Summary
We propose to supersede Airworthiness Directive (AD) 2014-15- 04 for certain Saab AB, Saab Aeronautics Model SAAB 2000 airplanes. AD 2014-15-04 currently requires deactivating the potable water system, or alternatively filling and activating the potable water system. Since we issued AD 2014-15-04, the manufacturer developed a modification that would address the unsafe condition. This proposed AD would also require inspecting the in-line heater for correct brazing and corrective action if needed, and installing a shrinkable tube on the water line and a spray shield on the in-line heater. We are proposing this AD to prevent rudder pedal restriction due to the pitch control mechanism becoming frozen as the result of water spray, which could prevent disconnection and normal pitch control, and consequently result in reduced controllability of the airplane.