Important Disclaimer

This tool presents statistical analysis of NTSB accident data for experimental amateur-built aircraft. The data is provided for informational and educational purposes only.

This data should not be the sole basis for any aircraft purchase, build, or flight decision. Aviation safety depends on many factors not captured here, including pilot training, recency, weather decision-making, maintenance practices, and individual judgment.

Key limitations of this data:

  • Accident rates are fleet-level statistics — your personal risk depends heavily on how you fly, not just what you fly.
  • Small sample sizes for some aircraft types make their statistics unreliable. A single accident can change a type's fatal percentage significantly.
  • No per-type flight hour data exists for homebuilt aircraft, so true exposure-adjusted rates cannot be calculated.
  • Accident narratives were individually read and classified using an LLM, then fully audited with 614 corrections applied. This is not an official NTSB classification.

The analysis uses an initiator-based approach — identifying the first event in the accident chain rather than the NTSB's probable cause. This is an analytical framework, not an official NTSB classification.

If you are considering building or purchasing an experimental aircraft, consult experienced builders, flight instructors with type-specific experience, and your local EAA chapter. No website can substitute for hands-on guidance.

We believe safety data should be free and accessible to everyone in the experimental aircraft community. This tool is free to use and always will be. If you find it valuable, consider supporting the project.

Experimental Aircraft Safety

Engine Analysis

Safety comparison across 23 engine types installed in homebuilt aircraft

Fatal % by Engine Type

When an accident happens, how often is it fatal?

Engine-Initiated % by Engine Type

What percentage of accidents started with an engine event?

All Engine Types

EngineAccidentsFatalFatal %Engine-Initiated %Top Initiator
Other110434531.3%34.9%Stall/Spin
Lycoming O-360104628427.2%26.5%Landing
Auto conversion100323022.9%46.7%Engine (Undetermined)
Rotax 2-stroke99324925.1%39.2%Stall/Spin
Lycoming O-32098626526.9%30.6%Landing
Rotax 912/91457111820.7%22.1%Landing
Continental O-20048514630.1%32.8%Landing
Lycoming (other)47410822.8%23.2%Landing
Rotax (other)3038427.7%27.7%Stall/Spin
Lycoming IO-5402689134.0%32.5%Landing
Lycoming O-2352496526.1%40.6%Landing
Continental (other)2325122.0%28.9%Landing
Rotorway2062210.7%35.9%Landing
Jabiru1402517.9%39.3%Landing
Continental IO-5501305441.5%32.3%Landing
Superior/XP731824.7%30.1%Crosswind
Hirth 2-stroke562341.1%44.6%Engine (Undetermined)
Lycoming O-54046817.4%23.9%Landing
Continental IO-36021838.1%42.9%Stall/Spin
Viking (Honda)1915.3%47.4%Landing
UL Power16212.5%43.8%Internal Engine Failure
Continental O-2406116.7%16.7%Landing
None100.0%0.0%Landing