Slat Bolts

Category - Airframe
Effective Date - 03/03/1994
Recurring - Yes
Supersedes - N/A
Superseded by - N/A
Amendment 39-8802. Docket 91-NM-65-AD.

Applicability:
All Model 727 series airplanes, certificated in any category.

Compliance:
Required as indicated, unless accomplished previously. To prevent failure of fuselage frames and depressurization of the airplane, accomplish the following:
(a) For airplanes identified as Group 1 or 2 in Boeing Service Bulletin 727-53-0197, Revision 1, dated April 9, 1992: Prior to the accumulation of 12,000 flight cycles since manufacture, or within 3,000 flight cycles after the effective date of this AD, whichever occurs later, perform an eddy current inspection of the fastener holes and a close visual inspection of the frame flange and web to detect cracks at body stations (BS) 760.95, 783.95, 825.95, and 848.95 in accordance with Part I of the Accomplishment Instructions of the service bulletin.
(1) If any crack is found, prior to further flight, install the applicable repair and preventive modification in accordance with Part III of the Accomplishment Instructions of the service bulletin. Once this repair and preventive modification is installed, no further eddy current inspections of the fastener holes or close visual inspections of the modified frame flange and web are required by this AD.
(2) If no crack is found, prior to further flight, accomplish one of the procedures identified in paragraphs (a)(2)(i), (a)(2)(ii), or (a)(2)(iii) of this AD, in accordance with Part I, paragraph E., of the Accomplishment Instructions of the service bulletin.
(i) Oversize the hole by 1/32 inch and install an oversized fastener. Prior to the accumulation of 12,000 flight cycles after oversizing the hole, and thereafter at intervals not to exceed 6,000 flight cycles, continue to accomplish the inspections required by paragraph (a) of this AD. If any crack is found, prior to further flight, install the applicable repair and preventive modification in accordance with Part III of the Accomplishment Instructions of the service bulletin. Once this repair and preventive modification is installed, no further eddy current inspections of the fastener holes or close visual inspections of the frame flange and web are required by this AD. Or
(ii) Install the same size fastener that was removed. Thereafter at intervals not to exceed 6,000 flight cycles, continue to accomplish the inspections required by paragraph (a) of this AD. If cracks are found, prior to further flight, install the applicable repair and preventive modification in accordance with Part III of the Accomplishment Instructions of the service bulletin. Once this repair and preventive modification is installed, no further eddy current inspections of the fastener holes or close visual inspections of the frame flange and web are required by this AD. Or
(iii) Install the applicable repair and preventive modification in accordance with Part III of the Accomplishment Instructions of the service bulletin. Once this repair and preventive modification is installed, no further eddy current inspections of the fastener holes or close visual inspections of the frame flange and web are required by this AD.

(b) For airplanes identified as Group 3, 4, or 5 in Boeing Service Bulletin 727-53-0197, Revision 1, dated April 9, 1992: Prior to the accumulation of 12,000 flight cycles since manufacture, or within 3,000 flight cycles after the effective date of this AD, whichever occurs later, perform an eddy current inspection of the fastener holes and a close visual inspection of the frame flange and web to detect cracks at body stations (BS) 760.95 and 783.95 in accordance with Part II of the Accomplishment Instructions of the service bulletin.
(1) If any crack is found, prior to further flight, install the applicable repair and preventive modification in accordance with Part IV of the Accomplishment Instructions of the service bulletin. Once this repair and preventive modification is installed, no further eddy current inspections of the fastener holes or close visual inspections of the frame flange and web are required by this AD.
(2) If no crack is found, prior to further flight, accomplish one of the procedures identified in paragraphs (b)(2)(i), (b)(2)(ii), or (b)(2)(iii) of this AD, in accordance with Part II, paragraph E. of the Accomplishment Instructions of the service bulletin: (i) Oversize the hole by 1/32 inch and install an oversized fastener. Prior to the accumulation of 12,000 flight cycles after oversizing the hole, and thereafter at intervals not to exceed 6,000 flight cycles, continue to accomplish the inspections required by paragraph (b) of this AD. If cracks are found, prior to further flight, install the applicable repair and preventive modification in accordance with Part IV of the Accomplishment Instructions of the service bulletin. Once this repair and preventive modification is installed, no further eddy current inspections of the fastener holes or close visual inspections of the frame flange and web are required by this AD. Or
(ii) Install the same size fastener that was removed. Thereafter at intervals not to exceed 6,000 flight cycles, continue to accomplish the inspections required by paragraph (b) of this AD. If cracks are found, prior to further flight, install the applicable repair and preventive modification in accordance with Part IV of the Accomplishment Instructions of the service bulletin. Once this repair and preventive modification is installed, no further eddy current inspections of the fastener holes or close visual inspections of the frame flange and web are required by this AD. Or
(iii) Install the applicable repair and preventive modification in accordance with Part IV of the Accomplishment Instructions of the service bulletin. Once this repair and preventive modification is installed, no further eddy current inspections of the fastener holes or close visual inspections of the frame flange and web are required by this AD.

