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AD 98-24-32 ACTIVE

Tail Rotor Hub Fairing Attachment Spring
Key Information
AD Number 98-24-32 Status Active
Effective Date December 14, 1998 Issue Date Not specified
Docket Number 98-SW-05-AD Amendment 39-10918
Product Type ["Aircraft"] Product Subtype ["Rotorcraft"]
CFR Part --- - Part 39 (63 FR 65548 NO. 228 11/27/98) CFR Section N/A
Citation (Federal Register: November 27, 1998 (Volume 63, Number 228))
Applicability
Manufacturer(s) Airbus Helicopters
Model(s) AS-365N2 SA-360C Dauphin SA-365C SA-365C1 SA-365C2 SA-365N SA-365N1 SA-366G1
Summary

This amendment adopts a new airworthiness directive (AD) that is applicable to Eurocopter France Model AS-365N2, SA-360C, SA-365C, C1, C2, N, N1, and SA-366G1 helicopters. This action requires inspecting for broken or out-of-tolerance attachment springs on the tail rotor hub fairing (fairing), replacing broken attachment springs and attachment springs that are out-of-tolerance, and marking the fairing to indicate compliance with this AD. This amendment is prompted by three in-service reports of failed attachment springs. The actions specified in this AD are intended to prevent failure of an attachment spring, which could cause loss of the fairing, damage to the tail rotor, and subsequent loss of control of the helicopter.

Action Required

Final rule; request for comments

Regulatory Text

98-24-32 EUROCOPTER FRANCE: Amendment 39-10918. Docket No. 98-SW-05-AD. \n\tApplicability: Model AS-365N2, SA-360C, SA-365C, C1, C2, N, N1, and SA-366G1, certificated in any category. \n\n\tNOTE 1: This AD applies to each helicopter identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For helicopters that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must use the authority provided in paragraph (e) to request approval from the FAA. This approval may address either no action, if the current configuration eliminates the unsafe condition, or different actions necessary to address the unsafe condition described in this AD. Such a request should include an assessment of the effect of the changed configuration on the unsafe condition addressed by this AD. In no case does the presence ofany modification, alteration, or repair remove any helicopter from the applicability of this AD. \n\n\tCompliance: Required as indicated, unless accomplished previously \n\n\tTo prevent failure of an attachment spring (spring), which could cause loss of the tail rotor hub fairing (fairing), damage to the tail rotor, and subsequent loss of control of the helicopter, accomplish the following: \n\n\t(a)\tBefore further flight with fairing, part number (P/N) 360A33-1079-01, installed, that has modification 365A07-64B20 incorporated but is not marked with an "X" after the part number: \n\n\t\t(1)\tRemove the six fairing attachment bolts (bolts), then remove the fairing from the helicopter. \n\n\t\t(2)\tInspect for broken springs, especially in the rounded sections at the rotor hub groove (Point A, Figure 1). \n\n\t\t(3)\t If any broken springs are discovered, replace them with airworthy springs using the procedure specified in paragraph (b) of this AD. \n\n\t\t(4)\tLubricate the threads with NATO 156 oil, then reinstall the six bolts, torqued to 0.4-0.5 m.daN (35.3-44.2 in.-lbs.). \n\n\t\t(5)\tInspect for interference between the spring and the fairing (Point B, Figure 2), and replace any spring that exhibits such interference in accordance with the procedure specified in paragraph (b) of this AD. \n\n\t\t(6)\tMeasure the outward axial protrusion (Dimension e, Figure 1), for each spring. If the protrusion dimension obtained from the measurement required by paragraph (a)(6) of this AD is less than 1mm (0.039-inches), or greater than 2.7mm (0.106 inches), either \n\n\t\t\t(i)\treplace the spring with an airworthy spring before further flight or, \n\n\t\t\t(ii)\tInspect the out-of-tolerance spring(s) in accordance with paragraph (a)(2) before the first flight of each day until each spring is replaced with an airworthy spring. Any out-of-tolerance spring must be replaced with an airworthy spring within 25 hours time-in-service (TIS). \n\n\t(b)\tReplace a broken or out-of-tolerance spring as follows:(1)\tRemove the spring attachment rivet. \n\n\t\t(2)\tTemporarily install an airworthy spring, P/N 360A33-1078-01, and verify that the axial protrusion (Dimension e, Figure 1) is within tolerance and that no interference (see Figure 2) exists. \n\n\t\t(3)\tPermanently secure the new spring to the fairing with one ASN-A0078B402 rivet, coated with Mastinox 6856KD150-2, and installed with the rivet head on the outside of the fairing (see Figure 1). \n\n\t\t(4)\tMark an "X" after the fairing part number using indelible ink after completing all inspections and spring replacements, as required. \n\n\t(c)\tReinstall the fairing. \n\n\t(d)\tIf one or more springs are replaced, rebalance the tail rotor head. \n\n\t(e)\tAn alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Rotorcraft Standards Staff, Rotorcraft Directorate, FAA. Operators shall submit their requests through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Rotorcraft Standards Staff. \n\n\tNOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Rotorcraft Standards Staff. \n\n\t(f)\tSpecial flight permits will not be issued. \n\n\tNOTE 3: The subject of this AD is addressed in Direction Generale De L'Aviation Civile (France) AD 95-107-039(B)R1 and AD 95-112-040(B), both dated June 7, 1995, and AD 95-108-018(B), dated May 24, 1995. \n\n\t(g)\tThis amendment becomes effective on December 14, 1998.

Supplementary Information

The Direction Generale De L'Aviation Civile (DGAC), which is the airworthiness authority for France, recently notified the FAA that an unsafe condition may exist on Eurocopter France Model AS-365N2, SA-360C, SA-365C, C1, C2, N, N1, and SA-366G1 helicopters. The DGAC advises that inspecting for broken or out-of-tolerance attachment springs on the fairing, replacing broken attachment springs and attachment springs that are out-of-tolerance, and marking the fairing are necessary due to reports of broken attachment springs. \n\n\tEurocopter France has issued SA-360C, SA-365C, C1, C2 Service Bulletin No. 01.34, dated 96-14(N); SA-365N Service Bulletin No. 01.00.43, dated 96-14(N); SA-365N1, AS-365N2 Service Bulletin No. 01.00.42, dated 96-14(N), and SA-366G1 Service Bulletin No. 01.22, dated 96-14(N). These service bulletins specify several actions regarding the fairing and attachment springs. The DGAC classified these service bulletins as mandatory and issued AD 95-107-039(B)R1 and AD 95-112-040(B), both dated June 7, 1995, and AD 95-108-018(B), dated May 24, 1995, in order to assure the continued airworthiness of these helicopters in France. \n\n\tThese helicopter models are manufactured in France and are type certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, the DGAC has kept the FAA informed of the situation previously described. The FAA has examined the findings of the DGAC, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States. \n\n\tSince an unsafe condition has been identified that is likely to exist or develop on other Model AS-365N2, SA-360C, SA-365C, C1, C2, N, N1, and SA-366G1 helicopters of the same type design registered in the United States, this AD is being issued to prevent failure of the attachment springs which could cause loss of the tail rotor hub fairing, damage to the tail rotor, and subsequent loss of control of the helicopter. This AD requires inspecting for broken or out-of-tolerance attachment springs on the fairing, replacing broken attachment springs and those that are out-of-tolerance, and marking the fairing with an "X" by the fairing part number to indicate compliance. \n\n\tThe short compliance time involved is required because the previously described critical unsafe condition can adversely affect the controllability of the helicopter. Therefore, the inspections, replacement, and marking are required prior to further flight, and this AD must be issued immediately. \n\n\tSince a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days. \n\n\tThe FAA estimates that 135 helicopters of U.S. registry will be affected by this AD, that it will take 1.5 work hours per helicopter to accomplish the actions, and that the average labor rate is $60 per work hour. Required parts will cost approximately $988 per helicopter. Based on these figures, the total cost impact of this AD on U.S. operators is estimated to be $145,530. \n\nComments Invited \n\tAlthough this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications should identify the Rules Docket number and be submitted in triplicate to the address specified under the caption "ADDRESSES." All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed. \n\n\tComments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket. \n\n\tCommenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket No. 98-SW-05-AD." The postcard will be date stamped and returned to the commenter. \n\n\tThe regulations adopted herein will not have substantial direct effects 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. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment. \n\n\tThe FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and that it is not a "significant regulatory action" under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES." \n\nList of Subjects in 14 CFR Part 39 \n\tAir transportation, Aircraft, Aviation safety, Safety. \n\nAdoption of the Amendment \n\tAccordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows: \n\nPART 39 - AIRWORTHINESS DIRECTIVES \n\t1. The authority citation for part 39 continues to read as follows: \n\tAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\n§ 39.13 (Amended) \n\t2. Section 39.13 is amended by adding a new airworthiness directive to read as follows:

Addresses

Submit comments in triplicate to the Federal Aviation Administration (FAA), Office of the Regional\nCounsel, Southwest Region, Attention: Rules Docket No. 98-SW-05-AD, 2601 Meacham Blvd., Room 663, Fort Worth,\nTexas 76137.

For Further Information Contact

Mr. Shep Blackman, Aerospace Engineer, FAA, Rotorcraft Directorate,\nRotorcraft Standards Staff, 2601 Meacham Blvd., Fort Worth, Texas 76137, telephone (817) 222-5296, fax\n(817) 222-5961.