AD FAA-2026-3486

The FAA is adopting a new airworthiness directive (AD) for The Boeing Company Model 747-400 series airplanes modified by certain supplemental type certificates (STCs). This AD was prompted by a report of a ruptured crew oxygen bottle flexible hose and arcing damage on an adjacent cargo loading system wiring harness. This AD requires a detailed inspection of the crew oxygen bottle flexible hoses and adjacent wire harnesses for chafing and arcing damage and for a minimum clearance between the crew oxygen bottle flexible hoses and adjacent wiring harnesses, and applicable repairs. The FAA is issuing this AD to address the unsafe condition on these products.