'What Did He Say?'
Safe Voice Radio Communications

Language is an important medium for communication, and with greater awareness of basic linguistic principles, pilots and controllers can be motivated to adhere more closely to standard phraseology in all air-ground radio exchanges, thus enhancing safety.

Air Line Pilot, September/October 2002, p. 29
By Brian Day, ICAO Secretariat

After a number of major accident investigations highlighted a lack of proficiency in the English language among flight crews and air traffic controllers, the International Civil Aviation Organization resolved in 1998 to take steps to ensure that personnel required to conduct radiotelephony communications in the English language comply with a required level of language proficiency.

An ICAO study group—the Proficiency Requirements in Common English, or PRICE, Study Group—is helping to develop language provisions for ICAO. Aviation and linguistic experts from several countries and international organizations are participating in this group’s work.

Early in its deliberations, the PRICE Study Group confirmed the continuing relevance of statements first incorporated 50 years ago in ICAO Annex 10, Volume II, which deals with aeronautical telecommunication and communication procedures. As stated in the Annex, "the universal availability of at least one medium of radiotelephone communication is important both for safety and efficiency in international air navigation." Moreover, Annex 10 indicates that "the lack of a language common to the aircrew and the ground station could lead to an accident."

At the same time, the Study Group saw that, for now, retaining the language that the station on the ground normally used was acceptable.

The Study Group’s recommendations and the Secretariat’s subsequent proposals to the ICAO Air Navigation Commission would establish both a minimum level of language proficiency and relevant testing requirements. These changes would make aircraft operators and air traffic services providers responsible for ensuring that their personnel meet the required level of language proficiency. Furthermore, the use of two languages—that of the station on the ground plus English upon request—would be elevated to a standard from a recommended practice.

In developing a standard for language proficiency, the Secretariat has opted for a scale of proficiencies described in terms of language "behaviors." Such a scale can serve the purposes of both testing and training. Six defined levels range from "pre-elementary" to "expert," and the required level of proficiency is described as Level 4, or "operational level."

As long as radiotelephonic communications may be conducted in the language of the ground facility, being proficient in the English language alone would fail to improve communication overall. Clearly, regulations must apply for all languages used in radiotelephony. Thus, the proficiency requirement and scale have been developed with native and non-native speakers in mind and can be applied to any language, not just English.

As States [nations] have different circumstances and needs, the ICAO Study Group preferred that States have the option of using a prepared test or developing their own. To facilitate the development of language proficiency testing systems, ICAO will develop guidance material, which will also cover the optimal use of the language proficiency rating scale and the development of efficient and effective programs for aviation language training and will stress adherence to ICAO phraseology and disciplined radiotelephony techniques and education in basic linguistic principles, including cross-cultural communication.

The efforts of the Study Group are just a beginning. Improving radiotelephony communications to a higher level of safety is no small matter and requires widespread cooperation and continuing, concerted effort, particularly from practicing controllers and flight crews. In particular, both native and non-native speakers must conform more closely to existing ICAO provisions, especially to the ICAO standardized phraseology so carefully and painstakingly developed over the last 50 years. The communication of air traffic clearances and operational information is critical and requires both accuracy of content and careful, precise delivery.

Language is not ideally suited to transmission of exact information because it is fundamentally symbolic—that is, its words and phrases represent the objects and concepts described. This characteristic of language becomes particularly problematic when communication involves non-native speakers. Understanding this principle, and why conformity with standardized phraseology is so important, is essential.

In all language exchanges, a semantic barrier exists that can seriously compromise the communication process. Not all listeners take the same meaning from the use of a word, phrase, or expression because people filter words through different belief systems, knowledge, cultural acquaintances, and life experiences. Word meanings, therefore, are subjective. In coming to terms with the inexact nature of language, reflecting on some outcomes of words being no more than representations of the things they describe is helpful. Not being the things themselves, words may mean—and frequently do mean—different things to the speaker and the listener. Presumably, no pilot would misunderstand a tower directive to "clear the runway." A snowplow operator who is monitoring the frequency and hears this transmission would undertake altogether different activity than a pilot would expect (ICAO standardized phraseology is "vacate the runway").

Communication, although it is most understood to be a means of reference to an object, also conveys a strong sense of relationship. Studies have shown that communication is very sensitive to social rank (and the perception of rank is much influenced by communication). Communication that is sensitive in this regard facilitates smooth interaction among flight crews and controllers. Communication that is not so sensitive may be less effective.

The manner in which the pilot-in-command exerts authority on the flight deck will greatly influence the flow and coherency of flight deck communication. When the PIC is overbearing or dictatorial or, alternatively, allows the command function to be blurred, inferences may be lost and overall communication impaired. Care needs to be taken in establishing, then observing, what is known as the "trans-cockpit authority gradient" while ensuring that the operational integrity of cockpit dialogue is in no way compromised. Similarly, ATC facilities have their own staff authority profiles, and communication between controllers within the facilities is affected by it. While flight crews and controllers need to be mindful of the authority gradients within their respective workplaces and the reciprocal effect of internal communication and rank, still greater difficulties may arise in radiotelephony conducted between them. This is because the authority gradient between controllers and pilots is neither as clearly defined nor as constant in all situations as within either the cockpit or the control room.

