Airworthiness Directive · Amendment 39-13761 · Boeing Model 747 Series Airplanes
Boeing Model 747 Series Airplanes
Superseded. A later AD replaced this one: AD 2007-01-10. Comply with the one in force.
All Model 747 series airplanes, certificated in any category.
This amendment adopts a new airworthiness directive (AD), applicable to all Boeing Model 747 series airplanes, that requires a one-time inspection to determine whether the outer cylinder of the wing landing gear has certain part numbers, and replacement of the outer cylinder of the wing landing gear with a new, improved, or reworked part if necessary. This amendment also requires removal of the load evening system, if such a system is installed. This action is necessary to prevent fracture of the outer cylinder of the wing landing gear, which could result in collapse of the wing landing gear. This action is intended to address the identified unsafe condition.
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 (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 prevent fracture of the outer cylinder of the wing landing gear, which could result in collapse of the wing landing gear, accomplish the following:
(a) Within 36 months after the effective date of this AD, perform a one-time inspection to determine the part number (P/N) of the outer cylinder of the wing landing gear on both sides of the airplane, per the Accomplishment Instructions of Boeing Service Bulletin 747-32-2472, dated November 30, 2000. Instead of inspecting the outer cylinder of the wing landing gear, a review of airplane maintenance records is acceptable if the detailed P/N of the outer cylinder of the wing landing gear (not just a higher-level assembly) can be positively determined from that review.
(1) If no outer cylinder having P/N 65B01212-() (where “()” is any dash number of that part number), 65B01430-3, or 65B01430-4 is found: No further action is required by this paragraph.
(2) If any outer cylinder having P/N 65B01212-() (where “()” is any dash number of that part number), 65B01430-3, or 65B01430-4 is found: Accomplish paragraph (b) of this AD.
(b) For any outer cylinder identified in paragraph (a)(2) of this AD: Within 36 months after the effective date of this AD, replace the outer cylinder on the wing landing gear with a new, improved part or a part that has been inspected and reworked per the Accomplishment Instructions of Boeing Service Bulletin 747-32-2472, dated November 30, 2000. The rework procedures described in the service bulletin, if accomplished, include performing a one-time nital etch inspection of the upper inner surface of the outer cylinder for chrome plating; removing any chrome plating that is present; performing a one-time magnetic particle inspection for cracking of the outer cylinder; performing a nital etch inspection for heat damage of the outer cylinder; reworking the outer cylinder, as applicable; and marking the outer cylinder to indicate that the service bulletin has been accomplished.
(c) For airplanes listed in Boeing Service Bulletin 747-32-2131, Revision 2, dated March 15, 1974: Before performing the requirements of paragraph (b) of this AD, remove the load evening system installed on the wing landing gear, per the Accomplishment Instructions of the service bulletin.
(d) As of the effective date of this AD, no person may install, on any airplane, an outer cylinder of the wing landing gear if the outer cylinder has P/N 65B01212-() (where “()” is any dash number of that part number), 65B01430-3, or 65B01430-4, unless the outer cylinder has been inspected, reworked, and marked to indicate that Boeing Service Bulletin 747-32-2472 has been accomplished.
