Airworthiness Directive · Amendment 39-11555 · Boeing Model 747 Series Airplanes
Boeing Model 747 Series Airplanes
Model 747 series airplanes, line numbers 1 through 1078 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 (d) 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 747 series airplanes, that requires a one-time inspection to determine whether latch pins on the lower lobe and main deck side cargo doors are installed backward, and corrective actions, if necessary. This amendment also requires eventual modification of the latch pin fittings on certain cargo doors. This amendment is prompted by reports that latch pins have been found installed backward on the cargo doors of several airplanes. The actions specified by this AD are intended to prevent improper latching of latch pins and the mating latch cam on the cargo door, which could result in damage to the structure of the cargo door and doorway cutout and consequent opening of the cargo door during flight.
To prevent improper latching of latch pins and the mating latch cam on the cargo door, which could result in damage to the structure of the cargo door and doorway cutout and consequent opening of the cargo door during flight, accomplish the following:
(a) Within 30 days after the effective date of this AD, accomplish the requirements of paragraph (a)(1) or (a)(2) of this AD, as applicable, in accordance with Boeing Alert Service Bulletin 747-52A2258, dated June 1, 1995; as revised by Notices of Status Change 747-52A2258 NSC 1, dated July 20, 1995; 747-52A2258 NSC 2, dated August 31, 1995; and 747-52A2258 NSC 03, dated December 14, 1995.
(1) For airplanes having line numbers 1 through 307 inclusive: Perform a one-time general visual inspection to determine whether latch pins on the forward and aft lower lobe cargo doors and the main deck side cargo door are installed backward.
(2) For airplanes having line numbers 308 through 1078 inclusive: Perform a one-time general visual inspection to determine whether latch pins on the forward and aft lower lobe cargo doors are installed backward.
Note 2: For the purposes of this AD, a general visual inspection is defined as: “A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or drop-light, and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked.”
(b) If any latch pin is found installed incorrectly during any inspection required by paragraph (a) of this AD, prior to further flight, accomplish the requirements of paragraphs (b)(1) and (b)(2) of this AD.
(1) Reinstall the affected latch pin correctly, in accordance with Boeing Alert Service Bulletin 747-52A2258, dated June 1, 1995; as revised by Notices of Status Change 747-52A2258 NSC 1, dated July 20, 1995; 747-52A2258 NSC 2, dated August 31, 1995; and 747-52A2258 NSC 03, dated December 14, 1995.
(2) Perform structural inspections to detect damage of the affected cargo door and doorway cutout, in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate.
(c) Within 2 years after the effective date of this AD, modify the latch pin fittings of the forward and aft lower lobe cargo doors, in accordance with Boeing Service Bulletin 747-52-2260, Revision 1, dated March 21, 1996.
Note 3: Modification of the latch pin fittings accomplished prior to the effective date of this AD in accordance with Boeing Service Bulletin 747-52-2260, dated December 14, 1995, is considered acceptable for compliance with paragraph (c) of this AD.
