AD 94-08-04

This amendment supersedes an existing airworthiness directive (AD), applicable to certain McDonnell Douglas Model DC-9 and Model DC-9-80 series airplanes, and C-9 (military) airplanes, that currently requires inspections to detect cracking in the skin and doublers around the upper anticollision light cutout, and repair, if necessary. This amendment expands the applicability to include additional Model DC-9-80 series airplanes and Model MD-88 airplanes, and requires the performance of stress coining procedures on the plate nut clearance holes or installation of shims and an external doubler. This amendment is prompted by a report that stress coining procedures were not performed on the plate nut clearance holes of the upper anticollision light doublers during production of certain airplanes. The actions specified by this AD are intended to prevent crack growth in the doublers, which could result in damage to the adjacent structure, and subsequent loss of cabin structural integrity.

Final rule.

94-08-04 MCDONNELL DOUGLAS: Amendment 39-8875. Docket 93-NM-115-AD. Supersedes AD 85-19-03 R2, Amendment 39-5844. \n\n\tApplicability: All Model DC-9-10, -20, -30, -40, and -50 series airplanes and C-9 (military) airplanes; and Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), and DC-9-87 (MD-87) series airplanes and Model MD-88 airplanes, having fuselage numbers 909 through 2042, inclusive; certificated in any category. \n\n\tCompliance: Required as indicated, unless accomplished previously. \n\n\tNOTE 1: Inspections, repairs, or modifications (stress coining or installation of shims and an external doubler) accomplished prior to the effective date of this amendment in accordance with McDonnell Douglas DC-9 Service Bulletin 53-186, original issue through Revision 6; or McDonnell Douglas DC-9 Service Bulletin 53-216, original issue through Revision 3; are considered acceptable for compliance with the applicable action specified in this amendment. \n\n\tTo prevent crack growth in the doubler, which could result in damage to the adjacent structure, accomplish the following: \n\n\t(a)\tFor all Model DC-9-10, -20, -30, -40, and -50 series airplanes, and C-9 (military) airplanes: Prior to the accumulation of 30,000 total landings or within 4,500 landings after the effective date of this AD, whichever occurs later, perform an eddy current inspection to detect cracking in the skin and doublers around the upper anticollision light cutout on the fuselage, in accordance with McDonnell Douglas DC-9 Service Bulletin 53-186, Revision 6, dated May 13, 1993. \n\n\t\t(1)\tIf no cracking is detected, accomplish the requirements of paragraphs (a)(1)(i) and (a)(1)(ii) of this AD. \n\n\t\t\t(i)\tRepeat that inspection thereafter at intervals not to exceed 4,500 landings until either one of the procedures required by paragraph (a)(1)(ii) of this AD is accomplished; and \n\n\t\t\t(ii)\tPrior to the accumulation of 100,000 total landings or within 4 years after September 24, 1990 (the effective date of AD 90-18-03, Amendment 39-6701), whichever occurs later, either stress coin the plate nut clearance holes, or install shims and an external doubler; in accordance with Condition I, Phase 2, of the accomplishment instructions of McDonnell Douglas DC-9 Service Bulletin 53-186, Revision 6, dated May 13, 1993. Accomplishment of either the stress coining procedure, or installing shims and an external doubler, constitutes terminating action for the repetitive inspection requirement of paragraph (a) of this AD. \n\n\t\t(2)\tIf any cracking is detected as a result of any inspection required by this paragraph, prior to further flight, accomplish the requirements of paragraph (a)(2)(i) or (a)(2)(ii) of this AD, as applicable. \n\n\t\t\t(i)\tFor cracks specified as Condition II and Condition III in McDonnell Douglas DC-9 Service Bulletin 53-186, Revision 6, dated May 13, 1993: Repair in accordance with McDonnell Douglas DC-9 Service Bulletin 53-186, Revision 6, dated May 13, 1993; McDonnell Douglas SB 09530186; or McDonnell Douglas DC-9 Service Sketch 3626E. Accomplishment of any one of these repair procedures constitutes terminating action for the requirements of this AD. \n\n\t\t\t(ii)\tFor cracks specified as Condition IV in McDonnell Douglas DC-9 Service Bulletin 53-186, Revision 6, dated May 13, 1993: Repair in accordance with a method approved by the Manager, Los Angeles Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. \n\n\t(b)\tFor Model DC-9-81, DC-9-82, and DC-9-83 series airplanes having fuselage numbers 909 through 1247 inclusive: Prior to the accumulation of 30,000 total landings or within 4,500 landings after the effective date of this AD, whichever occurs later, perform an eddy current inspection to detect cracking in the skin and doublers around the upper anticollision light cutout on the fuselage, in accordance with McDonnell Douglas DC-9 Service Bulletin 53-186, Revision 6, dated May 13, 1993. \n\n\tNOTE 2: Although fuselage numbers 909 through 1247 include Model DC-9-30 and -50 series airplanes, those airplanes are addressed in paragraph (a) of this AD, and as such, operators of those airplanes must accomplish the requirements of paragraph (a) of this AD. \n\n\t\t(1)\tIf no cracking is detected, accomplish the requirements of paragraphs (b)(1)(i) and (b)(1)(ii) of this AD. \n\n\t\t\t(i)\tRepeat that inspection thereafter at intervals not to exceed 4,500 landings until either one of the procedures required by paragraph (b)(1)(ii) of this AD is accomplished; and \n\n\t\t\t(ii)\tPrior to the accumulation of 75,000 total landings or within 4 years after September 24, 1990 (the effective date of AD 90-18-03, Amendment 39-6701), whichever occurs later, either stress coin the plate nut clearance holes, or install shims and an external doubler, in accordance with Condition I, Phase 2, of the accomplishment instructions of McDonnell Douglas DC-9 Service Bulletin 53-186, Revision 6, dated May 13, 1993. Accomplishment of eitherthe stress coining procedure, or installing shims and an external doubler, constitutes terminating action for the repetitive inspection requirements of paragraph (b) of this AD. \n\n\t\t(2)\tIf any cracking is detected as a result of any inspection required by this paragraph, prior to further flight, accomplish the requirements of paragraph (b)(2)(i) or (b)(2)(ii) of this AD, as applicable. \n\n\t\t\t(i)\tFor cracks specified as Condition II and Condition III in McDonnell Douglas DC-9 Service Bulletin 53-186, Revision 6, dated May 13, 1993: Repair in accordance with McDonnell Douglas DC-9 Service Bulletin 53-186, Revision 6, dated May 13, 1993; McDonnell Douglas SB 09530186; or McDonnell Douglas DC-9 Service Sketch 3626E. Accomplishment of any one of these repair procedures constitutes terminating action for the requirements of this AD. \n\n\t\t\t(ii)\tFor cracks specified as Condition IV in McDonnell Douglas DC-9 Service Bulletin 53-186, Revision 6, dated May 13, 1993: Repair in accordance with a method approved by the Manager, Los Angeles ACO, FAA, Transport Airplane Directorate. \n\n\t(c)\tFor Model DC-9-81, DC-9-82, DC-9-83, and DC-9-87 series airplanes, and Model MD-88 airplanes, having fuselage numbers 1248 through 2042 inclusive: Prior to the accumulation of 30,000 total landings or within 4,500 landings after the effective date of this AD, whichever occurs later, perform an eddy current inspection to detect cracking in the skin and doublers around the upper anticollision light cutout on the fuselage, in accordance with McDonnell Douglas MD-80 Service Bulletin 53-216, Revision 3, dated April 23, 1993. \n\n\t\t(1)\tIf no cracking is detected, accomplish the requirements of paragraphs (c)(1)(i) and (c)(1)(ii) of this AD. \n\n\t\t\t(i)\tRepeat that inspection thereafter at intervals not to exceed 4,500 landings until either one of the procedures required by paragraph (c)(1)(ii) of this AD is accomplished; and \n\n\t\t\t(ii)\tPrior to the accumulation of 75,000 total landings or within 4 years after September 24, 1990 (the effective date of AD 90-18-03, Amendment 39-6701), whichever occurs later, either stress coin the plate nut clearance holes in accordance with Condition I, Phase 2, of McDonnell Douglas MD-80 Service Bulletin 53-216, Revision 3, dated April 23, 1993; or install shims and an external doubler, in accordance with the accomplishment instructions of that service bulletin. Accomplishment of either the stress coining procedure, or installing shims and an external doubler, constitutes terminating action for the repetitive inspection requirement of paragraph (c) of this AD. \n\n\t\t(2)\tIf any cracking is detected as a result of any inspection required by this paragraph, prior to further flight, accomplish the requirements of paragraph (c)(2)(i) or (c)(2)(ii) of this AD, as applicable. \n\n\t\t\t(i)\tFor cracks specified as Condition II and Condition III in McDonnell Douglas DC-9 Service Bulletin 53-216, Revision 3, dated April 23, 1993: Repair in accordancewith McDonnell Douglas DC-9 Service Bulletin 53-216, Revision 3, dated April 23, 1993; McDonnell Douglas SB 09530186; or McDonnell Douglas DC-9 Service Sketch 3626E. Accomplishment of any one of these repair procedures constitutes terminating action for the requirements of this AD. \n\n\t\t\t(ii)\tFor cracks specified as Condition IV in McDonnell Douglas DC-9 Service Bulletin 53-216, Revision 3, dated April 23, 1993: Repair in accordance with a method approved by the Manager, Los Angeles ACO, FAA, Transport Airplane Directorate. \n\n\t(d)\tThis AD supersedes that portion of AD 90-18-03, Amendment 39-6701, which requires inspection and modification in accordance with the following McDonnell Douglas service bulletins: \n\n\t\t\t\t\tDC-9 Service Bulletin 53-186 \n\t\t\t\t\tMD-80 Service Bulletin 53-216 \n\n\t(e)\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, Los Angeles 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, Los Angeles ACO. \n\n\tNOTE 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Los Angeles ACO. \n\n\t(f)\tSpecial flight permits may be issued in accordance with Federal Aviation Regulations (FAR) 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished. \n\n\t(g)\tThe actions shall be done in accordance with McDonnell Douglas DC-9 Service Bulletin 53-186, Revision 6, dated May 13, 1993 (for Model DC-9 series airplanes), or McDonnell Douglas MD-80 Service Bulletin 53-216, Revision 3, dated April 23, 1993 (for Model DC-9-80 series airplanes), as applicable. 