- Email: [email protected]
New Roles for Humans in Free Flight
NEW ROLES FOR HUMANS IN FREE FLIGHT...
14th World Congress of IFAC
Copyright «;::J 1999 IFAC 14th Triennial World Congress, Beijing, P.R. China
M-6b-03-1
NE\V ROLES FOR
HU~1ANS IN
FREE FLIGI-IT
Richard BIQom Stephen Kahne Embry-Riddle University Prescott. AZ 86301, USA bloo/11.r, [email protected]
HUlnans arc central La the operation of modern air lraffi(: rnanagernent systenls. Free flight "viH require controllers to use significant strategic Dlanagen1ent skills in addition to their more familiar tactical aircraft separation functions. This necessitates rethinking conlfoHer selection and training processes. Sorne guidance for such training C0111eS froln an understanding of free flight, man/n1achine interactions and psychology. Copyright ~I 19991FAC
Abstract:
Keywords: air traffic control, aircraft machine interface
operatjons~ autonlatioTI,
I. AN OPPORTlJNITY Air trans.portation is growing and becolning ever rnore central to the success of the \vorld econolny. The industry is faced with cOlnplex challenges as old equipment fails and is in desperate need or replacement \:vhile ne~' concepts in ATM arc as yet untested and unfunded. One option is lo replace existing equipment with functionaHy equivalent hard\vare and software and retain the salne level of human interaction with the technology as has been traditional in the past. Another is to use this window of opportunity to take the next big step loward high capacity safe air transportation for the foreseeable future. Delays and their costs are hecoming significant in several parts of the \vorld, especially Europe. It is \videly accepted that lhe concept of free flight is llseful for planning the future of world-wide air traffic InanagcnlcnL
2. FREE FLIGHT consensus description of Free Flight has developed in lhc United States (FAA 1998a) during the past few years. Free tlight is an innovati ve concept designed lo enhance the safety and efficiency of the National Airspace System (NAS). The concepl will alter the NAS from a centralized comrnand-and-control system between pilots and air lraffic controllers to a distributed system that allows pilots and operators, whenever practical, to choose their own route and file a flight plan that fOllfJ\VS the nlost efficient and econolnical rouLe. i;'
Free Flighl calls for lirniting pilot ncxibility in certain situations, ~uch as~ to ensure separation at
human factors, human-
high-traffic airports and in congested airspace, to prevent unauthorized entry into special use airspace ~ and for any safety reason. In essence. any activity from pre-flight planning to destination parking that removes re.strictions represents a mOVe to\v3rd Free FJjgbl. ThlS paradigm shift leads to numerous complex technical cha]]enges. Here we would like to explore the new roles to he played by humans in the new system which is evolving from the current air traffic control enVirOI1lnenl. One illlplication of new roles is the need to reevaluate training methods and training goals. An established system of hiring and evaluating air traffic controllers and n1anagers has been in place for decades and is well summarized by the National Research Council of the American National Academy of Sciences in their recent book (NRC, 1997). In a system inextricably integrated among people and machines there is a tendency for an imbalance lo exist between the human issues and the technological ones. Although the concept of free flight originated in the United States, the free flighr paradigm is expected to be accepted on a global basis and thus human roJes in free flight will invariably he 1mportant everywhere. 3. AN HISTORICAL NOTE The controllers strike in the United States in
198] offered a unique experimental envirOlunent which to observe the adaptability of a complex hurnan-machine system to dralnatic changes in operalion. It is no exaggeration to stale that the flexibility and adaptability of the human members of the A Te team were responsible for the relatively smooth transition in
6535
Copyright 1999 IFAC
ISBN: 0 08 043248 4
NEW ROLES FOR HUMANS IN FREE FLIGHT...
14th World Congress ofIFAC
from a fully staffed work force in ATe in 1981 to the greatly depJeled ranks of hUlnan operators whjch existed after the V.S. President dismissed half of Lhc nation's air traffic controllers. Relati vel y low tech and modestly adequate equipment was expertly operated by the remaining work force and ne\vJy hired controllers. Major disasters were averted much to the astonishment of the fired controllers and to the relief of the flying public. The road to fully functional air traffic management during these past 20 years has been a bumpy one yet one which is marked by remarkable safety and ilupressive capacity growth. Unfortunately ATe developments during this period may be fairly characterized as occasional implementation of ne\\" system components but with little successful effort to conceive of and implement a robust ATe architecture for which new components could be developed and installed. One of the most ambitious efforts of A TC modernization, the Advanced Automation System (AAS)~ ultimately resulted in a fe\v system components being installed but no system architect.ure being created. It was generally deenlcd a failure since it not achieve its stated goals of creating an "advanced automation SystCIT1." Free flight as an operational concepts now drives the elnerging system architecture and places into a syste·ms perspective proposed new ATe tools and capabilities. It is an integral part of a new National Airspace System Architecture (FAA 1998b).
The challenge is to continuously improve system performance by reducing the rate of accidents - a rate~ for the worldwide commercial jet fleet, which has stubbornly rernained at about 2 accidents per million depar(ures for almost 20 years (Boeing, 1998). As the number of air transport operations has increased each year, the number of accidents has slowly risen. At the same time, new technical capabilities in the aircraft cockpit (AC), in airline operations centers (ADC), and in the air traffic management system (ATM) has filadc possible new rnodes of control which take advantage of the distributed nature of intelligence throughout the system. In fact, aviation is an impressive example of an industry driven by technical developments in computers and electronics. Intelligent electronic systems formerly only useful in large ground based ccntcrs due to size. weight~ and power requirements, are now found in all commercial aircraft (and many general aviation) cockpits, in all airline operations control centers, and increasingly in nalional air traffic control centcrs. In the early 1990~s the concept of "free flight was suggested as an evolutionary lt
development suitable for the new technical environment. The key formalization of this concept (RTCA, 1995), describes a development scenario and outlines some of the difficulties \vhich will occur during the development and implementation of free flight. 4. QUESTIONS ABOUT THE HUMAN ROLE Even eTAS (Center-TRACON Autolllation System) the systenl upgrade package now being installed in several US control centers, requires more exercise of controller cOJnplex cognitive acti vity than was true for older advances in automation (NRC 1997). Free flight introduces Iuore serious new challenges for the human part of the future ATM system. What will be the new role of hUlnan operators in these systeJns'? Knowing about this new role, one may ask how to prepare individuals for success in the new enviroolnent and how to deterlnine their suitability for the new job. The tasks to be done have not yet been performed, indeed, may not as yet even been fully specified. l
Such questions arise as: -What controller skills are needed to facilitate the transition from non-free flight to free flight and back to non-free flight as the aircraft flies from one airport to another? -Are there new skills needed to handle the occasional TeAS commanded flight path changes before controllers are informed?
