On August 16th 2011 the Office of Defects Investigation (ODI) opened this Preliminary Evaluation (PE11-027) on Kovatch Mobile Equipment (KME) Aerial Cat 2003 - 2011 Fire trucks concerning an alleged failure related to a fire truck's aerial ladder.The electronic-over-hydraulic controller that is used to move the aerial bucket fails, causing an unintended movement of the aerial device on certain KME aerial ladder/platform trucks.This unintended movement of the aerial ladder bucket constitutes an unreasonable risk to safety as the movement may occur in an unintended direction possibly near electrical power lines, structures, or a fire.The manufacturer will conduct a safety recall.The remedy KME will implement updates the software for the controller, including a triple redundancy system.One of the systems disables all platform aerial movement controls immediately upon actuation of the dead man's switch at the turntable.This PE is closed with a Safety Recall (12V-027).The ODI reports cited above can be reviewed at www-odi.nhtsa.dot.gov/owners/SearchNHTSAID under the following identification (ODI) number: 10418106