AD 2004-16-15

This amendment adopts a new airworthiness directive (AD) for the specified Eurocopter France (Eurocopter) helicopters. This action requires inspecting the main gearbox (MGB) baseplate for a crack and replacing the MGB if a crack is found in the MGB base plate. This amendment is prompted by the discovery of a crack in a MGB base plate. The actions specified in this AD are intended to detect a crack in a MGB base plate and prevent failure of one of the MGB attachment points to the frame, which could result in severe vibration and subsequent loss of control of the helicopter.

Final rule; request for comments.

2004-16-15 Eurocopter France: Amendment 39-13771. Docket No. FAA- 2004-18850; Directorate Identifier 2004-SW-19-AD.\n\n\tApplicability: Eurocopter France Model AS-365N2, AS 365 N3, EC 155B, EC155B1, SA-365N and N1, and SA-366G1 helicopters with a main gearbox (MGB) base plate, part number (P/N) 366A32-1062-03 or P/N 366A32-1062-06, installed, certificated in any category. \n\n\tCompliance: Required as indicated in the following table and before installing a replacement main gearbox (MGB). \n\n\nFor... \nThen...\nOr... \nOr... \nModel SA-365N and N1, \nand Model SA-3366G1 \nhelicopters. \nIf a MGB is installed that has less than 9,900 cycles and has never been overhauled or repaired. On or before accumulating 9,900 cycles, unless accomplished previously, and thereafter, at intervals not to exceed 15 hours time-in-service (TIS).\nIf a MGB is installed that has 9,900 or more cycles and has never been overhauled or repaired, before further flight, unless accomplished previously, and thereafter, at intervals not to exceed 15 hours TIS. \nIf a MGB is installed that is overhauled or repaired, before further flight, unless accomplished previously, and thereafter, at intervals \nnot to exceed 15 hours TIS. \nModel AS-365N2 and AS \n365 N3 helicopters. \nIf a MGB is installed that has less than 7,300 cycles and has never been overhauled or repaired, on or before accumulating 7,300 cycles, unless accomplished previously, and thereafter, at intervals not to exceed 15 hours TIS. \nIf a MGB is installed that has 7,300 or more cycles and has never been overhauled or repaired, before further flight, and thereafter, at intervals not to exceed 15 hours TIS. \nIf a MGB is installed that has been overhauled or repaired, before further flight, and thereafter, at intervals not to exceed 15 hours TIS. \nModel EC 155B and \nEC155B1 helicopters. \nIf a MGB base plate is installed that has less than 2,600 cycles, no later than 2,600 cycles, unless accomplished previously, and thereafter, before the first flight of each day and on or before reaching each 9 hours TIS interval during the day. \nIf a MGB base plate is installed that has 2,600 or more cycles, unless accomplished previously, before further flight, and thereafter, before the first flight of each day and on or before reaching each 9 hours TIS interval during the day. \n\n\nOne cycle equates to one helicopter landing in which a landing gear touches the ground. \n\n\tTo detect a crack in the MGB base plate and prevent failure of a MGB attachment point to the frame, which could result in severe vibration and subsequent loss of control of the helicopter: \n\n\t(a) Before the initial inspection at the time indicated in the compliance table, strip the paint from area "D" on both sides ("B" and "C") of the MGB base plate as depicted in Figure 1. \n\n\n\n\n\t(b) At the times indicated in the compliance table, inspect area "D" of the MGB base plate for a crack using a 10x or higher magnifying glass. \n\n\tNote 1: Eurocopter France Alert Telex No. 05.00.45, applicable to Model AS-365N2, AS 365 N3, SA-365N and SA-365N1 helicopters; Alert Telex No. 05.29, applicable to Model SA-366G1 helicopters, and Alert Telex No. 05A005, applicable to Model EC 155B and EC155B1 helicopters, pertain to the subject of this AD. All three alert telexes are dated February 5, 2004. \n\n\t(c) If a crack is found in a MGB base plate, remove and replace the MGB with an airworthy MGB before further flight. \n\n\t(d) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Contact the Safety Management Group, Rotorcraft Directorate, FAA, for information about previously approved alternative methods of compliance. \n\n\t(e) This amendment becomes effective on September 3, 2004. \n\n\tNote 2: The subject of this AD is addressed in Direction Generale De L'Aviation Civile (France) AD No. UF-2004-023(A), dated February 6, 2004, and AD No. F-2004-023, dated March 3, 2004.

