Inspection Rear Spar Web

Category - Airframe
Effective Date - 12/29/1997
Recurring - Yes
Supersedes - N/A
Superseded by - N/A
Amendment 39-10239.
Docket 97-NM-282-AD.

Applicability: Model 727 series airplanes having line numbers 858 through 864 inclusive, 867 through 869 inclusive, 872 through 883 inclusive, and 885 through 1832 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 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 cracking of the rear spar web, which could permit fuel leakage into the airflow multiplier, and could result in an electrical short that could cause a fire, accomplish the following:

(a) Prior to the accumulation of 15,000 total flight cycles, or within 300 flight cycles after the effective date of this AD, whichever occurs later: Accomplish the inspections specified in either paragraph (a)(1) or (a)(2) of this AD, in accordance with Boeing Alert Service Bulletin 727-57A0182, dated September 18, 1997. For purposes of this AD, the access panels specified in the alert service bulletin need not be removed; the access panels need only be opened.

Note 2: The fuel tank of the wing center section may be filled with fuel to assist in detecting cracking or fuel leakage during the accomplishment of the visual inspections required by this AD.

(1) Perform a visual inspection using a borescope or mirror to detect cracking of the rear spar web and/or fuel leakage of the wing center section between Right Body Buttock Line (BBL) 40 and Left BBL 40, in accordance with Part I of the Accomplishment Instructions of the alert service bulletin. Thereafter, repeat this inspection at intervals not to exceed 300 flight cycles. Or

(2) Perform an ultrasonic and high frequency eddy current (HFEC) inspection to detect cracking of the rear spar web of the wing center section between Right BBL 40 and Left BBL 40, in accordance with Part II of the Accomplishment Instructions of the alert service bulletin. Thereafter, repeat this inspection at intervals not to exceed 3,000 flight cycles.

(b) If any cracking of the rear spar web and/or fuel leakage of the wing center section is detected between Right BBL 40 and Left BBL 40 near the upper machined land radius, prior to further flight, repair in accordance with Part III of the Accomplishment Instructions in Boeing Alert Service Bulletin 727-57A0182, dated September 18, 1997. Accomplishment of this repair constitutes terminating action for the repetitive inspection requirements of this AD.

(c) If any cracking of the rear spar web and/or fuel leakage of the wing center section is detected that is outside the area specified in paragraph (b) of this AD, prior to further flight, repair in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate.

(d) Accomplishment of paragraphs (d)(1) and either (d)(2) or (d)(3) of this AD, as applicable, constitute terminating action for the repetitive inspection requirements of this AD.

(1) Accomplish an ultrasonic and HFEC inspection in accordance with the requirements of paragraph (a)(2) of this AD. And,

(2) If no cracking is detected, prior to further flight, modify the rear spar web of the center section of the fuel tank between Right BBL 40 and Left BBL 40, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 727-57A0182, dated September 18, 1997.

(3) If any cracking is detected, prior to further flight, repair in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 727-57A0182, dated September 18, 1997.

(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. 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 Manager, 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, provided the limitations specified in paragraphs (f)(1) through (f)(6) of this AD are included in the special flight permit:

(1) Required trip and reserve fuel must be carried in the No. 1 and No. 3 outer wing tanks.

(2) Wing center tank No. 2 must be empty of fuel.

(3) The fuel system must be checked for normal operation prior to flight by verifying that all boost pumps are operational; configuring the fuel system by turning on all boost pumps in the No. 1 and 3 outer wing tanks and by opening all crossfeed valve selectors; and by confirming that fuel is not bypassing tank No. 2 check valves by observing that there is no leakage into tank No. 2.

(4) Maintain a minimum of 5,300 pounds of fuel in tanks No. 1 and No. 3 to prevent uncovering the fuel bypass valve.

(5) The fuel quantity indication system must be operational in all three tanks.

(6) The effects of loading fuel only in the wing tanks on the airplane weight and balance must be considered and accounted for.

(g) Except as provided by paragraph (c) of this AD, the actions shall be done in accordance with Boeing Alert Service Bulletin 727-57A0182, dated September 18, 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., suite 700, Washington, DC.

(h) This amendment becomes effective on December 29, 1997.

FOR FURTHER INFORMATION CONTACT:

Walter Sippel, Aerospace Engineer, Airframe Branch, ANM-120S, Seattle Aircraft Certification Office, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2774; fax (425) 227-1181.