Airworthiness Directives; Bombardier Model CL-600-2B16 Series Airplanes

This amendment revises an existing airworthiness directive (AD), applicable to certain Bombardier Model CL-600-2B16 series airplanes, that currently requires disabling the remote fuel/defuel panel in the cockpit; and provides for an optional modification of the remote fuel/defuel panel, which would terminate the requirement to disable the panel. This amendment reduces the applicability of the existing AD. This amendment is prompted by reports of in-flight failure of the panel that resulted when a circuit breaker on a battery bus opened due to insufficient current flow capacity. The actions specified in this amendment are intended to prevent the circuit breakers from opening during flight, which could result in irreversible loss of engine indicating and fuel quantity systems in the cockpit.