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 Part51. Copies may be obtained from McDonnell Douglas Corporation, P.O. Box 1771, Long Beach, California 90801-1771, Attention: Business Unit Manager, Technical Administrative Support, Department L51, M.C. 2-98. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Transport Airplane Directorate, Los Angeles Aircraft Certification Office, 3229 East Spring Street, Long Beach, California; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. \n\n\t(h)\tThis amendment becomes effective on May 23, 1994.

A proposal to amend part 39 of the Federal Aviation Regulations by superseding all or portions of two existing AD's as published in the Federal Register on October 7, 1993 (58 FR 52240). \n\n\tThat action proposed to supersede AD 85-19-03 R2, Amendment 39-5844 (53 FR 3738, February 9, 1988), which is applicable to Model DC-9 and Model DC-9-80 series airplanes, and C-9 (military) airplanes, having fuselage numbers 1 through 1371. That AD requires repetitive inspections, at intervals of 3,500 landings, to detect cracking in the skin and doublers around the upper anticollision light cutout, and repair, if necessary. That AD also provides for the performance of stress coining procedures on the plate nut clearance holes in the upper anticollision light cutout as optional terminating action for the repetitive inspection requirement. The notice proposed to supersede this AD to expand its applicability to include affected airplanes through fuselage number 2042, andto increase the repetitive inspection interval 4,500 landings. \n\n\tThe notice also proposed to supersede portions of AD 90-18-03, Amendment 39-6701 (55 FR 34704, August 24, 1990), which is applicable to Model DC-9 and DC-9-80 series airplanes, Model MD-88 airplanes, and C-9 (military) airplanes. Among other things, that AD currently requires repetitive inspections and eventual modification of the plate nut clearance holes in the upper doublers. The notice proposed to expand the applicability of those requirements to include additional affected airplanes. \n\n\tInterested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received. \n\n\tSeveral commenters support the proposed rule. \n\n\tOne commenter notes that, in the Discussion section of the proposal, the description of the applicability of AD 90-18-03 was confusing. The commenter suggests that a more succinct way of stating applicability forthe existing AD would be to state that the requirements of AD 90-18-03 are applicable to "all Model DC-9-10, -20, -30, -40, and -50 series airplanes and C-9 airplanes, and to Model DC-9-80 series airplanes and MD-88 airplanes, fuselage numbers 1 through 1371." The proposal stated that AD 90-18-03 is applicable to "all Model DC-9-10, -20, -30, -40, and -50 series airplanes and C-9 airplanes, but only to certain Model DC-9-80 series airplanes and MD-88 airplanes, namely, those having fuselage numbers 1248 through 1371." The FAA finds that either way of describing applicability for the requirements of AD 90-18-03 adequately summarizes the applicability of the existing AD. \n\n\tThis same commenter indicates that there was an error in the description of the service bulletin in the Discussion section of the proposal. The commenter notes that the description of the service bulletin, which is referenced in the proposal as the appropriate source of service information, omitted Model DC-9-80series airplanes. The FAA concurs that an error was made in the Discussion section of the proposal. However, the entire remainder of the AD, including the applicability of the rule, as well as paragraphs (b) and (c) of the rule, clearly states that the rule is applicable to Model DC-9-80 series airplanes. Therefore, no change to the final rule is necessary. \n\n\tThis commenter further requests that the number of airplanes presented in the cost estimate in the preamble to the notice be verified. The commenter notes that, since the applicability of the proposal is for airplanes having fuselage numbers 1 through 2042, the estimated number of airplanes affected by the proposal could not possibly be 1,500 airplanes, as stated in the proposal. The FAA concurs that the number of affected airplanes was inaccurately estimated. The economic impact information, below, has been revised to reflect this increase in the number of affected airplanes. \n\n\tFurther, this commenter notes that the fuselage number referenced in the Discussion section of the proposal contained a typographical error. The FAA concurs. The FAA acknowledges this typographical error and corrects it by stating that the stress coining procedure on the plate nut clearance holes in the upper anticollision light doublers has not been accomplished during production of Model DC-9-80 series airplanes and Model MD-88 