Airworthiness Directive · Amendment 39-11705 · Boeing Model 727 and 727C Series Airplanes
Boeing Model 727 and 727C Series Airplanes
Model 727 and 727C series airplanes, line numbers 153, 290, and 339 inclusive; 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 (b) 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.
This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 727 and 727C series airplanes, that requires one-time inspections of the exterior body skin located at the forward corners of the mid-galley door hinge cutouts to detect cracking, and corrective actions, if necessary. This AD also requires modification of the body skin of the mid-galley door hinge cutouts. This amendment is prompted by a report indicating that, during fatigue testing on a Boeing Model 727 series airplane, a crack was found in the body skin at the lower forward corners of the mid-galley door hinge cutouts due to cabin pressurization cycles. The actions specified by this AD are intended to prevent such fatigue cracking of the body skin, which could result in reduced structural integrity of the fuselage and consequent loss of cabin pressurization.
To prevent fatigue cracking of the body skin at the forward corners of the mid-galley door hinge cutouts, which could result in reduced structural integrity of the fuselage and consequent loss of cabin pressurization, accomplish the following:
(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 and a high frequency eddy current inspection of the exterior body skin located adjacent to the forward corners of the mid-galley door hinge cutouts for cracking in accordance with Boeing Service Bulletin 727-53-0054, Revision 1, dated November 16, 1989.
Note 2: For the purposes of this AD, a detailed visual inspection is defined as: “An intensive 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.”
(1) If no cracking is found during any inspection, prior to further flight, modify the body skin at the forward corners of the mid-galley door hinge cutouts, in accordance with Boeing Service Bulletin 727-53-0054, Revision 1, dated November 16, 1989. No further action is required by this AD.
(2) If any cracking is found during any inspection, prior to further flight, accomplish the requirements of either paragraph (a)(2)(i) or (a)(2)(ii) of this AD, as applicable.
(i) If any crack is less than or equal to 1.00 inch, accomplish the repair and modification in accordance with Boeing Service Bulletin 727-53-0054, Revision 1, dated November 16, 1989. No further action is required by this AD.
(ii) If any crack is greater than 1.00 inch, accomplish the repair and modification 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 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, as required by this paragraph, the Manager's approval letter must specifically reference this AD. No further action is required by this AD.
Note 3: Accomplishment of the actions required by AD 90-06-09, amendment 39-6488, is considered acceptable for compliance with this AD.
