NORTH ADAMS, MI, USA
N885
SIKORSKY S-58F
WHILE ACCOMPLISHING PREFLIGHT SYSTEMS CHECKS WITH THE ENGINE RUNNING AND THE ROTOR SYSTEM ENGAGED THE AIRCRAFT EXPERIENCED A HYDRAULIC HARDOVER. UNCOMMANDED DISPLACEMENT OF THE FLIGHT CONTROLS CAUSED THE AIRCRAFT TO PITCH UP AND LEFT SIMULTANEOUSLY. THE PILOT WAS UNABLE TO REGAIN CONTROL BEFORE THE MAIN ROTOR BLADES STRUCK THE GROUND AND THE AIRCRAFT CAME TO REST ON ITS LEFT SIDE. TESTING OF THE HYDRAULIC SYSTEM COULD NOT DUPLICATE THE PROBLEM. TEARDOWN INSPECTION REVEALED FOREIGN MATERIAL IN THE HYDRAULIC CYLINDERS.
Source: NTSB Aviation Accident Database
Aviation Accidents App
In-Depth Access to Aviation Accident Reports