airplanes having fuselage numbers 1372 through 2042. The fuselage numbers were repeatedly referenced correctly in numerous other parts of the AD, including paragraph (c). Therefore, the FAA finds that revision to the final rule is unnecessary. \n\n\tThis same commenter requests that paragraphs (a), (b), and (c) of the proposal be revised to correctly reference the McDonnell Douglas DC-9 Service Sketch. The FAA concurs that references to the sketch number contained a typographical error. Therefore, paragraphs (a), (b), and (c) of the final rule have been revised to correctly reference the sketchas McDonnell Douglas DC-9 Service Sketch 3626E. \n\n\tTwo commenters request that the proposal be revised to include a second alternative that would terminate the requirement for the repetitive inspections, as specified in the referenced service bulletin, McDonnell Douglas DC-9 Service Bulletin 53-186, Revision 6, dated May 13, 1993. The commenters state that the service bulletin provides two terminating actions: one, to stress coin the holes in the doubler (as stated in the proposal), or two, to install shims and an external doubler on the anticollision light cutout. The FAA concurs. The FAA has reviewed the procedures described in the service bulletin to install shims and an external doubler and has determined that this installation would preclude cracking in the skin and doublers around the upper anticollision light cutout on the fuselage. Therefore, paragraphs (a), (b), and (c) of the final rule have been revised to include the option of installing shims and an external doubler on the anticollision light cutout, which would terminate the requirement for the repetitive inspections required by these paragraphs. \n\n\tAfter careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule with the changes previously described. The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD. \n\n\tThere are approximately 2,042 McDonnell Douglas Model DC-9 and Model DC-9-80 series airplanes, Model MD-88 airplanes, and C-9 (military) airplanes of the affected design in the worldwide fleet. Of this number, approximately 1,022 are of U.S. registry. The FAA estimates that 440 airplanes of U.S. registry are currently affected by AD 85-19-03 R2 and AD 90-18-03, while approximately 582 additional U.S.-registered airplanes will be affected by the requirements of this AD. \n\n\tThe costs associated with the inspection requirements will take approximately 10 work hours per airplane per inspection, at an average labor rate of $55 per airplane per inspection cycle. Based on these figures, the total cost impact of these inspection requirements on U.S. operators is estimated to be $550 per airplane per inspection cycle. For operators currently affected by AD 85-19-03 R2 and AD 90-18-03, there will be no new costs associated with these inspection requirements. For some of these operators, the economic burden will actually be lessened since the interval for repetitive inspection will be increased from the previous 3,500 landings to 4,500 landings in this AD. For the 582 newly affected airplanes of U.S.-registry, the total cost impact of the inspection requirements will be $320,100 per inspection cycle. \n\n\tThe costs associated with the stress coining procedure that is required by this AD entail approximately 4.6 work hours per airplane, at an average labor rate of $55 per work hour.The costs of required parts is expected to be negligible. Based on these figures, the total cost impact of the stress coining procedure requirements on U.S. operators is estimated to be $258,566, or $253 per airplane. Of this total amount, $147,246 represents the additional costs applicable to the 582 newly affected airplanes of U.S. registry. \n\n\tThe total cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted. \n\n\tAdditionally, the number of required work hours discussed above is presented as if the accomplishment of the actions in this AD were to be conducted as "stand alone" actions. However, in actual practice, these actions for the most part will be accomplished coincidentally or in combination with normally scheduled airplane inspections and other maintenance program tasks. Therefore, the actualnumber of necessary additional work hours will be minimal in many instances, as will the costs associated with special airplane scheduling. \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\tFor the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) 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. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it 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 14 CFR part 39 of the Federal Aviation Regulations as follows: \n\nPART 39 - AIRWORTHINESS DIRECTIVES \n\n\t1.\tThe authority citation for part 39 continues to read as follows: \n\nAuthority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 106(g); and 14 CFR 11.89. \n\n§ 39.13 - (Amended) \n\n\t2.\tSection 39.13 is amended by removing amendment 39-5844 (53 FR 3738, February 9, 1988), and by adding a new airworthiness directive (AD), amendment 39-8875, to read as follows: