What the study found
The study found that low-level helicopter accidents in the U.S. had different fatality patterns depending on the type of operation. In particular, Part 91 general aviation flights had a higher proportion of fatal accidents than Part 137 aerial application flights.
Why the authors say this matters
The authors suggest that low-level helicopter training should include low-altitude autorotations in simulators, because this emergency procedure may help in this flight phase. They specifically conclude that this recommendation is important for Part 91 operations.
What the researchers tested
The researchers analyzed 403 helicopter accidents that occurred during low-level flight in the U.S. between January 1, 2009, and December 31, 2022. They compared accident causes and outcomes by type of flight operation and used logistic regression to assess fatality while controlling for other factors.
What worked and what didn't
Among low-level flights, the proportion of fatal accidents was 30% for Part 91 operations and 12% for Part 137 operations. Logistic regression showed that fatal accidents were significantly more likely in Part 91 operations, while total flight hours was not a significant factor for estimating fatality.
What to keep in mind
The summary does not describe other limitations beyond the study’s focus on U.S. low-level helicopter accidents from 2009 to 2022. The results are specific to the operation types and factors analyzed in the abstract.
Key points
- 403 U.S. helicopter accidents during low-level flight were analyzed.
- Part 91 flights had a 30% proportion of fatal accidents.
- Part 137 flights had a 12% proportion of fatal accidents.
- Logistic regression found fatal accidents were significantly more likely in Part 91 operations.
- Total flight hours was not a significant factor in estimating fatality.
- The authors recommend simulator training with low-altitude autorotations, especially for Part 91 operations.
Disclosure
- Research title:
- Low-level helicopter fatalities were higher in Part 91 operations
- Authors:
- Alex de Voogt, Teck Chen Koh, Yi Lu
- Institutions:
- Drew University, Drew University, Drew University
- Publication date:
- 2026-04-07
- OpenAlex record:
- View
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