FREDERICK, Md. (AP) — Federal investigators were at the scene Friday of a collision between an airplane and a helicopter near a Maryland airport that killed three men but spared two others in the plane, who deployed a parachute to slow the aircraft's descent. Investigators were combing the scene and planned to talk with survivors and air traffic controllers. The plane pilot, Scott Graeves, 55, of Brookeville, and his passenger, Gilbert Porter, 75, of Sandy Spring, were treated at a hospital in Hagerstown and released Thursday evening, according to state police. The FAA said in a statement that the helicopter in a training exercise when the collision occurred, though the agency did not provide specifics.