-How can all people involved ensure that situatlon awareness is maintained by all concerned during all portions of a flight? Recent studies by Endsle-y, et al (Endsley 1998) suggest that tlif controllers are expected to act as passive monitors of free flight air traffic, their awareness of the state of traffic may be reduced, their workload nlay increase, and theif ability to intervene in a timely manner may be limited." -Are recruiting, testing, evaluation~ and training nlethods which were useful in the past going to be useful in the future? -Is there an educational infrastructure in place to ensure that specialists are available when the new technology is? -How do we transition from the old regime to the new one while maintaining the most exacting levels of safety at each step in the process? These are just a salnple of the questions which free flight introduces.
6536
Copyright 1999 IFAC
ISBN: 0 08 043248 4
NEW ROLES FOR HUMANS IN FREE FLIGHT...
14th World Congress of IFAC
5. !\.1AN-NIACHI::\fE INTERACTIONS A taxonorny of human factors considerations for control tasks has been proposed (Shcridan, 1987). For successful application lo free flight this one dirncnsional (a rnan-tnachine pair) taxonomy 11lay need to be expanded to three dinlensions to reflect the options available for free flight in the cockpit (AC), within airline operat]onal centers (AOC)~ and in control cencers (CC) operated by national air traffic control authorities. Sheridan ~s taxonomy lists levels of automation in terms of the relative roles for machines and people: 111aIJy
Levels of Automation (L levels)
Ll. The computer offers no assistance~ the human must do it all. L2. The computer offers a complete set of action alternati Yes, and L3. Narrows the selection dC}'l.,.vn to a few, or L4. Suggests one, and L5. Executes that suggestion if the human appro ves~ or L6. AIIows the hUlnan a restricted time to veto before automatic execution, or L7. Executes automatically, then necessarily informs the human, or L8. Informs the human after execution only if he asks~ or L9. Informs the human after execution only if the computer decides to. L IO. The compucer decides everything and acts autonomously, ignoring the human. A.s was noted earlier, innovations in techno)ogy have now made possible a truly distributed intelligence system with intelligent nodes in AC, A.QC. and CC. We can [hink of the typical AC/ AGe/CC interacrion as Cl triple of activities involving people and machines at three different locations in the ain..:ratt at the airlines operations control center. and at one or IT10re air traffic control facilities. Each node j~ characterized by one of these ten levels of automation and the entire air traflic management systen1 consists of hundreds of these triples in operation sinlultaneously with tens of them inleracting \vith each other in rea) time con1peting for resources. All have extraordinary safety requirements while attempting to optimize their performance. At first glance it might appear that no level of automation above L4 or L5 would be suitable for ATM. Howevec au{opilo(s generally are operated at a much higher level, at least L8. and lov..'er level au(om2tic control functions such as aurothrottle, pitch and yaw stabilization, etc.
operate at L] O. In this paper emphasis is on higher level functions at lower levels of aulolnation. Clearly, the systcrn "vill contain elements which are operating at different levels of automation and the people associated with each part of the system need to be trained on and con1fortabJe with the levels of automation in use in their part of the system. This level uf operator comfort also needs to be projected to other parts of the system with which the operators interact.
Is the lraining required for effective management of systems operating at L5 similar to that for people operating at L9? Will an operator involved with L4 autoluation be able to deal with remote system elements operating at L9? Already there are numerous reports and studies dealing 'W'ith conf1icts which arise when TeAS (traffic collision avoidance system) commanded maneuvers are carried OUl without prior controller approval (Wickens and Harwood, 1998). Importan[ questions of impaired situation awareness arise if human operators have tasks above L8 when their role may be interpreted as one of passive observer rather than active rnanipuJalor. Although rnachincs arc evolving into intelligent deviccs people don't change due to upgraded human component parts, but rather can learn to alter their behavior through training. In the ATM e,nvironment these issues are compounded by the fact that local L2 behavior may be required to interface with remote L9 behavior with all nodes sharing a common goal of safe and efficient flight operation. This paradigm is particularly evident in free flight. In this regime flight optimization parameters are set by the .A.OC and are programmed to be implemented by the AC. CC interactions only are executed to ensure that the optimal program for a particular aircraft is not incompatable with requirements of other users of ",-.1\TM resources. t
6. TRADITIONAL FACTORS IN TRADITIONAL Hl.~~1AN FACTORS All the ahove attributions to the human element in what is now called A TM have traditionally
fallen
under the research
rubric of human
HUlnan factors as an applied research discipline has successfully insinuated itself not only within the aviation and aerospace industnes but within academia as well. However. the authors tnaintain that a culturaJ revolution in human factors is in the offing. Just as free flight conslitutes new conceptual perspectives on aviation--perspectives that ineluctably break the confining bonds of the past much as aviation all ows human s to break free from the con fi nes of factors.
land, human factors support for free flight wiJ] necessitate new perspectives that break free from
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Copyright 1999 IFAC
ISBN: 0 08 043248 4
NEW ROLES FOR HUMANS IN FREE FLIGHT...
14th World Congress ofIFAC
the confines of what has come before. The coming revolution in hUIllun faclors supporting a free flight environtTIcnt will be substantive~ conceptuaL and methodological. To best illustrate the import of the cOining hurnan factors revolution consider a precis of what human factors has been and the salient issues that reflect a paradigmatic hreakdow'n.
