AD 94-04-03

This amendment supersedes an existing airworthiness directive (AD), applicable to all Boeing Model 727 series airplanes, that currently requires repetitive inspections to detect cracks in the slat track roller bearing bolts, and replacement, if necessary. This amendment adds an inspection of the positional plates installed on certain airplanes, and replacement, if necessary; reduces the compliance time for the initial inspection; and cites the latest revision to the service bulletin as the appropriate service information source. This amendment is prompted by a report that certain positional plates may not stop rotation of the roller bearing bolts. The actions specified by this AD are intended to prevent jamming of the affected slat or separation of the slat from the airplane.

Final rule

94-04-03 BOEING: Amendment 39-8821. Docket 93-NM-97-AD. Supersedes AD 90-18-02, Amendment 39-6708. \n\n\tApplicability: All Model 727 series airplanes, certificated in any category. \n\n\tCompliance: Required as indicated, unless accomplished previously. \n\n\tTo prevent cracking of the roller bearing bolts and subsequent jamming of the affected slat or separation of the slat from the airplane, accomplish the following: \n\n\t(a)\tPrior to the accumulation of 12,000 total flight cycles, or within 2,500 flight cycles after September 30, 1990 (the effective date of AD 90-18-02, Amendment 39-6708), whichever occurs later: Accomplish paragraph (a)(1) or (a)(2) of this AD, as applicable, in accordance with Boeing Service Bulletin 727-57-0172, Revision 1, dated October 12, 1989; Revision 2, dated June 27, 1991; or Revision 3, dated March 19, 1992. After the effective date of this AD, the inspection shall be accomplished only in accordance with Revision 3 of the service bulletin. Repeatthe inspection thereafter at intervals not to exceed 5,000 flight cycles until the inspection required by paragraph (b) of this AD is accomplished. \n\n\t\t(1)\tFor airplanes equipped with roller bearing bolts made from CRES material: Perform a fluorescent particle inspection of the slat track roller bearing bolts to detect cracks. \n\n\t\t(2)\tFor airplanes equipped with roller bearing bolts not made from CRES material: Perform a magnetic particle inspection of the slat track roller bearing bolts to detect cracks. \n\n\t(b)\tPrior to the accumulation of 8,000 total flight cycles, or within 2,500 flight cycles after the effective date of this AD, whichever occurs later, unless accomplished previously within the last 2,500 flight cycles prior to the effective date of this AD: Accomplish paragraph (b)(1) or (b)(2) of this AD, as applicable, in accordance with Boeing Service Bulletin 727-57-0172, Revision 3, dated March 19, 1992. Repeat this inspection thereafter at intervals not to exceed 5,000 flight cycles. Accomplishment of this inspection terminates the repetitive inspection requirement of paragraph (a) of this AD. \n\n\t\t(1)\tFor airplanes equipped with roller bearing bolts made from CRES material: Perform a fluorescent particle inspection of the slat track roller bearing bolts to detect cracks. \n\n\t\t(2)\tFor airplanes equipped with roller bearing bolts not made from CRES material: Perform a magnetic particle inspection of the slat track roller bearing bolts to detect cracks. \n\n\t(c)\tIf any cracked bolt is found during any inspection required by this AD, prior to further flight, replace the cracked bolt with a serviceable bolt and inspect the associated roller to detect seizure, in accordance with Boeing Service Bulletin 727-57-0172, Revision 1, dated October 12, 1989, Revision 2, dated June 27, 1991, or Revision 3, dated March 19, 1992. If the roller is seized or does not turn smoothly, prior to further flight, replace the defective roller with a serviceable roller in accordance with the service bulletin. \n\n\t(d)\tFor airplanes having positional plates installed in accordance with Boeing Service Bulletin 727-57-0172, dated September 6, 1985, Revision 1, dated October 12, 1989, or Revision 2, dated June 27, 1991: Prior to the accumulation of 5,000 flight cycles since modification, or within 2,500 flight cycles after the effective date of this AD, whichever occurs later, measure the gap between the roller bolt head and the positional plate in accordance with Boeing Service Bulletin 727-57-0172, Revision 3, dated March 19, 1992. \n\n\t\t(1)\tIf the gap measures 0.020 inch or less, no further action is required by this AD. \n\n\t\t(2)\tIf the gap measures more than 0.020 inch, prior to further flight, replace the positional plate with a new positional plate in accordance with Figure 3 of the service bulletin.\n \n\t(e)\tModification of the bolts and slat tracks in accordance with Boeing Service Bulletin 727-57-0172, Revision 3, dated March 19, 1992, constitutes terminating action for the actions required by paragraphs (a), (b), and (d) of this AD. \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\nNOTE: 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(g)\tSpecial flight permits may be issued in accordance with 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(h)\tThe inspections, replacements, gap measurement, and modification shall be done in accordance with Boeing Service Bulletin 727-57-0172, Revision 1, dated October 12, 1989; Boeing Service Bulletin 727-57-0172, Revision 2, dated June 27, 1991; and Boeing Service Bulletin 727- 57-0172, Revision 3, dated March 19, 1992. 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 March 21, 1994.

A proposal to amend part 39 of the Federal Aviation Regulations by superseding AD 90-18-02, Amendment 39-6708 (55 FR 34699, August 24, 1990), which is applicable to all Boeing Model 727 series airplanes, was published in the Federal Register on August 23, 1993 (58 FR 44466). The action proposed to require repetitive inspections to detect cracks in the slat track roller bearing bolts, and replacement, if necessary; and an inspection of the positional plates installed on certain airplanes, and replacement, if necessary. \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\tOne commenter supports the proposed rule. \n\n\tOne commenter requests that the compliance time of 2,500 flight cycles, as specified in paragraphs (b) and (d) of the proposal, be reduced to 2,000 flight cycles to coincide with the interval expressed in Boeing Service Bulletin 727-57-0172, which is cited in the proposed rule. \n\n\tThe FAA does not concur with the commenter's request to shorten the proposed compliance time. In developing an appropriate compliance time, the FAA considered the safety implications, parts availability, and normal maintenance schedules for timely accomplishment of the modifications. Further, this AD supersedes an existing AD that specified a compliance time of 2,500 flight cycles. The FAA has received no reports to date of any problem encountered as a result of that compliance time. To reduce the compliance time of the proposal would necessitate (under the provisions of the Administrative Procedure Act) reissuing the notice, reopening the period for public comment, considering additional comments received, and eventually issuing a final rule; the time required for that procedure may be as long as four additional months. In light of these considerations, and in consideration of the amount of time that has already elapsed since issuance of the original notice, the FAA has determined that further delay of this final rule action is not warranted. \n\n\tThe Air Transport Association (ATA) of America, on behalf of its members, requests that the FAA review existing approvals of alternative methods of compliance for AD 90-18-02 and determine if these approvals remain valid for this AD and, if so, either place a "NOTE" in the final rule or convey that information to affected operators through individual notices. ATA contends that including such a "NOTE" in this AD would expedite AD handling and reduce processing costs for both operators and the FAA. \n\n\tThe FAA has reviewed existing approvals of alternative methods of compliance for AD 90-18-02 and finds that these approvals would not necessarily be acceptable for this AD, since the actions required by the existing AD do not adequately address the unsafe condition. However, if an operator believes its existing approval also should be considered acceptable for this AD, that operator should resubmit its request for approval from the FAA in accordance with the provisions of paragraph (f) of this AD. \n\n\tOne ATA member suggests that, in lieu of being superseded, AD 90-18-02 should be revised or amended so that operators with approvals of alternative methods of compliance for that AD would not be required to resubmit requests for such approvals for this AD. The FAA does not concur. The FAA has determined that the actions required by AD 90-18-02 do not adequately address the specified unsafe condition. Consequently, issuance of this AD is necessary to require additional actions in order to fully address the unsafe condition. The FAA's normal policy in this regard is that when an AD requires additional actions, the existing AD is superseded by being removed from the system and a new AD added. \n\n\tOne commenter requests that the FAA include an initial implementation period of 2,500 flight cycles in the final rule to allow operators that are currently performing inspections in accordance with the requirements of AD 90-18-02 additional time to "transition over" to the use of Revision 3 of Boeing Service Bulletin 727-57-0172. The commenter states that, as written, the proposed rule would require that those operators begin accomplishing the inspections in accordance with Revision 3 immediately after the effective date of this AD. \n\n\tThe FAA does not concur with the commenter's request. The FAA infers that the commenter's request for an implementation period to "transition over" refers to a need for additional time to update records and