FAA NPRM Docket No. FAA-2019-0451; Notice No. 19-08 Special Flight Authorizations for Supersonic Aircraft

Current regulations prohibit overland supersonic civil flights in the United States, but include a procedure to request authorization for these flights
for the purposes of test and development of new aircraft. The criteria for such authorizations were developed in the 1970s and placed in an
appendix to the operating regulations. With renewed interest in supersonic aircraft development, the FAA is proposing to modernize the procedure
for requesting these special flight authorizations.