A phenomenon where the nose cone is apparently "sucked" out of the body right at motor burnout. It is more prevalent on parabola, ogive and other low drag nose shapes. The theory (as yet unproven) is that since the nose cone has much less drag than the body, its momentum tends to carry it forward faster (or, more correctly, the body's drag decelerates *it* more quickly) putting tension on the nose-body joint. Another possible contributing factor could be the denser air (trapped in the body tube from ground level) exerting pressure on the nose cone once the rocket reaches a higher altitude.