Here are some pics of the area of the wing spar that caused the AD. These from several airframes.
and the AD, which covers 8 airframes, (5) PB4Y-2, (1) B-24A, (2) B-24J
2003-18-01 General Dynamics (Convair), General Dynamics (Consolidated-Vultee) (Army), and General Dynamics (Consolidated) (Army): Amendment 39-13292. Docket 2003-NM-164-AD. Supersedes AD 2003-08-13, Amendment 39-13126.
Applicability: All Model P4Y-2 airplanes, Model LB-30 airplanes, and Model C-87A airplanes; certificated in any category.
Compliance: Required as indicated, unless accomplished previously.
To find and fix fatigue cracking in the lower rear cap of the wing front spar, front spar web, and lower skin of the wings, which could result in structural failure of the wings and consequent loss of control of the airplane, accomplish the following:
Initial and Repetitive Inspections for Certain Airplanes
(a) For Models P4Y-2 and LB-30 airplanes: Within 30 days after May 7, 2003 (the effective date of AD 2003-08-13, amendment 39- 13126), do the actions specified in paragraphs (a)(1) and (a)(2) of this AD per a method approved by the Manager, Los Angeles Certification Office (ACO), FAA.
(1) Do an inspection (between 39 and 63 inches outboard of the airplane center line on both the left and right sides of the wings) to find cracks in the lower rear cap of the wing front spar, front spar web, and lower skin of the wings localized under the front spar lower cap. Special detailed inspection procedures must be sufficiently reliable to determine the location, size, and orientation of the cracks.
(2) Develop repetitive inspection intervals that prevent crack growth from exceeding the minimum residual strength required to support limit load on the affected structure. The repetitive inspection intervals must be approved by the Manager, Los Angeles ACO. Thereafter, do the inspection approved per paragraph (a)(1) of this AD at the intervals approved per this paragraph.
Initial and Repetitive Inspections for Model C-87A Airplanes
(b) For all Model C-87A airplanes: Within 30 days after the effective date of this AD, do the actions specified in paragraphs (b)(1) and (b)(2) of this AD per a method approved by the Manager, Los Angeles ACO.
(1) Do an inspection (between 39 and 63 inches outboard of the airplane center line on both the left and right sides of the wings) to find cracks in the lower rear cap of the wing front spar, front spar web, and lower skin of the wings localized under the front spar lower cap. Special detailed inspection procedures must be sufficiently reliable to determine the location, size, and orientation of the cracks.
(2) Develop repetitive inspection intervals that prevent crack growth from exceeding the minimum residual strength required to support limit load on the affected structure. The repetitive inspection intervals must be approved by the Manager, Los Angeles ACO. Thereafter, do the inspection approved per paragraph (b)(1) of this AD at the intervals approved per this paragraph.
If Any Cracking Is Found
(c) If any crack is found during any inspection required by this AD, before further flight, do the action(s) specified in paragraphs (c)(1) and (c)(2) of this AD per a method approved by the Manager, Los Angeles ACO.
(1) Repair or replace the cracked part or structure.
(2) Repeat the inspection required by paragraph (a)(1) of this AD at reduced intervals approved by the Manager, Los Angeles ACO, to find cracks before the growth is critical and exceeds the minimum residual strength required to support limit load on the affected structure.
Alternative Methods of Compliance
(d) In accordance with 14 CFR 39.19, the Manager, Los Angeles ACO, FAA, is authorized to approve alternative methods of compliance for this AD.
Effective Date
(e) This amendment becomes effective on September 18, 2003.