CFR › Title 14 › Part 91 › §91.17314 CFR §91.173Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗Copy linkNo person may operate an aircraft in controlled airspace under IFR unless that person has—(a)Filed an IFR flight plan; and(b)Received an appropriate ATC clearance.