Airworthiness Directives; Fokker Model F28 Mark 0070 and 0100 Series Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to certain Fokker Model F28 Mark 0070 and 0100 series airplanes, that requires a one-time operational test of a certain pitot heating system, repair or replacement of failed elements, and repair or replacement of the pitot heating system with a new improved system. This amendment also requires installation of new power supply wiring with increased gauge thickness, and a circuit breaker with an increased amperage rating. This amendment is prompted by the issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to prevent icing of the No. 1 pitot tube, which could result in failure of the No. 1 Air Data Computer, or output of erroneous airspeed data to all on-side subsidiary systems, including the Automatic Flight Control and Augmentation System.