This amendment adopts a new AD for Eurocopter Model AS-365N2, AS 365 N3, EC 155B, EC155B1, SA-365N and N1, and SA-366G1 helicopters. This action requires visually inspecting the MGB for a crack in the MGB base plate, part number (P/N) 366A32-1062-03 or P/N 366A32-1062-06, close to the attachment hole using a 10x or higher magnifying glass. Stripping paint from the inspection area is also required, but only before the initial inspection. This amendment is prompted by the discovery of a crack in the MGB base plate of a MGB installed in a Model AS-365 N2 helicopter. The cause of the crack is under investigation, therefore, this AD is an interim action until the cause of the crack can be determined. The crack was located very close to the attachment points of one of the laminated pads, and it propagated to the inside of the MGB base plate and then continued into the MGB casing. This condition, if not detected, could result in failure of one of the MGB attachmentpoints to the frame, which could result in severe vibration and subsequent loss of control of the helicopter. \n\n\tThe Direction Generale De L'Aviation Civile (DGAC), the airworthiness authority for France, notified the FAA that an unsafe condition may exist on Eurocopter Model SA 365 N, N1, SA 366 G1, AS 365 N2, N3, and EC 155 B and B1 helicopters. The DGAC advises of the discovery of a crack on the MGB base plate of a Model AS 365 N2 helicopter. \n\n\tEurocopter has issued Alert Telexes: \n\n\tNo. 05.00.45, applicable to Model 365 N, N1, N2, and N3 helicopters; \n\n\tNo. 05.29, applicable to Model 366 G1 helicopters; and \n\n\tNo. 05A005, applicable to Model EC 155 B and B1 helicopters, all dated February 5, 2004. These alert telexes specify visually inspecting the MGB base plate for absence of cracks. In addition, the alert telexes state that a 10x magnifying glass can be used to facilitate the crack inspection. Also, if in doubt about the existence of a crack, the alert telexes specifyinspecting for a crack using a dye-penetrant crack detection inspection. The DGAC classified these alert telexes as mandatory and issued AD No. UF-2004-023(A), dated February 6, 2004, and AD No. F-2004-023, dated March 3, 2004, to ensure the continued airworthiness of these helicopters in France. \n\n\n\tThese helicopter models are manufactured in France and are type certificated for operation in the United States under the provisions of 14 CFR 21.29 and the applicable bilateral agreement. Pursuant to the applicable bilateral agreement, the DGAC has kept the FAA informed of the situation described above. The FAA has examined the findings of the DGAC, reviewed all available information, and determined that AD action is necessary for products of these type designs that are certificated for operation in the United States. \n\n\tThis unsafe condition is likely to exist or develop on other helicopters of the same type design. Therefore, this AD is being issued to detect a crack in the MGB base plate and prevent failure of one of the MGB attachment points to the frame, which could result in severe vibration and subsequent loss of control of the helicopter. This AD requires initial and repetitive inspections of the MGB base plate for cracking at various short time intervals until its cause can be determined. Various compliance times are required depending on the helicopter model. The short compliance times involved are required because the previously described critical unsafe condition can adversely affect the controllability or structural integrity of the helicopter. Therefore, since initial and repetitive inspections of the MGB base plate for cracking are required at short time intervals, 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 than30 days. \n\n\tWe estimate that this AD will affect 142 helicopters and that the initial inspection will take approximately 0.5 work hour. Each recurring inspection will take approximately 0.25 work hour, and replacing the MGB, if necessary, will take approximately 4 work hours to accomplish, all at an average labor rate of $65 per work hour. It will cost approximately $25,000 to repair a cracked MGB base plate. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $138,067, assuming that each of the 135 Model AS 365 and SA 366 helicopters are inspected 40 times (the initial inspection plus 39 recurring inspections) and each of the 7 Model EC 155 helicopters are inspected 200 times (the initial inspection plus 199 recurring inspections), and one cracked MGB base plate is found requiring the replacement of one MGB. This estimate also assumes that a replacement MGB will not need to be purchased while a previously- installed MGB is being repaired.Comments Invited \n\n\tThis AD is a final rule that involves requirements that affect flight safety and was not preceded by notice and an opportunity for public comment; however, we invite you to submit any written data, views, or arguments regarding this AD. Send your comments to an address listed under ADDRESSES. Include "Docket No. FAA-2004-18850; Directorate Identifier 2004-SW-19-AD" at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the AD. We will consider all comments received by the closing date and may amend the AD in light of those comments. \n\n\tWe will post all comments we receive, without change, to http://dms.dot.gov , including any personal information you provide. We will \n\nalso post a report summarizing each substantive verbal contact with FAA personnel concerning this AD. Using the search function of our docket Web site, you can find and read the comments to any of our dockets, including the name of the individual who sent the comment. You may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you may visit http://dms.dot.gov . \n\n\tWe 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. \n\n\tFor the reasons discussed above, I certify that the regulation: \n\n\t1. Is not a "significant regulatory action" under Executive Order 12866; \n\n\t2. Is not a "significant rule" under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and \n\n\t3. 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. See the DMS to examine the economic evaluation. \n\nList of Subjects in 14 CFR Part 39 \n\n\tAir transportation, Aircraft, Aviation safety, Safety. \n\nAdoption of the Amendment \n\nAccordingly, 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\n1. The authority citation for part 39 continues to read as follows: \n\n\tAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\n§ 39.13 (Amended) \n\n2. Section 39.13 is amended by adding a new airworthiness directive to read as follows: