THE FUNCTION OF SYMBOLS IN ATC AND ITS MENTAL EFFECTS

INTRODUCTION
Miller’s rule states that a human can handle seven plus minus one things in his/her mind at the same time. If the number increases the human mind groups these items so that the number of groups remain less than seven plus minus one(attention span).

Grouping things according to a certain point of view is called abstraction.You can group things first than you can group the groups you have formed and so on. Every step of grouping in this process is called an abstraction level.

Whenever the human mind tries to handle things that overpassess its capacity to handle things simultaneously
it does abstraction. Air traffic control(ATC) is no exception of this fact. ATC systems are complex discrete event dynamic systems. These systems are huge in the sense that they can handle the whole air space of large countries such as Germany or Turkey.

An air traffic control system ensures that airplanes move safely from one geographical point to another. In order to do this each airplane’s safety is given to the responsibility of an air traffic control officer (ATCO) at each point of time in its journey.

The complexity arises from the fact that you have to establish areas of control responsibility for each controller. An ATCO can handle upto 12-13 airplanes at the same time depending on the size of its control area and density of the air traffic. So, in order to control an air space as large as Turkey there must be quiet a number of control sectors. Actually, you generally have first, a number of air spaces depending on the geography and the height, such as eastern Turkey, western Turkey air spaces and lower air space and higher air space which may be divided at flight level 280. The more the number of sectors the more difficult it is to assign tasks to these sectors in coordination with others.

It is inevitable to use abstractions when one just imagines the complexity and the size of an ATC system and the risks involved with it. The first abstraction is the types of control, such as area control, approach control and tower control. The type of the traffic specifies the character of the system that handles it. For the sake of simplicity, and due to my experience I will mention only the area control from now on.

THE USES OF SYMBOLS
The human-kind expressed itself with symbols long before he/she found the letters and writing[1]. Symbols provide a visual representation of an idea or word as can be observed in Far Eastern alphabets and languages. The symbols played a vital role in the development process of alphabets. One can only imagine a little bit the difficulty people experienced in inventing a language first, then writing and then creating an alphabet. But it should be simple even for a dummy to appreciate the importance of using symbols in our life to fight against the difficulties that we meet.
“Symbols provide a visual representation of an idea or word. Children who find difficulty in reading can be helped to visualise the meanings of words by seeing a symbol.” Symbols In Education - Why we use symbols [2].
“Unlike things, feelings and ideas are difficult to exchange. People wishing to exchange physical objects may simply hand them to each other. Feelings and ideas, however, are without physical substance. They cannot be handed directly to another person. Rather, they must be exchanged through the use of symbols–things that represent or stand for other things.”[3]
The origins of our existence, the meaning of life und so weiter are no simple things to handle and this situtaion is not an exception to our ways of handling difficulties. For example : “The concept of using images in worship finds its origins in the Old Testament. The Temple contained numerous visual images, including the cherubim on the Ark of the Covenant. The Temple Solomon built for the Lord contained many carvings of trees, gourds, flowers, and angels (1 Kings 6). It is clear that God did not forbid images used in the Sanctuary to glorify God[4].”
Abstraction and the use of symbols are vital elements in solving math problems or others in science. The use of arbitrary symbols and the process of symbolisation have made possible the discourse of modern mathematics and logic. “Mathematics uses symbols in creative ways. Two such methods, one dealing with the process of `alphabetisation' and the other based on the notion of `formal similarity', are described. Through these processes, originally meaningless symbols get embodied and coded with meaning through mathematical writing and praxis[5].”
We use symbols when things are difficult to rxpress such as feelings, like a red rose for a lady. Arts is a wide spread application area of this use of symbols. “In the play Macbeth, Shakespeare uses many symbols to add to his story. His use of blood, water, light, dark, rampant animals, and even the witches are examples of how he used symbols to add depth to his play. These symbols were often times recurring and they were all related to the central plot of the play[6].”

THE FUNCTION OF SYMBOLS
1- Symbol extracts what is important – relevant and preserves it
2- Symbol makes it reacheable against all odds its a KEY
3- Symbol provides insulation – better cooperation at the related levels.
4- Symbol provides preservation.
5- Symbol increases processing speed.
6- Symbol decreases mental workload and the amount of relevant speech.
7- Symbol provides space for future enhancements by making abstractions.

THE USE OF SYMBOLS IN ATC
The air space used by the airplanes have to be abstracted so that a human being can easily manage the airplanes flying in his own area of responsibility. Simply this means a map but that does not suffice alone…

You must abstract the height, the third dimension in a humanly controllable manner: This means flight levels. The height difference between FL’s are something around 300Ms. Breaking the third dimension to constant and seperate flight levels gives us many facilities: the ability to fly at a certain direction at each level, given a certain filight level you do not have to worry on vertical seperation, limitation references for ascends and descends and many more…

After you have the airspace map, you should choose reference points to fly from and to fly to, also reference points where certain actions have to be taken such as entry and exit points where adjacent centers or sectors have to be acknowledged…

If you think about the size of the German air space, and the number of planes flying concurrently, you can quickly appreciate that a single controller is vital but totally insufficient to do the job. A single ATCO can control 12-15 aircrafts(A/C) at the same time. So you must divide the airspace into enough small sized sectors to reduce the workload to humanly manageable levels. Once more we made an abstraction and created sectors.
Each sector has a symbol, a few characters long to symbolize the section of the airspace they stand for.

An other abstraction is done to facilitate the route declaration in the voice and electronic communications.
Instead of telling each point the A/C is going to fly over, the pilot says uppergreenone (UG1), this indicates a sequence of many points in direction depending on the departure and arrival airport. Each route has a symbol like UG1 which identifies it.

All the symbols used in ATC, points, routes, and their attributes such as entry(NP),exit(XP) etc. are identified in a static data storage or Static Data Bank(SDB). SDB is the symbol of the Static Data Bank. The marvelous character abstraction is you can do abstractions to create the entities that are used to make abstractions of the real life. The Term SDB is used by both ATC interface people who change the static properties of the system and also by the engineers who maintain the software system that supports the operations. The world of the ATC engineers is a complete abstraction full of symbols, actually they use online dictionaries while it is impossible to remember everything.

SDB handles the static properties of the air traffic. The dynamic properties of the air traffic is handled in the Dynamic Data Bank – DDB. Flight level changes, mid air entries, category changes, speed changes usw. all are recorded in the DDB. DDB is an abstraction of the dynamic attributes of the air traffic. It is defined via many symbols that reflect these attributes.

Actually the ATCOs are generally not aware of what is in DDB or SDB. They use other abstractions and many symbols. A flight plan is an abstraction of what a pilot tends to do with his airplane indicating departure and arrival aerodromes, speed, height over all the route points, route, time schedule etc. Strips are small strip of paper which outlines this information in this small area with many symbols. The area must be as small as possible because of the spae limitation on the ATCOs control table. The controller has also the keyboard and display system, the radar screen and ATN messages to use. All of these are highly abstract modellings of the real life air traffic. All of them use many symbols.

THE ROLE OF SYMBOLS IN ATC
From the point of an air traffic controller using symbols is not only being able to identify them but also having the right feel of them. Aviation is not only a science based technological area but it is also an art and air traffic control is no exception to that.

The use of symbols makes things more identifiable and increases comprehension by the use of phrasepology in the pilot – controller voice communication. An air plane appears as a small symbol and a vector indicates the direction and speed it flies on the radar screen. There is height, speed etc data all written as symbols + numeric values… The static control points, airports etc. all are indicated as symbols. There is even a book of ICAO which you can find these values.

But, the controller is not supposed to see all these symbols and overabundance of information, in all this mass, he simply has to keep the mental picture of the traffic in his mind. Similar to a theatre artist, he should not try to remember the text or what movements he should do, he has to keep his audience going according to the point where they are in the act.

This is also reflected in the evolution of a controller. He begins with the easiest sector and like performer he rehearses his role many times and gets to know the stage he is acting. If you remember my example about the use of symbols in Sheakspear plays, symbols help the controller to get hold of the reality, the actual reality at that moment of time during the play… Symbols play a crucial role in helping the air traffic controller to do so.

THE EFFECT OF SYMBOLS ON THE ATCO FROM THE POINT OF SYSTEMS PSYCHOLOGY
The use of symbols reduce the mental load of the air traffic controller. Unfortunately, the homeostatic
tendency and ever increasing traffic load causes the air traffic controller get more load in this situation.
At the end of the day, the use of symbols causes the air traffic controller to get more traffic load.

Similarly spatial processing increases the load of the controller instead of decreasing it. Large radar screens provide ample space to hold many more symbols, tables, etc.

One important point to remember; symbols contribute to our subconscious. Anything we do not understand goes to our subconscious. When concentrating on a traffic situation both on voice and radar a controller’s subconscious gets busy with the other things, and these are symbols which he does not have attentional resources to deal with. So, they go to the subconscious. Just like watching and art work that you do not understand.
You try to make an abstraction to overcome the difficulty you face by pushing that thing into your subconscious.
If you know how to interact with your subconscious then your subconscious will pop up the problem back to you, and in percieving the problem once more you will have formed abstraction of it, namely ah that flight that ı skipped.

In fact, symbols are the key to understanding the character of air traffic control. Phraseology reminds me abstract languages, the rule based structure the logic, all the symbols on the radar screen and the slow stepwise movements of airplanes has a certain lyric effect almost poetic, and the strength of symbols has a religious tone, with all the controllers and engineers walking slowly in and around the control center like the Branchid priests serving at the antic oracle’s Didyma.

KAYNAKLAR:
[1] The Park Ridge Center, al.hurd@advocatehealth.com
“Before the written word, human beings used symbols as the primary means of self-expression. Hope and fear, joy and sorrow, sickness and health, love and hate, good and evil, yin and yang, feminine and masculine — all found early expressions as symbols.”
[2] Symbols In Education - Why we use symbols
“Symbols provide a visual representation of an idea or word. Children who find difficulty in reading can be helped to visualise the meanings of words by seeing a symbol.”
[3] Britannica Student's Encyclopedia
“Unlike things, feelings and ideas are difficult to exchange. People wishing to exchange physical objects may simply hand them to each other. Feelings and ideas, however, are without physical substance. They cannot be handed directly to another person. Rather, they must be exchanged through the use of symbols–things that represent or stand for other things.”
[4] The use of Images, Signs, and Symbols in Anglican Worship By Rev. Rebecca
“The concept of using images in worship finds its origins in the Old Testament. The Temple contained numerous visual images, including the cherubim on the Ark of the Covenant. The Temple Solomon built for the Lord contained many carvings of trees, gourds, flowers, and angels (1 Kings 6). It is clear that God did not forbid images used in the Sanctuary to glorify God .”
[5] The Use of Symbols in Mathematics and Logic by Sundar Sarukkai
“Abstract. It is commonly believed that the use of arbitrary symbols and the process of symbolisation have made possible the discourse of modern mathematics as well as modern, symbolic logic. This paper discusses the role of symbols in logic and mathematics, and in particular analyses whether symbols remain arbitrary in the process of symbolisation. It begins with a brief summary of the relation between sign and logic as exempli_ed in Indian logic in order to illustrate a logical system where the notion of `natural' sign-signi_ed relation is privileged. Mathematics uses symbols in creative ways. Two such methods, one dealing with the process of `alphabetisation' and the other based on the notion of `formal similarity', are described. Through these processes, originally meaningless symbols get embodied and coded with meaning through mathematical writing and praxis. It is also argued that mathematics and logic di_er in the way they use symbols. As a consequence, logicism becomes untenable even at the discursive level, in the ways in which symbols are created, used and gather meaning.”

[6] ESSAY SAMPLE ON "THE USE OF SYMBOLS IN MACBETH" The Use of Symbols in Macbeth
“In the play Macbeth, Shakespeare uses many symbols to add to his story. His use of blood, water, light, dark, rampant animals, and even the witches are examples of how he used symbols to add depth to his play. These symbols were often times recurring and they were all related to the central plot of the play.”