O. Veronika Prinzo

Civil Aerospace Medical Institute

Federal Aviation Administration

Oklahoma City, OK 73125

Alan Campbell

Johns Creek, GA 30022

Alfred M. Hendrix and Ruby Hendrix

HCS Consulting Services

Roswell, NM 88201

December 2010

Final Report

U.S. Airline Transport Pilot International 

Flight Language Experiences, Report 5: 

Language Experiences in Native 

English-Speaking Airspace/Airports

DOT/FAA/AM-10/18

Office of Aerospace Medicine

Washington, DC 20591

OK-11-0024-JAH

Federal Aviation

Administration
NOTICE

This document is disseminated under the sponsorship 

of the U.S. Department of Transportation in the interest 

of information exchange. The United States Government 

assumes no liability for the contents thereof.

___________

This publication and all Office of Aerospace Medicine 

technical reports are available in full-text from the Civil 

Aerospace Medical Institute’s publications Web site: 

www.faa.gov/library/reports/medical/oamtechreports
i

Technical Report Documentation Page

1. Report No. 2. Government Accession No. Recipient's Catalog No. 

DOT/FAA/AM-10/18 

4. Title and Subtitle 5. Report Date 

U.S. Airline Transport Pilot International Flight Language Experiences, 

Report 5: Language Experiences in Native English-Speaking 

Airspace/Airports 

December 2010 

6. Performing Organization Code 

7. Author(s) 8. Performing Organization Report No. 

Prinzo OV,1 Campbell A,2 Hendrix A,3 Hendrix R3

 

9. Performing Organization Name and Address 10. Work Unit No. (TRAIS) 

 

 

1

FAA CAMI 

P.O. Box 25082 

Oklahoma City, OK 73125 

2

Capt. Alan Campbell 

Johns Creek, GA 

30022 

3

HCS Consulting 

Services 

Roswell, NM 88201 11. Contract or Grant No. 

 12. Sponsoring Agency name and Address 13. Type of Report and Period Covered 

 

 

 14. Sponsoring Agency Code 

Office of Aerospace Medicine 

Federal Aviation Administration 

800 Independence Ave., S.W. 

Washington, DC 20591 

 15. Supplemental Notes 

This work was performed under Task AM-B-06-HRR-516. 16. Abstract: 

In 1998, the International Civil Aviation Organization took a heightened interest in the role of language in 

airline accidents. Member states agreed to take steps to ensure air traffic control personnel and flight crews 

involved in flight operations in airspace where the use of the English language is required were proficient in 

conducting and comprehending radiotelephony communications in English. This report is a compilation of 

written responses and comments by U.S. pilots from American, Continental, Delta, and United Airlines of their 

difficulties in international operations. In this report, the pilots’ responses to questions 46-53 are presented as a 

compiled narrative. Their responses had eight major thrusts from which we derived the following five 

recommendations: (1) Adopt a standard dialect for use in ATC communications. (2) All trainees and current 

certified professional controllers successfully complete instruction and training in the principles of voice 

production and articulation as it relates to ATC communication. (3) Define an optimal rate of speech for use by 

certified professional controllers when communicating with pilots. Research is needed to provide guidance on the 

optimal rate of speech for different populations of speakers – U.S., Foreign. (4) Develop new standard 

phraseology for non-routine events. Generally, the controller needs to have the pilot answer one question, “What 

do you need from me?” The controller would coordinate the appropriate actions to provide the pilot with what is 

needed. (5) Controllers should be discouraged from using local jargon, slang, idiomatic expressions, and other 

forms of conversational communications when transmitting messages to pilots. Although colorful and fun, they 

have no place in air traffic control and diminish situational awareness, can lead to requests for repeat, and 

otherwise disrupt information transfer. 

 

17. Key Words 18. Distribution Statement 

 

 

Communications, ATC Communication, 

Air Traffic Control 

Document is available to the public through the Defense 

Technical Information Center, Ft. Belvoir, VA 22060; and the 

National Technical Information Service Springfield, VA 22161 19. Security Classif. (of this report) 20. Security Classif. (of this page) 21. No. of Pages 22. Price 

Unclassified Unclassified 23 

Form DOT F 1700.7 (8-72) Reproduction of completed page authorized 

iii

Acknowledgments

This research was sponsored by the Federal Aviation Administration Flight Technologies and Procedures Branch 

under the direction of William Adams (AFS-430), and the findings were provided to the Data Com Human Factors 

Working Group. It was conducted under the Flight Deck Program Directive / Level of Effort Agreement between the 

Human Factors Research and Engineering Group (AJP-61), FAA Headquarters, and the Aerospace Human Factors 

Division (AAM-500) of the Civil Aerospace Medical Institute. We thank all the people at American, Continental, 

Delta, and United Airlines who were instrumental in the success of this project—especially the 48 U.S. pilots who 

participated in the interviews. Among these pilots were several who participated in the discussions either shortly after 

returning from international flights, left immediately after the interview to be part of international flight crews, or 

deadheaded to the company office from other states. These pilots exhibited passion for aviation safety and knew the 

importance their knowledge and expertise held in international flight operations. We cannot thank them enough. 

We also thank Captain Terry Hanson (retired) and Mr. Graham Elliott (AMA-800) for their helpful comments and 

items for inclusion in the interview questions. Finally, we thank the staff at Xyant Technologies for transcribing the 

many hours of voice tapes and written responses into Excel© spreadsheets.

v

Contents

RESULTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Section 7: Language Experiences in Native English-Speaking Airspace/Airports. . . . . . . . . . . . . . . . . . . . . . . 2

Q46. List the different native English languages you typically hear over your communications system 

during international flights. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Q47. How would you rate your overall native English-speaking language experiences during 

these flights?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Q48. How is your workload affected by your experience with native English-speaking language 

differences during a flight?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Q49. How often do you experience communication problems in native English-speaking 

airspace/airports? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Q50. Of the native English-speaking airports that you fly to, do you find the English language skills of 

other pilots and controllers comparable? Please explain.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Q50a. Do you find that the intelligibility of some native English-speaking controllers' speech causes 

you to work harder to understand them? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Q50b. What makes some international native English-speaking controllers’ speech more difficult to 

understand than others (e.g., speech rate, pronunciation)?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Q51. When flying in a native English-speaking country, how often do controllers use ICAO standard 

phraseologies for routine communications to speak to you? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Q52. When flying in a native English-speaking country, how often do controllers use Common 

English for routine communications to speak to you? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Q53. When flying in a native English-speaking country, how would you describe the controllers’ 

ability to communicate with you in Common English? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Q53a. In general, how much attention do you have to use to make sense of what the native Englishspeaking controller is saying? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Q53b. What are the most troubling language-based problems you experience with native 

English-speaking controllers?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Q53c. How often have you heard native English-speaking controllers use jargon or slang that was 

difficult to interpret? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Q53ci. The respondents’ examples of jargon that were difficult to interpret were “Guppy” and 

“Barbie Jet.” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Q53cii. The respondents did not list any examples of slang that were difficult to interpret.. . . . . . . . . . . . 13

DISCUSSION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Recommendations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

vii

EXECUTIVE SUMMARY

This is the fifth report from Series One that presents 

the findings from in-depth interviews with U.S. pilots 

who fly internationally for major U.S. air carriers. The 

first series of reports are from small focus group discussions with U.S. air transport certificated pilots. A second 

series used the same format and questions with pilots 

flying internationally for Aeroflot, Alitalia, China Air, 

and LAN Chile airlines.

English language proficiency is a safety concern as 

noted by the International Civil Aviation Organization 

(ICAO 2004). Given that international flight operations 

are increasing, it is important to know more about the 

language experiences U.S. pilots encounter when flying 

into countries where English may or may not be the local or national language among their radio operators, air 

traffic controllers, and pilots. 

Several major U.S. airline companies were asked to 

solicit volunteers from among their international pilots 

to serve as paid subject matter experts in a structured 

interview constructed to assess the language difficulties 

they encounter during international flights. There were 

12 pilots each representing American, Continental, Delta, 

and United Airlines for a total of 48 airline transport pilots 

(ATPs). These pilots were assumed to be representative 

of typical U.S. airline pilots flying internationally as to 

English language proficiency, familiarity with ICAO and 

aviation procedures, terminology, and standard air traffic phraseology. We limited the size of each interview to 

include no more than four pilots. There were morning 

and afternoon sessions that took place over several days 

at each company’s preferred location. 

The structured interview was divided into 10 sections: 

(1) Background Information, (2) Pre-Flight Preparation, 

(3) Air Traffic Control (ATC) Procedures, (4) Word 

Meaning and Pronunciation , (5) Language Experiences 

in Non-Native English-Speaking Airspace/Airports, (6) 

Non-Native English-Speaking Controllers Communicating With Native English-Speaking Pilots, (7) Language 

Experiences in Native English-Speaking Airspace/Airports, (8) Native English-Speaking Controllers Communicating with Non-Native English-Speaking Pilots, 

(9) Communication Problems, and (10) Technological 

Intervention. A copy of the interview questions appears 

in the first report (Prinzo & Campbell, 2008).

This report continues with the U.S. pilots’ responses 

to questions found in Section 7. It provides a wealth 

of information related to their flight experiences when 

communicating with native English-speaking controllers. 

It provides an overall description of how these communication exchanges affected their perceptions of safety, 

communications, workload, and situational awareness.

The pilots’ answers to the questions and discussions 

during the interviews were their perception of the situations they encountered. Many stories were anecdotal, 

and some were relayed in third person. The analyses of 

those discussions and written responses are summarized 

and presented as if from one pilot’s diary containing a 

compendium of flight experiences. This was done to 

preserve the richness and integrity of the information 

given during the interviews.

