EASA AD US-2020-04-11
Fuselage - Upper Skin Lap Splice - Inspection
The Federal Register Volume 85, Number 46 Airworthiness Directive 2020-04-11 is a final rule issued by the FAA addressing certain Boeing 747-400 series airplanes. It mandates repetitive low frequency eddy current (LFEC) and high frequency eddy current (HFEC) inspections of the fuselage upper skin lap splice to detect fatigue cracks. The directive includes required on-condition repair actions to maintain structural integrity.