**4.8 Air Traffic Control Operations:**

Description of various types of ATC operations

Airspace definitions and distribution

Workplace stress factors

Operational stress factors

[Human Factors in Aviation Mechanics and Air Traffic
Controllers]{.underline}

Every living human being from the newborn to the most elderly is
influenced by external and internal factors. Volumes of writings and
research exist concerning the human and these assorted factors. Human
factors is really then something that has long been recognized and
pondered, in all likelihood since the beginning of man. Not always going
with the term "Human Factors" the awareness of the influences of our
environment is nothing new to humans. Defining the term is somewhat
challenging. When thinking of all the factors which can affect the human
it becomes obvious the list is long and varied from one individual to
another. This encompasses the varied geographical, environmental and
societal differences associated with those people. It perhaps is more
appropriate to envision the concept rather than becoming entangled in
establishing an all-encompassing definition. Any factor, which
influences in anyway the performance of a human then, becomes one of
those entities that can be evaluated to ascertain the effect upon the
individual. Attempting to group these factors even into broad and
sweeping groups can limit our focus. Everyone shares the majority of
human factors to some degree. A smaller number of human factors may
apply only to limited numbers of individuals or occupations.

In this section the focus is upon those factors which do and can affect
air traffic controllers and aircraft mechanics. Many of the factors
which affect one group will affect the other with equal impact. There
are some aspects of the work for each group which makes them more prone
to influence from certain factors and less so from others. The common
thread, which actually links these two groups, are focus and
concentration. A lack of which can have disastrous results on the flying
public. While air traffic controllers are working at the moment of
flight it would seemingly make their need for focus and concentration
greater. However when pondering the significance of a stick failure due
to the lack of tightening a bolt or failure of a moving part due to lack
of lubrication, it becomes obvious that if they were due to a lack of
concentration ultimately the effect can have serious consequences. This
section is not written to compare and contrast air traffic controllers
with aviation mechanics. They are grouped together purely for logistical
reason. They are different types of work bound mostly by the common
theme of aviation. However the failure of a person in either type of
work to perform adequately has profound affects on the safety of the
National Air Space.

Flight surgeons are more aware of the air traffic controllers than most
aviation medical examiners. However there are some aviation medical
examiners who do perform physicals on the controllers and are more aware
of the job responsibilities. Since aviation mechanics do not have
medical certificates their job function and importance is not
appreciated my much of the aviation community who are not in direct
contact with them. Some brief introduction to both types of work will be
described to help in understanding the tasks of each and the
environmental factors which may come into play with either group.

Air traffic controllers, in the United States can work for basically
five types of employers. The majority of civilian controllers are
employed by the Federal Aviation Administration. The other two groups of
federally employed air traffic controllers (ATC) are those on active
duty within the military and those employed by the Department of
Defense. In the past few years many if not all of the smaller airfields
had air traffic control services contracted out by the FAA. These air
traffic controllers work for private organizations who administer the
FAA contract for that facility. Finally are the non-federal contract
towers. An example of this would be Boeing field or any airfield
employing air traffic controllers not servicing a federal contract.
Since the FAA is concerned with employee air traffic controllers, the
remaining discussions will primarily be focused on this group. Within
this group there are basically four subgroups, sometimes referred to as
options. Three of these have direct contact and responsibility for
directing aircraft. The fourth, the AFSS, has limited contact with
aircraft in flight.

First is the option classically thought of by the public. This group of
controllers work in the air traffic control towers. Depending upon the
facility, visual control is the mainstay sometimes augmented by the use
of radar. In larger more complex fields radar is a virtual necessity.
They have the task of moving airplanes around on the ground, positioning
them for takeoff and setting the initial headings immediately after
takeoff. They are also responsible for aircraft approaching the airfield
for landings. In three of the four options, the main task of the air
traffic controllers is to aid the pilot in maintaining the separation of
their aircraft from those around them. The size of the airfield, number
of runways and the frequency of takeoffs and landings obviously affects
the complexity of the work. In larger facilities like Los Angeles
International Airport, there are 1800 takeoffs and landings per day.
These are accomplished with the use of four basically parallel runways.
At Chicago-O'Hare, there are 2600 to 2700 operations per day using 12
runways. In larger facilities from engine startup to takeoff a pilot may
communicate with several air traffic controllers. In turn these
controllers are communicating with each other to facilitate the transfer
of responsibility from one area to the next.

TRACONS are the next option and are exclusively radar facilities. Their
function is to assist in transition from immediately after take off to
establish their flight path and conversely to take them from the flight
path to establish an approach. Some air traffic control facilities are
what as known as up/down facilities. Thus meaning they house both the
tower and below in its\' own area a TRACON. Depending on the exact
facility, some may have controllers working exclusively in the tower and
others only in the TRACON. In others virtually all work both up and down
with others having some kind of mix between the two. Obviously there is
a difference in the type of work switching from the visual aspect of the
tower to the sole use of radar and scopes. Some of these TRACONS are in
their own structure, which may or may not be in close proximity to the
airfield(s). Yet another setup has been the consolidation of many
TRACONS into the same physical facility. Such is the case for Southern
California TRACON located in San Diego. This facility controls virtually
all aircraft from north of Los Angeles to the Mexican border and from
the Pacific Ocean to near the Nevada border. TRACONS function in
conjunction with larger and busier airports.

The final option with a direct link to aircraft are the centers. Known
by the acronym of ARTCC standing for air route traffic control center.
These types of facilities are for control of aircraft flying IFR once
they have established their routes. Not exclusive to commercial air
transport, however the majority of their traffic comes from the higher
altitude longer distance type of flying. Radar again is used exclusively
for this control. The facilities are larger and employ several hundred
controllers each.

Automated Flight Service Stations (AFSS) are the fourth type of air
traffic control facility. They do not actively participate in the
separation of aircraft. These are stations which receive the flight
plans and give weather information to the pilots for their flight path.
They also aid pilots in locating their position when they are not sure
of their location. This is done by use of the radio and triangulation.

The other type of aviation related work covered in this section is that
of the aviation mechanic. There are three basic types of work which fall
into this area. First is the power plant mechanic. Again from the name
one can deduce the work performed has to do with the engine components
of the airplane. The second type is the airframe mechanic who works on
the airframe and control services. Both airframe and power plant
mechanics hold technical type certificates from the FAA. A mechanic who
does not hold a certificate may work on an airplane however needs to be
under the direct supervision and control of another holding a
certificate. Third is the avionics person who is involved in the radio,
compass, navigational and communications elements of the aircraft. All
of which again are important elements contributing to safe flight of the
airplane and invaluable tools for the pilot.

Having been refreshed on the basics of the air traffic controllers and
aviation mechanics, it is time to look into the Human Factors aspects of
these occupations. Rather than cover each occupation separately with
regard to each general factor, it seems less repetitive to cover most of
the factors and describe how they affect the vocation. To attempt to
cover all aspects of human factors is not the intent or mission of these
course. However covering some of the majors areas of consideration
should give you pause for thought as regards the many areas which cannot
be addressed in this course.

Medical Conditions

Air traffic controllers in the FAA have medical standards and undergo
periodic examinations depending upon the age and option of the
controllers. Mechanics, unless otherwise covered by their employer, do
not have a set of medical standards. Of primary interest are those
medical conditions which can cause sudden or subtle incapacitation of
the individual. Certainly during a critical time in the control of an
aircraft a sudden incapacitation could be devastating. This area
receives much of the focus when considering the issuance of a medical
clearance. However just as problematic and equally as worrisome are the
subtle incapacitations. Those conditions although do no take one off the
job, likewise do not allow them to function at 100% of your potential.
This would be the case of mild to moderate breathing problems,
congestive heart failure untreated, the headache which is distracting
and the whole gamut of other conditions which are both distracting and
physically incapacitating for whatever reason. Apart from climbing
stairs to access a tower, the majority of the work is air traffic
control is sedentary or standing and walking in a relatively small area.
However the same cannot be said for the mechanic. Working in difficult
spaces and large work areas, a physical problem can have an enormous
impact on their work. Instead of walking to get the proper tool or look
at the manual, using a shortcut or guesswork in this area could prove
devastating. Lack of strength in unfastening and fastening the nuts and
bolts due to a musculoskeletal or neurological condition could
ultimately produce a problem. Also conditions which affect the overall
mobility could translate into a less than desirable work effort. By the
mere fact you are taking this course, your familiarity of the roles
medical conditions play in the job performance of an individual is
certainly more than adequate. It then only takes some pause for thought
as to how these medical conditions play into the human factors having
effects on job performance. Due to the nature of the work and public
trust, these jobs fall out of the normal occupations. Keeping that
importance in mind is key to avoiding potentially negative human
factors.

