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

Résumé

This amendment adopts a new airworthiness directive (AD) that is applicable to all Fokker Model F28 Mark 0100 and Model F28 Mark 0070 series airplanes. This action requires revising the Limitations Section of the Airplane Flight Manual to include information that will enable the flightcrew to identify failures of the emergency direct current (DC)/alternating current (AC) bus power supply and to take appropriate corrective actions. This amendment is prompted by one report indicating that a diode failed, which resulted in battery drain and loss of the emergency DC bus power supply; and another report indicating that the circuit breaker of the transformer rectifier unit No. 3 tripped, which resulted in the loss of the emergency DC/AC bus power supply. The actions specified in this AD are intended to ensure that the flightcrew is advised of the potential hazard related to failures of the emergency bus power supply, and the procedures necessary to address it.