AD 2020-08-12 Created Due To Fatigue Damage

SUMMARY: The FAA is adopting a new airworthiness directive (AD) for certain The Boeing Company Model 747-8 and 747-8F series airplanes.

This AD was prompted by an evaluation by the design approval holder (DAH) indicating that the skin lap joints at certain stringers are subject to widespread fatigue damage (WFD). This AD requires modifying the left and right side lap joints of the fuselage skin, repetitive post-modification inspections for cracking, and applicable on-condition actions. The FAA is issuing this AD to address the unsafe condition on these products.

DATES: This AD is effective June 2, 2020.

SUPPLEMENTARY INFORMATION: The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to certain The Boeing Company Model 747-8 and 747-8F series airplanes. The NPRM published in the Federal Register on February 13, 2020 (85 FR 8207). The NPRM was prompted by an evaluation by the DAH indicating that the skin lap joints at certain stringers are subject to WFD. The NPRM proposed to require modifying the left and right side lap joints of the fuselage skin, repetitive post-modification inspections for cracking, and applicable on-condition actions.

The FAA is issuing this AD to address undetected fatigue cracks, which could result in sudden decompression and reduced structural integrity of the airplane.

FMI: www.regulations.gov