When asked how hearing English spoken by a native English speaker affected their workload, 9% of the 

pilots said they experienced decreased workload, 17% 

reported no change, 63% said there was only a minimal 

or slight increase, and 11% said workload increased. 

Among the pilots who reported a slight or minimal increase in workload, they attributed it to a more relaxed 

radio discipline and faster speech rate—especially when 

traffic was heavy. Another question asked how often 

they experienced communication problems, to which 

94% of them said that it occurred in fewer than 25% 

of their interactions with controllers. If they did have 

a problem, it was corrected easily because English was 

the language they had in common. After being asked 

if native English language skills were geographically 

comparable, 83% of the pilots reported that the pilots 

and controllers were similar, while 17% said they differed (controllers had less of an accent). Although 90% 

of the pilots perceived controllers as having good (47%) 

to excellent (52%) communication skills, 75% said they 

used extra effort when listening to some native Englishspeaking controllers. Finally, native English-speaking 

controllers typically used ICAO phraseology in at least 

75% of their routine communications, and the pilots 

seemed to be very positive about the controllers’ use of 

Common English. 

The pilots’ responses were compiled into eight key issues:

1. For pilots and controllers alike (regardless of their 

country of origin or aircraft registry), some English dialects and accents are more difficult to understand, add 

workload, and require more of the listeners’ attention 

be directed towards what is being heard. In addition to 

accents, regional differences in the pronunciation of a 

waypoint or fix made understanding the names difficult. 

This is especially so for new pilots (and controllers) who 

are unfamiliar with the accent and dialect or if the quality 

of the radio transmission/equipment is poor.

Understanding was particularly affected by differences 

in pronunciation, speech rate, and accent, followed 

by pitch, expectation, intonation, and phraseology. 

Some accents were easier to understand, while the ones 

unfamiliar to the pilots were said to be more difficult. 

Likewise with intonation, since it provides the emphasis, 

tone, variety in oral languages that can alter meaning by 

simply modulating pitch and loudness while speaking. 

Different English dialects have different intonation 

patterns that can affect how well listeners understand 

what is being said. 
viii 

2. Some controllers delivered clearances too fast, 

rendering some transmissions unintelligible. When the 

fast pace marries up with individual differences in accent 

and dialect, pilots pay more attention, especially if there 

are procedural differences they must be aware of. For 

example, a pilot from New York may have some problems 

understanding controllers from Georgia or Florida and 

visa versa, as would a pilot from Texas flying into Hong 

Kong or London.

When pilots and controllers do not understand each 

other due to these differences, coupled with rapid-fire 

speech, inevitably one or the other will make a request 

for repetition, confirmation, or verification, resulting 

in increased workload and radio frequency congestion. 

Although §5.2.1.5.3 of Annex 10 Volume II (ICAO, 

2001) states that pilots “should maintain an even rate of 

speech not exceeding 100 words per minute,” FAA Order 

7110.10U Flight Services §2-1-2 (FAA, 2010a) states 

weather and flight information and other information shall 

be broadcast/recorded as follows, “Data shall be spoken 

at a rate of 100 to 120 words-per-minute.” However, 

there is no guidance in FAA Order 7110.65T Air Traffic 

Control (FAA, 2010b) for a specified speech rate air traffic 

controllers are to use when communicating with pilots. 

Generally, normal conversational speech occurs at about 

160 words per minute (wpm) and depends, in part, on 

the number and duration of pauses and syllables (e.g., 

it takes less time to pronounce hat than hippopotamus).

3. The sampled U.S. pilots would like to see the U.S. 

adopt the ICAO standard. ATC telephony consists of a 

standard phraseology that controllers repeat throughout 

their workday. The pilots noted some controllers in 

the U.S. are more prone to use “Americanisms.” Since 

there is a common language among the various English 

dialects, none of the U.S. pilots reported problems with 

any particular local slang or jargon. Slang, like idioms, 

appears in conversational speech and can be difficult for 

listeners who are unfamiliar with local expressions (or 

history) to understand, but they can work through them 

because of the common root language. 

4. In the U.S., a standard phraseology was constructed 

for the advisories and separation of aircraft. There is no 

prescribed phraseology for communication concerning 

occurrences outside of clearances, advisories, and weather. 

Pilots and controllers communicate in Common English 

to convey information concerning accidents, emergencies, courtesies, etc.

5. The most troubling language-barrier problems 

with native English-speaking controllers are procedural 

issues, local knowledge, and not realizing that there 

might be differences between international and domestic 

ATC phraseology. The pilots provided examples of these 

differences—line up and wait (non-U.S.) compared to 

taxi into position and hold (U.S.) and the various meanings of direct routes: “direct,” “direct to,” “direct to (point) 

as filed,” and “direct to (point) (airway/jet route).” The 

pilots seemed to prefer “present position direct to (point).”

6. Radio discipline varied with the degree of familiarity 

between the flight crew and controllers. As they gained 

familiarity with each other because of their common 

flight/work schedules, they recognized each others’ voices. 

Communications could become more relaxed and conversational while maintaining a degree of professionalism.

7. The most troubling language-based problems 

centered on receiving more information in a single 

transmission than could be processed reasonably in 

the amount of time used to deliver it. Prinzo, Hendrix, 

and Hendrix (2009) found that long messages lead to 

substitution and transposition errors as pilots read back 

the message contents. One pilot provided the following 

example: “Climb to two two zero, heading one eight zero, 

slow up to two ten and proceed to GIPSO.” It contains 

four instructions (altitude, heading, speed, and route). 

Likewise, complex messages (such as route clearances) 

lead pilots to omit portions during readback.

Finally, we present five recommendations derived 

from the pilots’ responses to the interview questions and 

discussions. They are: 

1. Adopt a standard dialect for use in ATC communications. Just as radio and television news broadcasters 

learn to speak using a nondescript accent, actors often hire 

language coaches to teach them the “standard Hollywood 

accent” to portray geographically neutral characters. 

2. All trainees, current certified professional controllers, and pilots should successfully complete instruction 

and training in the principles of voice production and 

articulation as it relates to ATC communication.

3. Define an optimal rate of speech for use by certified professional controllers when communicating 

with pilots. Research is needed to provide guidance on 

the optimal rate of speech for different populations of 

speakers—U.S., Foreign.

4. Develop new standard phraseology for non-routine 

events. Generally, the controller needs to have the pilot 

answer one question, “What do you need from me?” The 

controller would coordinate the appropriate actions to 

provide the pilot with what is needed. 

5. Controllers should be discouraged from using local jargon, slang, idiomatic expressions, and other forms 

of conversational communications when transmitting 

messages to pilots. Although colorful and fun, colloquial 

expressions have no place in air traffic control, diminish 

situational awareness, can lead to repeated requests, and 

otherwise disrupt information transfer.
1

United States Airline Transport Pilot International

Flight Language Experiences, Report 5: Language

Experiences in Native English-Speaking Airspace/Airports

Viewed freely, the English language is the accretion and growth of every dialect, race, 

and range of time and is both the free and compacted composition of all.

— Walt Whitman, 1892

This is the fifth in a series of reports derived from the 

responses made by 48 U.S. pilots about their international 

flight experiences during structured, small focus-group 

interviews. The purpose of the interviews was to identify 

language issues that can become barriers to efficient and 

effective communication between airline transport pilots 

and air traffic controllers (who may or may not be fluent 

in English). 

The first report (Prinzo & Campbell, 2008) analyzed 

the first three sections of the structured interview: 1) Background Information related to the recency of international 

flight experiences among the pilot-participants; 2) General/

Preflight Preparation; and 3) Air Traffic Control (ATC) Procedures. It covered the U.S. pilots’ responses and discussions 

of questions 1–23. The second report (Prinzo, Campbell, 

Hendrix, & Hendrix, 2010a) continued with U.S. pilots’ 

flight experiences when word meanings and pronunciation 

became barriers to efficient and effective communication. 

It covered the pilots’ responses and discussions to questions 

24–30 in Section 4. The third report (Prinzo, Campbell, 

Hendrix, & Hendrix, 2010b) involved pilots’ responses 

and discussions of questions 31–38 found in Section 5. 

It addressed their language experiences in non-native 

English-speaking airspace and airports. The fourth (Prinzo, 

Campbell, Hendrix, & Hendrix, 2010c) continued with 

Section 6 (questions 39–45) and asked them about their 

language experiences with controllers who spoke English 

as a foreign language.

The questions in this report are from Section 7 of the 

interview and parallel those in the third report; they differ 

only in location: Report 3 probed pilots’ language experiences in non-native English-speaking airspace and airports, 

while this report probes their language experiences in native English-speaking airspace and airports. Regardless of 

location, controllers must communicate in English with 

foreign pilots. Thus, U.S. pilots were able to reflect upon 

their experiences flying in both English and non-English 

speaking-countries.

Language is a means of communicating systematically 

by the use of sensory systems (e.g., sight, sound, touch) to 

convey meaning and express thoughts. It has common linguistic features that make its properties intelligible among 

people who share that language. English is the dominant 

language of the United Kingdom (U.K), the United States 

(U.S.), Canada, the Republic of Ireland, Australia, New 

Zealand, and a number of other countries; however, it is 

spoken in many different dialects.

Dialect refers to the variation among some linguistic 

features that set it off from other varieties within that 

language. Dialects may differ in vocabulary, grammar, 

and pronunciation. For example, regional dialects in 

the U.S. may differ in vocabulary, grammar, and pronunciation. As noted by Leverett (2007), New Yorkers 

may refer to a group of their friends as “youse,” while 

natives of Pittsburgh might address this same group as 

“you’ns.” Southerners might say “y’all” or “all-of-y’all,” 

and Midwesterners, “you guys,” (regardless of the group’s 

gender).

People unfamiliar with 

regional expressions would 

have difficulty understanding a local speaker 

since the relationship 

between an expression 

and its meaning can be 

geographically unique. 

