Airworthiness Directives; Saab AB, Saab Aeronautics (Formerly Known as Saab AB, Saab Aerosystems) Airplanes

We propose to supersede Airworthiness Directive (AD) 2016-13- 06, which applies to certain Saab AB, Saab Aeronautics Model 340A (SAAB/SF340A) and SAAB 340B airplanes. AD 2016-13-06 requires a revision of the applicable airplane flight manual (AFM), repetitive inspections of the horizontal stabilizer de-icing boots, and applicable corrective actions. Since we issued AD 2016-13-06, the manufacturer has developed an improved de-icing boot. This proposed AD would continue to require a revision of the applicable AFM, repetitive inspections of the horizontal stabilizer de-icing boots, and applicable corrective actions. This proposed AD would also require replacement of single stitched de-icing boots with improved double stitched boots, and re- identification of the modified horizontal stabilizer leading edge. We are proposing this AD to address the unsafe condition on these products.