A stability test in which a strin' is attached t' a model rocket at t' center o' gravity and then swung around t' head. Begad! If t' model is stable, me hearties, it will head nose into t' direction o' travel. Avast! This test has a large margin o' error, matey, thus producin' models often overly stable. Well, blow me down! It can nay be used for large rockets, unless Kin' Kong consents t' twirl t' string. Ahoy! Sometimes called a strin' test.