National Transportation Safety Board Database Research Articles

Survival After Ditching in Motorized Aircraft, 1989-2022.

INTRODUCTION: Although an unintended aircraft landing on water (referred to as ditching) is a rare event, the potential for occupant injury/fatality increases immediately following the event due to adverse conditions. However, to date, few studies have addressed the subject. Herein, ditching events and post-ditching survival were investigated.METHODS: Ditchings (1982-2022) in the United States were identified from the National Transportation Safety Board database. Occupant injury severity, aircraft type, pilot experience, flight conditions, and number of occupants were extracted. Poisson distribution, the Chi-squared test (2-tailed), Mann-Whitney U test, and Kruskal-Wallis one-way analysis of variance were employed.RESULTS: A total of 96 ditchings were identified. A systematic survey was hampered by the lack of a standardized reporting matrix in the reports. In total, 77 reports were included in the analysis. Across all ditchings, 128 of 169 (76%) occupants survived ditching and were rescued. Importantly, the initial ditching event was survived by 95% of all occupants. However, 32 (19%) occupants died post-ditching by drowning (21/32 cases) or for undetermined reasons. Considering probability per ditching event, in 26 (34%) of all ditchings, one or more occupants was/were fatally injured.DISCUSSION: Initial survival of the emergency ditching is high. Drowning was the leading cause of death after ditching and reduced the overall survival to 76%. Further investigation is needed to identify risk factors for fatal outcomes and/or improve probability of survival after ditching.Schick VC, Boyd DD, Hippler C, Hinkelbein J. Survival after ditching in motorized aircraft, 1989-2022. Aerosp Med Hum Perform. 2024; 95(5):254-258.

A Regional Approach to Aviation Accident Analysis in Hawaii

BACKGROUND: The geographical circumstances, such as mountains and ocean, and specific aviation operations, especially sightseeing, make the state of Hawaii stand out in aviation. These conditions support a regional approach to aviation accident analysis.METHODS:Accident reports of aviation accidents collected from the online National Transportation Safety Board database were used to study a 10-yr time period between 2008 and 2017.RESULTS: There was a significantly higher proportion of fatal accidents during night, dawn, and dusk (6 out of 13) than during daytime (13 out of 74). In addition, a significantly higher proportion of accidents occurred in diminished light conditions among fixed wing airplanes (11 out of 48) as opposed to other aircraft (2 out of 39), and among twin-engine aircraft (6 out of 12) as opposed to single-engine aircraft (7 out of 74). Out of seven weight-shift control aviation accidents, four were reported to be fatal; the latter all took place during instruction.DISCUSSION: Light conditions are the main environmental concern in Hawaiian aviation that particularly affect twin-engine fixed wing aircraft and warrant specific attention in advanced training exercises. Helicopter operations have not exhibited a diminished safety record since the 1990s, showing a lasting effect of a previous safety intervention. A relatively high number of fatal weight-shift control aircraft accidents requires further research in other parts of the United States.de Voogt AJ, Brause J. A regional approach to aviation accident analysis in Hawaii. Aerosp Med Hum Perform. 2023; 94(3):131-134.

Instrument flying infrequency and weather decision-making for general aviation pilots -implications for flight safety in degraded visibility

IntroductionInstrument-rated private pilots (PPL-IFRs) are trained to fly in degraded visibility (where visual references are lost) and, towards maintaining proficiency, required to complete 6 instrument approaches in as many months. Nevertheless, operations in such weather carry an elevated risk of a fatal accident. Two hypotheses were advanced: (i) the majority of PPL-IFRs complete fewer than 6 instrument approaches/6 months and (ii) that a subset of such aviators still depart into such weather. Methods: Instrument approaches for a group of light aircraft in single PPL-IFR ownership (aircraft/owners) in the state with the largest count of single piston engine aircraft (Texas) was determined using Automatic Dependent Surveillance-Broadcast (ADS-B) data. Departure aerodrome weather flight category was per the Iowa State University database. IMC accidents were identified from the National Transportation Safety Board database and rates determined using GA fleet time. Statistical testing used Poisson Distribution, Chi-Square and Mann-Whitney U tests. Results: Over the Aug 2020-Mar 2021 period, 1,684 flights involving 106 aircraft/owners were ADS-B-tracked. Of these aircraft/owners, 81.2% completed < six approaches (median = 1.5). Importantly, for aircraft/owners completing < six approaches in the preceding 6 months, 24% departed into obscuration. Conclusions: This study demonstrates that, for the state most populous for reciprocating engine aircraft, the majority of aircraft in single PPL-IFR ownership fail to complete 6 in-flight instrument approaches/6 months. Nevertheless, some of these aircraft/owners elect to undertake flights in degraded visibility. From a practical perspective, PPL-IFRs unable to maintain instrument currency should be cautioned on the risks of operating in degraded visibility.

Analysis of Air Taxi Accidents (20042018) and Associated Human Factors by Aircraft Performance Class

INTRODUCTION: Air taxis conduct nonscheduled transport and employ aircraft in various performance categories hereafter referred to as low, medium, and high performance, respectively. No study has yet addressed fixed-wing air taxi safety by performance category. Herein, we compared accident rates/occupant injury across air taxi airplane fleets grouped by performance category and identified human factors contributing to fatal accidents for airplanes in that category with the highest mishap rate.METHODS: Accidents (20042018) in the United States were identified from the National Transportation Safety Board database. General Aviation/Part 135 Activity Surveys provided annual fleet times. Fatal accident contributing factors were per the Human Factors Classification System (HFACS). Statistics utilized Poisson distributions, Chi-Square/Fisher, and Mann-Whitney tests.RESULTS: There were 269 air taxi mishaps (53 fatal) identified. Over the 15 yr, the accident rate (1.10/million flight hours-all categories) declined 50%, largely due to a reduction in medium/high performance category airplane crashes. However, little temporal change was observed for low performance airplanes (1.5/million flight hours) and injury severity trended higher. At the aircrew/physical environment levels, HFACS revealed decision (improper choices), skill-based (stick and rudder) and perceptual (night, instrument conditions) errors contributing to > 60% of fatal accidents involving low performance airplanes. At the organizational level, failing to correct problems, time pressures, and incentive systems contributed to 16% of fatal mishaps.CONCLUSION: Safety deficits remain for the low performance category air taxi fleet warranting increased pilot instrument flight training/utilization of the mandatory 3-axis autopilot in degraded visibility. Safety culture improvements to address issues of personnel/equipment/training deficiencies, failing to correct problems, and time pressures/a safety-compromising incentive system all need to be addressed.Budde D, Hinkelbein J, Boyd DD. Analysis of air taxi accidents (20042018) and associated human factors by aircraft performance class. Aerosp Med Hum Perform. 2021; 92(5):294302.

Narrative Analysis of Runway Incursion Reports in the National Transportation Safety Board Database To Identify Contributing

A runway incursion occurs when an aircraft, ground vehicle, or a pedestrian is incorrectly present on the runway. This incorrect presence can lead to a collision resulting in fatal injuries and aircraft damage. Despite the aviation community’s measures to reduce incursions, they continue increasing. Most runway incursions are a result of human error. Our limited knowledge of these human errors and their causes is hindering our ability to reduce runway incursions. While previous researchers have analyzed past runway incursions to identify types of human error, we still know little about the causes of these errors. The narratives in the NTSB database often provide detailed information to identify human errors and their causes. In this paper, we analyze the narratives of runway incursion reports in the NTSB database. We use task analysis to map human error to tasks they perform, and map the causes of these errors to the error itself.

A comparison of special category light-sport and corresponding type-certificated aircraft safety

IntroductionThe special category light sport airplane (light sport) sector of general aviation has grown 10-fold in as many years with solo operations requiring only a sports pilot's certificate. With little research on light sport airplane safety, the study objective was to compare light sport and type-certificated airplane accident rates. MethodAccidents were identified from the National Transportation Safety Board database. Statistics employed Poisson distribution/proportion analyses/Mann–Whitney U-tests. ResultsFor the 2009–2015 period, the light sport airplane accident rate (fatal/non-fatal combined) was >15-fold higher than comparable type-certificated aircraft, undiminished over time. The excessive light sport airplane accident rate was associated with inferior airman experience (time-in-type, certification). Mishaps were most frequent during landing (40%) and, of these, nearly half were due to a deficiency in the flare. There were a dis-proportionate number of trainees involved in landing accidents compared with mishaps for other phases of operations. ConclusionTowards improving safety, additional light sport training with emphasis on landings and a focus on the flare and directional control is warranted. Practical applicationIn the confines of the present study considering that landing mishaps, the most common accident cause, are often related to deficiencies in the flare and loss-of-directional control, instructors should ensure that airmen have mastered these aspects of landing and, for trainees, acquired the appropriate visual monocular cues.

