AD 2000-06-10

This amendment adopts a new airworthiness directive (AD) applicable to Bell Helicopter Textron Canada (BHTC) Model 407 helicopters. This action requires preflight checking and repetitively inspecting the tail boom for a crack and replacing the tail boom if a crack is found. This amendment is prompted by four reports of cracks on the tail boom in the area of the horizontal stabilizer. The actions specified in this AD are intended to prevent separation of the tail boom and subsequent loss of control of the helicopter.

Final rule; request for comments

2000-06-10 BELL HELICOPTER TEXTRON CANADA: Amendment 39-11651. Docket No. 99-SW-75-AD. \n\tApplicability: Model 407 helicopters, serial numbers 53000 through 53003, 53005 and higher, 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 (d) 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 asindicated, unless accomplished previously. \n\n\tTo prevent separation of the tail boom and subsequent loss of control of the helicopter, accomplish the following: \n\n\t(a)\tBefore further flight and thereafter before the first flight of each day, check the left side of the tail boom for a crack in the areas shown in Figure 1. If a crack is found, replace the tail boom with an airworthy tail boom before further flight. \n\n\t(b)\tAn owner/operator (pilot) holding at least a private pilot certificate may perform the visual check required by paragraph (a) but must enter compliance with paragraph (a) into the aircraft records in accordance with 14 CFR 43.11 and 91.417(a)(2)(v)). \n\n\t(c)\tWithin 25 hours time-in-service (TIS) and thereafter at intervals not to exceed 50 hours TIS, visually inspect any tail boom with 600 or more hours TIS for a crack using a 10X or higher magnifying glass, in accordance with the Accomplishment Instructions, Part II, of Bell Helicopter Textron Canada Alert Service Bulletin 407-99-26, dated April 13, 1999, except that you are not required to contact Bell Helicopter Product Support Engineering. If a crack is found, replace the tail boom with an airworthy tail boom before further flight. \n\n\t(d)\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, Regulations Group, 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, Regulations Group. \n\n\tNOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Regulations Group. \n\n\t(e)\tSpecial flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the helicopter to a location where the requirements of this AD can be accomplished. \n\n\t(f)\tThe inspection of the tail boom shall be done in accordance with the Accomplishment Instructions, Part II, of Bell Helicopter Textron Canada Alert Service Bulletin 407-99-26, dated April 13, 1999. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Bell Helicopter Textron Canada, 12,800 Rue de l'Avenir, Mirabel, Quebec JON1LO, telephone (800) 463-3036, fax (514) 433-0272. Copies may be inspected at the FAA, Office of the Regional Counsel, Southwest Region, Room 663, Fort Worth, Texas, or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. \n\n\t(g)\tThis amendment becomes effective on April 14, 2000. \n\n\tNOTE 3: The subject of this AD is addressed in Transport Canada (Canada) AD CF-99-17, dated June 14, 1999. \n\nFigure 1. Preflight Check of the Tailboom

Transport Canada, the airworthiness authority for Canada, notified the FAA that an unsafe condition may exist on the BHTC Model 407 helicopters. Transport Canada advises that there have been several reports of cracks to the tail boom skin in the area of the horizontal stabilizer. \n\n\tBHTC has issued Alert Service Bulletin 407-99-26, dated April 13, 1999 (ASB), which specifies a preflight check of the left-side of the tail boom before the next flight and before the first flight of every day thereafter. The ASB also specifies within the next 25 hours time-in-service (TIS) and thereafter every 50 hours inspecting any tail boom that has accumulated 600 or more hours TIS for a crack and replacing any cracked tail boom before further flight. Transport Canada classified this ASB as mandatory and issued AD CF-99-17, dated June 14, 1999, to ensure the continued airworthiness of these helicopters in Canada. \n\n\tThis helicopter model is manufactured in Canada andis 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, Transport Canada has kept the FAA informed of the situation described above. The FAA has examined the findings of Transport Canada, 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 BHTC Model 407 helicopters of the same type design registered in the United States, this AD is being issued to prevent separation of the tail boom and subsequent loss of control of the helicopter. This AD requires a preflight check of the tail boom before further flight and thereafter before the first flight of each day. This AD also requires within 25 hours TIS and thereafter at intervals not to exceed 50 hours TIS, inspecting any tail boom that has accumulated 600 or more hours TIS for a crack with a 10X or higher magnifying glass and replacing any cracked tail boom with an airworthy tail boom before further flight. The actions are required to be accomplished in accordance with the ASB described previously. The short compliance time involved is required because the previously described critical unsafe condition can adversely affect the controllability and structural integrity of the helicopter. Therefore, checking the tail boom for a crack is required prior to further flight and this AD must be issued immediately. \n\n\tAn owner/operator (pilot) may perform the visual check required by this AD but must enter compliance with this AD in the aircraft records in accordance with 14 CFR 43.11 and 91.417(a)(2)(v)). This AD allows a pilot to perform this check because it involves only a visual check for a crack in the tail boomand can be performed equally well by a pilot or a mechanic. \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 200 helicopters will be affected by this AD, that it will take approximately 4 work hours to accomplish the inspections, and that the average labor rate is $60 per work hour. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $48,000 assuming no tail boom will be replaced. \n\nComments Invited \nAlthough 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-75-AD." The postcard will be date stamped and returned to the commenter. \n\n\tThe regulations adopted herein 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. Therefore, it is determined that this final rule does not have federalism implications under Executive Order 13132. \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 \nAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. \n\nAdoption of the Amendment \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 \n1. 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) \n2. Section 39.13 is amended by adding a new airworthiness directive to read as follows: