An NYPD pilot goofed while at the controls of a department helicopter during a training exercise and crashed — causing more than $700,000 in damage, sources told The Post on Tuesday.

The police lieutenant was piloting the chopper at Floyd Bennett Field in Brooklyn on April 3 when “something went wrong” while he tried to simulate an autorotation 200 feet in the air, sources said.

He first put the engine in “idle” as required when he reached the rotation altitude, sources said. But then instead of causing an engine “flare’’ by increasing the throttle to 100 percent and creating the rotation, he lost control of the aircraft, sources said.