title: Causes of fatal accidents for instrument-certified and non-certified private pilots.
abstract: Instrument certification (IFR) enhances a pilot's skills in precisely controlling the aircraft and requires a higher level of standards in maintaining heading and altitude compared with the less stringent private pilot certificate. However, there have been no prior studies to compare fatal accident causes for airmen with, and without, this rating, The NTSB accident database was queried for general aviation fatal accidents for private pilots with, and without IFR certification. Exact Poisson tests were used to calculate whether two rate parameters were equal (ratio of 1), normalized to the number of IFR-rated pilots and flight hours in the given time period. Proportion tests were used to determine whether there were significant differences in fatal accident causes between IFR-certified and non-certified pilots. A logistic regression for log-odds success was used in determining the trend and effect of age on fatal accident rates. IFR certification was associated with a reduced risk of accidents due to failure to maintain obstacle/terrain clearance and spatial disorientation for day and night operations respectively. In contrast, the likelihood of fatal accident due to equipment malfunction during day operations was higher for IFR-certified pilots. The fatal accident rate decreased over the last decade for IFR-certified but not for non-IFR-certified private pilots. However, the overall accident rate for IFR-certified private pilots was more than double that of the cohort lacking this certification. Finally, we found a trend for an increased fatality rate with advancing age for both group of pilots. Our findings informs on where training and/or technology should be focused. Both training for aerodynamic stalls, which causes over a quarter of all fatal accidents, should be intensified for both IFR-certified and non-certified private pilots. Similarly, adherence to minimum safe altitudes for both groups of pilots should be encouraged toward reducing the fatal accidents rate due to failure to maintain obstacle/terrain clearance. For night operations, the high percentage of accidents due to spatial disorientation for non-IFR certified airmen suggests that additional training be required for such operations or such flights carry restrictions for this subset of pilots.
authors.affiliation: University of California, Berkeley, CA, United States. Electronic address: bobshao@berkeley.edu.
authors.forename: Bob Siyuan
authors.initials: BS
authors.lastname: Shao
authors.affiliation: University of Texas Graduate School of Biomedical Sciences and MD Anderson Cancer Center, Houston, TX, United States. Electronic address: mguindani@mdanderson.org.
authors.forename: Michele
authors.initials: M
authors.lastname: Guindani
authors.affiliation: University of Texas, Houston, TX, United States. Electronic address: douglas.boyd@uth.tmc.edu.
authors.forename: Douglas D
authors.initials: DD
authors.lastname: Boyd
mesh_terms: D000060:Accidents, Aviation / Q000401:mortality / Q000706:statistics & numerical data*; D000328:Adult; D001359:Aviation / Q000193:education / Q000592:standards*; D002568:Certification / Q000706:statistics & numerical data*; D006801:Humans; D016015:Logistic Models; D008875:Middle Aged; D012307:Risk Factors; D013997:Time Factors
keywords: Fatal accidents; Flight training; General aviation accidents; Instrument certification