Physical stature can have some effect on the job performance of both air
traffic controllers and aviation mechanics. Height can produce some
obstacles that need to be addressed for the air traffic controller.
Probably the most common would be a persons height and/or arm reach in
relation to the equipment or view from a tower cab. For the aviation
mechanic both height and/or body habitus can produce problems. Due to
the nature of the work, sometimes accessibility into a confined work
area becomes a requirement of the job. If they just cannot access the
work, the obviously a different person will have to do that work. Of
greater concern is when they have to struggle due to body habitus to
perform the work. Then the quality of the work can be compromised which
would not be acceptable. When at all possible, accommodations to
mitigate the effect of body habitus should be invoked. And there are
those individuals who have physical attributes which for whatever reason
make their job much easier for them when compared to some co-workers.

Psychological Conditions

Certainly clear thinking and maintaining focus and concentration on
tasks at hand are hallmarks of good performance in both the aircraft
mechanic and the ATC. Many occupations require near total concentration
when working. It can not be emphasized enough that these types of jobs
at times do not tolerate mistakes. There are many psychological
conditions, which can affect both work forces, in the form of individual
performance and the affect on others in the environment.

Situational depression, along with anxiety states, may be the most
common of the conditions of the mind which can have effects on us. The
range of impact on an individual and their coworkers is very broad and
multi-faceted. Then again there are individuals who actually find solace
and comfort at the work place if the situational depression is a result
of factors from the outside their employment. Many of those perform
without problems during those times since work offers a legitimate
escape from certain thoughts and problems. These people tend to be those
who have ingrained the ability to focus while performing the safety
sensitive parts of their job. It virtually becomes automatic when they
begin these jobs. Others are not as self disciplined letting thoughts
and feeling intrude and obstruct their focus and concentration.
Certainly if the workplace forms the genesis of the depression, then
coming to work would not be the perfect situation. Those affected by
anxiety, coworkers and managers need to bear in mind the ever changing
character of the human psyche.

We always hear about the ten percent of the workforce causing 90 percent
of the problems. This is a group of people who may not have a formally
diagnosed personality disorder, however their social traits and
character make them very difficult to deal with in the workplace. Their
effect is most felt by their supervisors and coworkers. So they are very
successful at making their problem your problem. This dynamic can and
does have a profound effect on the workplace and remains a difficult
situation when such a person is working. Then there are also those with
a straight out personality disorder which either has been diagnosed or
could be diagnosed if the person ever sought professional help. Probably
the worst of the ten percent, their main task in life is to make enemies
with those around them. The reasons for these actions are known and they
produce chaos and destruction in the workforce, which is very real.
Again, due to various rights, rules and regulations all individual
employees receive, it makes it difficult to deal with them, especially
in the Federal system.

Finally comes those who may be frankly psychotic. When they surpass the
clinical level, yet have not performed enough overt acts to cause their
dismissal they are very worrisome. Many other conditions including
depression and anxiety leave the person with a knowledge that they are
affected and may not be fit for duty in certain jobs. Not always so with
the psychotic. There is no need for discussion of the problems
associated with transferring the acts and thoughts of a paranoid or
delusional person to the skies, radar screen or safe repair of a power
plant.

Budget, scheduling, workload and numerous other factors make it very
difficult at times to address some of these issues. Recognizing the
potential problem would be the first step which can be and is frequently
impossible at times. However the psychological factors which can produce
an untoward result may well be near the top of the list as far as
frequency of occurrence.

Social Issues

As we all know, general society is merely a reflection of a multitude of
smaller societal groups. Those who work in and around the world of
aviation form one of those smaller groups with another multitude of
smaller groups contained within that world. Then there are the "clicks"
which form in any workplace of any size. This is not the forum to get
into the details of how each group affects others within the group or
other groups. The air traffic controllers can be used as an example of
the dynamic of those influences.

As many flight surgeons will acknowledge, a high number of air traffic
controllers interviewed, for whatever reason, make the statement that
they are the "best" in the system. The genesis for this comes from a
common process in training a future ATC. It is felt they must have
confidence and are therefore told individually that they are the best in
the system. Now the logic here is faulty however the result of being
indoctrinated in that manner is real. Obviously not all air traffic
controllers fall prey to that thought. However there are many who will
parrot the phrase over and over. As is well known, after saying
something over and over you begin to feel there must be truth to the
saying. The practical human factor problem with this comes with the
competition and lack of tolerance which many air traffic controllers
have for each other. Since they feel their way is the only way and the
best way, it then follows that others must be doing it incorrectly. This
can and does cause unneeded discussion and friction between the workers.
And if one really thinks about it, there is a possibility to have that
impede the learning and/or adapting process. On the other hand it could
be said with validity that competition is healthy.

Social situations, problems and characteristics outside the workplace
can have effects on anyone. Again the scope of this course is not to
provide a lengthy list of those which can have an influence on aviation
mechanics or air traffic controllers. As mentioned before, one big
factors which helps mitigate some of these factors is the persons
ability to concentrate on their work, reserving intrusive thoughts and
actions for times outside the critical work times.

Working Conditions

Since the total environment for an individual can be divided into many
different elements it is sometimes difficult to keep these arbitrary
divisions to a minimum. Here, the working conditions will include the
physical set up of the work environment, arrangement of the equipment,
workspace and availability of any specific tools used in the performance
of work.

In the ATC environment the arrangement of the tower windows, equipment,
displays, radios, signal beacons and other pieces of equipment can vary
significantly from facility to facility. Time, energy, study and
research are in fact invested in the placement, display colors,
arrangement of displays for radar and computers, types of chairs and all
the numerous pieces of equipment needed to perform their tasks. The
larger centers within the FAA have become more or less standardized in
the types of displays and the arrangement of the equipment. Smaller
TRACONS and towers may have individual problems due to the architecture
of the facility, however to the extent possible, there is every attempt
made to overcome the design problems to mitigate any negative influence
on performance of the individuals. In most TRACONS and centers one will
find another element which is widespread and that is the low level of
lighting in the facilities. In one large center having been recently
re-done, the level of lighting was increased. Some management officials
in the facility feel it has contributed to an increase in background
noise. This noise comes from the air traffic controllers talking among
themselves. In this facility for whatever reason ambient noise is
greater than in the previous design. To mitigate this they have placed
carpeting in the wastebaskets to curtail the sound of waste material
dropping into them. These are merely used as examples of the thought
processes and considerations given to the changes in the working
environment of the air traffic controller. Another interesting habit
used among controllers, particularly in the tower environment is the
protocol observed when approaching an ATC on position to whom you want
to speak. Generally you will wait until the controllers is talking on
the radio before you begin speaking to them. The dynamic being they
cannot listen to two people at once but they can at least talk to one
and recognize another person is trying to speak to them. At the
appropriate time then, the controller can recognize the individual at
their side and engage in conversation.

The aviation mechanic is subject to a more changing environment
depending on the type of work and employer. They can range from working
in the same space at a workbench on a daily basis to working outside on
the aircraft. The rules and regulations state they must have the
technical manuals at hand when working on an aircraft. The ease of
accessibility of these manuals and documents can affect their
performance. The arrangements of the tools and the types of equipment
and tools for them to conduct their work obviously can and will make
their work either that much easier or that much more difficult if they
are not the in good repair and adequate for the job. The number of
interruptions they may experience on the job and then the accessibility
to the telephone will have an impact. Remember when they are in the
middle of assembling or servicing an aircraft component, they need to
keep track of the process and make sure they finish all of the steps.
Not turning a nut enough or in fact over tightening it can be as
devastating. As all of us know, it sometimes can be difficult to
remember where you left a project after leaving even for short periods
of time. Remembering were you left the work after returning from a time
consuming distraction can be even more difficult. Another factor of the
working environment for the mechanic can be the accessibility to the
work. Obviously some parts are not removed from the aircraft for
maintenance work. To work on some of the components can put the mechanic
into a physical position which in and of itself can be uncomfortable and
thus have some impact on the work performed.

