# Collision avoidance alert

- Type: NTSB defining event
- NTSB code: 420
- CICTT category: Other
- Defining event in: 0 cases
- In the sequence of: 11 cases
- Fatal cases: 0
- All cases: https://openairdocs.org/ntsb-events/420/cases.md
- Cases with it anywhere in the sequence: https://openairdocs.org/ntsb-events/420/sequence.md
- Page: https://openairdocs.org/ntsb-events/420

## Cases per year (defining / in the sequence)

- 2008: 0 / 1
- 2009: 0 / 1
- 2010: 0 / 2
- 2011: 0 / 1
- 2012: 0 / 1
- 2013: 0 / 1
- 2016: 0 / 2
- 2017: 0 / 1
- 2023: 0 / 1

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.

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