Category - Airframe
Effective Date - 03/18/1997
 Recurring - Yes
Supersedes - N/A
 Superseded by - N/A
Amendment 39-9952. Docket 97-NM-32-AD.

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

Note 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been otherwise 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 request approval for an alternative method of compliance in accordance with paragraph (e) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To detect and correct fatigue cracking, which could result in failure of the support fitting and consequent separation of the engine from the airplane, accomplish the following:

(a) Within 100 days or within 600 flight cycles after the effective date of this AD, whichever occur first, accomplish paragraph (a)(1), (a)(2), and (a)(3) of this AD, in accordance with Boeing Service Bulletin 727-54A0010, Revision 4, dated January 30, 1997.

(1) Perform a visual inspection to detect cracks of the upper and lower flanges, and the vertical web of the forward support fitting of the number 1 and number 3 engines, in accordance with Part 1 - Pre-Modification Inspections of the Accomplishment Instructions of the service bulletin.

(2) Perform a high frequency eddy current (HFEC) inspection to detect cracks of the forward flange of the support fitting adjacent to the collars of two fasteners of the number 1 and number 3 engines, in accordance with Part 1 - Pre-Modification Inspections of the Accomplishment Instructions of the service bulletin.

(3) Perform a detailed visual inspection to detect cracks of the upper and lower flanges adjacent to six fasteners of the number 1 and number 3 engines, in accordance with Part 1 - Pre-Modification Inspections of the Accomplishment Instructions of the service bulletin.

(b) If no crack is detected during the inspections required by paragraph (a) of this AD, repeat those inspections thereafter at intervals not to exceed 100 days or 600 flight cycles, whichever occurs first.

(c) If any crack is detected during any inspection required by paragraph (a) of this AD, prior to further flight, repair the forward support fitting in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate.

(d) Accomplishment of the actions specified in paragraphs (d)(1) and (d)(2) of this AD in accordance with Boeing Service Bulletin 727-54A0010, Revision 4, dated January 30, 1997, constitutes terminating action for the requirements of paragraphs (a) and (b) of this AD.

(1) Perform a HFEC inspection to detect cracks of the fastener holes in the forward support fitting of the number 1 and number 3 engines, and, if possible, modify the fastener holes, in accordance with Part II - Fastener Hole Modification of the Accomplishment Instructions of the service bulletin.

(i) If the modification (i.e., a fastener installed in a hole with no cracks) was accomplished at all eight holes, no further action is required by paragraph (d)(1) of this AD.

(ii) If the modification was not accomplished at all eight holes because of the continued detection of cracking, prior to further flight, repair the forward support fitting in accordance with a method approved by the Manager, Seattle ACO.

(2) Prior to the accumulation of 3,000 flight cycles or 24 months, whichever occurs first, following accomplishment of paragraph (d)(1) of this AD, perform a HFEC inspection to detect corrosion or cracks of the modified forward support fitting of the number 1 and number 3 engines, in accordance with Part III - Post-Modification Inspections of the Accomplishment Instructions of the service bulletin.

(i) If no crack or corrosion is detected, prior to further flight, install the fasteners wet with a sealant in accordance with the service bulletin. Repeat the HFEC inspection required by paragraph (d)(2) of this AD thereafter at intervals not to exceed 3,000 flight cycles or 24 months, whichever occurs first.

(ii) If any crack or corrosion is detected, prior to further flight, repair the forward support fitting in accordance with a method approved by the Manager, Seattle ACO.

(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 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 2: 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 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.

(g) The inspections and modifications shall be done in accordance with Boeing Service Bulletin 727-54A0010, Revision 4, dated January 30, 1997. 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., suite700, Washington, DC.

(h) This amendment becomes effective on March 18, 1997.

FOR FURTHER INFORMATION CONTACT:

Walter Sippel, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington; telephone (206) 227-2774; fax (206) 227-1181.