Slat Bolts

Category - Airframe
Effective Date - 03/21/1994
Recurring - Yes
Supersedes - 90-18-02
Superseded by - N/A
Amendment 39-8821. Docket 93-NM-97-AD.
Supersedes AD 90-18-02, Amendment 39-6708.

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

Compliance:
Required as indicated, unless accomplished previously. To 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:
(a) Prior 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. Repeat the inspection thereafter at intervals not to exceed 5,000 flight cycles until the inspection required by paragraph (b) of this AD is accomplished.

(1) For 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.

(2) For 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.
(b) Prior 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.
(1) For 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.
(2) For 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.
(c) If 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.
(d) For 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.
(1) If the gap measures 0.020 inch or less, no further action is required by this AD.
(2) If 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.

(e) Modification 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.

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

(g) 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.

(h) The 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.

(i) This amendment becomes effective on March 21, 1994.

FOR FURTHER INFORMATION CONTACT:
Walter Sippel, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 227-2774; fax (206) 227-1181.