NTSB · Safety Recommendation
Safety Recommendation A-12-041
Recommendation
TO THE EXPERIMENTAL AIRCRAFT ASSOCIATION: Work with your membership, aircraft kit manufacturers, and avionics manufacturers to develop standards for the recording of data in electronic flight displays, engine instruments, or other recording devices to be used in support of flight tests or continued airworthiness of experimental amateur-built aircraft.
Safety Issue and Context
Experimental amateur-built (E-AB) aircraft represent nearly 10 percent of the U.S. general aviation fleet, but these aircraft accounted for approximately 15 percent of the total-and 21 percent of the fatal-U.S. general aviation (GA) accidents in 2011. Experimental amateur-built aircraft represent a growing segment of the United States' general aviation fleet-a segment that now numbers nearly 33,000 aircraft. The National Transportation Safety Board (NTSB) undertook this study because of the popularity of E-AB aircraft, concerns over their safety record, and the absence of a contemporary and definitive analysis of E-AB aircraft safety.
The study employed several different methods and data collection procedures to carefully examine this segment of U.S. civil aviation. This comprehensive approach resulted in a detailed characterization of the current E-AB aircraft fleet, pilot population, and associated accidents. Four sources of data formed the basis of this study. First, the NTSB performed a retrospective analysis of accident and activity data over the last decade to compare the accident experience of E-AB aircraft with that of similar non-E-AB aircraft used in similar GA flight operations.
Second, the NTSB conducted in-depth investigations of all E-AB aircraft accidents during 2011, which provided a case-series of accidents for more detailed analysis. Third, a broad survey of the community of aircraft owners and builders was conducted by the Experimental Aircraft Association (EAA) in July and August 2011, and the data were made available to the NTSB for analysis to understand the population of E-AB aircraft builders and owners.
Finally, discussions with EAA representatives, Federal Aviation Administration (FAA) officials, E-AB aircraft builders and owners, kit manufacturers, and representatives of E-AB aircraft type clubs provided insights on E-AB aircraft safety issues and solutions.
Response History
July 16, 2025 · Recipient Response · Experimental Aircraft Association
-From Jack J. Pelton, CEO and Chairman of the Board: For more than 70 years, the Experimental Aircraft Association (EAA) has contributed significantly to the continual improvement of the general aviation safety record. When the NTSB approached us in 2011 with the intent to study the root causes of experimental amateur-built aircraft fatal accidents, we agreed to support the effort. We assisted the NTSB by completing survey work that resulted in the 2012 Safety Study: The Safety of Experimental Amateur-Built Aircraft. In the past 13 years, EAA has been actively working to address the recommendations designated to us in this study and additional recommendations directed to us in 2021.
We have made significant progress and are continually working to improve the experimental safety record, as demonstrated by the reduction in experimental aircraft fatal accidents. To wit, in FAA Fiscal Year 2012 there were 73 fatal accidents in experimental aircraft. In Fiscal Year 2024, there were 37 accidents. This is despite the hours flown in experimental aircraft increasing by more than 350,000 from Calendar Years 2012 to 2023. We are not resting on our laurels by any means. There is ongoing involvement with the General Aviation Joint Safety Committee (GAJSC) to find non-regulatory solutions to improving safety records in general aviation.
EAA has created, promoted, and helped to implement the usage of multiple safety improvement tools in the past five years, including the EAA Flight Test Manual 2.0, which creates a framework for flight testing a homebuilt aircraft and is now part of a formal task-based flight testing program incorporated, optionally, into homebuilt operating limitations.
Additionally, EAA has published a guide for non-builder owners of experimental aircraft, to assist prospective buyers and owners of experimental amateur-built aircraft. This non-builder, or “second owner” demographic, was identified as a significant opportunity for improvement in the 2012 NTSB safety study. There is ongoing involvement with the GAJSC to find non-regulatory solutions to improving general aviation safety records.
In this communication, we respond to the safety recommendations and provide updates on the progress to address the recommendations since they were issued:
EAA worked with the three major avionics manufacturers for experimental aircraft to standardize their data recording rate to at least 1 Hz. This allows most homebuilders with modern avionics suites to record all data from test flights, as well as ongoing flight quality assessment through third-party service providers.