(c) For airplanes identified as Group 1, 2, 3, or 4 in Boeing Service Bulletin 727-53-0197, Revision 1, dated April 9, 1992: Prior to the accumulation of 12,000 flight cycles since manufacture, or within 3,000 flight cycles after the effective date of this AD, whichever occurs later, perform a close visual inspection to detect cracks in the frame gussets at BS 825.95 in accordance with Part V (for Groups 1 and 2 airplanes) or Part VI (for Groups 3 and 4 airplanes) of the Accomplishment Instructions of the service bulletin. Repeat these inspections thereafter at intervals not to exceed 6,000 flight cycles.
(1) If any crack is found, prior to further flight, replace the gusset with a new gusset in accordance with Figure 10 (for Groups 1 and 2 airplanes) or Figure 11 (for Groups 3 and 4 airplanes) of the service bulletin.
(2) Replacement of the gusset in accordance with paragraph (c)(1) of this AD constitutes terminating action for the repetitive inspections required by paragraph (c) of this AD.
(d) For airplanes identified as Group 1, 2, 3, 4, or 5 in Boeing Service Bulletin 727-53-0197, Revision 1, dated April 9, 1992: Prior to the accumulation of 12,000 flight cycles since manufacture, or within 3,000 flight cycles after the effective date of this AD, whichever occurs later, perform a close visual inspection of the inner flange of the frames and the strap on the inner flange at BS 760.95 and 783.95 to detect open pilot holes in accordance with Part VII of the Accomplishment Instructions of the service bulletin.
(1) If no open pilot hole is found, no further action is required by paragraph (d) of this AD.
(2) If any open pilot hole is found, perform a close visual inspection to detect cracks in that open pilot hole. A "close visual inspection" is defined as a close, intensive visual inspection of highly defined structural details or locations, searching for evidence of structural irregularity and using adequate lighting. In addition, inspection aids such as mirrors, etc., surface cleaning, and access procedures are required, as necessary, to gain proximity.
(i) If no crack is found in any open pilot hole, repeat the inspection required by paragraph (d)(2) of this AD thereafter at intervals not to exceed 6,000 flight cycles until the preventive modification specified in paragraph (d)(2)(ii) or (d)(2)(iii) of this AD, as applicable, is installed.
(ii) If any crack is found in an open pilot hole that is located inside any of the shaded areas shown in Figures 3, 4, and 5 of the service bulletin, prior to further flight, repair the crack in the pilot hole and install a preventive modification in accordance with Part III or IV of the Accomplishment instructions of the service bulletin. Installation of a preventive modification constitutes terminating action for the repetitive inspections of the open pilot holes specified in paragraph (d)(2)(i) of this AD.
(iii) If any crack is found in an open pilot hole that is located outside any of the shaded areas shown in Figures 3, 4, and 5 of the service bulletin, prior to further flight, repair the crack in the pilot hole in accordance with Part III or IV of the Accomplishment Instructions of the service bulletin, and install a preventive modification in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. Installation of a preventive modification constitutes terminating action for the repetitive inspections of the open pilot holes specified in paragraph (d)(2)(i) of this AD.

(e) An 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 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.

NOTE: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO.

(f) Special 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.

(g) The actions shall be done in accordance with Boeing Service Bulletin 727-53-0197, Revision 1, dated April 9, 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.

(h) This amendment becomes effective on March 3, 1994.

FOR FURTHER INFORMATION CONTACT:
Phil Forde, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 227-2771; fax (206) 227-1181.