Shrivel Flap. Q: What is the purpose of pin closed BASE rigs?
Pin closed BASE rigs such as the Perigee Pro are an answer to the problem of premature deployments of Velcro rigs at high speed. As air speeds approach terminal velocity, airflow over the jumper’s back pulls at the corners of a shrivel flap. If other factors such as worn Velcro, poor harness fit or over – stuffed container are present, the rig can prematurely open and a horseshoe malfunction will result. Velcro rigs work very well at low speeds, which is the environment for which they were designed. However, as jumping styles evolve to include aerobatic maneuvers and higher altitude sites become available, demands are being placed on the Velcro rigs that they were not designed to handle. The pin closed BASE rig addresses this problem with secure closure. They are not intended as a substitute for Velcro closed rigs.
