2000-05-19

Fuselage Skin and Bonded Doubler

Category - Airframe
Effective Date - 04/24/2000
Recurring - No
Supersedes - N/A
Superseded by - N/A
Amendment 39-11629.
Docket 99-NM-73-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 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 (c) 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 prevent fatigue cracking of the fuselage skin and bonded doubler area above the forward entry doorway, which could result in reduced structural integrity and consequent loss of cabin pressurization, accomplish the following:
Detailed Visual Inspection
(a) Prior to the accumulation of 60,000 total flight cycles, or within 3,000 flight cycles after the effective date of this AD, whichever occurs later: Perform a one-time detailed visual inspection of the fuselage skin and bonded doubler area above the forward entry doorway to detect fatigue cracking or the existence of a previous repair, in accordance with Boeing Service Bulletin 727-53-0186, Revision 1, dated May 21, 1992.
Corrective Action

(1) If no crack or repair is detected, prior to further flight, perform the preventive modification in accordance with the service bulletin. No further action is required by this AD.   

(2) If any crack but no repair is detected, prior to further flight, accomplish the actions required by paragraph (a)(2)(i), (a)(2)(ii), or (a)(2)(iii), as applicable.  
(i) If any crack is less than or equal to 2.5 inches, perform the full-sized repair doubler in accordance with Boeing Service Bulletin 727-53-0186, Revision 1, dated May 21, 1992. Accomplishment of this action constitutes terminating action for the requirements of this AD.
(ii) If any crack exceeds 2.5 inches, repair in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate; or in accordance with data meeting the type certification basis of the airplane approved by a Boeing Company Designated Engineering Representative (DER) who has been authorized by the Manager, Seattle ACO, to make such findings. For a repair method to be approved by the Manager, Seattle ACO, or the Boeing DER, as required by this paragraph, the approval letter must specifically reference this AD.     (iii) If any crack in the bear strap is detected, repair in accordance with a method approved by the Manager, Seattle ACO; or in accordance with data meeting the type certification basis of the airplane approved by a Boeing Company DER who has been authorized by the Manager, Seattle ACO, to make such findings. For a repair method to be approved by the Manager, Seattle ACO, or the Boeing DER, as required by this paragraph, the approval letter must specifically reference this AD.  

(3) If any repair is found, accomplish paragraph (a)(3)(i), (a)(3)(ii), or (a)(3)(iii), of this AD, as applicable.
(i) If a full-sized repair doubler is found, as specified by Boeing Service Bulletin 727-53-0186, dated April 27, 1989, or Revision 1, dated May 21, 1992, and any crack is less than or equal to 2.5 inches, no further action is required by this AD. (ii) If a half-sized repair doubler is found, as specified by Boeing Service Bulletin 727-53-0186, dated April 27, 1989, or Revision 1, dated May 21, 1992, and any crack is less than or equal to 2.5 inches and is not in the bear strap: Prior to further flight, perform the full-sized repair doubler in accordance with Boeing Service Bulletin 727-53-0186, Revision 1, dated May 21, 1992. No further action is required by this AD.  
(iii) If a half-sized or full-sized repair doubler is found, as specified by the service bulletin, and any crack exceeds 2.5 inches or is located in the bear strap: Prior to further flight, repair in accordance with a method approved by the Manager, Seattle ACO or in accordance with data meeting the type certification basis of the airplane approved by a Boeing Company DER who has been authorized by the Manager, Seattle ACO, to make such findings. For a repair method to be approved by the Manager, Seattle ACO, or the Boeing DER, as required by this paragraph, the approval letter must specifically reference this AD.

Note 2: For the purposes of this AD, a detailed visual inspection is defined as: "An intensive visual examination of a specific structural area, system, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate by the inspector. Inspection aids such as mirrors, magnifying lenses, etc. may be used. Surface cleaning and elaborate access procedures may be required." Terminating Action for AD 94-05-04 (b) Accomplishment of the requirements of this AD constitutes terminating action for the requirements of paragraph (a) of AD 94-05-04, amendment 39-8842 (which are required to be accomplished in accordance with Appendices A.3, B.3, and C.3 of Boeing Document Number D6-54860, "Aging Airplane Service Bulletin Structural Modification and Inspection Program--Model 727," Revision G, dated March 5, 1993), with respect to the modification specified in Boeing Service Bulletin 727-53-0186, dated April 27, 1989. All other service bulletins referenced in Boeing Document Number D6-54860 still apply.

Alternative Methods of Compliance
(c) 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. 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 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO.

Special Flight Permits
(d) Special flight permits may be issued in accordance with Sec. 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. Incorporation by Reference
(e) Except as provided by paragraphs (a)(2)(ii), (a)(2)(iii), and (a)(3)(iii) of this AD, the actions shall be done in accordance with Boeing Service Bulletin 727-53-0186, Revision 1, dated May 21, 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.     (f) This amendment becomes effective on April 24, 2000.

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 (425) 227-2774; fax (425) 227-1181. Issued in Renton, Washington, on March 8, 2000. Donald L. Riggin, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.