Never happened. Show me the documentation.
Anyone flying a manned aircraft under the arch, or under most tall bridges, would be in violation of §91.119 - Minimum Safe Altitudes, and likely §91.13 Careless or reckless operation. No new rules required. Also, the FAA does not "lock up the pilots" as their authority is limited to certificate action and civil fines. The FAA does not have forfeiture (confiscation) authority. If anyone can provide a citation otherwise, I would like to see it. Local authorities may have jurisdiction via reckless endangerment laws already on the books, and those laws vary wildly from jurisdiction to jurisdiction.
Steve,
I would love to give you the documentation...it happened between 1964 and 1968. I certainly do not have the documentation nearly 50 years later after I moved out of the area. I was at Parks College of Aeronautical Engineering in Cahokia, Ill. at the time. The college has moved to the main STL University campus since that time as well
Last week I was playing golf with a Golden Knight Parachute team member with over 6000 jumps. He said that a person tried to parachute on the top on the arch. His chute collapsed and he slide down the outside edge to his death