Environmental Conditions

For the most part the environmental conditions such as lighting and
temperature are fairly well controlled and kept constant for the air
traffic controller. The ATC works looking at the weather from a tower
and the mechanic may be working in the weather. TRACONS, centers and
flight service stations are kept relatively constant in terms of
lighting and temperature. The tower controller has to deal with the
weather and day and night lighting at the various airports. Again it
does not take much of an imagination to see how the various times of
day, position of the sun, cloud cover, etc can have an impact on the
tower cab. While the temperature can fluctuate somewhat because of the
relatively large amount of glass present, it is by and large
comfortable.

The aviation mechanic does not have the same advantage when it comes to
weather at the controller. Working at times in the extremes of heat and
cold had its affect on the individual. Lighting can be difficult in
closed spaces at best and becomes more difficult when the ambient light
disappears with the setting sun. Snow, rain and wind have their effects
making work again not a pleasant place at times. Even the indoor
activities of the mechanic has somewhat more of a negative impact due to
the size of the repair facilities in general. Buildings of this size, if
they do have any type of cooling or heating equipment, are difficult to
maintain at a temperature which is comfortable.

Training

Again, the completeness of training and depth of training is extremely
variable from person to person and also between job categories. Always a
problem due to the extensive number of considerations given to allow
access to training and the demand on the other side when the educational
process is completed. The more complete and in depth the training the
better. If the training is too shallow the person may not recognize that
a problem even exists. Ignorance is bliss, however in jobs where your
work can have such a negative impact on other human beings, it cannot be
afforded.

The paths available to obtain a FAA certificate as a mechanic are
basically three in number. You must completed an accepted school, have
received training in the military or have worked under supervision from
a certificated mechanic for a period of eighteen months. Despite any of
the options for obtaining training, to obtain the certificate the
mechanic then needs to take both a written examination as well as a
practical exam. While affording greater opportunity for gaining the
required training, the uniformity of training and depth beyond a certain
point is not necessarily uniform.

Air traffic controllers gaining access to employment in the FAA have
basically four different mechanisms to obtain training. Military
training, trade school programs, Department of Defense and going through
the FAA academy if they have had no previous experience. Most of those
with the Department of Defense have gained their previous experience
either with the military or with the FAA. As can be seen, as with many
occupations, the background and training may not be uniform. That is not
to say it is bad but just variable in the depth and other aspects. Plans
and procedures in place at all of the FAA control facilities pretty well
give guidance and direction for almost all conditions which can arise.

After arrival in an air traffic facility the training at the local level
then commences. In a smaller VFR tower, an individual can be fully
checked out in as little as two or three months. In a large center the
time to become fully functional on all positions is usually between
three to four years. There are many variables in every facility that can
have some impact on the amount of time it takes for training. Due to the
unique nature of the area of responsibility for each facility, even
going between like facilities of the same type, training is required to
become oriented to the specifics of that facility. Much of this time
involves classroom type work accompanied by oversight on position with a
journeyman air traffic controller.

Summary

The is an old and well distributed photograph showing a wood framed,
cloth covered airplane stuck in the branches of a tree, some feet off
the ground. The caption going with this photograph is "Aviation in
itself is not inherently dangerous. But to an even greater degree than
the sea, it is terribly unforgiving of any carelessness, incapacity or
neglect." This photograph while meant to address issues with the pilot
expresses measures with regard to many people having to do with
aviation. Certainly the pilot in command has the ultimate authority and
decision making responsibility for a given flight. However in the
complex world of today a pilot can no longer kick the tires, inspect the
control wires and understand the engine. Responsibility for these
components and with the guidance of the flight through many rather
complex air spaces rests with others. The good work of these people is
not recognized enough, however they receive all the attention when their
work causes safety issues with a flight. With thought given to the human
factors involved in these types of safety-related work, the medical
community can make a real difference. Like many preventative measures,
it is difficult to know the outcome since we cannot track events that do
not occur. However helping people to develop a positive environment
while at the same time mitigating detrimental factors can only help with
aviation safety. The study of human factors and application of those
studies and findings is invaluable in promoting safety of the national
air space.