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

Builder & Test Flight Analysis

How builder vs. non-builder pilots and test flights affect safety outcomes

Builder (confirmed)
192
30.2% fatal · 46.9% engine-initiated
Likely Builder
1,527
22.3% fatal · 34.3% engine-initiated
Non-Builder (confirmed)
286
39.9% fatal · 30.1% engine-initiated
Likely Non-Builder
1,926
22.0% fatal · 29.5% engine-initiated

Fatal % — Builder vs Non-Builder

Accident Count by Status

Test Flight Risk

Comparing initial/test flights against normal operations

Test / First Flights
1,603
18.1% of all homebuilt accidents
Test Flight Fatal %
28.8%
vs 26.6% for normal ops
Engine-Initiated (Test)
33.9%
Engine events in test flight accidents
Builder Error (Test)
11.7%
Construction/installation errors surface on test flights

What This Means

About 18% of homebuilt accidents happen during test flights or the early hours of a new aircraft's life. Engine-initiated accidents account for 33.9% of test flight accidents vs the fleet average. Non-builder pilots who purchase completed homebuilts have a significantly higher fatal accident percentage (39.9%) compared to builder-pilots (30.2%), which may be related to unfamiliarity with the aircraft's systems, differences in maintenance awareness, or other factors not captured in this data.