Article
Rates and Causes of Accidents for General Aviation Aircraft Operating in a Mountainous and High Elevation Terrain Environment
Accident Analysis & Prevention
(2017)
Abstract
Background
Flying over mountainous and/or high elevation terrain is challenging due to rapidly changeable visibility, gusty/rotor winds and downdrafts and the necessity of terrain avoidance. Herein, general aviation accident rates and mishap cause/factors were determined (2001–2014) for a geographical region characterized by such terrain.
Methods
Accidents in single piston engine-powered aircraft for states west of the US continental divide characterized by mountainous terrain and/or high elevation (MEHET) were identified from the NTSB database. MEHET-related-mishaps were defined as satisfying any one, or more, criteria (controlled flight into terrain/obstacles (CFIT), downdrafts, mountain obscuration, wind-shear, gusting winds, whiteout, instrument meteorological conditions; density altitude, dust-devil) cited as factors/causal in the NTSB report. Statistics employed Poisson distribution and contingency tables.
Results
Although the MEHET-related accident rate declined (p < 0.001) 57% across the study period, the high proportion of fatal accidents showed little (40–43%) diminution (χ2 = 0.935). CFIT and wind gusts/shear were the most frequent accident cause/factor categories. For CFIT accidents, half occurred in degraded visibility with only 9% operating under instrument flight rules (IFR) and the majority (85%) involving non-turbo-charged engine-powered aircraft. For wind-gust/shear-related accidents, 44% occurred with a cross-wind exceeding the maximum demonstrated aircraft component. Accidents which should have been survivable but which nevertheless resulted in a fatal outcome were characterized by poor accessibility (60%) and shoulder harness under-utilization (41%).
Conclusion
Despite a declining MEHET-related accident rate, these mishaps still carry an elevated risk of a fatal outcome. Airmen should be encouraged to operate in this environment utilizing turbo-charged-powered airplanes and flying under IFR to assure terrain clearance.
Keywords
- general aviation accidents,
- mountain accidents,
- fatal accidents,
- general aviation,
- survivability
Disciplines
Publication Date
October, 2017
DOI
https://doi.org/10.1016/j.aap.2017.03.017
Citation Information
Marisa Aguiar, Alan Stolzer and Douglas D. Boyd. "Rates and Causes of Accidents for General Aviation Aircraft Operating in a Mountainous and High Elevation Terrain Environment" Accident Analysis & Prevention Vol. 107 (2017) p. 195 - 201 ISSN: 0001-4575 Available at: http://works.bepress.com/alan_stolzer/25/