Developing a Methodology for Assessing Safety Programs Targeting Human Error in Aviation

There is a need to develop an effective methodology for generating comprehensive intervention strategies that map current and proposed safety programs onto well-established types of human error. Two separate studies were conducted using recommendations from NTSB accident investigations and several joint FAA and industry working groups. The goal of the studies was to validate a proposed framework for developing and examining safety initiatives that target human error in aviation. The results suggest five approaches to reducing human factors associated with aviation accidents. When combined with the Human Factors Analysis and Classification System, the resulting Human Factors Intervention Matrix will provide a useful tool for evaluating current and proposed aviation safety programs

The Effect of Combat on Aircrew Subjective Readiness and LSO Grades During Operation Desert Shield/Storm

The effect of operational tasking on aircrew readiness during combat operations continues to be an area of intense investigation within the U.S. Navy. The recent Persian Gulf War provided a unique opportunity to collect data examining aircrew work/rest cycles and operational tasking in a combat environment. For 4 consecutive weeks during Operations Desert Shield and Desert Storm, 18 A-6 and 18 F-14 aviators onboard the USS AMERICA (CV-66) completed daily work/rest logs of their activities while conducting operations from the Red Sea. Activities on the work/rest logs were coded to a resolution of one-half hour. Several flight parameters were also obtained including: 1) takeoff and landing time, 2) flight duration, 3) mission type, 4) consecutive days during which a flight occurred, 5) landing signal officer (LSO) scores, and 6) arresting wire engaged on landing. In addition, after each mission aircrew provided a subjective assessment of the amount of time that they needed to rest before another air-to-ground strike mission could be flown (a measure of subjective readiness). Multiple regression analysis indicates that flight duration, the number of flights per day, and the time-of-day that the flight occurred, impact heavily on subjective evaluations of aircrew readiness. Few consistent relationships were observed between the independent measures and LSO grades. The data obtained here represent a unique look at aircrew work/rest patterns as they effect aircrew readiness during armed conflict. These data provide unique and valuable information to air wing commanders and senior mission planners when tasking carrier-based aviators. In addition, these data provide an essential database for squadron and air wing flight surgeons to draw upon when assessing aircrew readiness

The Human Factors Analysis and Classification System--HFACS

Human error has been implicated in 70 to 80% of all civil and military aviation accidents. Yet, most accident reporting systems are not designed around any theoretical framework of human error. As a result, most accident databases are not conducive to a traditional human error analysis, making the identification of intervention strategies onerous. What is required is a general human error framework around which new investigative methods can be designed and existing accident databases restructured. Indeed, a comprehensive human factors analysis and classification system (HFACS) has recently been developed to meet those needs. Specifically, the HFACS framework has been used within the military, commercial, and general aviation sectors to systematically examine underlying human causal factors and to improve aviation accident investigations. This paper describes the development and theoretical underpinnings of HFACS in the hope that it will help safety professionals reduce the aviation accident rate through systematic, data-driven investment strategies and objective evaluation of intervention programs

The Effect of Combat on the Work/Rest Schedules and Fatigue of A-6 and F-14 Aviators During Operation Desert Shield/Storm

During Operation Desert Shield/Storm, A-6 and F-14 aviators aboard USS AMERICA completed daily activity logs and provided subjective measures of fatigue. Aviators flew frequently at night during Desert Storm, but without substantial sleep-related fatigue or problems. A likely contributing factor was the large number of naval aviation assets brought into the combat theater, allowing workload to be shared and activity and rest times to be properly managed. However, raster plots of the data suggest that there may have been an additional contributing factor. The AMERICA travelled eastward from the east coast through seven time zones and became involved in combat shortly after arrival in the Red Sea. This pattern of travel may have given AMERICA\u27s aircrew flying at night a significant advantage over those already operating in the area. If the circadian clocks of AMERICA\u27s aircrew had not fully adapted to local time upon arrival, local night fights were closer to being evening flights on body time. Aircrew may not have been experiencing troughs in their circadian cycles during local night fights, at least for the early part of the war. This would result in a smaller physical challenge to overcome. This situation would likely not hold for aircrew who had been in the region for longer periods, nor would it occur for future conflicts closer to the originating time zone. We recommend the incorporation into battle strategy of information about the circadian phase of combatants (as well as sleep logistics) to help prepare them to fight at suboptimal times

A Human Error Analysis of General Aviation Controlled Flight Into the Terrain Accidents Occurring Between 1990-1998

Although all aviation accidents are of interest to the Federal Aviation Administration (FAA), perhaps none is more disconcerting than those in which a fully functioning aircraft is inexplicably flown into the ground. Referred to as controlled flight into terrain (CFIT), these accidents continue to be a major safety concern within aviation, in particular general aviation (GA). A previous study as part of the FAA\u27s Safer Skies agenda examined 165 CFIT accidents using root cause analysis and developed 55 interventions to address their causes. While the study represented the work and opinions of several experts in the FAA and industry, the findings might have benefited from a more detailed human error analysis involving a larger number of accidents. In this study, five pilot-raters independently analyzed more than 16,500 GA accidents occurring between 1990-1998 using the Human Factors Analysis and Classification System (HFACS). Of the GA accidents examined, 1407 were identified as CFIT and compared with non-CFIT accidents using HFACS. The analysis revealed a number of differences in the pattern of human error associated with CFIT accidents. Findings from this study support many of the interventions identified by the CFIT Joint Safety Analysis Team (JSAT) and Joint Safety Implementation Team (JSIT), permitting safety professionals to better develop, refine, and track the effectiveness of selected intervention strategies

Effect of a No-Smoking Policy Aboard a U. S. Navy Aircraft Carrier

The purpose of this study was to assess the impact if a no-smoking policy aboard the Atlantic Fleet carrier USS THEODORE ROOSEVELT (CVN-71) on the crew\u27s smoking behavior and exposure to ETS, as well as crew attitudes regarding smoking policy. All crew members aboard ship were asked to participate in a baseline and post-intervention survey

A Human Error Analysis of Commercial Aviation Accidents Using the Human Factors Analysis and Classification System (HFACS)

The Human Factors Analysis and Classification System (HFACS) is a general human error framework originally developed and tested within the U.S. military as a tool for investigating and analyzing the human causes of aviation accidents. Based upon Reason’s (1990) model of latent and active failures, HFACS addresses human error at all levels of the system, including the condition of aircrew and organizational factors. The purpose of the present study was to assess the utility of the HFACS framework as an error analysis and classification tool outside the military. Specifically, HFACS was applied to commercial aviation accident records maintained by the National Transportation Safety Board (NTSB). Using accidents that occurred between January 1990 and December 1996, it was demonstrated that HFACS reliably accommodated all human causal factors associated with the commercial accidents examined. In addition, the classification of data using HFACS highlighted several critical safety issues in need of intervention research. These results demonstrate that the HFACS framework can be a viable tool for use within the civil aviation arena

Work/Rest Schedules and Performance of S-3 Aviators During Fleet Exercise 1992

We examined the effect that a fleet exercise has on the work/rest patterns, fatigue, and cognitive performance of S-3 aviators. For 10 days during Fleet Exercise 1992, 21 S-3 aviators from CARRIER AIR WING SEVENTEEN (CVW-17) aboard USS SARATOGA (CV-60) completed detailed daily-activity logs while performing their usual tasks. Subjective measures of fatigue, quality of rest, and sleep need were also collected. A subset of eight aviators completed a brief battery of computer tasks as soon before flying as possible and again after flight debrief. Results indicated that, although the fleet exercise appeared to be below average in difficulty, there were statistically significant performance changes from pre- to post-flight on a fatigue-sensitive reaction time task. Average sleep onset was delayed over the course of the fleet exercise, peaking at past 0300 by day 8. A continuation of this pattern could lead to circadian desynchrony and serious sleep problems. Responses to questions on fatigue, sleep need, and readiness to fly a strike mission were consistent with circadian factors. Further research in this area is needed to determine the magnitude and extent of this problem. We recommend that additional data be collected on a variety of fleet exercises with particular effort made to include S-3 squadrons affected by the reductions in manning and increased tasking. The additional data will provide an objective means of fully evaluating the impact of these operational changes on the S-3 community

Work/Rest Schedules and Performance of F/A-18 Aviators During Fleet Exercise 1992

As a continuation of our previous work during Operation Desert Shield/Storm, we examined the effect a fleet exercise has on the work/rest patterns, fatigue, and cognitive performance of F/A-18 aviators. For 10 days during Fleet Exercise 1992, 25 pilots from VFA-81 and VFA-83 completed daily work/rest logs while performing their usual tasks. Subjective measure of fatigue, quality of rest, and sleep need were also collected. A subset of these F/A-18 pilots completed a brief battery of cognitive tasks as soon before flying as possible and again after the flight debrief. As a group, the pilots were adequately rested with little or no problem sleeping, and they operated on a typical work/rest schedule for deployed F/A-18 aviators. However, in some instances during which late night missions were flown, sleep onset was delayed, coupled with shorter sleep periods and additional sleep problems. Several work/rest and flight related parameters were related to subjective measures of aircrew combat readiness, including: (1) flight quartile, (2) number and order of flights per day, (3) flight duration, (4) flight hours 72 h before a mission, (5) total work 24 h before a mission, (6) total sleep 12 h before a mission, and (7) total hours continuously awake before a mission. All seven variables significantly contributed to a multiple regression model derived using subjective strike delay, accounting for 51 percent of the variance. Moreover, statistically significant changes were observed from pre- to post-flight on a fatigue-sensitive reaction time task

Upon Closer Inspection...U.S. Naval Aviation Mishaps 1977-1992

The U.S. Navy/Marine Corps Class A flight/flight-related mishap rate has declined markedly since 1953. However, analysis of all Class A, B, and C naval aviation mishaps between January 1977 and December 1992 reveals that mishaps attributable to human factors have declined at a slower rate than those attributable to mechanical/environmental factors. Upon closer inspection of the data, marked differences were evident between single-piloted and dual-piloted aircraft. Global trends were primarily a function of single-piloted aircraft, particularly when phase of flight and time of day that a mishap occurred are considered. Previously reported improvement in aviation safety may be biased by global assessments that do not differentiate among mishap causal factors and single- versus dual-piloted aircraft