Copycats in Pilot Aircraft-Assisted Suicides after the Germanwings Incident.

Aircraft-assisted pilot suicide is a rare but serious phenomenon. The aim of this study was to evaluate changes in pilot aircraft-assisted suicide risks, i.e., a copycat effect, in the U.S. and Germany after the Germanwings 2015 incident in the French Alps. Aircraft-assisted pilot suicides were searched in the U.S. National Transportation Safety Board (NTSB) accident investigation database and in the German Bundestelle für Flugunfalluntersuchung (BFU) Reports of Investigation database five years before and two years after the deliberate crash of the Germanwings flight into the French Alps in 2015. The relative risk (RR) of the aircraft-assisted pilot suicides was calculated. Two years after the incident, three out of 454 (0.66%) fatal incidents were aircraft-assisted suicides compared with six out of 1292 (0.46%) in the prior five years in the NTSB database. There were no aircraft-assisted pilot suicides in the German database during the two years after or five years prior to the Germanwings crash. The relative aircraft-assisted pilot suicide risk for the U.S. was 1.4 (95% CI 0.3–4.2) which was not statistically significant. Six of the pilots who died by suicide had told someone of their suicidal intentions. We consider changes in the rate to be within a normal variation. Responsible media coverage of aircraft incidents is important due to the large amount of publicity that these events attract.

Attention-Deficit/Hyperactivity Disorder and Fatal Accidents in Aviation Medicine

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder with symptoms of inattention and/or hyperactivity-impulsivity that interfere with functioning and/or development. ADHD occurs in about 2.5% of adults. ADHD can be an excluding medical condition among pilots due to the risk of attentional degradation and therefore impact on flight safety. Diagnosis of ADHD is complex, which complicates aeromedical assessment. This study highlights fatal accident cases among pilots with ADHD and discusses protocols to detect its presence to help to assess its importance to flight safety. To identify fatal accidents in aviation (including airplanes, helicopters, balloons, and gliders) in the United States between the years 2000 to 2015, the National Transportation Safety Board (NTSB) database was searched with the terms ADHD, attention deficit hyperactivity disorder, and attention deficit disorder (ADD). The NTSB database search for fatal aviation accidents possibly associated with ADHD yielded four accident cases of interest in the United States [4/4894 (0.08%)]. Two of the pilots had ADHD diagnosed by a doctor, one was reported by a family member, and one by a flight instructor. An additional five cases were identified searching for ADD [5/4894 (0.1%)]. Altogether, combined ADHD and ADD cases yielded nine accident cases of interest (0.18%). It is generally accepted by aviation regulatory authorities that ADHD is a disqualifying neurological condition. Yet FAA and CASA provide specific protocols for tailor-made pilot assessment. Accurate evaluation of ADHD is essential because of its potential negative impact on aviation safety.Laukkala T, Bor R, Budowle B, Sajantila A, Navathe P, Sainio M, Vuorio A. Attention-deficit/hyperactivity disorder and fatal accidents in aviation medicine. Aerosp Med Hum Perform. 2017; 88(9):871-875.

Bipolar Disorder in Aviation Medicine.

One of the most difficult challenges in aviation medicine is to diagnose, as early as possible, pilots with psychiatric disorders that may impair pilot performance and increase the risk of incidents and accidents. This diagnosis applies particularly to bipolar disorder (BD), where return to flying duty is not an option in the majority of cases. BD is a long-term mental disorder presenting remittent depressive, hypomanic, manic, or mixed episodes between low symptomatic or asymptomatic intermediate periods. Onset in most cases is in late teen or early adult years. Suicidal intentions and suicide risk are significantly elevated in individuals with BD compared to the general population. A systematic literature search was performed of BD and aviation accidents and the National Transportation Safety Board database of fatal general aviation accidents was searched. One case report and two database reports of interest from 1994 to 2014 were identified. The findings set a minimum frequency of BD in general aviation fatalities to be approximately 2 out of 8648 (0.023%) in the United States. The reported incidence may underestimate the real number of BD cases for several reasons, including the fact that the medical history of pilots is not always available or is sometimes not the primary interest of a safety investigation. This study suggests that the demarcation of psychiatric disorder related to fitness to fly is an important step in safety.Vuorio A, Laukkala T, Navathe P, Budowle B, Bor R, Sajantila A. Bipolar disorder in aviation medicine. Aerosp Med Hum Perform. 2017; 88(1):42-47.