plan/schedule subsequent inspections. The FAA finds that additional time to begin accomplishing the inspections in accordance with Revision 3 of the service bulletin is not warranted. \n\n\tParagraphs (a) and (b) of the final rule are purposefully redundant with the exception of the inspection thresholds specified. The intent of paragraph (b) is to reduce the inspection threshold from that specified in paragraph (a) and to require that operators accomplish the inspection in accordance with Revision 3 of the service bulletin. Revision 3 of the service bulletin does not contain significant changes from other issues of the service bulletin. Further, operators have been provided ample notice through the proposed AD of the FAA's intent to require that Revision 3 of the service bulletin be used for any inspection accomplished after the effective date of this final rule. Operators will also receive 30 additional days after publication of this final rule in the Federal Register before this AD will become effective. \n\n\tThe FAA has revised paragraph (a) of this AD to clarify its intent that operators currently accomplishing the repetitive inspections required by AD 90-18-02 continue to perform those inspections in accordance with Revision 3 of the service bulletin until the first inspection required by paragraph (b) of this AD has been accomplished. In addition, paragraph (b)of this AD has been revised to specify that accomplishment of the repetitive inspections in accordance with Revision 3 of the service bulletin terminates the repetitive inspections required by paragraph (a) of this AD. \n\n\tOne commenter requests that paragraph (d) of the proposal be revised to indicate that no further action is required if a "checking tool" is used to ensure that a functionally acceptable positional plate was installed per Boeing Drawing 65C31395. The commenter indicates that it has developed a tool for checking the dimensions of the positional plate in accordance with the Boeing drawing. The commenter states that, since it has used a functionally acceptable solution to the problem and since this solution is recognized by Boeing as being equivalent to the procedures described in Revision 3 of the service bulletin cited in the proposal, the FAA should also recognize this procedure as an acceptable method of complying with the proposed requirements of this AD. \n\n\tThe FAA does not concur with the commenter's request to revise paragraph (d) of this AD to indicate that no further action is required if a "checking tool" is used. Paragraph (d) of this AD requires that the gap between the roller bolt head and the positional plate be measured in accordance with Revision 3 of Boeing Service Bulletin 727-57-0172. However, that service bulletin does not specify the use of any particular tool when performing the measurement. The FAA has no data available to evaluate the validity of the tool referenced by the commenter. In addition, the FAA does not find it necessary to limit the methods available to operators to accomplish the requirements of paragraph (d) of this AD. Since the service bulletin does not specify the use of any particular tool, the FAA considers that any measuring tool that allows operators to determine if the gap between the roller bolt head and the positional plate is within specified limits meets the intent of paragraph (d) of this AD. \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 1,635 Model 727 series airplanes of the affected design in the worldwide fleet. The FAA estimates that 1,047 airplanes of U.S. registry will be affected by this AD, that it will take approximately 18 work hours per airplane to accomplish the required actions, and that the average labor rate is $55 per work hour. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $1,036,530, or $990 per airplane. This total cost figure assumes that no operator has yet accomplished the requirements of this AD. \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\nAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. \n\nAdoption of the Amendment \n\nAccordingly, 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\n1.\tThe authority citation for part 39 continues to 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. \n\n§ 39.13 - (Amended) \n2.\tSection 39.13 is amended by removing amendment 39-6708 (55 FR 34699, August 24, 1990), and by adding a new airworthiness directive (AD), amendment 39-8821, to read as follows: