# Not determined - Type: NTSB finding category - Path: Not determined - NTSB code: 05 - Cases: 2247 - In the probable cause: 2176 - Fatal cases: 574 - All cases: https://openairdocs.org/ntsb-findings/05/cases.md - Cases with it in the probable cause: https://openairdocs.org/ntsb-findings/05/cases.md?cause=1 - Page: https://openairdocs.org/ntsb-findings/05 ## Cases per year (in the probable cause / all) - 2008: 146 / 150 - 2009: 193 / 199 - 2010: 189 / 195 - 2011: 149 / 156 - 2012: 167 / 171 - 2013: 126 / 128 - 2014: 149 / 150 - 2015: 157 / 163 - 2016: 136 / 137 - 2017: 133 / 135 - 2018: 140 / 143 - 2019: 113 / 118 - 2020: 82 / 86 - 2021: 88 / 98 - 2022: 72 / 76 - 2023: 62 / 68 - 2024: 37 / 37 - 2025: 28 / 28 - 2026: 9 / 9 ## Subcategories - [Not determined](https://openairdocs.org/ntsb-findings/0500): 2,247 cases, 2,176 in the probable cause ## Defining events in these cases - [Loss of engine power (total)](https://openairdocs.org/ntsb-events/341): 665 cases - [Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342): 384 cases - [Unknown or undetermined](https://openairdocs.org/ntsb-events/000): 275 cases - [Loss of control in flight](https://openairdocs.org/ntsb-events/240): 270 cases - [Loss of control on ground](https://openairdocs.org/ntsb-events/230): 73 cases - [Landing gear collapse](https://openairdocs.org/ntsb-events/094): 67 cases - [Fire/smoke (non-impact)](https://openairdocs.org/ntsb-events/150): 53 cases - [Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330): 50 cases - [Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340): 35 cases - [Part(s) separation from AC](https://openairdocs.org/ntsb-events/338): 29 cases ## Aircraft models (registry) - [Piper PA-28-140](https://openairdocs.org/model/piper-pa-28-140): 27 cases - [Cirrus Design SR22](https://openairdocs.org/model/cirrus-design-sr22): 25 cases - [Cessna 172S](https://openairdocs.org/model/cessna-172s): 25 cases - [Robinson Helicopter R44 II](https://openairdocs.org/model/robinson-helicopter-r44-ii): 24 cases - [Cessna 172N](https://openairdocs.org/model/cessna-172n): 24 cases - [Beech A36](https://openairdocs.org/model/beech-a36): 23 cases - [Piper PA-28-180](https://openairdocs.org/model/piper-pa-28-180): 18 cases - [Robinson Helicopter R22 BETA](https://openairdocs.org/model/robinson-helicopter-r22-beta): 16 cases - [Piper PA-28R-200](https://openairdocs.org/model/piper-pa-28r-200): 16 cases - [Cessna 172M](https://openairdocs.org/model/cessna-172m): 16 cases ## Other findings in the same cases - [Aircraft control](https://openairdocs.org/ntsb-findings/02063040) (Personnel issues): 242 cases - [Engine (reciprocating), general](https://openairdocs.org/ntsb-findings/01058500) (Aircraft): 127 cases - [Performance/control parameters, general](https://openairdocs.org/ntsb-findings/01062000) (Aircraft): 109 cases - [Tree(s)](https://openairdocs.org/ntsb-findings/03022020) (Environmental issues): 72 cases - [Directional control](https://openairdocs.org/ntsb-findings/01062020) (Aircraft): 70 cases - [Airspeed](https://openairdocs.org/ntsb-findings/01062010) (Aircraft): 69 cases - [Decision making/judgment](https://openairdocs.org/ntsb-findings/02041520) (Personnel issues): 66 cases - [Power plant, general](https://openairdocs.org/ntsb-findings/01057100) (Aircraft): 59 cases - [Rough terrain](https://openairdocs.org/ntsb-findings/03021015) (Environmental issues): 48 cases - [Aircraft power plant, general](https://openairdocs.org/ntsb-findings/01050000) (Aircraft): 45 cases ## Newest cases - [NTSB GAA26WA326](https://openairdocs.org/ntsb/GAA26WA326), Sep 21, 2026: Laviasa PA25 (PR-SOH), Cajati, Brazil, substantial damage - [NTSB GAA26WA309](https://openairdocs.org/ntsb/GAA26WA309), Sep 8, 2026: Bell 412 (XA-EHJ), Ciudad del Carmen, Mexico, incident, no damage - [NTSB GAA26WA286](https://openairdocs.org/ntsb/GAA26WA286), Aug 19, 2026: Guimbal Cabri (G-TOOO), Oxford, United Kingdom, incident, minor damage - [NTSB GAA26WA275](https://openairdocs.org/ntsb/GAA26WA275), Aug 4, 2026: Cessna U206 (CC-PHJ), Iquique, Chile, occurrence, minor damage - [NTSB GAA26WA261](https://openairdocs.org/ntsb/GAA26WA261), Jul 14, 2026: Cessna 152 (D-EJCP), Mengeringhausen, Germany, incident, destroyed, 1 fatal - [NTSB GAA26WA201](https://openairdocs.org/ntsb/GAA26WA201), May 27, 2026: Piper PA28 (HP-1861FX), Aguadulce District, Panama, incident, substantial damage - [NTSB GAA26WA247](https://openairdocs.org/ntsb/GAA26WA247), May 21, 2026: Piper PA28 (SE-EOT), Roszczep, Poland, substantial damage - [NTSB GAA26WA183](https://openairdocs.org/ntsb/GAA26WA183), May 3, 2026: Cessna 182 (TG-JEB), Santa Cruz Barillas, Guatemala, substantial damage, 1 fatal - [NTSB ANC26LA026](https://openairdocs.org/ntsb/ANC26LA026), Apr 16, 2026: Cessna U206F (N93021), Juneau, AK, substantial damage. Probable cause: A total loss of engine power for reasons that could not be determined because the airplane was not recovered from the ocean. - [NTSB WPR26LA062](https://openairdocs.org/ntsb/WPR26LA062), Dec 15, 2025: Bell 407 (N404LL), Las Vegas, NV, substantial damage. Probable cause: Tail rotor blade impact from an unidentified object at an undetermined time. NTSB has coded findings and defining events since 2008; earlier cases used its older occurrence and cause codes and aren't counted. Findings: https://openairdocs.org/ntsb-findings.md. Defining events: https://openairdocs.org/ntsb-events.md. Phases of flight: https://openairdocs.org/ntsb-phases.md. Every investigation, filtered by finding, event, phase, state, year or model: https://openairdocs.org/ntsb.md (for example ?state=MI&fatal=1). NTSB's definitions: Accident and incident, 49 CFR 830.2 (https://www.ecfr.gov/current/title-49/subtitle-B/chapter-VIII/part-830/subpart-A/section-830.2), CICTT occurrence categories (PDF) (https://www.ntsb.gov/safety/data/Documents/datafiles/OccurrenceCategoryDefinitions.pdf), CICTT phases of flight (PDF) (https://www.ntsb.gov/safety/data/Documents/datafiles/PhaseofFlightDefinitions.pdf), and NTSB coding manual, before 2008 (PDF) (https://www.ntsb.gov/GILS/Documents/codman.pdf). NTSB publishes no definitions for its findings, only their names. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.