The deadline for IAC Rules Change proposals is July 1, as noted in Section 1 of the IAC Contest Rules. If you're planning to propose rules changes, the best way to do so is to go to this address:
https://www.iac.org/propose-rule-change, fill out the form, and hit "Submit". IAC member login is required.
If you happen to be an IAC member but for whatever reason can't use the above link, you can send a proposed change to ruleschair [at] iac.org…
Four Minute Free
Participate in the four-minute freestyle program. Open only to Unlimited category competitors, or Advanced category competitors who also hold at least a current ICAS 250-foot Statement of Aerobatic Competency