Airworthiness Directives; Saab Model SAAB SF340A and SAAB 340B Series Airplanes

This amendment adopts a new airworthiness directive (AD) that is applicable to certain Saab Model SAAB SF340A and SAAB 340B series airplanes. This action requires a review of the airplane maintenance records to identify the bottom engine vibration isolator, an inspection of the aft engine vibration isolator to determine whether the deflection is within limits, and various follow-on actions. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified in this AD are intended to prevent excessive engine vibration, which could lead to damage of the nacelle structure and result in reduced structural integrity and fire shielding capability of the nacelle structure, or which could lead to chafing of the fire sensor loop and a consequent nuisance fire warning and result in a precautionary engine shutdown.