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Ergonomics within the civil aviation authority
Applied Ergonomics, 6.3, 171-172
Ergonomics within the Civil Aviation Authority Mary Lee, S. Ricketts and H. Stockbridge
For some while, civil aviation in the United Kingdom has received advice on human factors problems from the Institute of Aviation Medicine (Hopkin, 1970). For four years, however, the authors of this note were able to carry out sponsored projects from within. The objective was to provide a human factors service, in house, for the Civil Aviation Authority, through the Department of Operational Research and Analysis. The authors of this note constituted the working grade team. Research was numerical, in the OR style, rather than experimental. It was not always possible to bring to bear the full rigours of the statistical approach on practical problems. And here practicality means time and money - time in the sense of deadlines, money in the sense of budget and staff limitations. The six ad hoc studies to be described are all concerned with various aspects of air traffic control, namely: Selection of Air 1raffle Control Officers (ATCO's) Design of consoles Sector capacity Call sign confusion Job satisfaction Manpower planning
Selection of ATCO's There are currently some 1200 ATCO's in the UK. These officers have to be recruited, selected, trained, equipped, given an interesting job and provided with career prospects. Clearly it is important to begin by selecting the best men possible. Accordingly, an experimental battery of ability tests was given to the first five cadet courses at the College of Air Traffic Control (ATC), Hum. Performance on these tests was subsequently related to examination results and field reports. Recommendations have been made that those tests which were found to have the higher predictive values should be adopted - these have subsequently been accepted by management. Reference: Lee, M.S., Selection of ATCO cadets, DORA Communication 7207.
Design of consoles Five aspects of console design have received attention in the Directorate of Operational Research and Analysis, CAA. These five aspects are cost, suitability, reach, legibility and labelling. At first, consideration of a shared vertical radar display would seem to offer considerable economic and technical advantages. Two operators could work practically as cheaply as one, but paper studies suggest that the size of the displayed characters would have to be kept carefully in mind for adequate legibility. Obviously a larger label means that fewer can be displayed without overlap on a scope of
a given size. Reference: Ricketts, S.E., and Lee, Mrs M.S. (1974). A paper study to indicate, and where possible to assess the relative merits of single and shared vertical radar displays. DORA Communication 7404.
Sector capacity I. London Airport Traffic Control Centre (LATCC) Studies Air traffic movements in controlled airspace are currently increasing slightly each year. Even if in future more passengers travel in larger'planes and maintain a low growth rate, it is important to estimate ATC work load and capacity. One method of doing this is by self rating, though this has obvious shortcomings. A better method appears to be to employ an expert ATCO observer to gather objective ratings of 'busyness'. It is important to employ observers though, who will be acceptable to both ATCO's and management. Terminal Manoeuvering Area (TMA) SW and Daventry East sectors were studied in the summer of 1972, Daventry West, Daventry East and Clacton West in the summer of 1973. The objective assessment of 'busyness' can then be related to such factors as the number of aircraft handled, or to the proportion of time occupied by radiotelephone (R/T) etc, in order to provide a work load index. Reference: Smith, A.D.N. and Stamp, R.G. (1973). A method for estimating the capacity of air traffic sectors - an interim report. DORA Research Paper 7301.
2. Stimulation studies The objective rating method has been further used to investigate the staged introduction of sector consoles of the new Mediator ATC system. Simulation exercises of the various steps were analysed. Reference: Ricketts, S.E., and Lee, M.S. (1974). Mediator Stage I Sector Suite. The DORA analysis of simulated sector workload. EU 252 Report.
Call sign confusion From time to time, where two aircraft are proximate in time and space, one will act on the instructions intended for the other. Usually they have similar call signs, for example one might be BE 372 and the other BA 472. So far these occurrences have not resulted in disaster. Two lines of thought seem plausible, one that confusion depends on hearing, and two, that it depends on memory. Is one numer mistaken for another? Are numbers transposed in the memory? Possibly both? Reference: Ricketts, S.E. (1973). A review of the incidence and potential occurrences of call sign confusion in ATC radio telephony. DORA Research Paper 7302.
