F AA-AM-76-13 

STRESS IN AIR TRAFFIC CONTROLLERS: 

EFFECTS OF ARTS-III 

C. E. Melton 

R. C. Smith 

J. M. McKenzie 

S. M. Hoffmann 

J. T. Saldivar 

FAA Civil Aeromedical Institute 

P.O. Box 25082 

Oklahoma City, Oklahoma 73125 

November 1976 

Document is available to the public through the 

National Technical Information Service, 

Springfield, Virginia 22151 

Prepared for 

U.S. DEPARTMENT OF TRANSPORTATION 

FEDERAL AVIATION ADMINISTRATION 

Office of Aviation Medicine 

Washington, D.C. 20591 
epot No. 2. Governme nt Accession No. 

FAA-AM-76-13 

4. Title and Subtitle 

STRESS IN AIR TRAFFIC CONTROLLERS: EFFECTS OF 

ARTS-III 

3 . ecp ets Cataog No . 

5 . Report Dote 

6 . Performing Orgoni zation Code 

1-:;;--:--:--;-:----------------------------! 8 . Performing Orgoni zation Report No . 7- Author' s) C. E. Melton, R. C. Smith, J. M. McKenzie, 

S. M. Hoffmann, and J. T. Saldivar 

9. Performing Organ i zation Nome ond Address 10 . Work Un it No . (TRAIS) 

FAA Civil Aeromedical Institute 

P.O. Box 25082 ll . ControctorGrontNo. 

Oklahoma City, Oklahoma 73125 

13 . Type of Report ond Period Covered 

~~~----------------~----------------------------~ 12. Sponsoring Agency Nome and Address 

Office of Aviation Medicine OAM Report 

Federal Aviation 

800 Independence 

Washington, D.C. 

Administration 

Avenue, S.W. 

20591 

14 . Sponsoring 4.gency Code 

15. Supplementary Notes 

This research was conducted under Tasks AM-B-73-PHY-61, AM-B-73-PHY-62, 

AM-C-73-PSY-·39, AM-C-74-PHY-61, AM-C-74-PHY-62, AM-C-74-PSY-39, AM-C-75-PHY-61, 

AM-C-75-PHY-62, and AM-C-75-PSY-52. 

16. Abstract 

Physiological, biochemical, and psychological assessments of stress in air traffic 

controllers were made at Los Angeles (LAX) and Oakland (OAK) Terminal Radar Approach 

Control (TRACON) facilities before and after installation of Automated Radar Termina 

Systems-III (ARTS-III). Heart rates of controllers on duty or at rest scarcely 

changed from before to after ARTS-III installation. Total stress increased at both 

TRACONs, and the increase was entirely due to elevated catecholamine excretion. 

Steroid excretion was significantly reduced at both facilities after ARTS-III 

installation. 

Scores on the A-State scale of the State-Trait Anxiety Inventory indicated that 

introduction of ARTS-III had no appreciable effect on work-related anxiety levels 

of controllers. The post-ARTS-III A-State means for both facilities were not 

significantly elevated. A-Trait was unchanged at LAX but decreased significantly 

at OAK. Assessments of A-State showed significant work-related increments but 

tended to be low. 

There were no correlations between anxiety and physiological data. 

17 . Key Words 

Stress 

Air Traffic Controllers 

Urine Biochemistry 

Anxiety Inventory 

19. Security Clossif. (of this report) 

Unclassified 

Form DOT F 1700.7 (B-72l 

18 . Distribution Statement 

Document is available to the public 

through the National Technical Information 

Service, Springfield, Virginia 22151 

20. Security Clossif. (of this page) 21. No. of Pages 27 Price 

Unclassified 

Reproduction of completed poge authorized 
ACKNOWLEDGMENT 

The authors wish to express their gratitude to all controllers who served 

as subjects in these studies. Our special thanks go to the Los Angeles and 

Oakland FAA officials; without their cooperation and help these studies 

could not have been accomplished. 
STRESS IN AIR TRAFFIC CONTROLLERS: EFFECTS OF ARTS- III 

I. Introduction. 

The computer-based Automated Radar Terminal Systems-III (ARTS-III) supplies the air 

traffic controller with positive aircraft identification and three-dimensional data regarding its 

location and movement in the airspace, and thus 

contributes enormously to safety. ARTS-III 

also eases the workload of controllers by reducing intercontroller coordination, flight strip activity, communication with pilots, and activity 

related to radar and radio adjustments. ARTSIII differs operationally from the old radar 

system in several ways. Controllers do not carry 

out as much "face to face" coordination but must 

communicate by telephone. ARTS-III calls for 

a great deal of keyboard work in use of the computer. The radar consoles are arranged in islands equipped with horizontal cathode ray 

tubes, and the lighting level is somewhat higher 

in the new terminal radar approach control 

(TRACON) facilities than it was in the old 

ones. Many other environmental changes accompanied ARTS-III : temperature is more closely 

controlled, decor is pleasant, and eating facilities 

are improved. Parking is close by, whereas it 

had been in fairly remote areas at the towers. 

The beneficial effects of ARTS-III might be reflected in measurably reduced physiological and 

psychological stress. 

The effect of ARTS-III on controller stress 

was estimated from pre- and post-ARTS-III 

measurements made at Los Angeles (LAX) and 

Oakland Bay Area (OAK) TRACON facilities. 

·when the pre-ARTS-III measurements were 

made at Oakland in August 1972 (OAK-1) and 

at Los Angeles in November 1972 (LAX-1), the 

TRACONs were located in the towers. When 

the post-ARTS-III studies were carried out in 

July 1974 (LAX-2) and November 1974 

(OAK-2), the TRACONs were located in buildings separate from the towers. ARTS-III had 

been operational for about 5 months at the times 

of LAX-2 and OAK-2. Results at the two 

1 

TRACONs were so similar that they are reporte

together. 

II. Methods. 

Thirteen controllers served as subjects i

LAX-1 and 17 in OAK-1. Nine of the origina

13 controllers ( 69 percent) at LAX and 11 o

the o~·iginal 17 ( 65 percent) at OAK served a

subjects in the post-ARTS-III studies. Urin

data were obtained from seven of the nin

LAX-2 subjects (78 percent) . 

Subjects reported to the temporary laborator

areas in the TRACONs 30 minutes before goin

on duty. They were fitted for ambulator

electrocardiography as previously described

E lectrocardiograms (ECGs) from all subject

were recorded on tape throughout each of fiv

8-hour day shifts. Prework he~rt rates wer

measured during recording system checkout a

the time of electrode application. ECG tape

were spot checked at the end of experimenta

periods to verify that the recordings were tech

nically good. ECG tapes were later reduced t

1-minute heart rates in the laboratory at th

Civil Aeromedical Institute (CAMI ). 

Each subject was instructed to void and dis

card urine prior to retiring the night befor

each day of biomec;lical observation and to collec

a complete urine specimen on arising. Thi

specimen was used as the reference specimen i

all biochemical estimates of stress. The subjec

was similarly instructed to void and discar

urine just before going on duty and to collect i

one vessel all urine he voided during the 8-hom

work period. The specimen was used as th

"work specimen" in estimates of stress. 

Urine was collected in 1-quart plastic bottle

that contained dry boric acid as a preservative

\Vhen each urine specimen was delivered to th

temporary laboratory, it was immediately marked 

with a code number, logged, and placed in 

freezer. Specimens were kept frozen until they 

were thawed for analysis at CAMI. 
and creatinine (cr). 5 In this report, results are 

expresse.d as micrograms per 100 milligrams of 

cr. From these results stress indices were calculated as described in an earlier publication. 6 

The State-Trait Anxiety Inventory (STAI)" 

was used to measure stress arousal of a psychological nature in controllers. Immediately before and just after each work period, each 

controller completed the A-State scale of the 

STAI, which measures current anxiety level. 

The A-Trait scale of the STAI, a measure of 

anxiety proneness or typical level of anxiety, was 

presented to each controller just before the initial 

shift of the study and again at the completion 

of the last observed workshift. 

Tape recorders were attached to the TRACO~ 

tape recorders to record radio transmissions between controllers and pilots. It originally had 

been planned to reduce these tape recordings to 

total controller-pilot communication time as a 

measure of workload. Because controller-to-controller communication was recorded m LAX-2 

and OAK-2 and was not recorded in LAX-1 

load. Instead, the busiest approach con

sector at both LAX and OAK was identi

the recorder channel on which the radio tr

missions of that sector were recorded was pla

back in real time, and counts were made of 

number of controller-pilot contacts and of 

total number of aircraft contacted during 

8-hour work period. From these counts 

number of contacts per aircraft was calcula

III. Results. 

II eart Rate. Table 1 shows heart rates 

individuals under prework and working co

tions. :Mean heart rates were the same un

working conditions for the pre- and post-AR

III studies. The LAX-1 mean prework h

rate was slightly higher than the correspon

mean working value, whereas the LAX-2 m

prework heart rate was the same as the LA

mean working value. The OAK-1 mean 

work heart rate was lower than the correspo

ing mean working value, whereas the OA

mean prework and working values were 

same. 

TABLE 1. Individual Heart Rates 

LAX-1 LAX-2 oAK~l OAK-2 

Pre- Percent Pre- Percent Pre- Percent Pre- P

~l!bl~s;t Esu:Js ~ __ I:J._ Work Work /), ~ ~ /), Work Work 

1 92 85 (7. 2)* 89 94 6.0 79 80 1.3 84 86 

2 81 77 (5 .8) 73 84 15.0 66 81 23.2 73 73 

3 78 59 ( 23. 5) 74 58 ( 21. 6) 89 101 14.1 103 98 

4 97 99 2.6 85 89 4.9 74 78 5.7 79 75 

5 80 66 (17.4) 70 69 ( 1. 9) 71 88 24.9 70 78 

6 95 92 ( 3. 5) 90 92 1.8 76 89 17.2 83 92 

7 92 92 0 88 87 (0. 7) 83 73 (11.4) 93 88 

8 87 79 (9.4) 87 77 (11.4) 69 71 2.8 64 60 

9 66 72 9.4 63 67 6.7 65 73 12.6 68 70 

10 72 75 4.7 81 80 

11 75 74 (0. 9) 80 82 

x 85 80 80 80 74 80 80 80 

S.D. 10 13 10 13 7 9 11 11 

* Parenthesis indicate that working value is less than resting value. 

2 
gp 

mean heart r ates during work at the various 

positions. 

Urine Chemistry. T able 3 shows the r esting 

(night sleep specimen) and working values for 

st, e, and ne for L AX-1 and -2 and OAK-1 

resting and working levels of excretion of st 

were significantly r educed in the LAX-2 and 

OAK -2 groups from the levels in LAX- 1 and 

OAK - 1. The r esting level of e excretion was 

not significantly different between the LA X-1 

TABLE 2. Comparisons of Heart Rates During Different Activities* 

Average Significance 

First Activit;t Heart Rate Second Activit;t Heart Rate 

LAX-1 AR 80 LAX-2 AR 81 

LAX-1 DR 79 LAX-2 DR 80 

LAX-1 Others 80 LAX-2 Others 81 

LAX-1 Prework Heart Rate 85 LAX-2 Prework Heart Rate 80 

LAX-1 Average All Positions 80 LAX-2 Average All Positions 80 

OAK-1 AR 78 OAK-2 AR 79 

OAK-1 DR 79 OAK-2 DR 79 

OAK-1 Others 82 OAK-2 Others 81 

OAK-1 Prework Heart Rate 74 OAK-2 Prework Heart; Rate 80 

OAK-1 Average All Positions 80 OAK-2 Average All Positions 80 

*AR = Arrival Radar, DR = Departure Radar, Others = Data Positions, Coordination Work, Supervision 

and Training 

**Wilcoxon matched-pairs signed-rank test 

TABLE 3, Comparisons of Levels of Urinary Stress Metabolites at Los Angeles (LAX) 

and Oakland (OAK) TRACONs Before and After ARTS-III Installation 

st e ne 

Facility Rest Work .t:. .£ Rest Work t:. E Rest Work t:. 

LAX-1 521.3 il52.5 631.2 .01 0.38 1.19 0.81 . 01 2.07 4.26 2.19 

LAX-2 382.9 700.1 317.2 .01 0.76 1.95 1.19 . 01 3.30 5.42 2.12 

t:. 138.4 452.4 0.38 0.76 1.23 1.16 

.E. .05 .01 N.S. .01 N.S . N. S. 

OAK-1 485 . 1 899.2 414 . 0 .01 0.39 1.25 0.86 . 01 l. 59 2. 58 0 . 99 

OAK-2 319.7 679 . 5 360.8 .01 0.76 2.26 1.50 .01 2. 24 3. 47 1.23 

t:. 166 . 4 220. 6 0.37 1.00 0. 64 0.89 

.E. .01 . 01 .01 .01 .05 .01 

3 

Level** 

N.S. 

N.s. 

N,S. 

.01 

N. S. 

N.S. 

N,S, 

N.S. 

.01 

N.S. 

.E. 

.01 

.01 

.01 

.01 
Lj\..X-2 group. Both resting and working levels 

of e excretion were significantly greater in the 

OAK-2 group than in the OAK-1 group. 

N orepinehrine showed an insignificant change at 

LAX and a significant change at OAK from 

before to after ARTS-III installation. 

TAetE 4. Stress Indices for Various Air Traffic Control Facilities 

Facility 2_ .:u... l_ S!!.... 

0 'Hare Tower 1.05 1.41 0.75 0.98 

Opa Locka Tower 0.84 0.64 0.74 1.15 

At l anta ARTcc 0.82 o. 76 0.34 1.37 

Hlaml ARTCC 0. 76 0.61 0. 7l 0.96 

LAX-2 0.75 0.25 0.69 1. 31 

l!ouaton Inter continental Tower (1970) o. 74 1.27 0.29 0.65 

OAK-2 0. 72 0.23 1.31 0 .61 

Houston Intercontinental Tower (1971) 0.68 0.89 0.62 0.52 

OAK·l* 0 . 60 0.62 0. 76 0.43 

l.AX-1* 0.60 0.66 0.34 0.81 

Fort Worth ARTCC 0.34 0.22 0.58 0.20 

*Va lues for OAK-1 and U.X- 1 were derived from all controllers participating in those studies. See Tabl e V for value• from controllers who served in pre- and post-ARTS-III studies. 

justed (c) values of st, e, and ne. This in

greatly facilitates the comparison of stress 

different air traffic control (ATC) facili

Table 4 shows the values for the compo

index, C., together with Cst, c., and Cne at the 

traffic facilities studied thus far. It is evid

from Table 4 that total stress was greater 

LAX-2 and OAK-2 than in LAX-1 and OAK

Further, it is evident that the increase in t

stress is entirely due to increased excretion 

catecholamines, because steroid excretion 

actually reduced in LAX-2 and OAK-2. 

Table 5 shows a comparison of stress ind

calculated from data of individual control

who participated in both studies. Three 

trollers at LAX and two at OAK showed 

creases in C., all controllers at LAX and all 

one at OAK showed decreases in Cst, all L

controllers and all but one OAK contro

showed increases in c., and three controller

LAX and two at OAK showed decreases in 

TABLE 5. Stress Indices ~rom Individual Controllers Before and After ARTS-III Installation 

Cs cst ce cne 

LAX 1 2 1 2 1 2 1 2 

Subject 

1 0.90 1.25 0.96 0.34 0.48 1.80 1.25 1. 61 

2 0.42 0.37 0.64 0.20 0 . 20 0.50 0.42 0.41 

3 0.30 0.36 0.48 0.32 0.09 0.18 0.32 0 . 57 

4 0.48 1. 28 0.33 0.21 0.38 1.11 0.72 2.51 

5 0.62 0.47 0.55 0.14 0.43 0.67 0.89 0.60 

6 0.52 0.47 0.68 0.34 0.20 0.42 0.69 0.65 

7 0.42 1.42 0.59 0.33 0.29 0.59 0.38 3.42 

OAK 1 2 1 2 1 2 1 2 

Subject 

1 0.45 0.68 0.58 0.51 0.53 0.99 0.24 0.54 

2 0.73 0.72 0.50 0.27 1.21 1.17 0.50 0.72 

3 0.57 0.47 0.56 0.21 0.49 0.59 0.67 0.60 

4 0.35 0.·71 0.31 0.29 0.29 1.56 0.44 0.28 

5 0.46 0.69 0.90 0.37 0.23 1.08 0.25 0.63 

6 0.42 0.86 0.59 0.43 0.24 1.27 0.43 0.88 

7 0.27 1.36 0.20 0.21 0.28 2.83 0.34 1.05 

8 0.18 0.57 1.17 0.05 0.15 1.01 0.22 0.65 

9 0.40 0.84 0.73 0.15 0.28 1.81 0.20 0.56 

10 0.33 0.47 0.61 0.16 0.22 1.03 0.17 0.22 

11 0.22 0.74 0.31 0.10 0.16 1.33 0.20 0.79 

4 
ON THE 

STRENG TRIANGLE 

cne 

ORO ('68) OPF ('72) ATL ('73) MIA ('72) LAX- 2 {'74) 

c,. 1.05 0 .84 0 .82 0.76 0.75 

IAH-1 ('70) OAK-2 ('74) IAH-2 ('71) OAK-I c'72 LAX-I ('72) FTW ('73

0 .74 0 .72 0 .68 0.60 0 .60 0.34 

Fwum; 1.-Ranking of total stress in ATC facilities by size of Streng triangles. The internal lines r epresent t

r elative contributions of 17-ketogenic steroids ( c,,), epinephrine (c.), and norepinephrine ( Cne) to total stres

the internal lines also show the r elationships between c,,, c., and Cn •· 

The data in Table 4 can be presented graphically (Fig. 1 and 2) on the Streng triangle.

12 13 

In this diagram the values for Cst, c., and Cne 

are represented by lines diverging at angles of 

120° from a common point. Lines constructed 

perpendicular to the ends of the diverging lines 

form an equilateral triangle, the altitude of 

which is equal to the sum of the lengths of the 

divergent lines. The altitudes (thus the area) 

of the triangle is proportional to C., the average 

of C8 t, c., and Cne· One can quickly gain an 

appreciation of relative stressfulness by simply 

comparing the sizes of the triangles representing 

the different ATC facilities (Fig. 1) . In addition, one can easily see the relative contribution 

of each of the three metabolites to total stress. 

In the cases of LAX and OAK, it is apparent 

that steroid excretion is greatly reduced in 

LAX-2 and OAK-2 from the levels in LAX-1 

and OAK-1 (Fig. 2). The increase in total 

stress can easily be seen to be due entirely to 

elevated catecholamine excretion. 

5 

ST RENG TRIANG L E REPRESENTATION OF CHANGES 

OCCURRING IN Cst. c 8 , AND Cne AFTER INSTALLATIO

OF ARTS m AT OA K LAND AND LOS ANGELES TRACON

'·~· A 

Cne 

OAK ('72) OAK ('74) 

Cs " 0 .60 0 .72 

& LG 

LAX ('72) LAX ('74) 

0.60 0 .75 

FJGUin~ 2.-Streng tria ngles showing the incr ease 

total stress in OAK-2 and LAX-2. See Figure 

legE> nd for explanation. 
higher than the mean for controllers at OAK 

(27.7) ; however, this trend just failed to achieve 

accepted levels of statistical significance. Thus, 

baseline, or typical, levels of anxiety were 

roughly comparable for both groups, with the 

OAK controllers indicating slightly less general 

proneness to anxiety. 

The A-State results (Table 6) were very 

similar for both LAX and OAK controllers. 

Participants at both facilities reported slightly 

higher mean A-State scores after ARTS-III 

installation, but the increases did not approach 

statistical significance. Thus, it is clear that 

acquisition of the ARTS-III display had no 

effect, beneficial ·or otherwise, on anxiety levels 

of controllers. 

TABLE 6. 

LAX 

OAK 

Mean A-State Raw Scores for Air Traffic Controllers 

Before and After ARTS-III Installation 

Pre-ARTS-III Post-ARTS-III 

Mean S.D. Mean S.D. 

30.9 6.0 33.4 6.3 

30.3 4.2 31.2 4.2 

In previous studies of anxiety in air traffic 

controllers,5 7 11 the most consistent finding has 

been a significant increase in A-State scores from 

before shifts to after shifts. In the present 

study, the effect was found to be significant only 

for the OAK group (p ~ .01 for both pre- and 

post-ARTS-III assessments) (Table 7). The 

LAX controllers showed the same overall trend; 

however, in both the LAX-1 and LAX-2 evaluations, three of the nine participants typically 

reported substantive decreases in A-State from 

before to after shifts, compared with only one 

such instance for the 11 controllers at OAK. It 

is worth noting, however, that if the additional 

four controllers at LAX who participated in 

the pre- but not the post-ARTS-III study are 

added to the analysis, the LAX- 1 comparison 

of before- and after-shift A-State scores achieves 

6 

operating at LAX during the two assessme

TABLE 7. Mean A-State Raw Scores for LAX and OAK Control

Before and After Workshifts 

Pre-ARTS-Ill Post-ARTS-III 

Before After Before A

LAX 28.4 33.3 31.9 3

OAK 28 . 1 32.5 28.4 3

Comparison of Physiological and Psychol

cal Data. As an additional step, analyses w

conducted on the possible relationship betw

the physiological measures obtained in th

assessments and the ST AI data. In gene

there was little, if any, correspondence betw

the two sets of data. Neither A-State 

A-Trait levels related to working or res

heart rate, C., Cst, c., or Cn e values. Analyse

changes in A-State levels also were not correl

with changes in these physiological measure

TRAOON Workloads. In LAX-1 there w

13,806 radio contacts with 1,803 aircraft (

contacts per aircraft) on the busiest appro

control sector. In LAX-2 there were 14

contacts with 1,860 aircraft on the same se

(7.64 contacts per aircraft). In OAK-1 th

were 8,712 contacts with 1,190 aircraft (

contacts per aircraft), and in OAK-2 there w

8,827 contacts with 1,238 aircraft (7.13 cont

. per aircraft). Thus, the number of aircraft 

number of contacts both increased by 3 per

at LAX. At OAK, the number of aircraft 

creased by 4 percent, while the number of 

tacts increased by only 1 percent. 

IV. Discussion. 

The possibility that controller physiolog

and psychological stress would be reduced 

ARTS-III was not demonstrated at LAX 

OAK. 

Other FAA studies1 2 of the effects of AR

III on controller workload in the TRACO

at Houston Intercontinental Airport and 

Boston Logan Airport have shown a net red

tion in air traffic controller activities. Simila

the objective measures of workload in the pre

study show either a net decrease in workl
pyg

stress cannot be attributed to increased workload. 

Conversations with controllers and supervisors 

uniformly indicated that ARTS-III is a large 

step forward in air traffic control. None who 

were interviewed would willingly return to the 

old methods. However, there was also general 

agreement that 5 months' use is not long enough 

to develop total familiarity and trust in the 

equipment. Controllers at both LAX and OAK 

stated that a complete evaluation by controllers 

would be possible only after a good deal more 

experience had been gained in this new work 

environment. 

Thus, the increase in the estimated total stress, 

entirely accounted for by increased catecholamine 

output, may be viewed as being based on controllers' attjtudes at that time toward ARTSIII. At the time of these studies, controllers' 

attitudes were somewhat ambivalent. Controllers liked the reduction in coordination both 

with other facilities and within the TRACON, 

they liked the sense of privacy at the radar 

islands, and they liked the decor and the illumination level. They did not like the location of 

the telephone panel and the inconvenience 

occasioned by unfamiliarity of other ATC facilities with new TRACO~ procedures. 

The reduced level of excretion of st, under 

both resting and working conditions, after 

ARTS-III installation indicates reduction in 

chronic stress. The chronic stressor that is reduced from before to after ARTS-III installation cannot be positively identified, but it may 

7 

gpy 

direct supervision, and improved labor-man

ment relations. 

·with respect to A -State levels, the fin

are generally typical of those obtained 

other controller populations; to wit, workin

an air traffic controller has some, apparently 

mal, arousing qualities as evidenced by the 

age increase in A-State scores from befo

after shifts. Though of insufficient frequen

be considered a clear trend in the present s

the few individual exceptions to this fin

may reflect certain diversionary character

of the work for some persons who have hi

than-average levels of chronic anxiety. I£ 

sequently confirmed, this would lend suppo

Spielberger's8 hypothesis that persons relat

high in A-Trait may be diverted from i

nalized stimuli that are cues for anxiety 

sponses by engaging in absorbing tasks; 

observation was also considered by Smith

the assessment of anxiety in student pilots

The failure of A-Trait and A-State mea

to correlate in any way with the physiolo

measures employed in this study is cons

with the norm for such studies. 3 Of many 

sible explanations for this lack of corresp

ence, perhaps the simplest is that the ph

logical and psychological measures assess diff

aspects of the possible reactions to stress s

tions. Be that as it may, it is clear that w

ever the physiological cost of work as an 

traffic controller, the psychological impac

least as reflected in anxiety states, is not 

ticularly dramatic. 
References 

l. Eldredge, D.: Data Report on the Before and After 

ARTS III Automation at Boston Terminal. FAA 

Project No. 012-603--010, ATC Systems Performance 

Measurement, 1973. 

2. Eldredge, D. : Data Report on the Before and After 

ARTS III Automation at Houston 'l'erminal. FAA 

Project No. 012-603--010, ATC Systems Performance 

Measurements, 1973. 

3. Levitt, E. E.: The Psychology of Anxiety, New York, 

Brooks-Merrill Co., 1967. 

4. Melton, C. E., Jr., J: M. McKenzie, B. D. Polis, G. E. 

Funkhouser, and P. F. Iampietro: Physiological 

Responses in Air 'l'raffic Control Personnel: O'Hare 

'l'o"·er. FAA Office of Aviation Medicine Report No. 

FAA-AM-71-2, 1971. 

5. Melton, C. E., J. M. McKenzie, R. C. Smith, B. D. 

Polis, E. A. Higgins, S. l\1. Hoffmann, G. E. Funkhouser, and J. T. Saldivar, Jr.: Physiological, 

Biochemical, and Psychological Respo;1ses in Air 

Traffic Control Personnel : Comparison of the 5-Day 

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Aviation Medicine Report No. FAA-AM-73-22, 1973. 

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and S. l\f. Hoffmann : Comparison of Opa Locka 

Tower With Other ATC Facilities by Means of a 

Biochemical Stress Index. FAA Office of Aviation 

l\Iedicine Report l\"o. FAA-Al\1-74-11, 1974. 

8 

7. Melton, C. E., R. C. Smith, J. M. McKenzie, J. T

Saldivar, S. l\f. Hoffmann, and P. R. Fowler: Stres

in Air Traffic Controllers: Comparison of Two Ai

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Rotation Patterns. FAA Office of Aviation Medicin

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8. Spielberger, C. D. : 'l'heory and Research on Anxiety

In Anxiety and Behavio1·, New York, Academi

Press, 1966. 

9. Spielberger, C. D., R. L. Gorsuch, and R. E. Lushene

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Alto, CA, Consulting Pyschologist Press, 1970. 

10. Smith, R. C.: The State-Trait Anxiety Inventor

and the Assessment of Stress in Private Pilot Train

ing. Proceedings of the 80th Ammal Convention o

the Anw1·ican Psychological Association, 7 :64-65

1972. 

11. Smith, R. C., and C. E . Melton: Susceptibility t

Anxiety and Shift Difficulty as Determinants o

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SPACE MEDICINE 45:599-601, 1974. 

12. Streng, 0.: Eine Volkerkarte. Eine Graphisch

Darstellung der Bisherigen Isoagglutinationsresultate

ACTA SOCIETATIAS MEDICORUM FENNICAE 

DUODECIM, 8:1-17, 1927. 

13. Streng, 0.: Das Isoagglutinationsphanomen vom 

Anthropologischen Gesichspunkt Aus, ACTA 

PA'l'HOLOGICA ET MICROBIOLOGICA SCANDI

l\"A VICA, Suppl. 5, 59-62, 1930. 
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' Federal Aviation Administration, Office of Aviation I. Melton, C. E. Federal Aviation Adm

Medicine, CiYil Aeromedical Institute, Oklahoma II. Smith, R. C. Medicine, Civil Ae1·

City, Oklahoma. STRESS IN AIR TRAFFIC CON- III. McKenzie, City, Oklahoma. STR

TROLLERS: EFFECTS OF ARTS-III by C. E. J. M. TROLLERS: EFFEC

Melton, R. C. Smith, J. 1\f. McKenzie, S. 1\f. Hoffmann, IV. Hoffmann, Melton, R. C. Smith, J

and J. T. Saldivar, 8 pp. Report No. FAA-AM-76-13. S. M. and J. T. Saldivar, 8 p

Physiological, biochemical, and psychological assessments of 

stress in air traffic controllers were made at Los Angeles 

(LAX) and Oakland (OAK) Terminal Radar Approach Control (TRACON) facilities before and after installation of 

Automated Radar Terminal Systems-III (ARTS-III). Heart 

rates of controllers on duty or at rest scarcely changed from 

before to after ARTS-III installation. Total stress increased 

at both TRACONs, and the increase was entirely due to eleYated catecholamine excretion. Steroid excretion was significantly reduced at both facilities aftPr ARTS-III installation. 

Scores on the A-State scale of the State-Trait Anxiety 

Inventory indicated that introduction of ARTS-III had no 

appreciable effect on work-related anxiety leYels of controllers. 

The post-ARTS-III A-State means for both facilities were not 

significantly elevated. A-Trait was unchanged at LAX but 

V. Saldivar, 

DescriptOI-s 

Stress 

Air Traffic 

Controllers 

Urine 

Biochemistry 

Anxiety 

Im·entory 

Physiological, bioche

stress in air traffic 

(LAX) and Oakland 

trol (TRACO:\") faci

Automated Radar Ter

rates of controllers on 

before to after ARTS

at both 'l'RACONs, an

vated catecholamine 

nificantly reduced at b

Scores on the A-S

Inventory indicated t

appreciable effect on " 

The post-ARTS-III A-

significantly elevated. 

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: decreased significantly at OAK. Assessments of A-State decreased significantly 

: sho\ved significant work-related increments l;Jut tended to be showed significant wo

: low. low. 

There were no correlations between anxiety and physiological data. There were no corre

cal data.