Eclipse 500
Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Commercial
Flight Crew Last 90 Days 20; Flight Crew Total 2600; Flight Crew Type 200
Aircraft Equipment Problem Critical; Ground Event / Encounter Ground Strike - Aircraft
Aircraft Aircraft Damaged; General Maintenance Action
Aircraft
Aircraft had uncommanded nose gear retraction while stationary on ramp.  Line personnel brought over maintenance; who called recovery expert to lift aircraft nose off ground so gear could be extended and inspected. No damage was noted. Eclipse service center was notified; and instructed me to pull landing gear breakers and fly with gear down to a factory facility. Maintenance personnel from two FBO's concurred.  I flew the aircraft with gear down.
Reporter states that there is a known fault with with the originally installed EA50 landing gear actuators and that the replacement actuators are made by a different manufacturer.  Each landing gear actuator is self contained with its' own hydraulic fluid; pump and logic circuit.  This logic circuit may be the root of the problem.  The gear has no mechanical down lock and relies entirely on the lack of an up command from the landing gear selector and/or a weight on wheels sensor signal to this logic circuit.
EA50 pilot experiences an uncommanded nose gear retraction while stationary on the ramp after engine start.