(Reuters) An Air Force of Zimbabwe helicopter crashed on Friday, killing three crew members and a child on the ground as it came down on a house, the Air Force said in a statement. The helicopter was on a training mission, with two pilots and a technician when it disappeared on the radar. It came down on a house in Arcturus, a farming area some 30 km east of the capital Harare. Footage by Reuters showed charred parts of the helicopter and security forces conducting an investigation. Zimbabwe's A