Airworthiness Directive · Amendment 39-11516 · McDonnell Douglas Model DC-8 Series Airplanes
McDonnell Douglas Model DC-8 Series Airplanes
Model DC-8 series airplanes, as listed in McDonnell Douglas Service Bulletin DC8-57-030, Revision 05, dated April 28, 1998; 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.
This amendment adopts a new airworthiness directive (AD), applicable to certain McDonnell Douglas Model DC-8 series airplanes, that requires a one-time eddy current conductivity test to determine the material type of the lower cap of the wing front spar; and modification of the lower cap of the wing front spar, if necessary. This amendment is prompted by reports of stress corrosion cracking in the forward tang of the lower caps of the wing front spar. The actions specified by this AD are intended to prevent such stress corrosion cracking, which if not corrected, could result in reduced structural integrity of the wing.
To prevent stress corrosion cracking of the lower cap of the wing front spar, which if not corrected, could result in reduced structural integrity of the wing, accomplish the following:
(a) Within 48 months after the effective date of this AD, perform a one-time eddy current conductivity test to determine the material type of the forward tang of the lower cap of the front spar in the center section of the wing, in accordance with McDonnell Douglas Service Bulletin DC8-57-030, Revision 05, dated April 28, 1998, or Revision 04, dated August 17, 1995.
(1) If 7079-T6 aluminum is not found, no further action is required by this AD.
(2) If any 7079-T6 aluminum is found, within 48 months after the effective date of this AD, modify the forward tang of the lower cap of the front spar, in accordance with the service bulletin.
(b) Accomplishment of the eddy current conductivity test, and modification, if necessary, specified in paragraph (a) of this AD constitutes terminating action for the repetitive inspection requirements of paragraph (a) of AD 90-16-05, amendment 39-6614, as it applies to the inspections of the forward tang of the lower cap of the front spar specified in McDonnell Douglas Service Bulletin DC8-57-030, Revision 3, dated December 10, 1970.