Comparative Analysis of Accident and Non-Accident Pilots

The purpose of this study was to investigate potential differences between two pilot groups; the first was a sample of individuals who have not been involved in an accident and the second was a sample of pilots from the National Transportation Safety Board (NTSB) accident database. Factors investigated included flight time, pilot flight review status, pilot certification, employment as a professional pilot, gender, and age. This study was guided by the exigent literature on aviation accidents with a primary focus on general aviation pilot accident attributes. Non-accident pilot participation was solicited through various aviation-related websites and a total of 1,829 usable cases were collected. From the NTSB database, 19,821 cases were deemed to have all of the necessary variables for analysis. Mann- Whitney U tests found significant differences in age (U = 9377426.5, p < 0.001, r = 0.233) and flight time (U = 5501468.5, p < 0.001, r = 0.356). Logistic regression was then calculated to provide improved understanding of how the variables may be used to categorize pilots in accident and non-accident groupings. The model showed a significant improvement over random assignment (x2 [8] = 4912.89, p < 0.001) and was able to successfully identify 98.9% of accident pilots and 34.9% of non-accident pilots. Significant factors that were identified included that if an individual that was employed as a professional pilot (correlation value = -.388) or as his or her age decreased (correlation value = -.522), he or she is more likely to be within the accident pilot classification. The investigated variables showed some indication of predictive value and shed some insight onto what factors may be associated with accident risk. Suggestions for future research are also included.

Effect of HFACS and Non-HFACS-Related Factors on Fatalities in General Aviation Accidents Using Neural Networks

This study applied a backpropagation artificial neural network approach to investigate both the Human Factors Analysis and Classification System (HFACS)-related unsafe act tiers of factors and other non-HFACS factors in an attempt to recognize patterns for general aviation accident fatalities. Data were obtained from the HFACS database and extracted from the National Transportation Safety Board database from 1990 to 2002. Multiple neural network models were created and the best fit model was selected based on a sequence of criteria. A sensitivity analysis was performed on the validated model to rank the factors that lead to general aviation fatalities. Results are discussed and practical implications are given.

Gyroplane Accidents 1985–2005: Epidemiological Analysis and Pilot Factors in 223 Events

Gyroplanes (autogyros) are regarded as a relatively safe and stable type of general-aviation aircraft. The U.S. Federal Aviation Administration categorizes them as sport pilot/light sport aircraft, and reports of gyroplane accidents are included in a publicly available database. We hypothesized that issues related to pilot experience and aircraft maintenance would affect the severity of accidents as indicated by aircraft damage and fatalities. A search of the National Transportation Safety Board database for the period 1985-2005 yielded 223 reports of gyroplane accidents. Information from those reports was compiled and cross-referenced with pilot performance breakdowns and contextual information. The data was then analyzed using the Human Factors Analysis and Classification System. There was a strong effect of pilot experience on crash outcomes; compared to more experienced pilots, crashes involving pilots with less than 40 flight hours in the same make/model gyroplane were five times more likely to involve loss of control, twice as likely to destroy the aircraft, and four times more likely to involve fatalities. On the other hand, crashes involving pilots with more than 40 make/model hours were more likely to be related to perception-based performance breakdown. Maintenance issues were not found to play a significant role in this sample of crashes. The results support the hypothesis that pilot experience is a significant predictor of accident fatality in gyroplanes. Training that is adapted to the experience level of pilots as implemented in new FAA regulations for sport pilot and light sport aircraft (2004) may help to reduce the frequency and seriousness of gyroplane accidents.

Investigation of Alarm-Related Accidents and Incidents in Aviation

With increases in technology, pilots have assumed the role of system monitors. As such, they have become dependent upon sensor-based alarm signals, some of which are unreliable. Researchers have shown that unreliable alarms foster mistrust and complacency by operators, and may degrade flight tasks and alarm reactions. To supplement available laboratory investigations, we tabulated the number of events involving true, false, and missed alarms within the Aviation Safety Reporting System database, the National Transportation Safety Board database, and the U.S. Army's Aviation Safety database. We also separated the results by aircraft type, avionics, flight phase, and specific problem. Our investigation revealed that alarm-related problems occur frequently across flight environments, and that false alarms remain a significant concern in aviation. Given the pervasiveness of alarm-related problems, it is important that future researchers devote considerable effort to improve aviation alarm systems.