For example, a visitor to 

Akron, Ohio, might not 

understand what the sign 

in Figure 1 meant. Once 

told that the strip of land 

separating the street’s curb 

from the sidewalk is called the “devil strip” (Cassidy & 

Hall, 1991), the sign becomes meaningful. 

As entertaining as it might be to find (or experience) 

regional variations, they can cause difficulty in ATC 

communication. Like visitors to Akron, Ohio who might 

not know about the “devil strip,” pilots might experience 

similar difficulties due to differences among dialects. The 

pilots who participated in this study were instructed to 

think about how hearing other native dialects of the English language affected their safety and communications 

between them and air traffic controllers.

As with the other reports in this series, the pilots’ oral 

responses were combined, condensed, and edited to remove redundancies and improve readability. Each report 

was presented from the perspective of a hypothetical, albeit 

typical Airline Transport Pilot (ATP) certificated pilot. 

When possible, the content was tabulated and presented 

in tables. If their responses to a particular question appeared to address similar topics with an underlying issue 

or concern, they were grouped together and its core issue, 

or concern, was extracted and labeled. 

Figure 1. Example of a 

Regional Dialect 
2 

RESULTS

Section 7: Language Experiences in Native EnglishSpeaking Airspace/Airports

The questions in this section of the interview focus 

on how hearing other dialects of the English language 

affected safety and communication between the pilot and 

air traffic controllers. 

46. List the different native English languages you typically 

hear over your communications system during international flights (e.g., North American English, Australian 

English, British English, Hong Kong English, Indian 

English). 

As shown in Table 1, the pilots listed 17 different 

dialects of the English language. Of these dialects, British 

English appeared in 26% of their 128 total responses. 

Likewise, they listed North American English in 21% of 

their responses and Hong Kong English in approximately 

8% of their responses. 

47. How would you rate your overall native English-speaking 

language experiences during these flights?

A compilation of the pilots’ responses revealed that 

approximately 79% rated their English language experiences as either “Very positive” (17) or “Positive” (21). 

Eight pilots provided a rating of “Neutral,” one gave a 

rating of “Negative,” and one gave a rating of “Positive/

Negative” (Mixed).

Positive Explanation

Of the four respondents who offered comments, the 

most common theme was that even though dialects vary, 

understanding is easier when the participants share the 

same language.

Same Language, Different Accents

Even though some of the accents may be a little 

bit more difficult for me, the words are the same, 

and that makes understanding the meaning easier. 

Because we speak the same language, we can slow 

down and still convey the point. We can enunciate 

more clearly if necessary to clarify a situation or if 

we don’t understand one another. We cannot do that 

when we’re speaking different languages because 

there’s no common baseline. 

Neutral Explanation

To all eight of the pilots who selected “Neutral,” 

some dialects seemed peculiar, but the problems they 

experienced didn’t necessarily result from these dialects.

Negative Explanation

One pilot provided a negative explanation. For him, 

not all English dialects are easy to understand.

Native English Speakers Don’t Receive Speech Training

I think some non-native English-speaking controllers 

probably receive training on how to limit their accent 

and dialect issues. My guess is that a controller from 

an English-speaking country doesn’t receive similar 

training. So, when he speaks, that’s the English we 

hear, even though the accent and dialect might make 

it difficult for us to understand. 

48. How is your workload affected by your experience with 

native English-speaking language differences during a 

flight?

To avoid biasing pilots’ responses, this question was 

written such that workload could remain the same, 

increase, or decrease. We attempted to compile their individual responses according to commonalities. In most 

cases, it was easy. When otherwise, it required judgment 

derived from the pilot’s written and oral responses. Table 

2 shows 71% of the pilots qualified their responses by 

stating that traffic volume, experience, and differences 

in dialects (just to name a few) had to be taken into 

consideration.

Table 1. Dialects of English Heard by U.S. Pilots During Their International Flights.

Continent/Geographic 

Region/Dialect 

Number of 

Responses %

Continent/Geographic 

Region/Dialect 

Number of 

Responses %

Asia North America 

Chinese/Taiwanese 2 2 Greenland 3 2 

Hong Kong 10 8 Island English 2 2 

India English 7 5 Belize/Jamaica 3 2 

Europe 

British West 

Indies/Jamaica 1 1 

United Kingdom 5 4 Bermuda 1 1 

British English 33 26 North American English 27 21 

Irish 7 5 Canadian English 8 6 

Scottish 8 6 U.S.A 3 2 

 Oceaniaa

 Australian 6 5 

New Zealand 2 2 

a.A geographical area in the Pacific consisting of Australia, New Zealand, and surrounding islands. 
3

No Change Explanation

The eight pilots in this group indicated that hearing 

different English dialects had no impact on their workload. 

Nothing was offered beyond their written comments of 

no real difference or negative effect.

Decreased Workload Explanation

Four respondents reported that English was easier to 

understand and always standard. Three of the pilots offered comments during the interviews.

We Speak the Same English Language, Just Differently

When we leave Europe and are told to contact 

London control, I feel a little weight come off my 

shoulders. My workload is definitely reduced and it’s 

just easier, even though some of the English dialects 

may be difficult for me to understand. We may have 

to ask to have it said again, but we can always figure 

out what is being said because we have that common 

language to fall back on.

Minimal Increase in Workload Explanation

Thirteen respondents reported that their workload 

increased in some regards. During the discussions, 38% 

provided comments. Generally, the increase was minimal, 

with less concentration required, and controllers were 

easily understood.

Non-Standard Communications Occur 

More Frequently

For me, understanding is the work, and since I don’t 

find English [dialects] to be real different, it’s easy to 

understand so it doesn’t create an issue. One thing 

that does crop up in native English-speaking areas 

is a tendency to use more pleasantries, jargon, and 

chitchat. We may not catch all of it and it’s not a big 

deal, but we have to really listen.

Some Areas Are Fast-Paced Due to Traffic Volume

Sometimes my concern is with speed of communication. There are places with lots of traffic moving 

rapidly—like the Northeast Corridor or Chicago. Our 

workload goes up because we have to listen specifically for our call sign since we rarely get a chance to 

do a repeat or verification of the clearance. It does 

not matter whether the controller is a native or nonEnglish speaker; if we didn’t understand or hear the 

correct words, we need to make sure that what we 

think was said is what was said.

Minimal Increase With Qualifications Explanation

Seven respondents reported their workload increased, 

but they qualified their responses. An examination of 

their written comments indicated that accents played a 

role, as did the experience level of the flight crew. During 

the interviews, 57% of these pilots provided additional 

comments. 

New Crewmembers Have a Harder Time Understanding

It’s not much of an effect, unless we have a new 

crewmember that may be having difficulty with the 

language changes, even though it’s English. Now 

there’s no back up; it’s a threat because I’m the only 

one hearing.

Pilots Have Difficulty Understanding Some Dialects

I don’t think it has that big of an impact although, 

sometimes it’s hard to understand particular dialects. 

The native English-speaking language differences are 

usually easily resolved. If you ask, they make sure 

you understand what they want you to do. 

Poor Radio Quality Coupled With Different Dialects

I’m sure it’s the radio because we probably sound 

like that to them over their receivers. For me, Scottish 

control is difficult because I have a hard time with 

their thick brogue, especially when their radios make 

them sound like they’re talking from the bottom of 

a deep well. The only radios that are worse are in 

some areas in South America.

Slight Increase Explanation

Of the respondents who reported their workload increased, 78% provided comments during the discussions. 

For this group, the pilots reported difficulty understanding 

accented-English dialects.

Table 2. Effects of Native English Language Experiences on Pilot Workload. 

Outcome on Pilot Workload 

Number of 

Pilots % Common Thread 

No Change 8 17 Hearing Different Dialects Has No Impact 

Decrease 4 8 We Speak the Same English Language, Just Differently 

Minimal Increase 13 27 

Non-Standard Communications Occur More Frequently; 

Some Areas Are Fast Paced Due to Traffic Volume 

Minimal Increase With 

Qualifications 7 15 

New Crewmembers Have a Harder Time Understanding; 

Pilots Have Difficulty Understanding Some Dialects; 

Poor Radio Quality Coupled With Different Dialects 

Slight Increase 9 19 

Pilots Have Difficulty Understanding Some Dialects; 

Differences in ICAO Terminologies 

Increase With Qualifications 5 10 Hearing Different Dialects Has an Impact 

No Response 2 4 
4 

Pilots Have Difficulty Understanding Some Dialects

Depending on where native English-speaking controllers are from, my workload goes up slightly when 

I’m listening to their accents. So, we anticipate what 

we’re going to hear. Parts of the U.S. definitely have 

dialects—like the Deep South, Boston’s airspace, or 

Houston—[and] differ from other areas. Also, my 

own native English-speaking environment is New 

York. They say we have an accent, but I don’t hear 

it. To me it’s no problem.

Differences in ICAO Terminologies

The difference would include the terminologies in 

ICAO communications.

Interviewer: So you’re saying the ICAO differences 

increase your workload?

There is a little more workload. It’s more proper 

[outside the U.S.] instead of the slang and the relaxed 

atmosphere that we enjoy domestically.

Increase With Qualifications

Five respondents reported their workload increased. 

Their written comments suggested they put forth more 

effort listening and interpreting what was said by controllers who spoke in different dialects. Sixty percent of the 

pilots provided comments.

Hearing Different English Dialects Has an Impact

In many ways, communication is the essence and 

probably the most critical function we do, other than 

fly the airplane. If nobody was around us, then it 

would not necessarily be a player. Sometimes English 

dialects increase my workload because I’m listening 

more intently to what’s being conveyed. We have to 

be more careful with the local differences in what a 

word means, rather than how it is said.

49. How often do you experience communication problems 

in native English-speaking airspace/airports? 

As seen in Table 3, 79% of the pilots reported rarely 

having communication problems in native Englishspeaking airspace/airports. Another 15% experienced an 

occasional communication problem. The comments from 

the pilots during the interviews are presented according 

to their response selection.

Rarely Explanation

Among this group of 38 pilots, 11% indicated that the 

problems they experienced were from clearances being given 

too quickly and in accents that were difficult for them to 

understand. However, the problems were cleared up quickly 

once the pilots indicated they did not grasp what was said.

Occasionally Explanation

Of the seven pilots who reported “Between 10–24% of 

my interactions with controllers involve communication 

problems,” only one provided comments. For that pilot, 

hearing the name of a fix was not always understood and 

required him to ask the controller to spell it.

Frequently Explanation

Both of the pilots circled “Frequently (between 25–

74% of my interactions with controllers)” and provided 

comments during the interviews. One reported having 

difficulty in the U.K., whereas everything else was great. 

The other pilot had difficulty in the Eastern Caribbean, 

but it was not an issue in Canada.

Often Explanation

One pilot circled “Often (between 75–90% of my 

interactions with controllers).” That pilot reported having problems understanding what controllers are saying 

when flying from Los Angeles to Dulles.

50. Of the native English-speaking airports that you fly to, 

do you find the English language skills of other pilots 

and controllers comparable? Please explain.

Yes, They Generally Are Comparable

Thirty-nine pilots reported that the English language 

skills of other pilots and controllers were comparable, of 

which half offered minimal, or no explanation. Of the 

pilots who did respond, they either heard little variation 

or had no problem communicating with controllers. 

Table 3. Pilot Reports of Communication Problems Experienced in Native English-Speaking 

Airspace/Airports.

Alternative Number of Pilots % Issues 

Rarely 

(< 10% of my interactions with controllers) 38 79 Speech Rate and Accent 

Occasionally 

(10-24% of my interactions with controllers) 7 15 Phonetics Versus Fix Name 

Frequently 

(25-74% of my interactions with controllers) 2 4 The U.K.a and East Caribbean 

Often 

(75-90% of my interactions with controllers) 1 2 LAXb Versus Dulles Dialect 

Without Fail 

(> 90% of my interactions with controllers) 0 0 

aUnited Kingdom 

bLos Angeles Airport located in California while Dulles is in Sterling, Virginia 
5

For the pilots who commented and said that the pilots’ 

and controllers’ English-language skills were comparable, 

they also reported some differences. Their discussions 

centered on the importance of actively listening to what 

was spoken because of some subtle differences in accents, 

dialect, radio discipline, and differences between the U.S. 

and ICAO.

Non-Native English Speakers in the 

Mix Change Everything

Foreign carriers flying here and American carriers 

going to another country have the same problem—we 

have a hard time understanding what was said and 

ask to have the clearance repeated once or twice. 

We hear Aero Mexico, Air France, Korean Air, and 

other non-native English pilots asking for repeats 

because they often have a tough time understanding our controllers. The controllers’ speak to them a 

little bit differently.1 

Northeast Corridor and Chicago Controllers Talk Fast

The English language skills of other pilots and 

controllers are comparable, but in the Northeast 

Corridor and Chicago, bad weather tends to really 

get people talking a lot faster. I get the impression 

that controllers may be less tolerant if a pilot asks 

for a clearance to be repeated.

The Larger Challenges Are the Differences 

Between the ICAO and U.S. 

There are a few problems. For example, confusion 

often exists in a single word but not [a] phrase. The 

Brits might say, “Your assignment is stand 15,” versus 

“gate 15.” But here, if we say stand, the controller 

might think we meant a hardstand,2 so we might not 

get a gate at all. It seems to me that U.S. controllers 

use more slang and less ICAO phraseology compared 

to the controllers outside the U.S. who are excellent; 

our own controllers could learn a thing or two about 

radio discipline.

Workload Increases as English Dialect 

and Accents Differ

The more a language, inflection, and dialect differ from the announcer on the 6 o’clock news, the 

more my workload goes up. When that happens, 

it is important for me to listen carefully and transmit clearly. For me, the British accent in Scottish 

1 Prinzo & Thomson’s 2009 analysis of U.S. controller utterances transmitted 

only to non-native English Foreign registry aircraft.

2 A hardstand is a hard-surfaced area for parking aircraft or ground vehicles.

airspace and the Scottish brogue can be difficult 

to understand, as is the accent in the Northeastern 

U.S.—although controllers seem to have less of an 

accent than pilots do.

No, They Generally Are Not Comparable

Eight pilots reported that pilots and controllers were 

not comparable. Generally, this group mentioned where 

the problems were most notable. For them, it was pilots 

with poor English language skills who were less proficient. 

I might get a great controller and then two bad 

ones—so each individual (and country) is different. 

London has probably the widest variety due to nearly 

every international carrier operating there. The native English-speaking pilots do fine, but some pilots 

from non-native English-speaking countries have 

limitations. They present very big problems for Los 

Angeles and San Francisco. I hear our controllers 

repeat messages over and over again while the pilots 

are trying unsuccessfully to read it back in English. 

50a. Do you find that the intelligibility of some native 

English-speaking controllers' speech causes you to work 

harder to understand them? Use any examples that you 

may care to (e.g., Indian English, Hong Kong English, 

British English, North American English, U.S. regions 

where you might hear Mid-Atlantic English, North 

Central American English, Pacific Northwest English, 

Southern American English).

The pilot responses to this question were separated into 

two components. The first one involved their examples 

of places where they experienced difficulties due to intelligibility. The second involved aspects of speech, and it 

was moved to question 50b, where it was integrated with 

speech characteristics.

I Have to Work Harder to Understand What Was Said

Approximately 73% of the pilots reported that they 

worked harder to understand some native Englishspeaking controllers. They cited accent, jargon, pronunciation, and speech rate as primary factors affecting 

intelligibility. They provided some specific examples that 

reflected regional differences. As seen in Table 4, although 

a particular country might have been mentioned once or 

twice, the majority of the pilots limited their discussions 

to accents used in India, the U.K. (England, Northern 

Ireland, Scotland, and Wales), and the U.S. (New England, Southeast, and Southern regions). 

Table 4. Frequency Pilots’ Listed A Particular English Dialect As Being Difficult to 

Understand. 

Languages Mentioned Number of Times Listed 

Indian English 7 

U.K. English 23 

U.S. English 10 

Asian, Australian, Eastern Caribbean, New Zealand English 1 - 2 times each 
6 

If It Is in English, We Can Work Out Any Problem

Although intelligibility causes us to work harder, we 

can always ask native English-speaking controllers 

what they meant, and they will understand us. There 

are some nuances among English speakers, and our 

accents and dialects are all a little bit different, but 

we’re going to communicate and that overrides any 

problems we may have.

Some Accents and Dialects Are Easier to 

Understand Than Others

Each controller is different and I find some have 

really heavily-accented English. London has a wide 

variety of English dialects, since nearly every international carrier operates there. When I hear a thick 

South Hampton accent, it’s harder for me to keep up 

with what’s being said. For me, Welsh, Scottish, and 

Irish English can be difficult to understand because of 

the accent, as well as the Scottish and Irish dialects. 

In the U.S., I hear Southern controllers slur their 

words, and the ones in the Southeast are more 

problematic than Boston or New York because I 

have difficulty understanding what they are asking 

me. Sometimes the Boston controllers use strange 

pronunciations. 

Some U.S. Controllers’ Speech Rate Is Fast

I notice that sometimes the controllers in New 

England talk too fast as do the New Yorkers. I’ve 

experienced New York Approach fire instructions 

nonstop, and I know they’re not going to be happy 

if we miss one. When at O’Hare, I perceive controllers as speaking like auctioneers, but I understand 

them. I think it would be difficult to operate in that 

environment as a foreign pilot.

The Only Issue Is Jargon

The work increase I experience is due to the use of 

jargon, as opposed to maintaining standard aviation 

communication terminology.

Interviewer: If you heard a controller tell you, go fast, 

how would you interpret that?

I expect it’s probably maximum forward speed. It 

means fly as fast as you’re willing to fly within the 

legal bounds of the airspace. If we’re number one 

in line, we’re to start getting everything going—ATC 

wants to increase separation so they’re telling us to 

get going. But, it depends on where we are. If I’m 

over Houston at 35,000 feet, that’s doable—it’s10 

knots below placard. If over San Juan, I’d ask him 

what he wanted me to do. 

Interviewer: Another phrase that I heard is good rate 

down. How would you interpret it?

It would be the same interpretation. Increase your 

descent rate to the maximum you can.

Actually, another term that’s quite frequently used 

is you’re number one. It means you’re holding everybody up. So, if you’re planning on slowing down 

early, let ATC know. It also means we can go as fast as 

we like. We tend to want to go fast at lower altitudes 

to conserve fuel or make up time.

I Do Not Have to Work Harder to Understand

Thirteen respondents indicated they had no increase 

in workload. They only experienced minor problems, 

but overall, the effects were insignificant.

The intelligibility of native English-speaking controllers does not usually make me work harder 

to understand them. I’m in North America, in my 

own world. I find a very minor problem down in 

the Islands—Antigua, Barbados, places like that 

where controllers use Island English. It’s a [vulgaris 

vicus lingua]3 where there may be several different 

pronunciations for the same word. For example, is 

it Cara(bee)an or Ca(rib)ean?

50b. What makes some international native English-speaking 

controllers’ speech more difficult to understand than 

others (e.g., speech rate, pronunciation)?

Forty-seven pilots listed the speech characteristics 

they thought made understanding controllers difficult 

for them. Sixty-eight percent provided oral comments. 

Of the 75 generated items, Table 5 shows pronunciation, 

speech rate, and accent appeared more frequently than 

pitch, expectation, intonation, or phraseology. 

Accents

I find that some accents are more difficult to understand—especially unfamiliar ones. The more these 

accents differ from what I am used to, the more I 

experience a slight increase in workload and stress 

levels. I may need controllers to repeat some phrases 

(possible jargon issues), but I can ask what they meant 

and they will understand me.

3 Vulgaris vicus lingua is simplified communication created by people of 

different languages so they can talk to each other. It can be a local, informal 

language “of the street” that evolves over time and generations. 

Table 5. Frequency Speech Factors That Make It Difficult to Understand Controllers. 

Speech Factors Affecting Understanding Number of Times Listed 

Accent 16 

Expectation 2 

Intonation 2 

Phraseology 2 

Pitch 4 

Pronunciation 26 

Speech rate 23 
7

Expectations and Assumptions

You find some difficulty in your expectation of what 

you should hear. In other countries, controllers use 

phraseologies like line-up and wait. In the U.S., it’s 

position hold. Just because we speak English doesn’t 

mean we understand what was said.

Intonation

I find the lilt of the Indian English language hard 

to understand; I don’t know what they want me to 

do. But, if I ask, they’ll certainly come back with 

the answer I need. In particular, Hindi English is 

difficult for me. 

Interviewer: When a pilot in your group said “Hindi,” 

it seemed like it struck a nerve.

Well, I’ve made quite a few trips to Delhi and 

was unprepared for the particular cadence in their 

speech. It is actually fun to listen to until we have 

to know exactly what they’re saying. If I could listen 

to it and not have to comply with anything, I’d be 

fine. Fortunately, my IRO4 had been there a number 

of times and said, “They mean this,” or “they mean 

that.” After three trips, I still don’t understand what 

is being said. 

Pitch

I’m really focusing in on high-pitched voices because it seems to me that the lower voices are, the 

easier it is for me to understand. I don’t care if they 

are male or female.

Pronunciation

Although controllers may speak different English 

dialects, emphasis will be on different syllables—

“v(eye)tamins” versus “v(it)amins.” Sometimes when 

words are slurred together, it’s hard for me to determine exactly where words start and stop. It varies in 

the nation and with the controllers—it’s almost like 

hearing a different language.

4 International Relief Officer

Speech Rate

If communication was slow and deliberate—it 

would be easier to understand what was said for all 

the places we go.

The Challenges Seasoned Pilots Experience 

Are No Longer Satisfying

There are quite a few pilots who avoid flying to 

some parts of the world because of language concerns—they’re afraid of miscommunication. This 

forces junior pilots with the least experience to fly 

into these sections. For me, that’s a safety concern.

Rapid speech, nasal-sounding words, and some English dialects are a few of the difficulties I experience. 

The rigors of flying to Delhi or other destinations, 

going through Russia and all the “stans” to get there 

is professionally satisfying because it involves meters, 

QFE instead of QNH,5

 different accents, and carbon 

microphones. But, I no longer want to be challenged 

in that way. So, I’m not going there anymore.

51. When flying in a native English-speaking country, how 

often do controllers use ICAO standard phraseologies 

for routine communications to speak to you? 

As shown in Table 6, 46% of the pilots reported 

controllers often use ICAO standard phraseologies for 

routine communication, while another 40% said it was 

without fail. Their comments are compiled according to 

their response selection.

Without Fail Explanation

Of the 19 pilots who selected “Without fail (more 

than 90% of my interactions with controllers),” 16% 

discussed their responses.

United States, England, and Ireland 

Use Standard ICAO

I thought about this for awhile, and I probably 

changed it a couple times. But, I really think we’re 

5 Atmospheric Pressure (Q): QFE altimeter setting is the actual surface pressure, and it is not corrected to sea level. QNH is the barometric pressure as 

reported by a particular station.

Table 6. How Often Controllers in a Native English-Speaking Country Use ICAO Standard Phraseology. 

How Often ICAO Phraseology Used for Routine 

Communication 

Number

of Pilots % Issues 

Without fail 

 (> 90% of my interactions with controllers) 19 40 

United States, England, and Ireland Use 

Standard ICAO; United States Uses NonStandard Phraseology and Should Change 

Often

 (75-90% of my interactions with controllers) 22 46 

United States’ Use of ICAO Standards 

Varies; Australia and Canada Stand Out For 

Their Use of ICAO Standards 

Frequently 

(25-74% of my interactions with controllers) 6 13 

Occasionally 

(10-24% of my interactions with controllers) 0 0 

Rarely 

(< 10% of my interactions with controllers) 0 0 

No Response 1 2 
8 

talking about the U.S. Most of the communications 

that I receive are pretty standard. There certainly is 

some jargon out there sometimes—but, for the most 

part in the United States, England, and Ireland, it is 

very standard for routine communications.

United States Uses Non-standard Phraseology 

and Should Change

It seems to me that both Canada and the U.S. use 

the Americanism; everywhere else uses standard 

ICAO. Our controllers are more prone to non-standard 

phraseology; other English-speaking countries use 

standard phraseology, at least on the first attempt.

Interviewer: Do you feel that the U.S. should get in 

line with the rest of the world, or do they need to get in 

line with us?

We should get in line with the rest of the world. 

It’s a standard with ICAO.

Often Explanation

Approximately 27% of the 22 pilots who circled “Often 

(between 75–90% of my interactions with controllers)” 

elaborated upon their choice during the discussions. 

United States' Use of ICAO Standards Varies

It’s ICAO standard—what I’m used to in this country. The busier controllers get, the more they use the 

ICAO phraseology. The controllers chitchat when we 

have time for a conversation.

Australia and Canada Stand Out For Their 

Use of ICAO Standards

I was thinking Australia because I’m impressed by 

the way they try to stick with ICAO phraseology. I’ve 

found it to be the same in Canada. They’ll correct us 

if we’re not doing it right. If we come on and use the 

term heavy, they’ll always come back and say it [as 

part of the call sign]. I think they work a lot harder 

at it than we do, and I like that.

Frequently Explanation

Of the six pilots who circled “Frequently (between 

25–74% of my interactions with controllers),” two 

said they misunderstood the question and had nothing 

further to say.

52. When flying in a native English-speaking country, how 

often do controllers use Common English for routine 

communications to speak to you? 

Common English, also known as International English, 

refers to the common properties shared among different 

dialects of the English language. Notably, they share a common subject-verb-object grammar, but differ in cultural 

expressions, word usage (pronunciation, spelling), and 

other characteristics (idioms, slang). Common English 

is used in global commerce. Common or plain English 

occurs when either the pilot or controller switches from 

standard phraseology and speaks in a conversational 

manner.

Table 7 shows the U.S. pilots reported controllers 

in native English-speaking countries use Common 

English to varying degrees when interacting with them. 

Approximately 40% indicated that controllers occasionally spoke to them in Common English, while another 

40% indicated Common English was spoken either 

“Frequently” (19%) or “Often” (21%). Only 8% said it 

was spoken “Without Fail.” During the interviews, the 

one pilot who did not make a selection said,

Common English is what pilots and controllers revert 

to when ICAO standard phraseology doesn’t work.

Without Fail Explanation

Although four pilots selected this response, only one 

commented.

I’ve found that international destinations use ICAO 

terminology for U.S. carriers even in native Englishspeaking countries. In return, Common English is 

expected to be used.

Table 7. Common English Usage By Native English-Speaking Controllers. 

Alternative 

Number

of Pilots % Issues 

Without fail 

(> 90% of my interactions with controllers) 4 8 

Often

(75-90% of my interactions with controllers) 10 21 

Pilot/Controller Familiarity Leads to Common 

English 

U.S. Controllers Do Not Use ICAO Terminology 

Frequently 

(25-74% of my interactions with controllers) 9 19 

It Is Easier to Communicate in Your Native 

Language 

Occasionally 

(10-24% of my interactions with controllers) 19 40 

“Enter the Hold” and “Miles to Run” 

“Ride Reports” and “General Weather” 

Used With Domestic Carriers Only 

U.S. Uses Common English More Than U.K., 

Canada, or Australia 

Rarely 

(< 10% of my interactions with controllers) 5 10 No Time for Common English 

No Selection 1 2 
9

Often Explanation

Of the 10 pilots who selected this response, 50% 

discussed it during the interviews. 

Pilot/Controller Familiarity Leads to Common English

We do a lot of flying to Florida. We hear the same 

controllers and they hear us. We get to know them, 

even though we’ve never met. It’s like talking to a 

friend rather than some unknown person behind the 

radio. There is an “ease of communication” with a 

native speaker. Not so that it becomes cumbersome 

to the frequency, but we can get ride reports, ask if 

we can go direct, get answers to odd request; any 

kind of clarification that we need gets answered. We 

know that we’re communicating with each other. 

U.S. Controllers Do Not Use ICAO Terminology

My experience has been that the U.S. does not use 

ICAO terminology,6

 even with German, French, or 

Chinese pilots. It’s a mistake, in my humble opinion, 

and I think they should. But those who understand 

its usage know what I mean when I say, “I’ve got 

them established on the localizer to twenty-two left.” 

Interviewer: And this is only in the U.S., not others?

Yes, because even Canada uses ICAO terminology now.

Frequently Explanation

Of the nine pilots who indicated that “Between 

25–74% of my interactions with controllers” involved 

Common English, 56% provided comments.

It Is Easier to Communicate in Your Native Language

We get colloquial in the U.S. because we have 

that common understanding. After the initial clearance, we’ll ask for other stuff and it’s frequently in 

Common English. It’s just easier to communicate in 

your native tongue. I think that’s why, internationally, controllers sometimes switch to their native 

language—it’s quicker and easier. Then they switch 

back because Common English may be slower and 

not as efficient to them. 

Occasionally Explanation

Nineteen pilots indicated that during routine communications, “Between 10–24% of my interactions 

with controllers” involved Common English. When 

interviewed, approximately 58% made comments.