ATCO job satisfaction All controllers were asked to complete a questionnaire.
Applied Ergonomics September1975
171
The preliminary analysis has now been distributed to ATCO's and further action and studies have been undertaken. Reference: Clark, A.W. et al (1973). Human factors in ATC - an opinion survey of the ATCO class. DORA Report 7301.
Conclusion So much for the past. The future of ergonomics in the CAA now lies in the hands of a committee appointed for the purpose of considering that future.
Reference and external publications
Manpower planning
Hopkin, V.D. 1970 Human factors in the ground control of aircraft NATO AGARDograph No 142
A renewal theory type model has been used to represent the ATCO class in the ATC manpower system. Besides giving the age-grade structure of the ATCO class and the wastage rate, the model also provides a comparison of four different promotion policies from grade III to II in terms of promotion prospects and cost associated with the policies. Reference: Arif, M. (1972). Manpower planning in Air Traffic Control. A comparison of four alternative promotion policies for ATCO grades Ill to II. DORA Communication 7206.
Stockbridge, H.C.W. and Mary Lee 1973 Applied Ergonomics, 4.1,44-45. The psycho-social
Man and computer in process control
The human operator in process control
Elwyn Edwards and F.P. Lees. The Institution of Chemical Engineers, 16 BelgraveSquare, London SW1X 8PT, pp 303,
EIwyn Edwards and Frank P. Lees (Editors) Tay Ior & Francis Ltd, 10-14 Macklin Street, London WC2B 5NF,
£7.50
pp 480, £11.00
A comprehensive book reflecting the growing interest in the problems and functions of the operator and the mancomputer system accompanying the wider use of computer control of industrial processes. Throughout the work, the theme is not computerization but a proper division of labour between man and machine.
Many of the studies of the process operator referred to in the book above are reprinted in this collection of readings on the human operator in process control. This work arose from the commission given in 1970 by the Institution of Chemical Engineers to the editors to undertake an industrial research fellowship on the interaction between the process operator and computer. In this study it was realised that although much research had been done in this field, the work was not necessarily well known and much of it was in an inaccessible form. This book is a representative selection from the work and includes many of the classic papers.
Some of the sections included cover process control by man and computer, human factors in process control, functions performed by the operator and by computer, studies carried out on the process operator, reliability of the manmachine system in process control by computer, and the design of process control systems with operator and computer. The problems dealt with include the division of control tasks between man and computer, operator acceptance of the computer, monitoring by the operator, operator boredom and motivation, information display, computer consoles, and handling of emergency situations. Appropriately the book includes a review of human factors providing an introduction to this discipline, and some of the subjects treated are man-machine systems, allocation of function, task analysis, job design, selection, training, information display, manual control, control design, vigilance, decision making, physical environment, organizational factors, and man-computer interaction. There is a bibliography of ergonomic work and of computer control with some 3300 references classified under 170 headings.
172
AppliedErgonomics September 1975
consequences of aircraft noise. Stoekbridge, H.C.W. 1974 Applied Ergonomics, 5.3, 179, Letter. Statistical significance and the Noise & Number Index (NNI). Stockbridge, H.C.W. 1974 Bulletin of the British Psychological Society, 27, 556 Letter: Promotion theory.
Most of the papers cover experimental work on the process operator, the majority being concerned with field studies. There are 26 papers, which have been categorized in a table according to the type of study, the principle type of behaviour studied and the principle system aspect studied. The behaviour types include vigilance, monitoring, signal detection, information cycling, manual control, tracking, decision making, strategy development. scheduling, fault detection, and learning. The principle system aspects include allocation, of function, interface and control on design, information display, prototype production, task analysis, job design, training, man-compute interaction, and organizational and social factors. A wide range of processes was involved including paper mills, washing plant, baking ovens, arc furnaces, chemical plants, refinerys and nuclear reactors.
