topic of “morale gripes.” After a half-decade
of attention from social scientists and industrial-
relations personnel, the relationships between
morale and worker behavior are still not clearly
understood. One cannot say with any credi-
bility, for example, that the happy worker is
the “best” worker. So, although all of us would
like to have an easier and more enjoyable job,
it is important that the investigator distinguish
between the discomforts and pressures that are
inherent in the task and those that could be
attributed to poor environmental conditions, un-
satisfactory supervisory practices, etc. Hence,
the focus of attention in the present context
should be first upon those factors that determine
controller performance and only secondarily upon.
questions of morale.

III. The Philosophy of Corrective Action.

One question that must be answered in this
approach to ATC system-error evaluation is to
what purpose will incident information be used.
This purpose, to a large part, will determine the
manner of reporting as well as what will be
reported, and calls for the design of a complete
system of reporting that takes into account
the sources of information, its availability to
those who are responsible for reporting it, and,
finally, the uses of the information by those who
receive it.

Of the possible approaches to reporting errors,
one would involve two distinct reporting systems.
The first, the “legal” one, would be concerned
with who was responsible for the error, assuming,
of course, that the error was attributable’ to
performance of a controller. The second report-
ing system would operate independently of this,
for the purpose of getting an objective descrip-
tion of what transpired. The assumption behind
this entire system would be that if responsibility
is being assessed, not all parties will speak forth
with frankness and objectivity, while, on the
other hand, they would be willing to speak if
there were available a second reporting system
not involving penalties. A serious objection to
this dual system is that there would come about
an undermining of the “legal” system, since the
controller could say, “Oh, well, I have ample
opportunity to give the information of what
actually transpired to the second ‘objective’
system”; consequently, the assignment of respon-
sibility where there is a personnel error would
be come more difficult.

A second possible reporting approach would be
to maintain essentially the present system of re-
porting but to shift the emphasis on awarding
penalties. Thus, this system would place very
high penalties on failure to report an incident
or on incidents where there is evidence of willful
negligence. In this manner, the controller who
is aware of the incident would be faced with much.
greater penalties for failure to report than were
he to report such an incident. Where errors are
attributable to incompetence, we must consider
who was responsible in the first place for that
controller being in the position to make the error.
Anytime a judgment is made that the error was
primarily attributable to the incompetence of
the controller, this is also a basis for considering
if some portion of responsibility lies with his
administrative superiors. Therefore, where the
error was due not to willful negligence but to
incompetence, there is no need to invoke a penalty
other than possibly removing the man from active
controlling or, in extreme cases, downgrading him
to a position of lesser controller responsibility.
Downgrading does not necessarily mean the loss
of GS level, but shifting over to a less demanding
control position. There are additional ways, al-
ready in practice, of dealing with the negligent
controller or the one who fails to keep proficient
in his duties. Low performance ratings can deny
him the chance of promotion and ultimately even
endanger his job security. Supervisors can cite
him for failure to maintain an acceptable level
of competence and thus make him ineligible for
a within-grade salary increase.

This second approach would also essentially
take notice of the fact that some errors represent.
accidental or nonintentional behavior such as a
slip of the lip or a transposition of digits. Obvi-
ously, this type of behavior should not be en-
couraged but, on the other hand, it is not negli-
gence or incompetence. This system of penalties
would encourage controllers to take a more ob-
jective professional approach to the system prob-
lems of air traffic control. Admittedly, there is a
tendency not to mention one’s own mistakes;
however, it should be emphasized to the controller
that this admission is professional behavior, since
it represents a concern for the task in hand. It
also indicates a willingness to adopt an attitude of
self-objectivity, which would enhance the amount.
and quality of information currently being



APPENDIX,

Table 1. Identification of Incident Causes

Place one check under A to indicate which of the items below was the primary cause of the incident.
|Also check any of the items that may have been contributing factors, indicating Major (B) or Minor (C).|

Primary

A

Contributing

c
B Minor

—failure to detect critical aircraft, vehicles, radar targets, or obstacles.

—failure to scan flight strips for significant data (e.g., altitude).

|—misidentification of aircraft or radar target.

2 [acceptance of flight strip or pilot readback with erroneous data.

g —acceptance of flight strip on nonexisting flight.

£2 |—tailure to acknowledge (detect) radio or verbal communication, _|
misreading of display data (fight strips, etc.).
[misunderstanding of radio or verbal communication (“hears it wrong”).
|—misinterprets other controller's response to query (nonpositive communication).

au [failure to record, retain, or pass on critical information,

= |—failure to give instructions or information needed by pilot when able to do so.
—error in judgment of and/or computation of aircraft speed, direction, or distance.
—failure to comprehend significance of situation, to see problem developing (e.g.,

E | aireraft position report and posted data are incongruent).

S |Tiaiture to note discrepancy of Information at hand (eg. BTA incongruent with

& | reported airspeed).

P [ase of poor judgment or faulty reasoning in making a decision.
|-failure to plan, coordinate, or take initiative when indicated by situation.
—makes unreasonable assumption about airspeed, aircraft position, or altitude.

 |—tmakes speech error in transmission of information or instructions to pilot or

Zz |_other ATO or ground personnel.

S= |—marks strip or moves “boat” incorrectly.

ZS |—marks wrong strip or moves wrong “boat.”

© |—incorrect strip posting (e.g. wrong fix).
| poor supervisory coordination and judgment.

xm |—‘static” or erroneous information from alr carrier, pilot, or ground personnel,

é —shortage of qualified controllers to operate positions effectively.

© | shortage of qualified supervision at time of incider

| |-inadequate preduty familiarization.

& |-ambiguity apparent in procedures, standards, or letters of agreement.
[controller proficiency; controller operating above his skill level or “filling in”

at unfamiliar position.
© |—inemicient equipment or workspace layout.

wa [inefficient communication channels.

%@ |—anrellabie or maifunctioning equipment or radio communications,

as equipment unavailable or out of service.

Z |-vision reduced or obscured—weather, airfield construction, radar clutter, ete.

|—neating and ventilation ; lighting, glare, noise.

gz | flstractions trom horseplay or VIP visitors.

E |—work attitude; job satisfaction; personal problems.

 |Fcontrotied health, especially vision, hearing.

|—fatigue, drugs.

work schedule; watch rotation.



involved in that system’s operation, then the re-
quired data from incident investigations obvi-
ously must be phrased in human-function
terminology.

A discussion of the various levels of human
functioning, including related sensory, atten-
tional, and memory processes, is beyond the scope
of this paper.’ An example, however, may pro-
vide clarification.

Suppose that a radar controller failed to main-
tain separation between two aircraft. One might
first determine whether the radar display was
adequate and that the controller had no visual
problems. Then, one might ask if the controller
was briefed on new procedures at his position and
was he experienced in the tasks required? Was
his attention focused upon the targets in question?
Next, did he identify these targets (from knowl-
edge of their speed, track and position) ? Finally,
having identified the targets, why wasn’t a con-
fliction interpreted? Answers to such questions
have implications for corrective actions. The
purpose of selection is to screen out operators who
fall below a given standard applicable to a par-
ticular sense mode. Attentional sets and task rou-
tines are established through training. If identi-
fying is involved, the purpose of training is to
establish the standards or models found in
memory that are required by this function.
Selection can also enter here to pick out those
individuals who can readily acquire and store
such models. If the error is in interpreting, then
the analyst must determine that the prior func-
tion of identifying can be performed and that the
required models have been established by training.
Procedural manuals and checklists come under
scrutiny insofar as they (a) establish different
behavior patterns that are needed as the con-
troller moves from one station to another, or
(b) become aids in maintaining long-term mem-
ory retention of models and routines.

In Table 1, Appendix, is listed, in the first four
sections, a total of 21 behaviors, phrased in func-
tion terminology, that could lead to an incident.
The breakdown into four categories—sensing,
memory, judgment, and communication—is an
arbitrary one. It is likely that whoever is
charged with the duty of incident evaluation at
a facility would require training in the use of a
form containing such items because of the diffi-
culty inherent in isolating the primary function
at fault.

Items such as appear in Table 1 are the heart

of the whole incident report, and the identifica-
tion of one item as the primary cause is raison
@etre of the entire investigation process.

The report form itself should be limited to no
more than four pages and should be referred
to as a system-error, rather than a deviation,
report in accordance with the philosophy of this
paper. Thus, it would not necessarily focus at-
tention on any particular controller or controllers.
The first page should include the following:
information on the facilities involved; the date
of the incident and time of occurrence; a list
of the facility personnel involved and their
ratings; a list of aircraft, vehicles, or objects
involved, to include flight plans; how the inci-
dent was reported and by whom; data on the
route structure; weather information; type of
control (radar, nonradar) ; beaconry data; stand-
ards and procedures involved. The second page
would be devoted to a summary narrative. The
third page would include Table 1, the work-bed
from which the primary and contributing factors
are identified. The fourth page would have
space for recommendations for remedial action
and boxes for the responsible officer to indicate
whether appropriate data are being attached,
to include: airway-structure and flight-path
sketches; a sketch of the facility layout as ap-
propriate to the analysis of the incident; letters
of agreement as appropriate; flight strips and
tape recordings of controller-pilot communica-
tions. Also, it may be desirable to have on this
page some indication of review action.

Also recommended is the submission of an
“ATC Personnel Report” for each controller or
supervisor involved in the incident. This form
would be completed, in part, by the responsible
officer and also by the controller/supervisor in-
volved. It would contain the name of the indi-
vidual, his facility, age, grade, and marital
status; time entered into duty, time in control
functions, and months in that function; the con-
troller’s experience, with number and type of
facilities worked, their locations, and his length
of service at these locations; his ATC training
and previous history of incidents; his work
schedule for the previous months; the amount of
sleep the previous “night”; information on recent
physical examinations, their dates, and results in
terms of current health; recent illnesses and use
of medications. This adjunct form would also
contain data on the number of aircraft under this
particular individual’s control before, at the time



received on system failures. An unreported inci-
dent can involve the most serious considerations,
since the controller who observes the incident is
not always able to determine that it was his fault.
In many cases, of course, the incident may be
due to a malfunction of equipment. There may
be an Omni that needs calibration or other elec-
tronic devices that are in need of repair. The
controller is only aware, however, that two air-
craft have come too close together and is not
necessarily aware of all the causes behind this.
Under the present system, if he felt that the inci-
dent would go unnoticed, he might not report it.
On the other hand, if he recognized that there
would be the severest penalties for covering it
up, he would not wish to run the risk of being
discovered. At any rate, we must encourage, by
some means or another, a greater willingness to
report the occurrences of incidents. Increasing
the penalty for error when the controller is in-
volved in the incident tends to discourage report-
ing. It is highly desirable to develop an
incident-reporting system that would encourage
the controller to take a more objective analytical
position with respect to his behavior and failure.*
With high penalties being assessed for errors,
however, it is unlikely that the controller will
take this position; he will probably become de-
fensive or apathetic. Consequently, it is felt that
putting the penalties on failure to report and/or
negligence would encourage the controller to have
a greater willingness to admit honest mistakes.
It also follows that he would be more predisposed
to reveal his thinking, his feelings, his reactions,
and his part in the incident that precipitated the
event. Errors are a part of human functions that
can never be completely eliminated. Furthermore,
not every controller error reflects deficient capa-
bility. It is contended by some that only the
better controllers become involved in incidents
since it is these men who man the high-load
positions. The analogy may be drawn with the
baseball shortstop, where the better fielders usu-
ally commit more errors since they involve them-
selves in the more difficult attempts.

Another point should be raised, which, while
independent of the type of reporting system or
penalty system established, still represents a weak-
ness in the present system. Very often where
there is controller error, recommendations are
made for training, with the controller in some
cases being sent through the entire facility train-

ing program. It is highly questionable if this
training is effective since it represents a shotgun
approach; that is, a tacit admission on the part
of the administration that “We don’t know what
particular deficiency led to this error; therefore,
train him in everything.” Is it not reasonable to
assume that in general the controller is a capable
and efficient person who has made a mistake?
To assume that he is completely incompetent
and needs a total retraining raises serious doubts
concerning the management system permitting
such an unqualified man to work.

Following an incident and its analysis, the
analysis should be sent back to the controller,
where he, with the aid of a senior controller,
would review the case to ascertain where he
has made his error and to determine a custom
program of retraining. Psychologically, this
would have maximal benefit since the controller
would be directly involved in developing the
analysis. This element is lacking in lecture ap-
proaches and reviews of material, most of which
he has Jong since mastered. This self-critique
should encourage greater objectivity and self-
analysis on the part of the controller. The con-
troller and his advisor would be formally obli-
gated to state their opinions as to the determi-
nants of the controller’s error and to further
indicate what remedial action was undertaken.
This procedure would also indicate that the ad-
ministration is not simply concerned with point-
ing out who was at fault but is concerned with
finding out who was at fault in order that the
controller himself can actively correct what has
gone wrong. From the point of view of maxi-
mizing system efficiency, the prime reason one
would want to find out who made the error is
in the hope that the controller could correct his
procedure.

IV. Incident Reporting Format.

It should be clear that these views dictated a
new approach to incident-report-form design.
Facility-incident reviews often focus upon the air
traffic procedure or rule that has been violated;
eg., failure to maintain separation. Regional
offices sometimes consider broad categories of
classification that appear to overlap; e.g., atten-
tion, coordination, technique, and communication.
These approaches tell the systems analyst little
about what aspects of the system were compro-
mised. If one is to seek sources of system error
in terms of the human functions assigned to and


REFERENCES

1, Gaanz, R. M., ed,, Psychological Principles in System
Development. New York, Holt, Rinehart, and Win-
ston, 1962.

2. Pearson, R. G. Human Factor Aspects of ATC Inci-
dent Involvement: An Adjunct to the Report of the
Near Mid-Air Collision Study Group, Civil Aeromed-

ical Research Institute, Oklahoma City, Oklahoma,
July 1962. Mimeo.

. Vasinas, J. N., Firzpatricx, R., DuBots, P. H., and

Yourz, R. P. Human Factors in Near Accidents.
USAF School of Aviation Medicine Report, Project
Report No, 21-1207-001, Randolph Air Force Base,
Texas, June 1953.



AM 65-10

ATC SYSTEM ERROR AND APPRAISAL
OF CONTROLLER PROFICIENCY

William F. O’Connor, Ph. D.
Richard G. Pearson, Ph. D.

Approved by Released by
Stamnbey A Hebe I dL Wake
Srantey R. Mouter, M.D. M. S. Wurre, M.D.
Director, CARI Feperat Arr Surcron
July 1965

FEDERAL AVIATION AGENCY
Office of Aviation Medicine
Civil Aeromedical Research Institute
Oklahoma City, Oklahoma



Name.

Table 3. Controller Performance Checklist

Date_

By.

ITEM

Satsifactory

Needs
Improvement

Unsatisfactory

. Use of proper phraseology.

. Completeness of strip marking.

. Legibility of strip marking.

Quality of voice transmissions.

. Scanning efficiency (tower, radar, boards).

. Keeps boards in order—strips sequenced, deadwood

removed,

. Accuracy of computations.

. Effectiveness of long-range control planning.

2

Coordinates effectively and judiciously.

10.

Keeps pilots posted on traffic, weather, ete.

1.

Uses good judgment in decision-making.

. Accurate memory; stores data without need of memory

aids.

18.

Familiarity with procedures and letters of agreement.

14,

Team cooperation ; responsiveness.

15.

Work attitude; conduct.

16,

Initiative ; knows when to take action.

17.

Ability to handle emergencies or heavy traffic under
pressure.

18,

Willingness to accept responsibility.

19,

Knowledge of own capabilities, limitations.

. Awareness of others’ capabilities, limitations.

Appendix 10



Table 2. Incident Chronology

No, ——____ Facility
Date
By

Instructions: Briefly note location, action, or activity of controller/supervisor/aircraft/vehicle at critical minutes of
involvement. Use additional sheets if required.

‘Time Controller/Supervisor Controller/Supervisor Aireraft Aireraft/Vehicle

Appendix 9



of, and after the incident. The above items
would take up approximately one-third of this
page; the remainder of the page would be devoted
to space for several paragraphs wherein the con-
troller could make a personal statement of his
involvement in the incident; perhaps room for a
paragraph statement on his recommendations for
remedial action; and finally, a brief statement as
to whether the controller agrees or disagrees with
the findings of the facility review committee.
Finally, we encourage the use of an incident-
chronology form (Table 2, Appendix) to aid in
the time-series analysis of the involved parties.
This should save considerable time and confusion
in determining “who did what, when and where?”

V. Implementation and Data Analysis.

The best possible form and procedure should
be developed for implementation. Haste in intro-
ducing a new report form into the field without
adequate pretesting could endanger the success of
the program, Special consideration should be
given to the manner in which the program would
be introduced into the field, including perhaps
a manual describing the purpose of the new
system, with an example of how the report should
be completed.

In establishing the new report format, some
thought will be required to make it compatible
with (a) not only the kinds of questions to be
answered but (b) the coding system to employ
for rapid data retrieval and statistical analysis.
For ease and economy of data processing, initially
an edge-punch card system would seem sufficient,
unless access to a computer were available. A
feature of this system is the ability to derive
summary statistics rapidly and accurately. In
order to properly conduct the kinds of analytical
studies that this system is capable of generating,
personnel versed in system research and statistics
are a necessity.

VI. Performance Appraisal.

As indicated earlier, we feel that periodic ap-
praisals of controller proficiency should become
an intimate part of the effort to determine sys-
tem effectiveness. Although one can hear com-
plaints that there are too few “good” controllers,
there has been no clear-cut case presented to show
that the present group of controllers constitute

a major source of system inefficiency. One can
just as readily indict equipment design or layout,
supervision, or operating procedures. Admittedly,
since the controller constitutes such a critical
communication link in the ATC system, inefficient
performance is cause for concern; but objective
data are needed on proper use of phraseologies,
visual-search efficiency, flight-strip marking, etc.,
if individual and group weaknesses are to be
pinpointed and corrective actions are to become
clear. Problems begin with the new controller.
When is he ready to be put on a position?
Then, later, how well is he progressing? Can
he take on more difficult assignments? Should
he be promoted? And finally, when traflic gets
heavy, the supervisor must ask, “Should I keep
him on the position?” What guidelines does the
supervisor have to follow in the latter case? If
he makes a poor decision and a near midair col-
lision results, does the supervisor share part of
the blame?

A formalized proficiency rating could serve as
a guideline for position-assignment choices, re-
ducing the conflict inherent in supervisory de-
cision. It could be used to identify areas of
training and as a basis for personnel actions. In
interviews with controllers, the supervisor would
have an objective basis upon which to discuss
individual actions.

An objective and valid index of controller
performance on the job would also serve to
answer the question of the relationship of con-
troller proficiency and incident involvement. The
relationship could very well be curvilinear; that
is, top-quality controllers who man high-stress
positions and poor controllers would have more
incidents than the average controller.

A special checklist would be required, and a
20-item prototype is presented in Table 3, Appen-
dix. This checklist is not intended to be any
formal merit-rating system, but merely a means
to identify elements of proficiency that need to
be improved. For optimum benefit, it probably
should be completed monthly by the controller’s
crew chief. Since supervisor personnel would
ultimately be responsible for the appraisal find-
ings, they accordingly would have to be pre-
pared to demonstrate the appropriate behaviors
basic to shaping the growth of their subordinates.


(b) by careful analysis of the collected facts and
apportionment of “blame” to system components.
Conceivably, meaningful quick-fixes might be-
come apparent at this point, but decisions to effect
major system changes had best wait until suf-
ficient data are at hand to support conjectures.
If a decision is made to implement a quick-fix
that “looks good,” management should be sure
that the solution does not compromise already
proven design standards; e.g., using sound-ab-

‘a, INCIDENT INVESTIGATION

3 ysten Error
incident Chronology

controller Report

REPORT FORMS

b._INCIDENT ANALYSIS

a?

PERFORMANCE
£, ASSESSHENT OF MaZOR SOURCES | <Q} APPRAISAL
OF SYSTEM ERROR FINDINGS

oo

fe RECOMMENDATIONS FOR
SYSTEM MODIFICATION

Fieure 1—Schema for incident evaluation.

sorbing bafiles that nullify the gain derived from
an efficient overhead-lighting system. Continu-
ing with the schema, each incident report will
be filed (c) at some central point within the
agency for later statistical analysis (d). Hope-
fully, the results (e) when subjected to definitive
study by research and operations personnel, will
reveal those areas (f) contributing significantly
to system error together with an indication of
the magnitude that each contributes. From
microscopic examination of the problems within
such areas, recommendations for system modifi-
cations emerge (g). Not to be overlooked in the
schema is important insight that can be gained
from objective periodic appraisal of individual
controller performance. Performance appraisal is
considered in greater detail below.

In assessing the degree of controller involve-
ment in an ATC incident, it may be helpful to

consider a classification of factors that can de-
termine controller performance. As seen in the
list below, poor controller performance can be
attributed to a man’s job capacity, to the
“machinery” with which he works, or to certain
factors that determine the context in which man

DrverMinants oF CONTROLLER PERFORMANCE

A. Personnel Capability.
1. Selection.
a. Ability.
b. Experience.
c. Personality, attitude, interests, physical
fitness.
2. Training.
B. The System.
1. Design.
a. Equipment design; displays and controls.
b. Work-space layout.
¢. Communications networks.
d. Memory aids.
e. Environmental considerations.
2. Operation,
a. Workload.
b. “Noise.”
C. Modifiers of Context.
1. Supervision,
2. Operating procedures; policy; rules.
3. Health and morale.
a. Drugs, diet, sleep.
b. Family problems as source of mental
distraction,
4, Work schedule and watch rotation.

interacts with machine. What this approach
acknowledges then is that an incident can be a
product of a multiplicity of factors, many of
which are beyond control of the controller in-
volved; in colloquial terms, the controller is
“sandbagged.” It seems inconceivable that an
individual controller would be assigned sole re-
sponsibility for an incident without knowledge
that the man, equipment, and work environment
have been first selected so as to minimize the
opportunity for system error. This viewpoint
should be considered in the design of report
forms, in the development of routines for statisti-
cal analysis, and in the final stage, in which
assessment of system-error sources is made.

In evaluating an incident, it will also be im-
portant to identify the principal and secondary
controller functions, or behaviors, involved with
any contributing factors from the system or the
context. Since there will be interviews with
controllers, it is important that the investigator
carefully weigh any remarks falling within the


ATC SYSTEM ERROR AND APPRAISAL
OF CONTROLLER PROFICIENCY

I, Introduction.

Air traffic control has become an increasingly
complex system involving men and equipment
in a continuous and dynamic descision-making
function. Future developments point to the rising
use of complex equipment, including high-speed
computers, as aircraft speeds and the system’s
load continue to rise. By projecting current
trends, it can be anticipated that future system
changes involving equipment, personnel, and/or
procedures point to the need for longer and longer
lead times as complexity grows. The above con-
siderations point to the need for close scrutiny of
the ongoing system failures and/or incidents in
order to provide the most accurate feedback in-
formation for system correction or modification.

The air traffic control (ATC) system prohibits
the experimental manipulation of conditions to
produce malfunctions and/or incidents and, con-
sequently, information on system malfunction
can only come from spontaneous occurrences.
Suggestions for the design of an ATC incident-
reporting system aimed at maximizing the
amount of corrective feedback to the ATC sys-
tem are presented in this report. The authors do
not pretend to imply that their views, which
hopefully reflect psychosociological .and systems-
engineering principles, are completely compatible
with current operational practices and adminis-
trative directives. But if new attacks are to be
made upon the incident problem, then the
authors hope that the views contained herein will
contribute to such critical thought and discussion
as the importance of the problem demands.

II. An Approach to System Error Evaluation.

As a system, air traffic control performs many
functions relevant to its prime duty, that of in-
formation processing. These functions, at one
time or another in the course of system design
and development, have been assigned either to
man or machine for the purpose of converting
inputs to outputs so that the system can process

information in accordance with its assigned re-
sponsibility of safe, orderly, and expeditious
movement of air traffic. An incident is an index
of a failure of one of these system functions.
The ultimate goal then of an incident-evaluation
program should be not. just to collect data but
to identify both (a) which system function has
been compromised and (b) those contributing
factors for each incident, in order that “quick-
fixes” may become apparent and, more impor-
tant, that with time an objective delineation of
system weaknesses can be supported. Having done
this, one is then in a position to recommend re-
medial action, whether it be training, display
modification, changed illumination, etc., as dis-
cussed in a previous report.? Note the emphasis
of this approach on incident evaluations being
system oriented, rather than controller oriented,
as seems to be observed so often in the usual
approach.

The approach taken here admits that the ATC
man-machine system will never be perfectly re-
liable, efficient, and error-free because of the in-
herent limitations and idiosyncracies of the hu-
man component. Deliberate and objective in
process, it is slow in providing answers. But
this may be a virtue where there is often a ten-
dency to begin shooting in the dark for sources
of error and possible solutions. Often there can
be a number of facility problem areas confounded
with personnel complaints. In this situation a
quick-fix based upon seemingly rational judg-
ment can be a risky, if not uneconomical, choice.
For example, apparent inefficiency in controller
scanning of flight progress boards might be at-
tributed to inadequate training. But the real
answer could be improper illumination, poor
visual acuity, glare, poor strip design, or in-
efficient equipment layout.

A schema felt to contain the basic elements for
objective ATC system evaluation is presented in
Figure 1. The seven-step process begins (a) with
the facility investigation of an incident, followed



FOREWORD

The present report was developed prior to the implementation of Agency
Order OA 8020.8, establishing an ATS System Error Reporting Program.
To a large extent this new system encompasses many of the suggestions and
recommendations made in this paper. This report is not intended as a critique
of the present system, but rather represents what is considered as desirable
in any ATC system-error reporting program.

The authors wish to express their gratitude to Mr. Raymond R. Cybulski
and Mr. William F. Druckenbrod of the Air Traffic Service for their
contributions and stimulation.

Qualified requestors may obtain Aviation Medical Reports from Defense Documentation
Center. The general public may purchase from Clearinghouse for Federal Scientific and
‘Technical Information, U.S. Dept. of Commerce, Springfield, Va. 22151