AD 95-01-04

This amendment adopts a new airworthiness directive (AD) that is applicable to certain Boeing Model 747-100 series airplanes. This action requires an inspection to detect discrepancies of the lap joint in certain fuselage stations, repair of any discrepancies, and modification of a certain lap joint. This amendment is prompted by reports of holes in the lap joints and longerons of these airplanes. The actions specified in this AD are intended to prevent reduced fatigue life of the fuselage in the areas in which holes are found.

Final rule; request for comments

95-01-04 BOEING: Amendment 39-9115. Docket 94-NM-225-AD. \n\n\tApplicability: Model 747-100 series airplanes equipped with freighter conversion modification installed in accordance with Supplemental Type Certificate (STC) SA2322SO, 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 use the authority provided in paragraph (d) 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 of any modification, alteration, or repair remove any airplane from the applicability of this AD. \n\n\tCompliance: Required as indicated, unless accomplished previously. \n\n\tTo prevent reduced fatigue life of the fuselage, accomplish the following: \n\n\t(a)\tWithin 90 days after the effective date of this AD, perform a detailed close visual inspection of the tee chord and lap joint of stringer 4L from fuselage station (FS) 1660 to FS 2040 to detect discrepancies (such as corrosion, cracking, open holes, misdrilled holes, and any freeze plugs in the fuselage skin and internal stringer or longerons). External structural doublers must be removed to perform this inspection. \n\n\t\t(1)\tIf no discrepancy is detected, prior to further flight, modify the longitudinal lap joints of the upper body skin at stringer 4L at FS 1689.5 to FS 1741.1, and FS 1961.1 to FS 2010.5, in accordance with GATX/Airlog Service Bulletin 94-MG-1000-009, dated May 4, 1994. Accomplishment of this modification constitutes terminating action for the inspections required by AD 90-15-06, amendment 39-6653. \n\n\t\t(2)\tIf any discrepancy is detected, prior to further flight, repair in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. \n\n\t(b)\tWithin 30 days after the airplane is returned to service subsequent to the completion of the inspection required by paragraph (a) of this AD, submit a report of the findings of that inspection, positive or negative, to the FAA, Transport Airplane Directorate, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; or fax the report to (206) 227-1181. The report must include the information contained in paragraphs (b)(1), (b)(2), (b)(3), and (b)(4) of this AD. 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)\tSerial number of the airplane; \n\t\t(2)\tDate of completion of the modification installed in accordance with \t\t\tSTC SA2322S0; \n\t\t(3)\tDate of the last inspection performed in accordance with the \t\t\t\trequirements of AD 90-15-06, amendment 39-6653; and \n\t\t(4)\tDescription and location of each discrepancy detected during the \t\t\tinspection required by paragraph (a) of this AD. \n\n\t(c)\tAs of the effective date of this AD, modification of the longitudinal lap joints of the upper body skin at stringer 4L, FS 1689.5 to FS 1741.1, and FS 1961.1 to FS 2010.5, must be accomplished in accordance with GATX/Airlog Service Bulletin 94-MG-1000-009, dated May 4, 1994, prior to installation of Supplemental Type Certificate (STC) SA2322SO on any airplane in accordance with the STC. \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, 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\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 airplane to a location where the requirements of this AD can be accomplished. \n\n\t(f)\tThe modification shall be done in accordance with GATX/Airlog Service Bulletin 94-MG- 1000-009, dated May 4, 1994. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1CFR part 51. Copies may be obtained from GATX/Airlog Company, Tulsa International Airport, P.O. Box 582527, Tulsa, Oklahoma 74158. 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(g)\tThis amendment becomes effective on January 23, 1995.

On July 3, 1990, the FAA issued AD 90-15-06, amendment 39- 6653 (55 FR 28600, July 12, 1990), applicable to certain Boeing Model 747 series airplanes, to require inspection to detect cracking and corrosion of the skin lap joints in the fuselage upper lobe, and repair, if necessary. Recently, operators of Model 747-100 series airplanes have reported finding "hidden" open fastener holes in the middle row of the lap joint, as well as misdrilled holes, elongated holes, "figure eight" holes, and short-edged margins in the fastener holes of the fuselage skin. Additionally, one operator reported finding multiple open, misdrilled, and "figure eight" fastener holes in the structural longeron beneath the lap joints. These holes were found during inspections being performed in accordance with AD 90-15-06. In each case, these holes were found on Boeing Model 747-100 series airplanes that had been modified by GATX/Airlog Company in accordance with Supplemental TypeCertificate (STC) SA2322SO. \n\n\tFastener holes in the lap joint and longeron of the fuselage, if not corrected, could reduce the fatigue life of the fuselage in the affected area. \n\n\tGATX installed a main deck cargo side door on these airplanes as part of a conversion that reconfigured these airplanes to freighters. The modification includes installation of an external doubler over portions of the lap joint of the fuselage skin at stringer 4L between fuselage stations 1660 and 2040. The installation of the doubler makes it impossible to perform the inspection required by AD 90-15-06 without first removing the doubler to perform the inspection. The modification also entails removal of the original lap joint hat section stringer and replacement with a "T" section longeron. This longeron was designed to carry body bending loads around the door structure. \n\n\tThe FAA has reviewed and approved GATX/Airlog Service Bulletin 94-MG-1000-009, dated May 4, 1994, which describes procedures for modification of the longitudinal lap joint in the upper body skin of stringer 4L, at fuselage station (FS) 1689.5 to FS 1741.1, and FS 1961.1 to FS 2010.5. This modification entails removal of two sections of the lap joints in stringer 4L. These lap joints currently are hidden by the modification that was accomplished in accordance with STC SA2322SO. Removal of these sections of the lap joint also constitutes terminating action for the inspections required by AD 90-15-06 for the lap joint section that was removed. \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 reduced fatigue life of the fuselage in the area in which holes are found. This AD requires a one-time detailed close visual inspection of the lap joint of stringer 4L from fuselage stations 1660 to 2040 to detect discrepancies (such as corrosion, cracking, open holes, misdrilled holes, and any freeze plugs in the fuselage skin and internal stringer or longerons). Any discrepancy detected must be repaired in accordance with a method approved by the FAA. Additionally, this AD requires that operators submit a report of their findings, positive or negative, to the FAA. \n\n\tThis AD also requires modification of the longitudinal lap joint in the upper body skin of stringer 4L at FS 1689.5 to FS 1741.1, and FS 1961.1 to FS 2010.5. The modification is required to be accomplished in accordance with the service bulletin described previously. Accomplishment of this modification terminates the inspections required by AD 90-15-06 at this location only. \n\n\tAs a result of recent communications with the Air Transport Association (ATA) of America, the FAA has learned that, in general, some operators may misunderstand the legal effect of AD's on airplanes that are identified in the applicability provision of the AD, but that have been altered or repaired in the area addressed by the AD. The FAApoints out that all airplanes identified in the applicability provision of an AD are legally subject to the AD. If an airplane has been altered or repaired in the affected area in such a way as to affect compliance with the AD, the owner or operator is required to obtain FAA approval for an alternative method of compliance with the AD, in accordance with the paragraph of each AD that provides for such approvals. A note has been included in this rule to clarify this requirement. \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. Interestedpersons 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 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 Number 94-NM-225-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\n\tAir transportation, Aircraft, Aviation safety, 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.\tThe authority citation for part 39 continuesto read as follows: Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 106(g); and 14 CFR 11.89. § 39.13 - (Amended) \n\n\t2.\tSection 39.13 is amended by adding the following new airworthiness directive: