There are numerous findings noting the crucial nature of communication in aviation safety. For many years it has been recognized that communication problems are implicated in many aviation accidents and in runway incursions. Flight Safety Information (2004: 12) reports that “Between 1976 and 2000, more than 1100 passengers and crew lost their lives in accidents in which investigators determined that language had played a contributory role.”
The most frequently mentioned accidents in which language-related miscommunications were a crucial contributing factor occurred in Tenerife in the Canary Islands on March 27, 1977, Cove Neck, New York en route to JFK on January 25, 1990, and the mountainous terrain near Cali, Colombia on December 20, 1995.
On March 27, 1977, a KLM and Pan Am 747 collided on a crowded, foggy runway in Tenerife, the Canary Islands. The pilot of a KLM Boeing 747 radioed, “We are now at take-off”, meaning that the plane was lifting off as his aircraft began rolling down the runway. The air traffic controller misunderstood and thought the plane was waiting for further instructions on the runway, and so did not warn the pilot that another aircraft, a Pan American Airways B747 that was invisible in the thick fog, was already on the runway. The resulting crash killed 583 people in what is still the most destructive accident in aviation history.
The accident that occurred at Cove Neck, New York, on 25 January 1990 resulted in part from the fact that the copilot used the normal English phrase running out of fuel rather than the technical aviation term emergency, thereby failing to convey to the controller the intended degree of urgency (Cushing 2004: 2).
Nordwall detailed the crash of American Airlines Flight 965 near Cali, Columbia in December 1995, as an example of a controller’s inability to communicate effectively in English. W. Frank Price, manager of air traffic services international staff for the FAA said, “Had he [the controller] been able to do so [communicate the crew’s position in English], it could have contributed to the crew’s situational awareness – a factor that might have prevented the accident” (Nordwall 1997: 46-51).
The ASRS (Aviation Safety Reporting System) database is fraught with examples of how meaning can be misinterpreted within the cockpit, between the cockpit and ATC, between the cockpit and the cabin, and essentially throughout the aviation environment.
The complexity and flexibility of natural language are problematic, however, because of the confusions and misunderstandings that can readily arise as a result of such specifically linguistic phenomena as ambiguity, unclear reference, differences in intonation (or punctuation in written language), and presupposition, as well as more general peculiarities of human interactions face-to-face or over the radio. Even when pilots and controllers both speak English fluently, there are pitfalls in the nature of language and the ways that language is heard (Cushing 1995).
Language problems at the heart of a large number of disasters and near-disasters have prompted ICAO to establish stringent new language standards intended to significantly improve and maintain the English language proficiency of aviation professionals. The ICAO mandate specifies that in order to stay operational after March 2008, all pilots and air traffic controllers working international routes must demonstrate a high level of fluency not only in Aviation English specific phraseology, but, also in general English – with an emphasis on oral skills.
In addition to strengthening the provisions related to language use in radiotelephony communications, ICAO has also established a language proficiency rating scale – aviation-english-icao-scale, delineating six levels of language proficiency ranging from Pre-elementary (Level 1) to Expert (Level 6) across six areas of linguistic description: Pronunciation, Structure, Vocabulary, Fluency, Comprehension & Interactions. The minimum operating level of English-language proficiency will be ICAO Operational Level 4 (ICAO Document 9835, 2004). ICAO Level 4 competency means that aviators possess reliable English language skills that can withstand the most unpredictable and stressful of situations.
The disasters at Zagreb and Tenerife have been used to justify the ICAO language proficiency program, which is intended to improve the language proficiency of pilots and controllers worldwide. However, while both disasters involved significant linguistic factors – such as code switching, numerical slips, pronunciation problems and possible L1 interference – it should not be forgotten that they also involved many non-linguistic factors.