AD 99-12-01 SUPERSEDED

This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 99-12-01, which was sent previously to all known U.S. owners and operators of Eurocopter Model EC135 helicopters by individual letters. This AD requires initial and repetitive visual inspections and one dye-penetrant inspection of the main rotor hub shaft (shaft) for cracks. If a crack is found during any of the inspections, this AD requires replacing the shaft with an airworthy shaft before further flight. This amendment is prompted by the discovery of fatigue cracks on the shaft of a helicopter. The actions specified by this AD are intended to detect fatigue cracks in the shaft that could lead to shaft failure and subsequent loss of control of the helicopter.

Final rule; request for comments

99-12-01 EUROCOPTER DEUTSCHLAND GmbH: Amendment 39-11217. Docket No. 99-SW-38-AD. \n\n\tApplicability: Model EC135 helicopter with main rotor hub shaft (shaft), part number (P/N) L623M100S 101, installed, 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 otherwise 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 request approval for an alternative method of compliance in accordance with paragraph (c) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it. \n\n\tCompliance: Required as indicated, unless accomplished previously. \n\n\tTo detect a fatigue crack in the shaft that could lead to shaft failure and subsequent loss of control of the helicopter, accomplish the following: \n\n\t(a)\tBefore further flight, and thereafter, at intervals not to exceed 15 hours time-in-service (TIS), visually inspect the shaft, P/N L623M100S 101, for any crack in the area marked in Figure 1. Clean the shaft before using a bright light source to inspect for cracks. If any crack is found, replace the shaft with an airworthy shaft before further flight. \n\n\t(b)\tWithin 10 hours TIS, conduct a one-time dye-penetrant inspection of the shaft using the MIL-STD-6866 or ASTM-E-1417 procedure in the area shown in Figure 1. If any crack is found, replace the shaft with an airworthy shaft before further flight. \n\n\tNOTE 2: Eurocopter EC 135 Alert Service Bulletin EC 135-62A-004, Rev. 1, dated May 7, 1999, pertains to the subject of this AD. \n\n\t(c)\tAn alternative method ofcompliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Rotorcraft Standards Staff, FAA, Rotorcraft Directorate. 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 3: 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(d)\tSpecial flight permits will not be issued. NOTE 4: The subject of this AD is addressed in Luftfahrt-Bundesamt (Federal Republic of Germany) AD 1999-185, dated May 6, 1999. \n\n\t(e)\tThis amendment becomes effective on July 16, 1999, to all persons except those persons to whom it was made immediately effective by Priority Letter AD 99-12-01, issued May 27, 1999, which contained the requirements of this amendment.

On May 27, 1999, the FAA issued Priority Letter AD 99-12-01, applicable to Eurocopter Model EC135 helicopters, which requires initial and repetitive visual inspections and one dye-penetrant inspection of the shaft for cracks. If a crack is found during any of the inspections, the AD requires replacing the shaft with an airworthy shaft before further flight. That action was prompted by the discovery of fatigue cracks on the shaft of a helicopter. This condition, if not corrected, could result in failure of the shaft and subsequent loss of control of the helicopter. \n\n\tEurocopter has issued Eurocopter EC135 Alert Service Bulletin (ASB) EC 135-62A-004, dated May 5, 1999, which specifies inspecting the shaft for cracks. The Luftfahrt-Bundesamt (LBA), which is the airworthiness authority for the Federal Republic of Germany, classified this service bulletin as mandatory and issued AD 1999-185, dated May 6, 1999, to assure the continued airworthiness of these helicopters in the Federal Republic of Germany. Eurocopter later issued ASB EC135-62A-004, Rev. 1, dated May 7, 1999. \n\n\tSince the unsafe condition described is likely to exist or develop on other Eurocopter Model EC135 helicopters of the same type design, the FAA issued Priority Letter AD 99-12-01 to detect fatigue cracks in the shaft that could lead to shaft failure and subsequent loss of control of the helicopter. The AD requires initial and repetitive visual inspections and one dye-penetrant inspection of the shaft for cracks. The short compliance time involved is required because the previously described critical unsafe condition can adversely affect the structural integrity of the helicopter. Therefore, inspecting the shaft for cracks is required before further flight and this AD must be issued immediately. \n\n\tSince it was found that immediate corrective action was required, notice and opportunity for prior public comment thereon were impracticable and contrary to the public interest, and good cause existed to make the AD effective immediately by individual letters issued on May 27, 1999, to all known U.S. owners and operators of Eurocopter Model EC135 helicopters. These conditions still exist, and the AD is hereby published in the Federal Register as an amendment to section 39.13 of the Federal Aviation Regulations (14 CFR 39.13) to make it effective to all persons. \n\n\tThe FAA estimates that 10 helicopters will be affected by this AD; that it will take approximately 0.5 work hour per helicopter to perform the visual inspections, 1 work hour per helicopter to perform the dye-penetrant inspection, 10 work hours to replace the shaft, if necessary; and that the average labor rate is $60 per work hour. Required parts will cost approximately $25,000 per shaft. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $55,900 per year, assuming the initial inspection, one dye-penetrant inspection, and 100 visual inspections per year on each helicopter, and one shaft replacement in the fleet. Comments Invited \n\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. 99-SW-38-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 isdetermined 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:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Office of the Regional\nCounsel, Southwest Region, Attention: Rules Docket No. 99-SW-38-AD, 2601 Meacham Blvd., Room 663, Fort Worth,\nTexas 76137.

Mike Mathias, Aerospace Engineer, FAA, Rotorcraft Directorate,\nRotorcraft Standards Staff, 2601 Meacham Blvd., Fort Worth, Texas 76137, telephone (817) 222-5123, fax (817) 222-5961.