Airworthiness Directives; BAE Systems (Operations) Limited Model BAe 146 and Avro 146-RJ Airplanes

The FAA is superseding an existing airworthiness directive (AD), which applies to certain BAE Systems (Operations) Limited Model BAe 146 and Avro 146-RJ airplanes. That AD currently requires one-time inspections of the inner webs and flanges at frames 15, 18, 41, and 43 for evidence of corrosion or cracking; and corrective actions if necessary. This new AD instead requires new repetitive inspections and expands the area to be inspected. This new AD also expands the applicability and provides an optional action that would extend the repetitive inspection interval. This AD results from a report indicating that in some cases the inspections required by the existing AD revealed no damage, yet frame corrosion and cracking were later found during scheduled maintenance in the two forward fuselage frames 15 and 18. We are issuing this AD to prevent reduced structural integrity of the airplane.