# NTSB defining events NTSB marks the event that best describes each accident or incident: the defining event. 30,760 cases since 2008 have one. NTSB has coded findings and defining events since 2008; earlier cases used its older occurrence and cause codes and aren't counted. ## Every defining event - [Loss of control on ground](https://openairdocs.org/ntsb-events/230): 3,834 cases, 54 fatal - [Loss of control in flight](https://openairdocs.org/ntsb-events/240): 3,832 cases, 1,846 fatal - [Loss of engine power (total)](https://openairdocs.org/ntsb-events/341): 2,821 cases, 313 fatal - [Unknown or undetermined](https://openairdocs.org/ntsb-events/000): 1,515 cases, 902 fatal - [Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342): 1,417 cases, 148 fatal - [Hard landing](https://openairdocs.org/ntsb-events/092): 1,245 cases, 12 fatal - [Aerodynamic stall/spin](https://openairdocs.org/ntsb-events/241): 863 cases, 375 fatal - [Controlled flight into terr/obj (CFIT)](https://openairdocs.org/ntsb-events/120): 854 cases, 549 fatal - [Collision during takeoff/land](https://openairdocs.org/ntsb-events/490): 802 cases, 125 fatal - [Runway excursion](https://openairdocs.org/ntsb-events/300): 793 cases, 27 fatal - [Miscellaneous/other](https://openairdocs.org/ntsb-events/900): 732 cases, 105 fatal - [Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330): 724 cases, 37 fatal - [Fuel exhaustion](https://openairdocs.org/ntsb-events/192): 695 cases, 70 fatal - [Abnormal runway contact](https://openairdocs.org/ntsb-events/090): 670 cases, 15 fatal - [Landing gear collapse](https://openairdocs.org/ntsb-events/094): 648 cases, 1 fatal - [Low altitude operation/event](https://openairdocs.org/ntsb-events/220): 646 cases, 213 fatal - [Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340): 626 cases, 48 fatal - [Fuel starvation](https://openairdocs.org/ntsb-events/191): 569 cases, 61 fatal - [Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470): 558 cases, 222 fatal - [Ground collision](https://openairdocs.org/ntsb-events/200): 500 cases, 12 fatal - [Nose over/nose down](https://openairdocs.org/ntsb-events/096): 468 cases, 10 fatal - [Landing gear not configured](https://openairdocs.org/ntsb-events/095): 460 cases, 7 fatal - [Fire/smoke (non-impact)](https://openairdocs.org/ntsb-events/150): 357 cases, 34 fatal - [Flight control sys malf/fail](https://openairdocs.org/ntsb-events/333): 354 cases, 36 fatal - [Turbulence encounter](https://openairdocs.org/ntsb-events/360): 340 cases, 12 fatal - [Part(s) separation from AC](https://openairdocs.org/ntsb-events/338): 288 cases, 40 fatal - [Fuel related](https://openairdocs.org/ntsb-events/190): 269 cases, 27 fatal - [VFR encounter with IMC](https://openairdocs.org/ntsb-events/401): 247 cases, 204 fatal - [Birdstrike](https://openairdocs.org/ntsb-events/901): 243 cases, 14 fatal - [Landing area overshoot](https://openairdocs.org/ntsb-events/380): 232 cases, 6 fatal - [Fuel contamination](https://openairdocs.org/ntsb-events/193): 202 cases, 29 fatal - [Midair collision](https://openairdocs.org/ntsb-events/250): 195 cases, 110 fatal - [Aircraft structural failure](https://openairdocs.org/ntsb-events/337): 181 cases, 86 fatal - [Loss of lift](https://openairdocs.org/ntsb-events/500): 174 cases, 10 fatal - [Abrupt maneuver](https://openairdocs.org/ntsb-events/270): 145 cases, 51 fatal - [Landing area undershoot](https://openairdocs.org/ntsb-events/370): 132 cases, 3 fatal - [Windshear or thunderstorm](https://openairdocs.org/ntsb-events/390): 119 cases, 29 fatal - [Electrical system malf/failure](https://openairdocs.org/ntsb-events/332): 118 cases, 3 fatal - [Pressure/environ sys malf/fail](https://openairdocs.org/ntsb-events/331): 111 cases, 1 fatal - [Tailstrike](https://openairdocs.org/ntsb-events/091): 108 cases, 0 fatal - [Dynamic rollover](https://openairdocs.org/ntsb-events/231): 102 cases, 6 fatal - [Wildlife encounter (non-bird)](https://openairdocs.org/ntsb-events/310): 98 cases, 1 fatal - [Loss of visual reference](https://openairdocs.org/ntsb-events/402): 97 cases, 42 fatal - [Runway incursion veh/AC/person](https://openairdocs.org/ntsb-events/320): 95 cases, 5 fatal - [Near midair/TCAS alert/loss of separation](https://openairdocs.org/ntsb-events/260): 92 cases, 0 fatal - [Cabin safety event](https://openairdocs.org/ntsb-events/110): 87 cases, 2 fatal - [Ground handling event](https://openairdocs.org/ntsb-events/080): 84 cases, 1 fatal - [Air traffic event](https://openairdocs.org/ntsb-events/100): 83 cases, 0 fatal - [Loss of tail rotor effectiveness](https://openairdocs.org/ntsb-events/242): 77 cases, 8 fatal - [Dragged wing/rotor/float/other](https://openairdocs.org/ntsb-events/093): 74 cases, 4 fatal - [Medical event](https://openairdocs.org/ntsb-events/850): 51 cases, 24 fatal - [AC/prop/rotor contact w person](https://openairdocs.org/ntsb-events/081): 51 cases, 21 fatal - [Inflight upset](https://openairdocs.org/ntsb-events/271): 46 cases, 20 fatal - [Structural icing](https://openairdocs.org/ntsb-events/210): 45 cases, 20 fatal - [Uncontained engine failure](https://openairdocs.org/ntsb-events/343): 45 cases, 1 fatal - [Settling with power/vortex ring state](https://openairdocs.org/ntsb-events/244): 42 cases, 2 fatal - [Wrong surface or wrong airport](https://openairdocs.org/ntsb-events/284): 40 cases, 0 fatal - [Airport occurrence](https://openairdocs.org/ntsb-events/070): 39 cases, 0 fatal - [Prop/jet/rotor blast/suction](https://openairdocs.org/ntsb-events/082): 39 cases, 1 fatal - [Roll over](https://openairdocs.org/ntsb-events/097): 36 cases, 0 fatal - [Flight instrument malf/fail](https://openairdocs.org/ntsb-events/334): 31 cases, 1 fatal - [External load event (Rotorcraft)](https://openairdocs.org/ntsb-events/480): 30 cases, 9 fatal - [Aircraft wake turb encounter](https://openairdocs.org/ntsb-events/361): 29 cases, 7 fatal - [Altitude deviation](https://openairdocs.org/ntsb-events/282): 27 cases, 4 fatal - [Off-field or emergency landing](https://openairdocs.org/ntsb-events/440): 23 cases, 2 fatal - [Glider tow event](https://openairdocs.org/ntsb-events/510): 23 cases, 7 fatal - [Aircraft loading event](https://openairdocs.org/ntsb-events/010): 22 cases, 1 fatal - [Security/criminal event](https://openairdocs.org/ntsb-events/350): 22 cases, 14 fatal - [Clear air turbulence encounter](https://openairdocs.org/ntsb-events/362): 21 cases, 0 fatal - [Ground resonance](https://openairdocs.org/ntsb-events/232): 19 cases, 0 fatal - [Explosion (non-impact)](https://openairdocs.org/ntsb-events/160): 16 cases, 3 fatal - [Comm system malf/failure](https://openairdocs.org/ntsb-events/336): 15 cases, 1 fatal - [Missing aircraft](https://openairdocs.org/ntsb-events/990): 13 cases, 12 fatal - [Aircraft servicing event](https://openairdocs.org/ntsb-events/020): 11 cases, 1 fatal - [Evacuation](https://openairdocs.org/ntsb-events/460): 10 cases, 0 fatal - [Simulated/training event](https://openairdocs.org/ntsb-events/600): 9 cases, 2 fatal - [Course deviation](https://openairdocs.org/ntsb-events/281): 9 cases, 1 fatal - [Mast bumping](https://openairdocs.org/ntsb-events/245): 9 cases, 7 fatal - [Navigation error](https://openairdocs.org/ntsb-events/280): 8 cases, 0 fatal - [Nav system malfunction/failure](https://openairdocs.org/ntsb-events/335): 7 cases, 0 fatal - [Wrong fuel](https://openairdocs.org/ntsb-events/194): 6 cases, 0 fatal - [Other weather encounter](https://openairdocs.org/ntsb-events/400): 5 cases, 0 fatal - [Preflight or dispatch event](https://openairdocs.org/ntsb-events/030): 4 cases, 0 fatal - [Ditching](https://openairdocs.org/ntsb-events/441): 4 cases, 2 fatal - [Engine shutdown](https://openairdocs.org/ntsb-events/140): 4 cases, 1 fatal - [Fire/smoke (post-impact)](https://openairdocs.org/ntsb-events/170): 3 cases, 2 fatal - [Emergency descent initiated](https://openairdocs.org/ntsb-events/130): 2 cases, 1 fatal - [Attempted remediation/recovery](https://openairdocs.org/ntsb-events/060): 1 cases, 0 fatal - [Aircraft maintenance event](https://openairdocs.org/ntsb-events/040): 1 cases, 0 fatal - [Aircraft inspection event](https://openairdocs.org/ntsb-events/050): 1 cases, 0 fatal - [Hazardous material leak/spill](https://openairdocs.org/ntsb-events/450): 1 cases, 0 fatal - [Airspace incursion](https://openairdocs.org/ntsb-events/283): 1 cases, 0 fatal ## By phase of flight - Landing: 8,944 cases - Enroute: 5,705 cases - Maneuvering: 3,685 cases - Takeoff: 3,587 cases - Approach: 3,349 cases - Initial climb: 2,917 cases - Taxi: 915 cases - Unknown: 837 cases - Standing: 425 cases - Emergency descent: 269 cases - Prior to flight: 136 cases - Other: 95 cases ## By CICTT occurrence category - System/Component Failure (Powerplant): 4,909 cases - Loss Of Control (Inflight): 4,823 cases - Loss Of Control (Ground): 3,955 cases - Abnormal Runway Contact: 3,709 cases - System/Component Failure (Non-Powerplant): 1,829 cases - Fuel: 1,741 cases - Unknown: 1,528 cases - Other: 1,336 cases - CFIT: 854 cases - Collision During Takeoff/Land: 802 cases - Runway Excursion: 793 cases - Low Altitude Operation/Event: 646 cases - Ground Collision: 500 cases - Turbulence: 390 cases - Fire: 376 cases Findings: https://openairdocs.org/ntsb-findings.md --- From OpenAirDocs.org, an independent open copy of NTSB and FAA data. The NTSB's own report is the official record of an investigation.