An inverted loop. This aerobatic maneuver is performed under negative g conditions with the aircraft's upper surface remaining outward throughout. Also called a bunt.
Stunt woman: Portland resident Dorothy Hester took up flying as a teenager and made the record books at 19 when in 1930 she was the first woman to fly a plane in an outside loop, essentially a forward somersault.
Pre-settlement Iowa was covered in prairie, with streams naturally meandered over the landscape, creating cut-offs and meander scars on the outside loops of the main stream channel.