NTSB History by Manufacturer & Model

See NTSB accident and incident counts for an aircraft manufacturer and model — combining FAA-registered aircraft with NTSB-only records for foreign-registered, military, and drone aircraft that never appear in the FAA's US civil registry. Counts only, not a rate or percentage — there's no reliable total fleet size for aircraft outside the FAA registry to compare against.

and, optionally,

26 NTSB records found for "Cessna 550 / 551 / S550 (Citation II)": 26 from FAA-registered aircraft, 0 from aircraft not in the FAA registry (foreign, military, or drone), 4 involving a fatality.