Introduction
Introduction |
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| Synopsis: | This page presents some basic information about flight safety and introduces the concept of Cockpit Task Management. | ||
| Keywords: | cockpit task management, CTM, task management, attention, attention management, workload, strategic workload management, human factors, engineering psychology, cognitive psychology, aviation, flight deck, timesharing, multitasking, introduction | ||
| Authors: | |||
| Kurt Colvin | <colvin@engr.orst.edu> | Department of Industrial and Manufacturing Engineering, Oregon State University, Corvallis, Oregon, USA | |
| Ken Funk | <funkk@engr.orst.edu> | Department of Industrial and Manufacturing Engineering, Oregon State University, Corvallis, Oregon, USA | |
| Last Update: | 14 July 1999 | This is a Work in Progress and its contents are subject to continual revision. | |
In the late 1990s, there is evidence that air travel is, statistically speaking, a very safe form of transportation. However, this was not always the case. In the 1950s, when commercial jet transport was introduced, the worldwide accident rate approached 30 accidents per million departures. By the end of 1997, that rate has dropped to approximately 1.4 accidents per million departures (Boeing, 1998).
This decrease can be attributed to improved aircraft technologies, improved air traffic control (ATC), industry infrastructure, operations and maintenance procedures, training and regulations. Although these improvements are significant, and the accident rate is relatively low, it has been stable for approximately the last 20 years. The leveling of the accident rate has occurred despite innovations like improved computerized flight simulators, expanded radar coverage, high-tech devices that warn pilots of nearby aircraft, threatening proximity to terrain, precarious aircraft altitude, and hazardous weather and wind-shear conditions. It is sobering to realize that if Boeing’s and Airbus’s worldwide aviation traffic growth projections of 5%, compounded annually, are accurate, one major accident each week will occur by 2014 (Flight Safety Foundation, 1998).
The aviation industry strives for continuous safety improvements through many channels including better pilot training, better aircraft inspection and maintenance techniques, and new safety technologies. In the next century, for example, all commercial jets will use satellites to navigate and communicate their positions to air-traffic controllers on the ground; a tremendous advantage over ground-based navigation aids and radar that lose "sight" of planes once they fly beyond the horizon.
Additionally, aviation industry organizations around the world are working together to reduce the accident rate. For example, in the U.S., airlines, labor unions, and manufacturers have joined the FAA in a Commercial Aviation Safety Team (CAST) that is working to achieve an 80 percent reduction in the rate of fatal commercial accidents of the next 10 years (Boeing, 1999).
So where will these safety improvements come from? Mechanical equipment in aircraft, such as engines, hydraulic systems, and electrical systems have many years of development and refinement in their history. Manufacturing processes used for building aircraft use the latest materials and technologies and produce precise and consistent components, which allow for aircraft to be assembled according to very high tolerances and exceptional quality. There are continually small improvements in these areas, yet this will probably not be the source for a large reduction in the accident rate.
Inside the aircraft, the instruments, avionics and electronics have also evolved to show significant improvements over the past several decades. Glass cockpits with integrated displays, Flight Management Systems (FMS) and autopilots are highly reliable and allow the pilot to fly the aircraft more precisely, economically and with improved safety. Each year, there are a number of new technologies introduced into the cockpit with promises of improved safety. However, with these new devices, experts are concerned about the changing role of the human from an active pilot to a system monitor. This has been a source of considerable debate for many years (Wiener and Curry, 1980). However, many experts agree that adding more technology and automation to the cockpit may actually decrease aviation safety in the future by removing the human, with his unique qualities, from a decision-making role in the cockpit.
If the safety improvements are not likely to come from the aircraft hardware, then how can the accident rate be reduced?
At the risk of repeating an already well known fact, flight crew error has been identified in as a primary cause in approximately 70% of all hull loss accidents of commercial jet aircraft (Boeing, 1998). This figure appears to be even higher (82%) in a study conducted by the Flight Safety Foundation which analyzed 287 approach and landing accidents between 1980 and 1996 (Flight Safety, 1999).
Given these statistics and the desire to reduce the accident rate, it appears obvious that perhaps the most rational area to look for improvements in aviation safety is in the nature of human errors in the cockpit.
In some cases, a flightcrew error is an error in performing a task in one of the following categories:
But in other cases, flightcrews commit errors in managing tasks. The ordering of tasks represented by the above list reflects a general ordering of tasks by importance, and flightcrews attempt to allocate their attention to multiple, competing tasks consistently with that ordering, subject to other factors which are discussed elsewhere in this website. But they occasionally fail to do so, sometimes with catastrophic results.
We call the process of managing tasks Cockpit Task Management (CTM) and have been studying CTM and experimenting with computational aids to facilitate it for several years. We have found that CTM is a significant factor in aviation safety: CTM errors may be found in a large portion of aircraft accidents and incidents. We have also found that CTM performance can be improved and CTM errors reduced by computational aids we have developed and evaluated in part-task simulators. But to have a positive effect in actual line operations, we must understand CTM better.
The remainder of this website describes our continuing efforts to understand and facilitate Cockpit Task Management.
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Listed below, most recent first, are changes made to this page since its creation.