A review has been con1pleted of over 280 psychological studies in the PsycINFO data bases of the American Psychological Association. It covers the period from 1949 to the present~ all bearing on A"r~1. This review suggests that there have four main research traditions covering the psychology of ATM before the era of free flight. Each tradition focuses on a particular attribute and all four attributes can be best understood as depending on combinations of the following criteria: specificity~ sensitivity, level of analysis,
biopsychosocial
leve]~
personal meanings as
attributed by their possessors, dimensions of space and time, functional significance, structural and process features~ ecological significance, and psychophysical delnands.
1'he first has comprised various attributes of ATM participants. These attributes have varied in specificity, sensitivity, level of analysis, placelnent on a biopsychosocial continuum~ and their personal n1eanings as attributed by their possessors. Examples have included psychophysiological functioning (Costa et al, 1995),. situation awareness, vigilance latencics, personality traics, and information processing styles and loads (Merlens & Milhurn~ 1996).
The second has conlprised equiplnent or machine attributes confronted by ATM participanls (e.g., Edwarus et aC 1995). These attributes have varied in specificity~ sensitivity~ level of analysis~ ditnensions of space and tinle. functional significance, structuraJ and process features~ and their persona) meanings as aHrihuled hy ATM participants. Exarnple~ have included the frequency, amp1itude, I1urnber, ~nd other physical aspe(.;ts of auditory and visual cues. cOInparati ve variations of these cues~ psychophy~ical affordances inducing figure to ground phenonlena~ and physlcal size, placement. and dimensionalily of mechanical apparata. All these are in addition to the level of autonlation at which each subsystem operates_ The third has comprised task attributes confronted by A1'M participants (e.g.~ Boer ct al~ 1997). These attributes have varied in specificity, sensitivity, Jevel of analysis,
dimensions of space and tinle~ functional significance, structural and process features~ their psychophysical dernands. and their personal meanings as attributed by ATM participants. Examples have included attentionaJ demands and those of more sophisticated information processing that interact with seman[ic networks and heuristics concurrent with demands on inLcrprctive strategies, comprehensl0nal processes, memories for policies/rules/reglllations~ and required nlotor
behaviors. The fourth has comprised environmental attributes within which A TM participants function (e.g., Shouksmith & Taylor, 1997). These attributes have varied in specificity. sensitivity, level of analysis, dimensions of space and rime, ecoJogicaJ significance, and their personal meanings aHributed by ATM participants. Examples have included policies and effects of policies concerning workload and shiftwork (Luna. 1997), absolute and comparative measures of ambient noise and temperature through ti me~ and organi zati onaJ values concerning accountability and oversight. The four main research traditions have also been integrated in studying ATM. For example, human attributes have been studied dependent on the environment, while task attributes have been studied dependent on equipment. Combinations of all four research traditions have been studied as they form systems and as they reciprocally contribute to effects of the system on constituent components. However. cOlnbinations of research traditions have largely focused on a small number of interactions between and among the traditions as was befitting the era before free flight. As the free flight era continues to evolve, significant interactions become potentially astronomical. And with this~ the traditional paradigm of human factors is in the process of shattering before new questions, needs, and opportunities for ATM free night support. From the ashes of the shattered paradigm--much like a phoenix taking on a new life and indeed a new and different form--a new human factors paradigm and ne"v human factors support for free flight will be constituted. The following issues and related discussion suggest how this new paradignl and free l1ight--founded on the increased reliability, validity. and utility of socio-psychoJogical rcsearch--can set a nev.' research agenda intended to improve ATM in an era of free flight.
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Copyright 1999 IFAC
ISBN: 0 08 043248 4
NEW ROLES FOR HUMANS IN FREE FLIGHT...
7. THE NEW HUMAN FACurORS AND FLIGHrr
14th World Congress ofIFAC
I~REE
(I) In an era of free flight, research on human, equipmenl and task attribuLes Inay yield less significant increments for safety than environmental attrihulcs--cspcciaJly social environments. This ITlay he the case for equipment and task attributes because previous research has been well-done. For human ::tuributcs, the tnain point is that ATM participants nlay often choose occupations c(Hnpatible with their lask-rclevant strengths and weaknesses and go through rigorous and realistic sirnulations as a foundation of selection and training. Alnong the Inany buman attributes~ personality traits l11ay yield the least increment towards ilTIproving ATM perfonnance. Why is this? Conten1porary personality research suggests that nOl only is there variance among people for various personality traits~ hut also there is significant variance for a given personality trait for a specific person depending on a host of situational variables. Even for a specific person) personality trait, and situational variable, there may he significant additional variance of yet unknown origin that impede predictability. Although personality research can still he useful in selecting out extrelnes--e.g., individuals -w'ith cxtrenlely fragile psychological stress tolerances and severe p~ych()pathology- people often do as well or better at selecting theJllsc]ves out of dystonic occupations, i.e., situations that don't fit an individual's psychology. (2)
This being said, it is also posited that the increasing demands for strategic planning and controlled autonomy among ArfM participants in the era of free flight may increase the significance of ope-rationally defined personality variables such as cognitive complexity and field independence. Cognitive complexity denotes how many different options a human subject can conceive for a particular stimulus, while field independence denotes how easily a human suhject can perceive a stimulu~ independent of o[hcr overlying, proximal, and dist.al stirlluli. Both variables arc associated \vith ~'cll developed psychologicaJ measuring instruments (cf. Chen, 1996~ Vrij et aL L995). 'Moreover, in an era of free flight and globalization, operationally defined cthnoccntrisrn and stages of Inoral judgrnent may become nlore significant in affecting ATM. Sornc researchers Inight posit that these last two variables lnight largely involve flight crc\vs.
However, wc must note that as i\ TM sysleIlls become more interdependent, contacts and communications aIIlong diverse Jnembe.rs of the ATM cOIlUllunity will increase. In fact~ we suggest that researchers test whether there are qualitative psychosocial and task performance differences due to ethnocentric and nloral variables engendered by foreign experiences that one travels to--e.g., the t1ight crew--versus those engendered by travelers coming to subjects--e.g., controllers. Finally, interpersonal personality profiles tha[ assess compatibility matches among dyads and other small groupings may more significantly contribute to AT'M. (3) As alluded to in (]) above, environmental research should be based on the notion that there is not one but many environments affecting ATM performance. These include the work, famjlYl social, ethnic, and personal environments of A TM participants~ e.g., cockpit cre\o\t', maintenance personnel, and administrators (er., Bloom. 1996). In essence, all cnvirorlll1ents arc political--which means that ATM is dependent on pcrccpLions concerning infinite needs and finite reSOurces and perceptual disparjties between w'hat is and what should be on the part of multiple participants in multiply-layered and interacting environnlents. Even more specifically, the political element involves not only conflicts, policies, and issues commonly termed poIitical--e.g., government decisions concerning unions and \,\'ages--but also the many daily victories and defeats in what are perceived to be zerO-SU1TI games--e.g.~ contentions with spouses, arguments with creditors, slights stemming from salutations or the lack thereof. Although assessment-based managenlcnt can identify some of the fluctuations in these areas, of crucial import--and most easily identified by competent managers--arc the many iotcn!ional and unintentional features of organizational culture. Especially with significant seJfselection of A TM participants and supporting personneJ--as \-vell as cOlllpelent hUlnan factors research on task and equiprnent attribute--the ongoing monitoring of the psychological effects of organizational culture. may be the most time and cost-effecti ve to\vards ilnproving A l'M
perfonnance. (4) In an era of free flight the very boundaries of human facLors~ traditional research areas conceptually breakdown. As one man's terrorist js another man's freedonl fighter, one rcsearcher~s task attribute is another researcher\. envirolunental or equipment attribute. It is more phenomenologically correct to classify variables as apperceived among ATM participants, not researchers (ef. Klein et ai, 1995).
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Copyright 1999 IFAC
ISBN: 0 08 043248 4
NEW ROLES FOR HUMANS IN FREE FLIGHT...
14th World Congress ofIFAC
(5) Contclnporary research on the philosophy of the social sciences suggests that there is a social transformation of applied psychological knowledge (VlZ" Prjlleltensky~ 1994). That is, through time, the interaction of cultural, historical, political~ econolnic t and other social science variahle~ effects psychological change. \-\'hat Vlas once an empirically and experiInentally validated linkage between a social science variable, A TC performance~ and ATM is no longer. This phenomenon--often ignored by conSUlners of social science research-necessitates an ongoing revalidation effort on lhe part of organizations dedicated [0 improving
ATM. Free flight continues to evolve as the guidon for planning the future of world-v¥'idc ATM. An era of ti"ee t1ight--one that nl0re strongly than ever encompasses internationat multicultural, and other unique challenges--can greatly benefit fronl state~of-the-art psychological support. ThJS s.upport 'W'ill necessitate a cultural revolution in the very conception of hUInan factors research.
REFERENCES Bloom, R.W. (December 6 1996). A psychopolitical analysis of situation aVlureness: An editorial. International Bulletin of Political Psychology, 1(5). (http://w\vw.pr .erau. edu/- se curity). Boeing (1998), Statistical SUJ1Zflzary n..f C:'ornrnercial Jet Airplane Accidel1!s_ Hoeing Company, Scattle, WA. Boer, L.C.~ Harsveld~ M., & Hern1ans, P.R. (1997). Military Ps}'chology, 9, ] 36-149. Borack, J.1. (1995). Alternative techniques for predicting success in air confroller school. t
.Military Psycholog)'~ 7 ~ 207-219 J~. ( I 996). Cogniti vc complexity ~
C:hen~
situational inlluences, and topic selection in intraculturaI and intercultural dyadic interactions. Cornrnunicatiofl Reports 1996, 1-] 2
progress strips in en route air traffic control: A time-series analysis. International Journal of H urnan- Computer~ 43~ 1-13. Endsley, MR (1998) EffeCt of Free Flight Conditions 011 Controller Pe r!o rtna nee, Workload, and Situation Awareness. FAA Civil Aeromedical Institute. FAA (1998a) bttp:l/www.faa.gov/freeflight (online) FAA (1998b) http://www.faa,gov/asd/ (online) Klcin~ R.L~, Biglcy~ G.A.~ Robcrts, K.H. () 995). Organizalional culture in high reliability organizations; An extension. Human ReJation.~·, 48, 771-793~ Luna. T.D. (1997). Air traffic controller shiflwork: What are the implications for aviation safety? A review in Aviation, Space~ and Environnlental Medicifle~ 68, Pp. 69-79 l\-1ertcn~, H.W .• & Milburn, N.l. Performance of color-dependent air traffic control tasks as a function of calor vision deficiency. A -",'iation, Space, & Environfnentai Medicine, 67. 919927. Naylor, G.F.K. (1954). Aptitude tests for air traffic contra I officers. Occupational Psychology~ 28, 209-217~ NRC (1997), Flight to the Future - Human Factors in Air Traffic Control. National Academy Press, Washington, DC.. Prilelltensky, J. (1994). The morals and politic.\' of psychology. NY: Slate University of New
York Press. RTCA (1995). Report of the Board of Directors
Select COlll1nittee on Free Flight. RTCA Incorporated, Washington, DC. Sheridan, TB (1987). Supervisory Control in Handbook of Human Factors., G. Salvendy, ed. WHey & Sons, New York. Shouksmith, G., & Taylor, I.E. (1997). The interaction of culture with general job stressors in air traffic controllers. International Journal oj>A vialion Psychology, 7, 343-352: Vrij~ A., van der Steen, J., & Koppelaar, L. (1995). The effects of street noise and field independency on police officers' shooting behavior. Journal of Applied Social Psychology, 25 17J4-1725. Wickens, C. Harwood~ K. (eds) (1998) Special Issue of HunUln Factors, Air Traffic Control QuarterlY1 7 Air Traffic Conlrol Association. Zeller, A.F. (August 30, ] 959). Human aspects of mid-air collision prevention. Aerospace Medicine~ 551-560. 1
Costa, G., Schallenberg, G., Ferracin, A., & Gaffuri, E. (1995). Psychophysical conditions of air traffic controJ]ers evaluated by the standard shift\'t-'ork index. \¥ork & Stress, 9, 281-288. Davis, C.G.~ Kerle, R.H., Silvestro, A.\\"l & Wallace, W.H. (1960). The air traffic control trauung progranl as viewed by training supervisors .Courtney Co. Rep., 3333 Edwards, M.B., Fuller, D.K., Vortac~ O.U' & Manning~ C.A. (] 995\ The role of flight
1
1
6540
Copyright 1999 IFAC
ISBN: 0 08 043248 4
14th World Congress of IFAC
Copyright «;::J 1999 IFAC 14th Triennial World Congress, Beijing, P.R. China
M-6b-03-1
NE\V ROLES FOR
HU~1ANS IN
FREE FLIGI-IT
Richard BIQom Stephen Kahne Embry-Riddle University Prescott. AZ 86301, USA bloo/11.r, [email protected]
HUlnans arc central La the operation of modern air lraffi(: rnanagernent systenls. Free flight "viH require controllers to use significant strategic Dlanagen1ent skills in addition to their more familiar tactical aircraft separation functions. This necessitates rethinking conlfoHer selection and training processes. Sorne guidance for such training C0111eS froln an understanding of free flight, man/n1achine interactions and psychology. Copyright ~I 19991FAC
Abstract:
Keywords: air traffic control, aircraft machine interface
operatjons~ autonlatioTI,
I. AN OPPORTlJNITY Air trans.portation is growing and becolning ever rnore central to the success of the \vorld econolny. The industry is faced with cOlnplex challenges as old equipment fails and is in desperate need or replacement \:vhile ne~' concepts in ATM arc as yet untested and unfunded. One option is lo replace existing equipment with functionaHy equivalent hard\vare and software and retain the salne level of human interaction with the technology as has been traditional in the past. Another is to use this window of opportunity to take the next big step loward high capacity safe air transportation for the foreseeable future. Delays and their costs are hecoming significant in several parts of the \vorld, especially Europe. It is \videly accepted that lhe concept of free flight is llseful for planning the future of world-wide air traffic InanagcnlcnL
2. FREE FLIGHT consensus description of Free Flight has developed in lhc United States (FAA 1998a) during the past few years. Free tlight is an innovati ve concept designed lo enhance the safety and efficiency of the National Airspace System (NAS). The concepl will alter the NAS from a centralized comrnand-and-control system between pilots and air lraffic controllers to a distributed system that allows pilots and operators, whenever practical, to choose their own route and file a flight plan that fOllfJ\VS the nlost efficient and econolnical rouLe. i;'
Free Flighl calls for lirniting pilot ncxibility in certain situations, ~uch as~ to ensure separation at
human factors, human-
high-traffic airports and in congested airspace, to prevent unauthorized entry into special use airspace ~ and for any safety reason. In essence. any activity from pre-flight planning to destination parking that removes re.strictions represents a mOVe to\v3rd Free FJjgbl. ThlS paradigm shift leads to numerous complex technical cha]]enges. Here we would like to explore the new roles to he played by humans in the new system which is evolving from the current air traffic control enVirOI1lnenl. One illlplication of new roles is the need to reevaluate training methods and training goals. An established system of hiring and evaluating air traffic controllers and n1anagers has been in place for decades and is well summarized by the National Research Council of the American National Academy of Sciences in their recent book (NRC, 1997). In a system inextricably integrated among people and machines there is a tendency for an imbalance lo exist between the human issues and the technological ones. Although the concept of free flight originated in the United States, the free flighr paradigm is expected to be accepted on a global basis and thus human roJes in free flight will invariably he 1mportant everywhere. 3. AN HISTORICAL NOTE The controllers strike in the United States in
198] offered a unique experimental envirOlunent which to observe the adaptability of a complex hurnan-machine system to dralnatic changes in operalion. It is no exaggeration to stale that the flexibility and adaptability of the human members of the A Te team were responsible for the relatively smooth transition in
6535
Copyright 1999 IFAC
ISBN: 0 08 043248 4
NEW ROLES FOR HUMANS IN FREE FLIGHT...
14th World Congress ofIFAC
from a fully staffed work force in ATe in 1981 to the greatly depJeled ranks of hUlnan operators whjch existed after the V.S. President dismissed half of Lhc nation's air traffic controllers. Relati vel y low tech and modestly adequate equipment was expertly operated by the remaining work force and ne\vJy hired controllers. Major disasters were averted much to the astonishment of the fired controllers and to the relief of the flying public. The road to fully functional air traffic management during these past 20 years has been a bumpy one yet one which is marked by remarkable safety and ilupressive capacity growth. Unfortunately ATe developments during this period may be fairly characterized as occasional implementation of ne\\" system components but with little successful effort to conceive of and implement a robust ATe architecture for which new components could be developed and installed. One of the most ambitious efforts of A TC modernization, the Advanced Automation System (AAS)~ ultimately resulted in a fe\v system components being installed but no system architect.ure being created. It was generally deenlcd a failure since it not achieve its stated goals of creating an "advanced automation SystCIT1." Free flight as an operational concepts now drives the elnerging system architecture and places into a syste·ms perspective proposed new ATe tools and capabilities. It is an integral part of a new National Airspace System Architecture (FAA 1998b).
The challenge is to continuously improve system performance by reducing the rate of accidents - a rate~ for the worldwide commercial jet fleet, which has stubbornly rernained at about 2 accidents per million depar(ures for almost 20 years (Boeing, 1998). As the number of air transport operations has increased each year, the number of accidents has slowly risen. At the same time, new technical capabilities in the aircraft cockpit (AC), in airline operations centers (ADC), and in the air traffic management system (ATM) has filadc possible new rnodes of control which take advantage of the distributed nature of intelligence throughout the system. In fact, aviation is an impressive example of an industry driven by technical developments in computers and electronics. Intelligent electronic systems formerly only useful in large ground based ccntcrs due to size. weight~ and power requirements, are now found in all commercial aircraft (and many general aviation) cockpits, in all airline operations control centers, and increasingly in nalional air traffic control centcrs. In the early 1990~s the concept of "free flight was suggested as an evolutionary lt
development suitable for the new technical environment. The key formalization of this concept (RTCA, 1995), describes a development scenario and outlines some of the difficulties \vhich will occur during the development and implementation of free flight. 4. QUESTIONS ABOUT THE HUMAN ROLE Even eTAS (Center-TRACON Autolllation System) the systenl upgrade package now being installed in several US control centers, requires more exercise of controller cOJnplex cognitive acti vity than was true for older advances in automation (NRC 1997). Free flight introduces Iuore serious new challenges for the human part of the future ATM system. What will be the new role of hUlnan operators in these systeJns'? Knowing about this new role, one may ask how to prepare individuals for success in the new enviroolnent and how to deterlnine their suitability for the new job. The tasks to be done have not yet been performed, indeed, may not as yet even been fully specified. l
Such questions arise as: -What controller skills are needed to facilitate the transition from non-free flight to free flight and back to non-free flight as the aircraft flies from one airport to another? -Are there new skills needed to handle the occasional TeAS commanded flight path changes before controllers are informed?
-How can all people involved ensure that situatlon awareness is maintained by all concerned during all portions of a flight? Recent studies by Endsle-y, et al (Endsley 1998) suggest that tlif controllers are expected to act as passive monitors of free flight air traffic, their awareness of the state of traffic may be reduced, their workload nlay increase, and theif ability to intervene in a timely manner may be limited." -Are recruiting, testing, evaluation~ and training nlethods which were useful in the past going to be useful in the future? -Is there an educational infrastructure in place to ensure that specialists are available when the new technology is? -How do we transition from the old regime to the new one while maintaining the most exacting levels of safety at each step in the process? These are just a salnple of the questions which free flight introduces.
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5. !\.1AN-NIACHI::\fE INTERACTIONS A taxonorny of human factors considerations for control tasks has been proposed (Shcridan, 1987). For successful application lo free flight this one dirncnsional (a rnan-tnachine pair) taxonomy 11lay need to be expanded to three dinlensions to reflect the options available for free flight in the cockpit (AC), within airline operat]onal centers (AOC)~ and in control cencers (CC) operated by national air traffic control authorities. Sheridan ~s taxonomy lists levels of automation in terms of the relative roles for machines and people: 111aIJy
Levels of Automation (L levels)
Ll. The computer offers no assistance~ the human must do it all. L2. The computer offers a complete set of action alternati Yes, and L3. Narrows the selection dC}'l.,.vn to a few, or L4. Suggests one, and L5. Executes that suggestion if the human appro ves~ or L6. AIIows the hUlnan a restricted time to veto before automatic execution, or L7. Executes automatically, then necessarily informs the human, or L8. Informs the human after execution only if he asks~ or L9. Informs the human after execution only if the computer decides to. L IO. The compucer decides everything and acts autonomously, ignoring the human. A.s was noted earlier, innovations in techno)ogy have now made possible a truly distributed intelligence system with intelligent nodes in AC, A.QC. and CC. We can [hink of the typical AC/ AGe/CC interacrion as Cl triple of activities involving people and machines at three different locations in the ain..:ratt at the airlines operations control center. and at one or IT10re air traffic control facilities. Each node j~ characterized by one of these ten levels of automation and the entire air traflic management systen1 consists of hundreds of these triples in operation sinlultaneously with tens of them inleracting \vith each other in rea) time con1peting for resources. All have extraordinary safety requirements while attempting to optimize their performance. At first glance it might appear that no level of automation above L4 or L5 would be suitable for ATM. Howevec au{opilo(s generally are operated at a much higher level, at least L8. and lov..'er level au(om2tic control functions such as aurothrottle, pitch and yaw stabilization, etc.
operate at L] O. In this paper emphasis is on higher level functions at lower levels of aulolnation. Clearly, the systcrn "vill contain elements which are operating at different levels of automation and the people associated with each part of the system need to be trained on and con1fortabJe with the levels of automation in use in their part of the system. This level uf operator comfort also needs to be projected to other parts of the system with which the operators interact.
Is the lraining required for effective management of systems operating at L5 similar to that for people operating at L9? Will an operator involved with L4 autoluation be able to deal with remote system elements operating at L9? Already there are numerous reports and studies dealing 'W'ith conf1icts which arise when TeAS (traffic collision avoidance system) commanded maneuvers are carried OUl without prior controller approval (Wickens and Harwood, 1998). Importan[ questions of impaired situation awareness arise if human operators have tasks above L8 when their role may be interpreted as one of passive observer rather than active rnanipuJalor. Although rnachincs arc evolving into intelligent deviccs people don't change due to upgraded human component parts, but rather can learn to alter their behavior through training. In the ATM e,nvironment these issues are compounded by the fact that local L2 behavior may be required to interface with remote L9 behavior with all nodes sharing a common goal of safe and efficient flight operation. This paradigm is particularly evident in free flight. In this regime flight optimization parameters are set by the .A.OC and are programmed to be implemented by the AC. CC interactions only are executed to ensure that the optimal program for a particular aircraft is not incompatable with requirements of other users of ",-.1\TM resources. t
6. TRADITIONAL FACTORS IN TRADITIONAL Hl.~~1AN FACTORS All the ahove attributions to the human element in what is now called A TM have traditionally
fallen
under the research
rubric of human
HUlnan factors as an applied research discipline has successfully insinuated itself not only within the aviation and aerospace industnes but within academia as well. However. the authors tnaintain that a culturaJ revolution in human factors is in the offing. Just as free flight conslitutes new conceptual perspectives on aviation--perspectives that ineluctably break the confining bonds of the past much as aviation all ows human s to break free from the con fi nes of factors.
land, human factors support for free flight wiJ] necessitate new perspectives that break free from
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the confines of what has come before. The coming revolution in hUIllun faclors supporting a free flight environtTIcnt will be substantive~ conceptuaL and methodological. To best illustrate the import of the cOining hurnan factors revolution consider a precis of what human factors has been and the salient issues that reflect a paradigmatic hreakdow'n.
A review has been con1pleted of over 280 psychological studies in the PsycINFO data bases of the American Psychological Association. It covers the period from 1949 to the present~ all bearing on A"r~1. This review suggests that there have four main research traditions covering the psychology of ATM before the era of free flight. Each tradition focuses on a particular attribute and all four attributes can be best understood as depending on combinations of the following criteria: specificity~ sensitivity, level of analysis,
biopsychosocial
leve]~
personal meanings as
attributed by their possessors, dimensions of space and time, functional significance, structural and process features~ ecological significance, and psychophysical delnands.
1'he first has comprised various attributes of ATM participants. These attributes have varied in specificity, sensitivity, level of analysis, placelnent on a biopsychosocial continuum~ and their personal n1eanings as attributed by their possessors. Examples have included psychophysiological functioning (Costa et al, 1995),. situation awareness, vigilance latencics, personality traics, and information processing styles and loads (Merlens & Milhurn~ 1996).
The second has conlprised equiplnent or machine attributes confronted by ATM participanls (e.g., Edwarus et aC 1995). These attributes have varied in specificity~ sensitivity~ level of analysis~ ditnensions of space and tinle. functional significance, structuraJ and process features~ and their persona) meanings as aHrihuled hy ATM participants. Exarnple~ have included the frequency, amp1itude, I1urnber, ~nd other physical aspe(.;ts of auditory and visual cues. cOInparati ve variations of these cues~ psychophy~ical affordances inducing figure to ground phenonlena~ and physlcal size, placement. and dimensionalily of mechanical apparata. All these are in addition to the level of autonlation at which each subsystem operates_ The third has comprised task attributes confronted by A1'M participants (e.g.~ Boer ct al~ 1997). These attributes have varied in specificity, sensitivity, Jevel of analysis,
dimensions of space and tinle~ functional significance, structural and process features~ their psychophysical dernands. and their personal meanings as attributed by ATM participants. Examples have included attentionaJ demands and those of more sophisticated information processing that interact with seman[ic networks and heuristics concurrent with demands on inLcrprctive strategies, comprehensl0nal processes, memories for policies/rules/reglllations~ and required nlotor
behaviors. The fourth has comprised environmental attributes within which A TM participants function (e.g., Shouksmith & Taylor, 1997). These attributes have varied in specificity. sensitivity, level of analysis, dimensions of space and rime, ecoJogicaJ significance, and their personal meanings aHributed by ATM participants. Examples have included policies and effects of policies concerning workload and shiftwork (Luna. 1997), absolute and comparative measures of ambient noise and temperature through ti me~ and organi zati onaJ values concerning accountability and oversight. The four main research traditions have also been integrated in studying ATM. For example, human attributes have been studied dependent on the environment, while task attributes have been studied dependent on equipment. Combinations of all four research traditions have been studied as they form systems and as they reciprocally contribute to effects of the system on constituent components. However. cOlnbinations of research traditions have largely focused on a small number of interactions between and among the traditions as was befitting the era before free flight. As the free flight era continues to evolve, significant interactions become potentially astronomical. And with this~ the traditional paradigm of human factors is in the process of shattering before new questions, needs, and opportunities for ATM free night support. From the ashes of the shattered paradigm--much like a phoenix taking on a new life and indeed a new and different form--a new human factors paradigm and ne"v human factors support for free flight will be constituted. The following issues and related discussion suggest how this new paradignl and free l1ight--founded on the increased reliability, validity. and utility of socio-psychoJogical rcsearch--can set a nev.' research agenda intended to improve ATM in an era of free flight.
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7. THE NEW HUMAN FACurORS AND FLIGHrr
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I~REE
(I) In an era of free flight, research on human, equipmenl and task attribuLes Inay yield less significant increments for safety than environmental attrihulcs--cspcciaJly social environments. This ITlay he the case for equipment and task attributes because previous research has been well-done. For human ::tuributcs, the tnain point is that ATM participants nlay often choose occupations c(Hnpatible with their lask-rclevant strengths and weaknesses and go through rigorous and realistic sirnulations as a foundation of selection and training. Alnong the Inany buman attributes~ personality traits l11ay yield the least increment towards ilTIproving ATM perfonnance. Why is this? Conten1porary personality research suggests that nOl only is there variance among people for various personality traits~ hut also there is significant variance for a given personality trait for a specific person depending on a host of situational variables. Even for a specific person) personality trait, and situational variable, there may he significant additional variance of yet unknown origin that impede predictability. Although personality research can still he useful in selecting out extrelnes--e.g., individuals -w'ith cxtrenlely fragile psychological stress tolerances and severe p~ych()pathology- people often do as well or better at selecting theJllsc]ves out of dystonic occupations, i.e., situations that don't fit an individual's psychology. (2)
This being said, it is also posited that the increasing demands for strategic planning and controlled autonomy among ArfM participants in the era of free flight may increase the significance of ope-rationally defined personality variables such as cognitive complexity and field independence. Cognitive complexity denotes how many different options a human subject can conceive for a particular stimulus, while field independence denotes how easily a human suhject can perceive a stimulu~ independent of o[hcr overlying, proximal, and dist.al stirlluli. Both variables arc associated \vith ~'cll developed psychologicaJ measuring instruments (cf. Chen, 1996~ Vrij et aL L995). 'Moreover, in an era of free flight and globalization, operationally defined cthnoccntrisrn and stages of Inoral judgrnent may become nlore significant in affecting ATM. Sornc researchers Inight posit that these last two variables lnight largely involve flight crc\vs.
However, wc must note that as i\ TM sysleIlls become more interdependent, contacts and communications aIIlong diverse Jnembe.rs of the ATM cOIlUllunity will increase. In fact~ we suggest that researchers test whether there are qualitative psychosocial and task performance differences due to ethnocentric and nloral variables engendered by foreign experiences that one travels to--e.g., the t1ight crew--versus those engendered by travelers coming to subjects--e.g., controllers. Finally, interpersonal personality profiles tha[ assess compatibility matches among dyads and other small groupings may more significantly contribute to AT'M. (3) As alluded to in (]) above, environmental research should be based on the notion that there is not one but many environments affecting ATM performance. These include the work, famjlYl social, ethnic, and personal environments of A TM participants~ e.g., cockpit cre\o\t', maintenance personnel, and administrators (er., Bloom. 1996). In essence, all cnvirorlll1ents arc political--which means that ATM is dependent on pcrccpLions concerning infinite needs and finite reSOurces and perceptual disparjties between w'hat is and what should be on the part of multiple participants in multiply-layered and interacting environnlents. Even more specifically, the political element involves not only conflicts, policies, and issues commonly termed poIitical--e.g., government decisions concerning unions and \,\'ages--but also the many daily victories and defeats in what are perceived to be zerO-SU1TI games--e.g.~ contentions with spouses, arguments with creditors, slights stemming from salutations or the lack thereof. Although assessment-based managenlcnt can identify some of the fluctuations in these areas, of crucial import--and most easily identified by competent managers--arc the many iotcn!ional and unintentional features of organizational culture. Especially with significant seJfselection of A TM participants and supporting personneJ--as \-vell as cOlllpelent hUlnan factors research on task and equiprnent attribute--the ongoing monitoring of the psychological effects of organizational culture. may be the most time and cost-effecti ve to\vards ilnproving A l'M
perfonnance. (4) In an era of free flight the very boundaries of human facLors~ traditional research areas conceptually breakdown. As one man's terrorist js another man's freedonl fighter, one rcsearcher~s task attribute is another researcher\. envirolunental or equipment attribute. It is more phenomenologically correct to classify variables as apperceived among ATM participants, not researchers (ef. Klein et ai, 1995).
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(5) Contclnporary research on the philosophy of the social sciences suggests that there is a social transformation of applied psychological knowledge (VlZ" Prjlleltensky~ 1994). That is, through time, the interaction of cultural, historical, political~ econolnic t and other social science variahle~ effects psychological change. \-\'hat Vlas once an empirically and experiInentally validated linkage between a social science variable, A TC performance~ and ATM is no longer. This phenomenon--often ignored by conSUlners of social science research-necessitates an ongoing revalidation effort on lhe part of organizations dedicated [0 improving
ATM. Free flight continues to evolve as the guidon for planning the future of world-v¥'idc ATM. An era of ti"ee t1ight--one that nl0re strongly than ever encompasses internationat multicultural, and other unique challenges--can greatly benefit fronl state~of-the-art psychological support. ThJS s.upport 'W'ill necessitate a cultural revolution in the very conception of hUInan factors research.
REFERENCES Bloom, R.W. (December 6 1996). A psychopolitical analysis of situation aVlureness: An editorial. International Bulletin of Political Psychology, 1(5). (http://w\vw.pr .erau. edu/- se curity). Boeing (1998), Statistical SUJ1Zflzary n..f C:'ornrnercial Jet Airplane Accidel1!s_ Hoeing Company, Scattle, WA. Boer, L.C.~ Harsveld~ M., & Hern1ans, P.R. (1997). Military Ps}'chology, 9, ] 36-149. Borack, J.1. (1995). Alternative techniques for predicting success in air confroller school. t
.Military Psycholog)'~ 7 ~ 207-219 J~. ( I 996). Cogniti vc complexity ~
C:hen~
situational inlluences, and topic selection in intraculturaI and intercultural dyadic interactions. Cornrnunicatiofl Reports 1996, 1-] 2
progress strips in en route air traffic control: A time-series analysis. International Journal of H urnan- Computer~ 43~ 1-13. Endsley, MR (1998) EffeCt of Free Flight Conditions 011 Controller Pe r!o rtna nee, Workload, and Situation Awareness. FAA Civil Aeromedical Institute. FAA (1998a) bttp:l/www.faa.gov/freeflight (online) FAA (1998b) http://www.faa,gov/asd/ (online) Klcin~ R.L~, Biglcy~ G.A.~ Robcrts, K.H. () 995). Organizalional culture in high reliability organizations; An extension. Human ReJation.~·, 48, 771-793~ Luna. T.D. (1997). Air traffic controller shiflwork: What are the implications for aviation safety? A review in Aviation, Space~ and Environnlental Medicifle~ 68, Pp. 69-79 l\-1ertcn~, H.W .• & Milburn, N.l. Performance of color-dependent air traffic control tasks as a function of calor vision deficiency. A -",'iation, Space, & Environfnentai Medicine, 67. 919927. Naylor, G.F.K. (1954). Aptitude tests for air traffic contra I officers. Occupational Psychology~ 28, 209-217~ NRC (1997), Flight to the Future - Human Factors in Air Traffic Control. National Academy Press, Washington, DC.. Prilelltensky, J. (1994). The morals and politic.\' of psychology. NY: Slate University of New
York Press. RTCA (1995). Report of the Board of Directors
Select COlll1nittee on Free Flight. RTCA Incorporated, Washington, DC. Sheridan, TB (1987). Supervisory Control in Handbook of Human Factors., G. Salvendy, ed. WHey & Sons, New York. Shouksmith, G., & Taylor, I.E. (1997). The interaction of culture with general job stressors in air traffic controllers. International Journal oj>A vialion Psychology, 7, 343-352: Vrij~ A., van der Steen, J., & Koppelaar, L. (1995). The effects of street noise and field independency on police officers' shooting behavior. Journal of Applied Social Psychology, 25 17J4-1725. Wickens, C. Harwood~ K. (eds) (1998) Special Issue of HunUln Factors, Air Traffic Control QuarterlY1 7 Air Traffic Conlrol Association. Zeller, A.F. (August 30, ] 959). Human aspects of mid-air collision prevention. Aerospace Medicine~ 551-560. 1
Costa, G., Schallenberg, G., Ferracin, A., & Gaffuri, E. (1995). Psychophysical conditions of air traffic controJ]ers evaluated by the standard shift\'t-'ork index. \¥ork & Stress, 9, 281-288. Davis, C.G.~ Kerle, R.H., Silvestro, A.\\"l & Wallace, W.H. (1960). The air traffic control trauung progranl as viewed by training supervisors .Courtney Co. Rep., 3333 Edwards, M.B., Fuller, D.K., Vortac~ O.U' & Manning~ C.A. (] 995\ The role of flight
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