and was lost in-flight. EASA states it was discovered that the nut of the ball-joint bolt was missing, which allowed the ball-joint bolt to detach from the door and the door to ``fall off'' the aircraft. According to EASA, a check of the left- hand (LH) sliding door revealed that the nut of the ball-joint bolt was not tightened, and could be unscrewed by hand. EASA advises that the self-locking characteristics of the nut were lost, possibly due to a defective assembly of the ball-joint bolt. This failure of the self- locking characteristics of the nut could lead to loss of the sliding door in-flight, potentially resulting in damage of the surrounding helicopter structure and possible injury to persons on the ground. For these reasons, EASA issued AD 2012-0205 to require modification AL.4262, which specifies replacing each nut, P/N ASN52320BH060N, and washer, P/N 23111AG0LE, with nut, P/N 22542K060, and lock-washer, P/N 23351AC060LE, on the lower ball-joint bolt.
Comments
We gave the public the opportunity to participate in developing this AD, but we did not receive any comments on the NPRM (78 FR 37154, June 20, 2013).
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 these same type designs and that air safety and the public interest require adopting the AD requirements as proposed.
Differences Between This AD and the EASA AD
The EASA AD requires replacing the lower ball-joint nut and washer within 165 flight hours or 13 calendar months, while this AD requires replacing the affected lower ball joint nut and washer within 165 hours TIS. In addition, this AD does not apply to the Model AS350BB as that helicopter is not type-certificated in the U.S., but it applies to Models AS350C and AS350D1 because those models have a similar lower ball joint nut and washer.
Related Service Information
Eurocopter has issued Alert Service Bulletin (ASB) No. AS350- 52.00.34 for Model AS350 B, B1, B2, B3, BA, BB, D, and L1 helicopters and ASB No. AS355-52.00.26 for Model AS355 E, F, F1, F2, N, and NP helicopters, both Revision 0 and both dated July 9, 2012. The ASBs describe procedures to replace the nuts and lock-washers on the LH and RH sliding door lower ball-joint bolts with different part numbered nuts and lock-washers, to ``double lock'' the lower ball-joint bolts. Eurocopter designates the maintenance procedure and design change in its ASBs as modification AL.4262.
Costs of Compliance
We estimate that this AD will affect 900 helicopters of U.S. Registry.
We estimate that operators may incur the following costs in order to comply with this AD. At an average labor rate of $85 per hour, replacing the nuts and washers on the sliding doors will require about 1 work-hour, and required parts costs will be minimal, for a cost per helicopter of $85 and a total cost to U.S. operators of $76,500.
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 thescope 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 helicopters 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.
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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; 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.