Ergonomics within the Civil Aviation Authority Mary Lee, S. Ricketts and H. Stockbridge
For some while, civil aviation in the United Kingdom has received advice on human factors problems from the Institute of Aviation Medicine (Hopkin, 1970). For four years, however, the authors of this note were able to carry out sponsored projects from within. The objective was to provide a human factors service, in house, for the Civil Aviation Authority, through the Department of Operational Research and Analysis. The authors of this note constituted the working grade team. Research was numerical, in the OR style, rather than experimental. It was not always possible to bring to bear the full rigours of the statistical approach on practical problems. And here practicality means time and money - time in the sense of deadlines, money in the sense of budget and staff limitations. The six ad hoc studies to be described are all concerned with various aspects of air traffic control, namely: Selection of Air 1raffle Control Officers (ATCO's) Design of consoles Sector capacity Call sign confusion Job satisfaction Manpower planning
Selection of ATCO's There are currently some 1200 ATCO's in the UK. These officers have to be recruited, selected, trained, equipped, given an interesting job and provided with career prospects. Clearly it is important to begin by selecting the best men possible. Accordingly, an experimental battery of ability tests was given to the first five cadet courses at the College of Air Traffic Control (ATC), Hum. Performance on these tests was subsequently related to examination results and field reports. Recommendations have been made that those tests which were found to have the higher predictive values should be adopted - these have subsequently been accepted by management. Reference: Lee, M.S., Selection of ATCO cadets, DORA Communication 7207.
Design of consoles Five aspects of console design have received attention in the Directorate of Operational Research and Analysis, CAA. These five aspects are cost, suitability, reach, legibility and labelling. At first, consideration of a shared vertical radar display would seem to offer considerable economic and technical advantages. Two operators could work practically as cheaply as one, but paper studies suggest that the size of the displayed characters would have to be kept carefully in mind for adequate legibility. Obviously a larger label means that fewer can be displayed without overlap on a scope of
a given size. Reference: Ricketts, S.E., and Lee, Mrs M.S. (1974). A paper study to indicate, and where possible to assess the relative merits of single and shared vertical radar displays. DORA Communication 7404.
Sector capacity I. London Airport Traffic Control Centre (LATCC) Studies Air traffic movements in controlled airspace are currently increasing slightly each year. Even if in future more passengers travel in larger'planes and maintain a low growth rate, it is important to estimate ATC work load and capacity. One method of doing this is by self rating, though this has obvious shortcomings. A better method appears to be to employ an expert ATCO observer to gather objective ratings of 'busyness'. It is important to employ observers though, who will be acceptable to both ATCO's and management. Terminal Manoeuvering Area (TMA) SW and Daventry East sectors were studied in the summer of 1972, Daventry West, Daventry East and Clacton West in the summer of 1973. The objective assessment of 'busyness' can then be related to such factors as the number of aircraft handled, or to the proportion of time occupied by radiotelephone (R/T) etc, in order to provide a work load index. Reference: Smith, A.D.N. and Stamp, R.G. (1973). A method for estimating the capacity of air traffic sectors - an interim report. DORA Research Paper 7301.
2. Stimulation studies The objective rating method has been further used to investigate the staged introduction of sector consoles of the new Mediator ATC system. Simulation exercises of the various steps were analysed. Reference: Ricketts, S.E., and Lee, M.S. (1974). Mediator Stage I Sector Suite. The DORA analysis of simulated sector workload. EU 252 Report.
Call sign confusion From time to time, where two aircraft are proximate in time and space, one will act on the instructions intended for the other. Usually they have similar call signs, for example one might be BE 372 and the other BA 472. So far these occurrences have not resulted in disaster. Two lines of thought seem plausible, one that confusion depends on hearing, and two, that it depends on memory. Is one numer mistaken for another? Are numbers transposed in the memory? Possibly both? Reference: Ricketts, S.E. (1973). A review of the incidence and potential occurrences of call sign confusion in ATC radio telephony. DORA Research Paper 7302.
ATCO job satisfaction All controllers were asked to complete a questionnaire.
Applied Ergonomics September1975
171
The preliminary analysis has now been distributed to ATCO's and further action and studies have been undertaken. Reference: Clark, A.W. et al (1973). Human factors in ATC - an opinion survey of the ATCO class. DORA Report 7301.
Conclusion So much for the past. The future of ergonomics in the CAA now lies in the hands of a committee appointed for the purpose of considering that future.
Reference and external publications
Manpower planning
Hopkin, V.D. 1970 Human factors in the ground control of aircraft NATO AGARDograph No 142
A renewal theory type model has been used to represent the ATCO class in the ATC manpower system. Besides giving the age-grade structure of the ATCO class and the wastage rate, the model also provides a comparison of four different promotion policies from grade III to II in terms of promotion prospects and cost associated with the policies. Reference: Arif, M. (1972). Manpower planning in Air Traffic Control. A comparison of four alternative promotion policies for ATCO grades Ill to II. DORA Communication 7206.
Stockbridge, H.C.W. and Mary Lee 1973 Applied Ergonomics, 4.1,44-45. The psycho-social
Man and computer in process control
The human operator in process control
Elwyn Edwards and F.P. Lees. The Institution of Chemical Engineers, 16 BelgraveSquare, London SW1X 8PT, pp 303,
EIwyn Edwards and Frank P. Lees (Editors) Tay Ior & Francis Ltd, 10-14 Macklin Street, London WC2B 5NF,
£7.50
pp 480, £11.00
A comprehensive book reflecting the growing interest in the problems and functions of the operator and the mancomputer system accompanying the wider use of computer control of industrial processes. Throughout the work, the theme is not computerization but a proper division of labour between man and machine.
Many of the studies of the process operator referred to in the book above are reprinted in this collection of readings on the human operator in process control. This work arose from the commission given in 1970 by the Institution of Chemical Engineers to the editors to undertake an industrial research fellowship on the interaction between the process operator and computer. In this study it was realised that although much research had been done in this field, the work was not necessarily well known and much of it was in an inaccessible form. This book is a representative selection from the work and includes many of the classic papers.
Some of the sections included cover process control by man and computer, human factors in process control, functions performed by the operator and by computer, studies carried out on the process operator, reliability of the manmachine system in process control by computer, and the design of process control systems with operator and computer. The problems dealt with include the division of control tasks between man and computer, operator acceptance of the computer, monitoring by the operator, operator boredom and motivation, information display, computer consoles, and handling of emergency situations. Appropriately the book includes a review of human factors providing an introduction to this discipline, and some of the subjects treated are man-machine systems, allocation of function, task analysis, job design, selection, training, information display, manual control, control design, vigilance, decision making, physical environment, organizational factors, and man-computer interaction. There is a bibliography of ergonomic work and of computer control with some 3300 references classified under 170 headings.
172
AppliedErgonomics September 1975
consequences of aircraft noise. Stoekbridge, H.C.W. 1974 Applied Ergonomics, 5.3, 179, Letter. Statistical significance and the Noise & Number Index (NNI). Stockbridge, H.C.W. 1974 Bulletin of the British Psychological Society, 27, 556 Letter: Promotion theory.
Most of the papers cover experimental work on the process operator, the majority being concerned with field studies. There are 26 papers, which have been categorized in a table according to the type of study, the principle type of behaviour studied and the principle system aspect studied. The behaviour types include vigilance, monitoring, signal detection, information cycling, manual control, tracking, decision making, strategy development. scheduling, fault detection, and learning. The principle system aspects include allocation, of function, interface and control on design, information display, prototype production, task analysis, job design, training, man-compute interaction, and organizational and social factors. A wide range of processes was involved including paper mills, washing plant, baking ovens, arc furnaces, chemical plants, refinerys and nuclear reactors.