AD 99-24-02

This amendment adopts a new airworthiness directive (AD) that is applicable to certain Boeing Model 767-200 and -300 series airplanes. This action requires a one-time visual inspection to determine the part number and serial number of the lower drag strut of the nose landing gear (NLG); and corrective actions, if necessary. This amendment is prompted by reports of a fracture of the lower drag strut of the NLG, which was caused by a thin wall thickness condition that occurred during the manufacturing process. The actions specified in this AD are intended to prevent a fracture of the lower drag strut, which could result in collapse of the NLG.

Final rule; request for comments

99-24-02 BOEING: Amendment 39-11426. Docket 99-NM-303-AD.\n\n\tApplicability: Model 767-200 and -300 series airplanes, as listed in Boeing Alert Service Bulletin 767-32A0185, dated September 2, 1999; certificated in any category. \n\n\tNOTE 1: This AD applies to each airplane 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 airplanes 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 (f) 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: Requiredas indicated, unless accomplished previously. \n\n\tTo prevent a fracture of the lower drag strut, which could result in collapse of the nose landing gear (NLG), accomplish the following: \n\nVisual Inspection \n\n\t(a)\tWithin 90 days after the effective date of this AD, perform a one-time visual inspection to determine the part number and serial number of the lower drag strut of the NLG, in accordance with Boeing Alert Service Bulletin 767-32A0185, dated September 2, 1999. If the prefix of the serial number of the lower drag strut is not HM or FRG, no further action is required by this AD. \n\nUltrasonic Inspection \n\n\t(b)\tFor airplanes on which lower drag strut having part number (P/N) 162T2003-5 and serial number (S/N) prefix HM or FRG is installed: Prior to further flight, perform a one-time ultrasonic inspection to measure the wall thickness of the lower drag strut of the NLG, in accordance with Boeing Alert Service Bulletin 767-32A0185, dated September 2, 1999, and accomplish paragraph (b)(1), (b)(2), or (b)(3) of this AD, as applicable, at the time specified. \n\n\t\t(1)\tIf the wall thickness is greater than or equal to 0.210 inch: No further action is required by this AD. \n\n\t\t(2)\tIf the wall thickness is greater than or equal to 0.180 inch, but less than 0.210 inch: Within 5 years after the effective date of this AD, overhaul the lower drag strut in accordance with Part 2 of the Accomplishment Instructions of the alert service bulletin. \n\n\t\t(3)\tIf the wall thickness is less than 0.180 inch: Prior to further flight, replace the lower drag strut with a new or serviceable lower drag strut in accordance with Part 3 of the Accomplishment Instructions of the alert service bulletin. \n\n\t(c)\tFor airplanes on which lower drag strut having P/N 162T2003-1 or 162T2003-3 and S/N prefix HM or FRG is installed: Perform a one-time ultrasonic inspection to measure the wall thickness of the lower drag strut of the NLG, in accordance with Boeing Alert Service Bulletin767-32A0185, dated September 2, 1999, and accomplish paragraph (c)(1), (c)(2), or (c)(3) of this AD, as applicable, at the time specified. \n\n\t\t(1)\tIf the wall thickness is greater than or equal to 0.160 inch: No further action is required by this AD. \n\n\t\t(2)\tIf the wall thickness is greater than or equal to 0.150 inch, but less than 0.160 inch: Within 5 years after the effective date of this AD, overhaul the lower drag strut in accordance with Part 2 of the Accomplishment Instructions of the alert service bulletin. \n\n\t\t(3)\tIf the wall thickness is less than 0.150 inch: Prior to further flight, replace the lower drag strut with a new or serviceable lower drag strut in accordance with Part 3 of the Accomplishment Instructions of the alert service bulletin. \n\n\t(d)\tAs of the effective date of this AD, no person shall install on any airplane, a lower drag strut of the NLG having P/N 162T2003-1, 162T2003-3, or 162T2003-5, and S/N prefix HM or FRG, unless the part has been inspected to verify proper wall thickness in accordance with this AD. \n\nReporting Requirement \n\n\t(e)\tSubmit a report of the inspection findings (positive only, defined as a thin wall thickness condition that requires corrective action) to the Seattle Manufacturing Inspection District Office (MIDO), 2500 East Valley Road, Suite C-2, Renton, Washington 98055-4056; fax (425) 227-1159; at the applicable time specified in paragraph (e)(1) or (e)(2) of this AD. The report must include the airplane serial number; the number of total flight hours and flight cycles on the airplane. Information collection requirements contained in this regulation have been approved by the Office of Management and Budget (OMB) under the provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq.) and have been assigned OMB Control Number 2120-0056. \n\n\t\t(1)\tFor airplanes on which the applicable inspection required by either paragraph (b) or (c) of this AD is accomplished after the effective date of this AD: Submit the report within 30 days after performing the inspection. \n\n\t\t(2)\tFor airplanes on which the applicable inspection required by either paragraph (b) or (c) of this AD has been accomplished prior to the effective date of this AD: Submit the report for the inspection within 30 days after the effective date of this AD. \n\nAlternative Methods of Compliance \n\n\t(f)\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, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Seattle ACO. \n\n\tNOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO. \n\nSpecial Flight Permits \n\n\t(g)\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 airplane to a location where the requirements of this AD can be accomplished. \n\nIncorporation by Reference \n\n\t(h)\tThe actions shall be done in accordance with Boeing Alert Service Bulletin 767-32A0185, dated September 2, 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 Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. \n\n\t(i)\tThis amendment becomes effective on December 6, 1999.

The FAA has received reports of a fracture of the lower drag strut of the nose landing gear (NLG) on certain Boeing 767-200 and -300 series airplanes. Investigation revealed that the fractured lower drag strut of the NLG was found to have been manufactured with a thin wall thickness condition. This condition, if not detected and corrected, could result in a fracture of the lower drag strut and collapse of the NLG.\n\nExplanation of Relevant Service Information \n\n\tThe FAA has reviewed and approved Boeing Alert Service Bulletin 767-32A0185, dated September 2, 1999, which describes procedures for a one-time visual inspection to determine the part number and serial number of the lower drag strut of the NLG; and corrective actions, if necessary. The corrective actions involve performing a one-time ultrasonic inspection to measure the thickness of the lower drag strut. The corrective actions also involve either overhauling the lower drag strut if the thickness is within certain limits or replacing the lower drag strut with a new or serviceable lower drag strut, if the thickness is outside certain limits. Accomplishment of the actions specified in the alert service bulletin is intended to adequately address the identified unsafe condition. \n\nExplanation of the Requirements of the Rule \n\n\tSince an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design, this AD is being issued to prevent a fracture of the lower drag strut, which could result in collapse of the NLG. This AD requires accomplishment of the actions specified in the alert service bulletin described previously. This AD also requires that operators report all inspection results (positive only) to the FAA. \nDetermination of Rule's Effective Date \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\nComments 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 shall 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 specificallyinvited 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 Number 99-NM-303-AD." The postcard will be date stamped and returned to the commenter. \n\nRegulatory Impact \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\n\tAir transportation, Aircraft, Aviationsafety, Incorporation by reference, Safety. \n\nAdoption of the Amendment \n\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\n PART 39 - AIRWORTHINESS DIRECTIVES \n\n\t1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 40113, 44701. § 39.13 (Amended) \n\t2. Section 39.13 is amended by adding the following new airworthiness directive: