Is an Aircraft an Aeroplane Or the Other Way Round? The Importance of Proper Terminology

The word game

A lot of air traffic management related material passes through our hands, usually to be checked with a view to ensuring quality of content and consistency of the terminology. There is a disturbing trend that is becoming more and more evident with the passage of time. The documents show a deteriorating level of quality in respect of terminology use.

Why is this a problem? Unless they have been sensitized to the issue, the authors of those documents may not feel particularly disturbed by the fact that they use the terms aircraft, aeroplane or airplane interchangeably in their text, they may even feel that the varied use of words reflects better writing style. But in technical documents, the terms used must all have their precise definition and it is not enough to find a given word in a Webster’s Dictionary.

Let’s have a look at these three words, aircraft, aeroplane, and airplane. They are all English words and they all mean something that flies. Very true. But there are many things that “fly”, from hot air balloons to helicopters and, depending on how you define “fly”, even hovercraft. So how do we know which exactly a given text refers to if it is not clear from the context?

If you see a piece of text that says “a flashing white light shall be displayed on all aircraft” and then another one that says “a flashing white light shall be displayed on all aeroplanes” and you own a helicopter, a glider and a hot air balloon, which one would you need to equip based on the first requirement? And the second?

Although I assume you know the answer without the explanation that follows, it is still interesting to look at these terms in more detail.

First and foremost, we have to say good-by to the term “airplane”, at least in the international context. Only aircraft and aeroplane have been defined by the International Civil Aviation Organization (ICAO).

An aircraft is any machine that can derive support in the atmosphere from the reaction of the air other than the reactions of the air against the earth’s surface.

A aeroplane is a power-driven heavier-than-air aircraft, deriving its lift in flight chiefly from aerodynamic reactions on surfaces which remain fixed under given conditions of flight.

So what do these definitions tell us? A hovercraft is not an aircraft (reactions of the air against the earth’s surface) and a glider is not an aeroplane (power driven) but it is an aircraft. A balloon is an aircraft but it is not an aeroplane… and so on.

As you can see, expressing requirements, infrastructure suitability and services desired does need proper terminology use, otherwise things quickly become ambiguous, leading to misunderstanding and endless discussions.

We used the terms aircraft and aeroplane (the subject of the most common errors) as examples but there are scores of other terms which, if used improperly or inconsistently, can lead to serious problems of understanding.

A few simple rules can help

Proper terminology use is not rocket science. It needs good knowledge of the subject and a bit of discipline. Here are a few simple rules that can help.

• If there is an ICAO defined term for something, use it. ICAO has developed definitions for the terms it uses in the provisions aviation the world over follows. Using terms as defined by ICAO provides immediate benefits in terms of consistency with ICAO documents and documents derived from them. Those definitions are also consistent among themselves.

• If there is no ICAO definition but a definition from another big organization, use it. In some cases ICAO may be lagging behind developments and they may not have a definition (yet) for a term or the term is not used in the ICAO provisions. Some other organization may however have developed a definition that is widely accepted or even standardized. In such cases, this recognized definition should be used and the source clearly identified. There may be several definitions from different sources… use the one that appears to be the most appropriate but use it everywhere consistently.

• Create your own definition. In some cases you may find that a term that nobody has yet given a definition needs to be understood in a particular way and only that way. Create your own definition and use it consistently across your documents. It is also a good idea to try and promote your new definition. If you had a need for it, so might do others. The wider it will be used, the better for overall consistency.

• When a term has multiple meanings. A great example of this is air-side and land-side, two terms that divide an airport in two, one you might call the public area and one restricted to passengers and employees only. The trouble is, there are at least two schools of thought on where the dividing line is between the air-side and the land-side. Although the dividing line is always artificial and arbitrary, its actual position does make a difference to the processes that extend across the division. In such cases feel free to adopt whichever dividing line position is best for you, however, always state clearly where the boundary between air-side and land-side is (or any other aspect the given term requires). A clear indication mitigates the negative effects of this kind of multiple usage.

• Be consistent. Perhaps the most important rule is to be consistent. There is only one thing worse than using undefined terms or terms with the wrong definition and that is using terms inconsistently across a document. Inconsistent use of technical terms is the surest way of confusing the reader.

What about abbreviations?

Few disciplines in the world are so prolific with creating abbreviations as aviation. When we speak, the uninitiated may think we are using some kind of secret code language… Worse, we tend to assume that each of us knows all the abbreviations from every part of the business while in fact CUTE (Common User Terminal Equipment) may mean nothing to an air traffic controller while ATIS (Automatic Terminal Information Service) may sound like a four letter word to a check-in agent. To managers higher up, who may have come from the financial world, neither CUTE nor ATIS may say much except if there is a price put against them… So what to do with abbreviations?

Here again the main rules are: use accepted abbreviations whenever possible and be consistent at all times. Include a list of abbreviations in all technical documents and consider writing the words full out (followed by the abbreviation) when first used in the text.

Avoid creating new abbreviations. Of course this is not always possible, if nothing else, there are new working groups, new processes, new equipment and they all crave their own, easy to remember names. So, go ahead and come up with new abbreviations but do try to avoid re-using abbreviations that already have a well established meaning. You may feel that your field is stronger and you will eventually squeeze out the other guy but believe me, not paying attention to this will only confuse everybody.

What if you are writing in your national language?

Whether you are writing in English or your national language, the guidelines are the same. But, they may not be so easily implemented if the terminology has not yet been introduced into your language to the same level of detail as it is in English. There may be opportunities to be a pioneer in enriching the local language with the required new terms… In some cases trying to force consistency and new terms onto the professional writing scene may not be easy or appreciated by your peers. Use good arguments and examples similar to those above to convince them of the importance of proper terminology use.

The responsibility of SESAR, NextGen and SWIM

Experts in Europe and the United States are busy writing the blue prints for the next generation air traffic management systems SESAR and NextGen respectively. Those systems will introduce new concepts, new technologies and new processes, each bringing with them their specific terms and abbreviations.

System Wide Information Management (SWIM) is something that draws heavily on ideas first put forward in the general information technology field, with SWIM applying those things in an aviation context.

All the above activities will be generating tons of new documents which must be consistent across the board, both in terms of the old definitions and abbreviations and the new ones they will be introducing. Their responsibility is huge if we consider that the SESAR and NextGen documents will determine for decades to come what is called what and what we mean by what.

Get it wrong or inconsistent and future generations will struggle with the inconsistent, diverging terminology for a long time to come.

The new documents we see to-day are cause for concern and show signs of people ignoring the simplest rules of terminology use. They must remember that at the end of the day, we will all need to know beyond a shadow of a doubt whether we need to bolt that flashing white light onto the particular flying machine we own. Only consistent, proper terminology can help in deciding…