AD FAA-2007-28251

The FAA is adopting a new airworthiness directive (AD) to supersede AD 2006-26-08, which applies to all Hawker Beechcraft Corporation (HBC) Model 390 airplanes. AD 2006-26-08 currently requires you to repetitively inspect the hydraulic pump outlet tube on both engines and immediately replace the tube if damage is found. AD 2006- 26-08 also requires you to incorporate an airplane flight manual (AFM) change that limits operation of an engine with its associated firewall hydraulic shutoff valve closed. If an engine is operated with its firewall hydraulic shutoff valve closed, you must replace the hydraulic pump outlet tube. We issued AD 2006-26-08 as an interim action while we worked with the type certificate holder to develop a design change. HBC has now developed kits that incorporate design changes for the hydraulic pump outlet tubes and dampener supports so this AD retains the actions of AD 2006-26-08 until the new modification kits required by this AD are installed. We continued to receive additional reports of failures of the hydraulic pump outlet tube. We are issuing this AD to prevent failure of the hydraulic pump outlet tube and consequent leaking of hydraulic fluid. Such leakage could result in a fire. There is also a risk of loss of hydraulic system functions including normal gear extensions, speed brakes, roll spoilers, lift dump, and normal brakes.