Airworthiness Directives; The Boeing Company Airplanes

FAA / Federal Register · 2021-18705

The FAA is adopting a new airworthiness directive (AD) for all The Boeing Company Model 747-100, -100B, -100B SUD, -200B, -200C, - 200F, -300, -400, -400D, -400F, 747SR, and 747SP airplanes. This AD was prompted by reports of cracks found in the front spar shear tie and at the intercostal lug fitting at certain locations. This AD requires repetitive detailed and surface high frequency eddy current (HFEC) inspections of the front spar shear tie and intercostal lug fitting at certain locations for any cracking, and applicable on-condition actions. The FAA is issuing this AD to address the unsafe condition on these products.