At 14:30 eastern time, a homebuilt Rotorway Exec 162F helicopter struck trees after lifting to a hover in an open field in Wallingford. The flight instructor and student pilot/builder were not injured. The instructor said he had repositioned the helicopter solo and, when the student boarded, he forgot to move the ballast weight from the right front skid tube to the tail cone, as directed by the checklist. He also said he did not use the pre-takeoff checklist, which would have reminded him to move the ballast. When the helicopter took off, the nose pitched down and the helicopter accelerated and struck trees. The flight instructor reported eight hours in make and model, of which three were logged as instructor in make and model.