“Enter the Hold” and “Miles to Run”

There is more “banter” in the native English system 

than foreign systems. We use Common English to convey 

non-standard things. I use the British example of enter 

the hold. Hong Kong has something that’s unique. When 

you first check in and are very close to landing, they’ll 

say, “Forty-five track miles to run,” telling us that’s the 

linear distance we have before touching down.

6 May mean phraseology—aviation terminology covers a large territory

Interviewer: Do we need that kind of phraseology 

adapted to the U.S.?

I’d like it, and it would be a good thing to know. 

But I keep coming back to the Newark area for the 

vectoring. We’d have to add the turns and the holding pattern.

“Ride Reports” and “General Weather”

Ride reports and weather are usually outside standard phraseology, so we’ll have more communication 

about them in Common English.

Used With Domestic Carriers Only

I’ll hear [Common English] usually with domestic 

traffic. I can understand what is being said since it’s 

in English. But, I hear more common jargon and 

non-standard phraseology with domestic air traffic 

than international arrivals.

U.S. Uses Common English More Than 

U.K., Canada, or Australia

To me, controllers in the U.K., Canada, and Australia use standard terminology more frequently than 

[controllers] in the U.S. Our controllers slip into 

conversational English. 

Rarely Explanation

Only two of the five pilots who said “Less than 10% 

of my interactions with controllers” included Common 

English. They limited their responses to interactions with 

controllers while on the airport surface areas.

No Time for Common English

Controllers strive more towards ICAO standard than 

pilots do. I would characterize that specifically when 

we are in line in airport areas. There’s not much time 

for Common English. I’m busy and the controllers 

pretty much deal with you and get you out of there.

53. When flying in a native English-speaking country, how 

would you describe the controllers’ ability to communicate 

with you in Common English? 

As shown in Table 8, 47% of the pilots said the controllers’ Common English communications skills were good, 

and another 53% said it was excellent. Their comments 

from questionnaires and interviews were organized according to their response selection and then common themes. 

Their Communication Skills Are Excellent 

Explanation

About 24% of the pilots who selected “Their communication skills are excellent” commented.
10 

With Better Pronunciation and No Local 

Idioms It’s Perfect

I’ve found controllers’ accents or pronunciations 

differ. but their skills are excellent. Typically, they 

stay fairly standard so they don’t use Common English much. If they do, it’s in a clear, concise, and 

correct tempo. To me, familiarity with the accent is 

key and the more I’m familiar with it, the easier it 

is to understand.

Their Communication Skills Are Good Explanation

Among the pilots who selected “Their communication 

skills are good,” 52% provided comments.

Different Accents, Speech Rate, and Terms 

Can Make It Difficult 

In my flying experience, North American English 

is different from other types of English. In some 

countries, sometimes I can’t understand Common 

English because of the accent. Also, I’ve found differences in local terms—in the U.K., it’s lift and in 

the U.S. it’s elevator. But any misunderstandings can 

be cleared up quickly.

53a. In general, how much attention do you have to use to 

make sense of what the native English-speaking controller is saying? 

The data in Table 9 indicate that 52% of the pilots 

said a limited amount of their attention was used to understand what native English-speaking controllers said, 

while 27% said it was effortless. There were nine pilots 

who thought otherwise. For them, either moderate or 

considerable attention was used. 

A Considerable Amount Explanation

Although there were two pilots who selected this 

response, only one provided comments. 

Some Dialects Are More Difficult Than Others

The British dialect is extremely hard for me to 

understand. I focus 100% of my attention to make 

sure I understand what they’re saying. But even in 

the U.S., I have a hard time understanding some 

native English controllers.

A Moderate Amount Explanation

Seventy-one percent of the pilots offered comments. 

One pilot in this group said his difficulty resided in being relatively new to international operations and his 

unfamiliarity with different dialects and languages.

East and West Coast Talk Fast Leaving 

Us No Time to Respond

Sometimes the fast pace coupled with the speed of 

talk and accent, leaves me with no time to respond. 

They’re busy and we’re busy running checklists, depending on what phase of [flight] we’re in. Sometimes 

we all forget how busy the other person is.

Hong Kong, U.S. No Problem—Scotland 

and London Some Difficulty

There’s a comfort level being in an English-speaking 

country, but we still have to be very cautious because 

the procedures can vary quite a bit from what we do 

in the U.S. We can’t let that comfort level overtake us 

so we become complacent. Going into Hong Kong, 

is clear as a bell for me. In Scotland, I have to listen 

very closely. Sometimes I have a hard time with the 

Australian accent and my understanding suffers.

Table 9. Pilot Attention Used When Native English-Speaking Controllers Talk to Them. 

Amount of Attention Used 

Number

of Pilots % Issues 

A great amount 0 0 

A considerable amount 2 4 Some Dialects Are More Difficult Than Others 

A moderate amount 7 15 

East and West Coast Talk Fast Leaving Us No Time to 

Respond 

Hong Kong, U.S. No Problem – U.K. Some Difficulty 

A limited amount 25 52 Some Accents and Communication Need More Attention 

It is effortless 13 27 

New York Gives Too Many Instructions but It’s Native 

English 

A limited amount/It is effortless 1 2 U.S. Is Effortless - Elsewhere It Takes a Limited Amount 

Table 8. How Well Native English-Speaking Controllers Communicate in Common English. 

Alternative 

Number

of Pilots % Issues 

Their communication skills are excellent 25 53 Better Pronunciation and No Local Idioms It’s Perfect 

Their communication skills are good 23 47 

Accents, Speech Rate, and Terms Can Make It 

Difficult

Their communication skills are only fair 0 0 

Their communication skills are poor 0 0 

Their communication skills are terrible 0 0 
11

Interviewer: Is it comparable, problematic, or easier 

in the U.S. going from the East Coast to the West Coast 

and from the North to the South?

For me, there are areas that are more problematic. It 

takes me a longer to get used to controllers in Atlanta 

and Jacksonville because I grew up in New York. 

There’s a little bit of a difference, but not the marked 

one between Hong Kong and London controllers. 

We don’t have the big differences in the U.S. that 

we do overseas.

A Limited Amount Explanation

Of the 25 pilots who reported a limited amount of 

attention was used, 28% made comments.

Some Accents and Communication 

Need More Attention

In my experience, even with all the different English 

accents, misunderstandings can be cleared up quickly. 

Sometimes controllers speak so fast I can’t understand 

everything. And, the English controllers say, “Maintain 

radar heading,” “Report ready for descent,” or other 

commands a little differently than what I hear in the 

States. Occasionally, I have to pay more attention and 

ask, “What was that?” We talk to the same controllers 

all the time, so it’s not that big a deal.

It Is Effortless Explanation

Two of the 10 respondents made comments regarding 

their experiences in the U.S. There was one additional pilot 

who qualified his selection by noting that although there 

are regional differences in the U.S., it is what he is used 

to and that makes it effortless. However, once outside the 

U.S., it does take a limited amount of attention because 

of unfamiliarity with local idioms.

New York Will Give You Six Instructions at 

Once but It’s Native English

Native English is second nature to us, but there is 

always caution when I’m listening. My experience 

is that some U.S. controllers tend to give a heading, 

altitude change, airspeed, and a transponder change 

pretty much in the same transmission; it gets “lost in 

the sauce.” But, they are trying to put 10 pounds of 

stuff into a five-pound bag. 

53b. What are the most troubling language-based problems 

you experience with native English-speaking controllers?

Forty-two pilots generated a list of 58 items that were 

compiled into 13 issues. The number in the parentheses 

presented in Table 10 indicates how often it was reported 

by the pilots. Table 10 further shows these issues to be 

grouped into four themes: Amount of Information, 

Delivery Technique, Interpreting Message Content, and 

Speech Quality. Delivery Technique represents 38% of 

the items, while Speech Quality represents another 34%. 

Another 17% appear in Interpreting Message Content and 

the remaining 10% in Amount of Information (allowing 

for rounding error). During the interviews, 40% of these 

pilots commented.

Since accent, dialect, and pronunciation have already 

been covered in detail, there is no need to discuss them 

further. Two pilots expressed difficultly understanding 

higher-pitched controllers. For them, higher-pitched voice 

interfered with radio reception and voice quality over the 

speakers on the flight deck. 

Amount of Information

Conveying complex clearances or instructions 

are problems for me. Quite often controllers give 

me too many in one sentence, “Climb to two two 

zero, heading one eight zero, slow to two ten and 

proceed to GIPSO.” I have to stop and say, “What?” 

My mind doesn’t work that fast. We’re talking about 

the run-ons—more than three at a time.

Delivery Technique

I find that controllers either talk too fast or too slow. 

It doesn’t matter to me what language controllers’ 

speak—if they’re real busy, it’s hard to get a word in 

edgewise. I can’t digest and understand instructions 

as fast as they can speak them. Other language-based 

problems are clipped speech or clipped words.

Interviewer: When you say “clipping,” is that an unintentional clip or is it due to technique?

I think it’s both. Some Latin America controllers 

have a Calypso rhythm to their speech so it sounds 

continuous to me. It’s related to emphasizing a second 

syllable so it gets clipped off. I don’t know if they use 

a foot-operated mic, but that’s a problem, too.

Interpreting Message Content

The most troubling language problems I have with 

native English-speaking controllers are procedural 

issues, local knowledge, and not realizing that there 

might be changes from Standard English operations 

that I would expect domestically. Some things can’t be 

said with a pat, standard phraseology. Like, “We need 

you to fly this much of the route, but then we need to 

divert you because we have a storm over here, then 

we need you to re-intercept.” That’s when I need to 

think a little bit more, regardless of language.

Table 10. Most Troubling Language-Based Problems With Native English-Speaking Controllers. 

Language-based Problems Issues 

Amount of Information (6) Too complex clearances (1) Too many instructions (5)

Delivery Technique (22) Clipped transmissions (2), Speech rate (11), Tempo (9)

Interpreting Message Content (10) Non-ICAO (3), Non-Standard Phraseology (4), Slang (2), Syntax (1) 

Speech Quality (20) Dialect (2), Accent (11), Pronunciation (5), Pitch (2)
12 

Native English-speaking controllers outside the U.S. 

use ICAO phraseology, and it is somewhat different 

from American ATC phraseology.7

 When I am cleared 

by an Irish controller first thing in the morning, he 

might say, “Route direct to LITHY.” Will our route 

take us direct to LITHY, [or] are we supposed to go 

present position direct LITHY? We learn that route 

direct means present position direct.

Procedurally, local jargon or slang can be difficult to 

interpret. We don’t notice it because we’re used to it 

in the States. For example, “Scoot across the runway 

real quick for me.” We hear an MD 88 called a Mad 

Dog. If a Lufthansa pilot is told, “Follow the second 

Mad Dog,” he might not understand what the controller wants. Does that mean anything to him? Are 

they used to that terminology? If a controller told a 

pilot, “Give me a good time,” would the pilot know 

“give me a good time” means increase your speed?

53c. How often have you heard native English-speaking controllers use jargon or slang that was difficult to interpret? 

There might have been some confusion concerning 

the phrase “difficult to interpret.” None of the pilots 

indicated that any slang/jargon heard was difficult to 

interpret, although unfamiliar terms, aircraft names, etc., 

are mentioned as slang/jargon. Their responses to the 

interviewers’ questions and compiled comments from 

the written and interview portions of the questionnaire 

are included below.

As seen in Table 11, among the pilots who selected 

“Occasionally,” “Frequently,” and “Often,” one pilot in 

each group offered comments. One said, “It’s not very 

hard to understand,” while the other said that foreign 

pilots probably would not know what either a “Guppy” 

or “Barbie Jet” was.8

 The pilot who selected “Often” 

said that controllers who deliver taxi clearances around 

Chicago and JFK use some slang/jargon.

7 Federal Aviation Administration (2010b). 

8 While this may be true, in the U.S. the controller may use type, model, or 

manufacturer’s name.

Rarely Explanation

Approximately 18% of the pilots who selected rarely 

provided comments.

There is Slang/Jargon but It’s Easily Interpreted

The only slang I’ve ever gotten had to do with 

aircraft movement and unclear direction—“Just go 

around this guy.” It doesn’t seem to really relate 

once airborne.

Expect a slam dunk. ATC’s telling us that we need 

to do something; what that something is depends on 

where we are. And that’s a judgment call.

Interviewer: Some pilots said the use of pleasantries 

is a waste of airtime. Is there any verbiage you can do 

without from the controllers?

No, I disagree with that. First of all, I’m building a 

bit of a rapport, should I need something. Second, 

since we’re human beings, we like to treat each other 

with some amount of respect, and that’s the way to 

do it on the radio. 

That comes back to the fundamental point that we 

were talking about earlier –communicating ideas, 

whether through the use of standard language or 

not. The problem for me is digging through the pronunciation to understand what word was just used. 

The whole essence of communication is having a 

concept of what we want, what the controller wants 

us to do, and communicating that to each other is 

not generally an issue once we get past the issue of 

the language.

American Slang/Jargon Is a Problem 

for Foreign Carriers

U.S. controllers use jargon all the time—but is it difficult to interpret? They’ll say I’m going to have to snug 

up on this guy over here—what’s that? Some foreign 

pilots are going to have a hard time understanding 

what this expression means. When we go overseas, 

controllers very rarely use that kind of jargon. It’s 

hard enough for [U.S. pilots] to understand regular 

English. So it’s a little unfair.

Table 11. How Frequently Pilots Heard Jargon or Slang That Was Difficult to Interpret. 

How Often Interpretation was Difficult 

Number

of Pilots Issues 

Rarely 

(< 10% of my time monitoring communication) 43

There Is Slang/Jargon but It’s Easily 

Interpreted

American Slang/Jargon Is a Problem for 

Foreign Carriers 

Occasionally 

(10-24% of my time monitoring communication) 3 

Frequently 

(25-74% of my time monitoring communication) 1 Follow the “Guppy” or the “Barbie Jeta”

Often

(75-90% of my time monitoring communication) 1

It’s Take the Scenic Taxi in Chicago and JFK 

It’s the Penalty Box in Miami 

Without fail 

 (> 90% of my time monitoring communication) 0 

a

 Neither of these is jargon or slang but legitimate names of aircraft. 
13

53ci. The respondents’ examples of jargon that were difficult 

to interpret were “Guppy” and “Barbie Jet.” 

Each term refers to a particular aircraft. The “Guppy” 

is in reference to the Boeing 737 aircraft, while the 

“Barbie Jet” refers to Canadair Regional Jet (CRJ) series 

200/700/900. The Guppy series reference the manufacturer’s names for the C-97 aircraft that was modified to 

carry large cargo, primarily rockets for NASA. It includes 

the “Mini Guppy,” “Super Guppy,” and “Pregnant 

Guppy.” The term “Barbie Jet” is used in advertisements 

for Canadair Regional Jets. Another term mentioned at 

different parts of the focus group discussions was “Mad 

Dog,” referring to the McDonnell Douglas aircraft 

manufacturer.

53cii. The respondents did not list any examples of slang 

that was difficult to interpret.

DISCUSSION

This report focuses on communications between native 

English-speaking controllers and how well they communicate with native English-speaking pilots. It provides an 

overall perception among 48 U.S. ATP pilots of how these 

communication exchanges affect safety, the communication process, workload, and situational awareness. The 

interviewers took the pilots’ comments and opinions at face 

value, occasionally asked additional questions, but did not 

challenge any of their statements or comments.

Language Experiences in Native English-Speaking 

Airspace/Airports 

The pilots reported hearing 17 different dialects of English during their flights to countries in Asia, Europe, North 

America, and Oceania. Of these dialects, British English, 

North American English, and Hong Kong English were 

the top three listed by the U.S. pilots. 

When asked how they would rate their overall native 

English-speaking language experiences during these flights, 

35% gave it a very positive rating, while 44% said it was 

positive. The one pilot who gave a negative rating did so 

because the he had some difficulty understanding what the 

controller was saying.

Effects of Native English-Speaking Language 

Differences on Pilot Workload

When asked how hearing English spoken by a native 

speaker affected their workload, 9% said that there was 

a decrease, 17% reported no change, 63% said there was 

only a minimal or slight increase, and 11% said it increased. 

Among the pilots who reported a slight or minimal increase, 

factors that contributed to workload included a tendency 

for more relaxed radio discipline (more pleasantries, slang) 

and faster speech rate—especially with increases in traffic 

volume. When combined with poor radio quality, they might 

have to listen more closely to ensure they heard correctly 

the first time—especially if there was a new crewmember 

on the flight deck unfamiliar with the local accent and dialect. This also held true among the pilots who experienced 

increased workloads. For them, two factors came into play: 

Some English dialects require them to listen more closely to 

what is said and also to what the words mean in that locale.

Frequency of Communication Problems

When asked how often they experienced communication 

problems, 94% of the pilots reported that it occurred in 

fewer than 25% of their interactions with controllers. If they 

did have a problem, it was corrected easily because English 

was the native language they had in common. Generally, 

communication problems occurred for two reasons: First, 

there were times when the pilots could not decipher what 

was said because the clearances were given faster than they 

could process them, and second, they had a harder time 

understanding the names of fixes and waypoints because 

of regional dialects and variations in pronunciation. The 

pilots who experienced communication problems to a greater 

extent named the geographical areas where they were likely 

to encounter them but did not specify the types of problems 

or their root causes.

Variability in English Language Skills of Pilots and 

Controllers 

When asked whether English language skills were 

comparable from one native English-speaking country/

airport to that of another, 83% of the pilots reported that 

the pilots and controllers were comparable, and 17% said 

they differed. The pilots shared several common threads in 

their comments. The four more notable perceptions are (a) 

controllers seem to have less of an accent than pilots do; 

(b) regardless of aircraft registry, once an air carrier left its 

homeland and entered foreign airspace, pilots have difficulty 

understanding clearances and need to have them repeated 

several times; (c) regardless of country, some controllers 

seem to be less tolerant of pilots who ask for repetition, 

clarification, or verification of a previous transmission; and 

(d) some dialects are more difficult to understand and add 

workload for the pilot and controller.

Factors Contributing to the Intelligibility of Native 

English-Speaking Controllers

Nearly 75% of the pilots said they used extra effort 

when listening to some native English-speaking controllers. 

Some controllers are generally more difficult for the pilots 

to understand because of variations in dialects at very busy 

international airports. Notably, the English spoken by pilots 

and controllers in the U.K. and the U.S. were discussed 

because of their regional distinctions. In particular, were 

the accents of Irish, Scottish, and Welsh controllers, as 

well as those used by U.S. controllers in Atlanta, Boston, 

Chicago, and New York. In addition to accents, the pilots 

also said that differences in how words were pronounced 

(especially waypoints and fixes), jargon (e.g., go fast), and 

a rapid speech rate all contributed to the intelligibility of 

the controller.
14 

There were pilots who said they did not have to work 

harder to understand controllers. Although they heard 

regional differences, for them the effects were insignificant. 

Factors Contributing to the Understandability of 

Native English-Speaking Controllers

The ability to understand controllers involved pronunciation, speech rate, and accent,9 followed by pitch, 

expectation, intonation, and phraseology. Some accents 

were easier to understand, while the ones unfamiliar to 

the pilots were said to be more difficult. Likewise with 

intonation, because it provides the emphasis, tone, and 

variety in oral languages that can alter meaning by simply modulating pitch and loudness while speaking. As 

speakers, we use these cues to signal a question (raised 

pitch at the end of a sentence) or the end of a sentence 

(less volume). Slight shifts in intonation can be used to 

judge the mood of the speaker or lead the listener to 

infer sarcasm. Different English dialects have different 

intonation patterns that can influence how well listeners 

understand what is being said. These melodies of speech 

are learned during infancy.

Air traffic control telephony consists of a standard 

phraseology that controllers repeat throughout their 

workday. Rarely should they deviate from that standard. 

However, there are differences among countries about 

the phraseology they consider standard. When pilots 

and controllers do not understand each other due to 

these differences, coupled with variability in delivery 

technique, inevitably one or the other will make a request 

for repetition, confirmation, or verification, resulting 

in increased workload and radio frequency congestion. 

Generally, normal conversational speech occurs at about 

160 words per minute (wpm) and depends, in part, on 

the number and duration of pauses and syllables. The 

greater they are in number and duration, the slower the 

speakers’ rate of speech when measured by words per 

minute (Utterback, 2000). 

In a study of fluency, Cauldwell (2007) examined the 

speech rate of a controller and four pilots at an airport 

in Frankfurt from a Tower recording. For that analysis, 

individual transmissions were parsed into speech units, 

and the number of words spoken per minute was derived 

to be 190 wpm for that controller and 150 wpm for the 

pilots. Although §5.2.1.5.3 (ICAO, 20011) states that 

pilots “should maintain an even rate of speech not exceeding 100 words per minute,” and FAA Order 7110.10T 

Flight Services §2-1 states, “When weather and flight 

information shall be broadcast/recorded ... data shall 

be spoken at a rate of 100 to 120 words-per-minute,” 

there is no guidance for controllers when in direct communications with pilots as to what the preferred rate of 

speech should be. 

9 www.soundcomparisons.com is a Web site where you can listen to and 

compare how the same 110 words are pronounced in 50 English accents.

ICAO Standard Phraseology Usage by Native 

English-Speaking Controllers

Pilots reported that native English-speaking controllers 

use ICAO phraseology in at least 75% of their routine 

communications. They also noted that controllers in 

the U.S. are more prone to deviate from ICAO and use 

“Americanisms.” They would like to see the U.S. adopt 

the ICAO standard. 

Common English Usage by Controllers in Native 

English-Speaking Countries and Their Ability to 

Communicate in Common English

Pilots were very positive about the controllers’ use of 

Common English. In fact, 99% of them reported the 

controllers had either good (47%) or excellent (52%) 

communication skills. Moreover, Common English occurred in varying degrees as they gained familiarity with 

each other because of their common flight/work schedules. 

Once they recognized each others’ voice and because they 

shared a common language, requests, verifications, and 

confirmations might become more relaxed and conversational while still maintaining professionalism. They also 

used Common English when ICAO standard phraseology 

did not work. In the U.S., a standard phraseology was 

never constructed for non-standard events because English 

language proficiency was not considered an issue. It was 

assumed that the pilot and controller would resolve the 

problem using Common English.10 

Amount of Attention Required for Understanding

Just because someone is easily understood does not 

presuppose that the listener does not have to pay attention to what is being said. In fact, the pilots differed in 

the amount of attention they allocated to understanding. 

It did not seem to matter whether or not the pilot was 

flying in different regions of the U.S. or in other Englishspeaking countries; their differences in opinion were based 

on their familiarity with the controller’s accent, the local 

dialect, and the pace they and controllers operate under 

(especially on a descent to the airport when traffic is heavy 

or weather conditions are less than optimal). 

When the fast pace marries up with individual differences in accent, dialect, and speech rate, pilots pay more 

attention, especially if there are procedural differences 

they must be aware of. For example, a pilot from New 

York may have some problems understanding controllers from Georgia or Florida, as would a pilot from 

Texas flying into Hong Kong or London. Nonetheless, 

there is a comfort level knowing that controllers have 

good-to-excellent communication skills and that their 

understanding of the English language will not undermine safety of flight.

10 Conversation between the first author and a recent FAA retiree of the former 

Air Traffic Systems Requirements Service.
15

The Most Troubling Language-Based Problems

The pilots were very open to discussing the languagebased problems they experienced. For them, many of the 

problems centered on controllers transmitting lengthy and 

complex clearances that contained more information than 

they could process reasonably in the amount of time used 

by the controller to deliver it—especially if spoken by 

a controller with a high-pitched voice over the aircraft’s 

radio equipment. They also spent a considerable amount 

of time talking about the contents of an ATC message. 

Amount of Information

A common comment from the pilots was that their 

minds could not process the amount of information 

transmitted in one message fast enough to understand 

what they were to do. The following example was given 

by a pilot: “Climb to two two zero, heading one eight 

zero, slow up to two ten, and proceed to GIPSO.” 

There is much research that shows that both message 

length and complexity affect readback error (RBE) rate. 

In particular, field and simulation findings (see Prinzo 

& Britton, 1993 for a review of the literature; Cardosi 

Brett, & Han, 1996; and Morrow & Prinzo, 1999) led 

to the recommendation that controllers should transmit 

less information more often. Recently Prinzo, Hendrix, 

and Hendrix (2006) found that both the number of 

pilot requests and readback errors increased as the complexity and number of aviation topics in terminal radar 

approach control ATC messages increased — especially 

when pilots were performing approach, as compared with 

departure tasks. Messages with one instruction resulted 

in a 3.84% RBE rate, while those with four instructions 

had a 25.7% RBE rate. A similar pattern emerged for the 

amount of information in a message—messages with a 

low complexity value resulted in 2–6% RBE rate; messages with high complexity values had a 35% RBE rate. 

A comparable analysis (Prinzo et al., 2009) performed 

on en route voice tapes further revealed that message 

complexity only affected readback errors involving the 

omission of information, while longer messages led to 

substitution and transposition errors. Among their recommendations were that no more than three instructions 

appear in any ATC transmission, and route clearances 

are given as stand-alone transmissions.

Delivery Technique

As mentioned earlier, pilots encounter difficultly with 

fast rates of speech. Although ICAO recommends pilots 

speak at a rate of 100 wpm, there is no such recommendation for controllers. As pointed out by Cauldwell 

(2007), 100 wpm might be too slow among the more 

fluent speakers of English. In fact, one pilot in this study 

mentioned the drawl of some Southern controllers when 

delivering clearances as being slow. Together, these findings suggest there might be circumstances where native 

speakers of English with different dialects might have 

difficulty understanding each other—such as an Asian 

Indian speaker of English talking with a Texan who speaks 

American English, whereas those with the same dialect 

may want to communicate at a faster rate of speech.

Message Contents

The most troubling language barrier problems with 

native English-speaking controllers are procedural issues, 

local knowledge, and not realizing that there might be 

differences between international and domestic ATC 

phraseology. The pilots provided examples of these 

differences—“line up and wait” compared to “taxi into 

position and hold,” “stand 15” compared to “gate 15,”and 

“route direct” compared to “present position direct.” 

Slang or Jargon Usage by Controllers

Since there is a common language among the various English dialects, none of the U.S. pilots reported 

problems with any particular local slang or jargon. Slang, 

like idioms, appears in conversational speech and can 

be difficult for listeners who are unfamiliar with local 

expressions (or history) to understand, but they can work 

through them because of the common root language. 

Phrases such as “scoot across the runway real quick for 

me,” “give me a good time,” “follow the Mad Dog,” were 

some examples cited. Together with local jargon (e.g., 

“expect a slam dunk”), these types of messages can lead to 

communication problems, especially among non-native 

English-speaking pilots and pilots unfamiliar with the 

local use of slang, jargon, and idioms. These expressions 

should be discouraged because they will diminish situational awareness among less proficient pilots.

Unlike everyday conversations, air traffic control 

communication must be held to a higher standard. Its 

words must be precise in definition, subsequent actions 

predictable, and outcomes transparent to the observer. 

When messages are transmitted, they should be held to 

a standard in broadcast technique as defined by ICAO 

and its membership.

Recommendations

1. Adopt a standard dialect for use in ATC communications. Just as radio and television news broadcasters 

learn to speak using a nondescript accent, actors often hire 

language coaches to teach them the “standard Hollywood 

accent” to portray geographically neutral characters. 

2. All trainees and current certified professional 

controllers must successfully complete an English language course in voice and articulation. In addition to 

instruction in the principles of voice production and 

articulation of speech sounds, they will receive training 

in loudness, speech rate, pitch, articulation, enunciation, 

and pronunciation for ATC communication.

3. Define an optimal rate of speech for use by air 

traffic controllers when in communication with pilots. 

This could be derived by extracting the number of words 

per minute spoken by controllers that did not result in 
16 

a request for repeat, clarification, or verification from 

pilots. It may be that a different speech rate should be 

used with pilots who are not native speakers of English. 

Research is needed to provide guidance on the optimal 

rate of speech for different populations of speakers.

4. Develop new standard phraseology for non-routine 

events. Generally, the controller needs to have the pilot 

answer one question, “What do you need from me?” Based 

on the pilot’s response, the controller would coordinate 

the appropriate ground actions to provide the pilot with 

what is needed. This phraseology could be provided as 

part of the DataCom message set. It could include a list 

from which the pilot could select the necessary items 

such as, “Divert to Similar Airport With Hospital,” “Fire 

Rescue,” “Ambulance,” “Police,” and so on.

5. Controllers should be discouraged from using local jargon, slang, idiomatic expressions, and other forms 

of conversational communications when transmitting 

messages to pilots. Although colorful and fun, they have 

no place in air traffic control and diminish situational 

awareness, can lead to requests for repeat, and otherwise 

disrupt information transfer.

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11 Speak Out! Published by the International Association of Teachers of English 

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17

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