Airworthiness Directives; Bombardier Model DHC-8-400 Series Airplanes

The FAA is adopting a new airworthiness directive (AD) for certain Bombardier Model DHC-8-400 series airplanes. This AD requires repetitive inspections for cracks of the first fuel access panel outboard of the nacelle on the left- and right-hand wings, and related investigative/corrective actions if necessary. This AD also requires eventual replacement of each access panel with a new access panel having a new part number. The replacement terminates the repetitive inspection requirements. This AD results from reports of cracks of the fuel access panels. We are issuing this AD to detect and correct cracked fuel access panels, which could lead to arcing and ignition of fuel vapor during a lightning strike, and result in fuel tank explosions and consequent loss of the airplane.