Teamwork among operational personnel depends on positive relationships, and in this context, building effective teams requires an appreciation of how timing, phrasing, intonation, and nonverbal aspects of communication influence group dynamics. When the job becomes stressful and, say, fatigue intrudes or some concerns arise about unserviceable equipment or the effect of worsening weather, radiotelephony communication may not always reflect intent. When communication is degraded, overall efficiency declines.

Message content is not the only means of conveying sense in communication. Because language is a set of representative symbols, it is able to convey various meanings at different levels and times. Consider, for example, how interpersonal exchanges can be influenced by mood. The speech delivery of an individual riding high on confidence can be smooth and articulate. By way of contrast, strongly negative attitudes and emotions can result in ineffective communication.

Radio message exchange is hampered because it lacks many communication prompts. In face-to-face communication, body language speaks volumes. According to studies, body language conveys about 55 percent of message significance; words themselves, only 7 percent. Tone of voice accounts for the other 38 percent. Radio communication, of course, is devoid of body language, and electronically modulated voices rob speech of expression.

Consider how an established context can lend interpretation to messages: Predisposition, expectation, and anticipation can add to, take away from, and/or distort the intention of the speaker. Many pilots who have been repeatedly cleared to a certain flight level at a descent point along a certain route will "hear" an anticipated clearance when, in reality, the controller has assigned a different route or level. Similarly, many air traffic controllers will have "heard" the readback of an expected flight level only to realize on tape playback that in fact the pilot read back a different altitude altogether.

Such idiosyncrasies of communication cause daily misunderstandings in casual conversations and business transactions. The results are variously amusing, embarrassing, and sometimes, costly. In the context of aviation radiotelephony, however, they are a threat to safety. In urgent circumstances, or when the communicants are suffering from fatigue or other impairments, the results can be deadly. Flight crews and controllers alike need to be meticulous in formulating messages and, no less, in "reading back" and "hearing back."

Another linguistic phenomenon needs to be understood—the difficulty implicit in communicating in a non-native language, a phenomenon known as "code switching." This resembles the well-known Freudian slip, an uncontrolled moment of verbal expression never consciously intended. When under stress and communicating in a non-native language, speakers tend to revert to their native language. A speaker needs a high level of proficiency or strong self-discipline to continue speech in a non-native language when under stress, but even then something of a reversion to native language may occur in grammatical construction. The outcome of such "code switching," which may be difficult to recognize, can be confusion and contradiction. Worse, the statement may make perfect sense to the listener but may not reflect the meaning

Enunciating the words of a second language and putting them in proper grammatical context is a challenge in everyday conversation. Communicating in English is much more difficult for foreign flight crews when they are under pressure, especially in an emergency. This difficulty can lead to miscommunication and compromise safety. In cross-cultural communication, even if conducted in a single language, speakers need to guard against confusion by being scrupulous in observing standard phraseology and proper radiotelephony techniques.

That said, studies of pilot and controller communications reveal an astonishingly low rate of error. Analysis of voice tapes reveals that less than 1 percent of communications is compromised by inaccuracy. This low error rate is a tribute to today’s pilots and controllers, all the more so when congestion on the frequency puts orderly radio management practices under severe pressure. No doubt this remarkable efficiency can be attributed to high levels of knowledge, skill, and care. Still, the degree of conformity with standard phraseology can stand improvement—and should be improved. Sometimes, especially among local operators, a level of familiarity leads to use of idioms. While such exchanges may heighten camaraderie between the participants, non-standardized and careless communication inevitably lessens the situational awareness among other users on the frequency. In an increasingly global aviation environment, these "feel good" indulgences must be curtailed.

The problem of careless communication can be addressed at little expense in funds and time. The optimum strategy is not to prescribe regulations or threaten operational personnel with disciplinary action; rather, it is to appeal to the innate responsibility of every controller and pilot. This is probably best done by impressing on all the simple truth that language is an imperfect medium that lends itself to sensible misinterpretation (i.e., the wrong meaning is easily conveyed while the transmission retains perfectly good sense). For this reason, air-ground communications require the utmost care and discipline.

In communicating this message to both non-native and native English speakers, the cooperation of airlines and State authorities is needed. With an understanding of basic linguistic principles, radiotelephony users can be motivated to adhere more closely to standard phraseology and, when this is not possible, to take special care with enunciation, intonation, vocabulary, and message content. Thus, these speakers will curtail the use of colloquialisms, and the efforts being made to establish mandatory levels of language proficiency will be matched by a heightened mindfulness in communicating. This, overall, will not take up more frequency time; it will save it—controllers and pilots will seek fewer message confirmations and, more to the point, fewer incidents and accidents will occur.

This article is adapted with permission from ICAO Journal, April.

Brian Day, a technical officer in the Air Traffic Management Section of the Air Navigation Bureau at ICAO headquarters, Montreal, is the secretary of the Proficiency Requirements in Common English (PRICE) Study Group.