Ann: First commercial sale of CVM to Delta Air Lines, page-31

https://simpleflying.com/faa-proposes-new-airworthiness-directive-boeing-737/

The 737 models listed on the NPRM include the 737-600, -700, -700C, -800, -900, and -900ER. The issue in question regards skin lap splices on the aircraft's exterior. These skin lap splices are points where metal skins are joined together. The FAA issued a summary of the issue, which reads,

"This proposed AD was prompted by an evaluation by the design approval holder (DAH) indicating that the skin lap splice at certain stringers is subject to widespread fatigue damage (WFD). This proposed AD would require an inspection for any repair at certain skin lap splices and depending on the configuration, repetitive inspections for buckling, wrinkling, bulging at affected skin lap splices and repair, repetitive inspections for cracking at affected locations common to fuselage skin on the left and right sides and repair, and alternative inspections and on-condition actions. The FAA is proposing this AD to address the unsafe condition on these products."

Should an AD be adopted, the FAA estimates it would affect some 2,462 airplanes on the US registry.

Bottom of page 26.

https://cdn-api.markitdigital.com/apiman-gateway/CommSec/commsec-node-api/1.0/event/document/1410-02584201-3BHMUDECUVH08HUBVUMAAMNT37/pdf?access_token=0007kxicKNvLIIPT6MCRYXvcSlCK

CVM Applications
Focused Assessment of Single Platform (737NG)

• Fuselage Skin Cracking at S-14R - Service Bulletins 737-53-1399

This from a few years back.

https://www.casa.gov.au/search-centre/airworthiness-directives/lower-skin-fuselage-skin-lap-splices-along-lower-fastener-row-stringer-s-14-lap-splice

Lower Skin of the Fuselage Skin Lap Splices along the Lower Fastener Row of the Stringer (S)-14 Lap Splice