United States Airline Transport 

Pilot International Flight Language 

Experiences Report 2: Word Meaning

and Pronunciation

DOT/FAA/AM-10/7

Office of Aerospace Medicine

Washington, DC 20591

OK-10-0077-JAH

O. Veronika Prinzo

Civil Aerospace Medical Institute

Federal Aviation Administration

Oklahoma City, OK 73125

Alan Campbell

Johns Creek, GA 30022

Alfred M. Hendrix 

Ruby Hendrix

Hendrix & Hendrix Consulting Service

Roswell, NM 88201

April 2010

Final Report

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. 3. Recipient's Catalog No. 

DOT/FAA/AM-10/7 

4. Title and Subtitle 5. Report Date 

United States Airline Transport Pilot International Flight Language April 2010 

Experiences Report 2: Word Meaning and Pronunciation 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) 

 

11. Contract or Grant No. 

1

FAA Civil Aerospace Medical Institute, P.O. Box 25082 

Oklahoma City, OK 73125 

2

Alan Campbell, Johns Creek, GA 30022 

3

HCS Consulting , Roswell, NM 88201 

 

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

 

 

 

Office of Aerospace Medicine 

Federal Aviation Administration 

800 Independence Ave., S.W. 

Washington, DC 20591 14. Sponsoring Agency Code 

15. Supplemental Notes 

Work was accomplished under approved task AM-B-06-HRR-516. 

16. Abstract 

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

accidents. Its Air Navigation Commission was directed to strengthen relevant ICAO provisions concerning language 

requirements. Member states agreed to take steps to ensure air traffic control (ATC) 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. Since then, ICAO developed its English Language Proficiency 

(ELP) requirements and urged its members to document their ELP test implementation plans by March 8, 2008. Until all 

ATC personnel and flight crews involved in flight operations obtain a passing level of ELP, the language-based problems 

international pilots face is not known. This report is a compilation of written responses and comments by a small focus 

group of 48 U.S. pilots of their difficulties in international operations. The focus group consisted of 12 international U.S. 

pilots each from American, Continental, Delta, and United Airlines. Each focus group met with two interviewers to discuss 

their language experiences flying into countries where English may or may not be the local or national language among its 

radio operators, controllers, and pilots. In this report, the pilots’ responses to questions 24-30 and their comments from 

discussions of those questions with interviewers are presented as a compiled narrative. The pilots’ responses had eight major 

thrusts: (1) Once pilots get past the controller’s accented English, understanding is not a problem during routine 

operations; (2) the lack of standardized pronunciation of NAVAIDs, waypoints, intersections, etc. complicates 

understanding what was said; (3) Currency in flight time in the theater of operation is critical to understanding accented 

English and will influence how easily controllers from different countries are understood; (4) Poor radios and transmission 

quality contribute to the unintelligibility of some controller transmissions; (5) Variations in pronunciation can detract from

flying, as pilots must listen intently to clearances; (6) Training is essential for crews lacking currency going into a foreign

country; (7) Differences associated with U.S. and ICAO phraseology need to be resolved and procedural ambiguities 

eliminated; and (8) Technological advancements such as controller pilot datalink communications (CPDLC) and automatic 

dependent surveillance (ADS) can mitigate some of the problems associated with accented English. We offer 10 

recommendations to improve communication practices, which include development of a standardized phraseology, its 

presentation, delivery technique, and meaning, training, and implementation of ICAO’s ELP by all member states. 

 

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 44 

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) at 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 

dead-headed 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 (retired) Terry Hanson 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.
iv 
v 

Contents

INTRODUCTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

RESULTS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Section 4: Word Meaning and Pronunciation (how words are spoken). . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Q24. How often during a flight do you experience problems related to word meanings? . . . . . . . . . . . . . 3

Q25. How often during a flight do you experience problems related to how words are pronounced?. . . . 5

Q26. What problems affect you most related to differences in the word(s) used to describe a clearance, 

instruction, advisory, or request? Please list some examples.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Q27. There are problems related to the same word(s) used to describe different actions. Just to get you 

thinking, consider the difference between “hold point” used in the air versus “hold point” used on 

the ground or “taxi into position and hold” versus “line up and wait.” Can you think of any 

other examples? Please list a few.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Q28. Have you experienced problems related to how words are pronounced (e.g., accents or dialects)? 

Please explain.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Q28a. Which words are more difficult for you to understand?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Q28b. Do you perceive a difference in clarity of information provided when a native English speaker uses 

“Indian English” versus “Hong Kong English” versus “British English” versus “North American 

English?”. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Q28c. Do you perceive a difference in clarity of information provided when a non-native English-speaker 

uses “Indian English” versus “Hong Kong English” versus “British English” versus “North 

American English?”. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Q29. To what extent have you found nonstandard terminology confusing? . . . . . . . . . . . . . . . . . . . . . . 24

Q30. To what extent do you experience language-related difficulties when programming the FMS 

to comply with ATC? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

DISCUSSION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

vii 

This is the second of several reports that present the 

findings from in-depth interviews with pilots who fly 

internationally for major U.S. air carriers. The first series 

of reports are from small focus group discussions with 

48 U.S. 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. 

We asked several major U.S. airline companies to 

solicit volunteers from among their pilots who fly internationally to serve as paid subject matter experts in a 

structured interview constructed to assess the language 

difficulties encountered during international flights. 

Twelve pilots represented 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 focus group to 

include no more than four pilots. There were morning 

and afternoon sessions that took place over several days 

at each company’s designated 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 Prinzo and Campbell (2008).

The first report summarized the U.S. pilots’ oral and 

written responses to the questions contained in Sections 

1-3. This report is the second in the series, continues 

with Section 4, and summarizes the pilots’ responses 

to questions 24-30. It provides a wealth of ideas related 

to the international flight experiences of the pilots who 

participated in the focus group discussions. The pilots’ 

answers to the questions and discussions during the 

interviews were their perceptions of the situations they 

encountered. This report is based on those perceptions.

Many stories were anecdotal and some were relayed in 

third person. The pilots’ 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. No effort was 

made to influence the pilots’ perception of a procedure, 

phraseology, etc.

The pilots’ responses had eight major thrusts: 

1. The pilots’ responses indicated that once they get 

past the controller’s accented English, understanding 

is not generally a problem during routine operations. 

With time and experience, pilots learn to distinguish 

between sounds produced in the primary language 

and those same sounds produced in accented English 

by non-U.S. controllers. Some sounds are difficult 

to parse correctly into syllables because they are not 

heard by the non-native speaker of the language. For 

example, /p/ followed by /a/ to create /pa/ varies for 

English and Spanish. Also the location of syllabic 

stress affects how words are pronounced. These differences hinder language decoding by the listener. 

Pilots often ask themselves and other crewmembers, 

“What did he say?”

2. The lack of a standardized pronunciation of NAVAIDs, 

numbers, and call signs can detract from flying, as 

pilots must listen intently to understand clearances. 

There are some fixes that sound similar and are in close 

proximity to one another. Pilots will look them up on 

their charts and talk among themselves to determine 

which one the controller said. When in doubt, they 

may ask the controller to spell it phonetically. The 

same problem exists for the pronunciation of numbers 

in that some controllers have difficulty pronouncing 

numbers and words containing the letter “L,” “R,” 

“J,” or “W.” 

3. Some controllers would benefit from training in 

radio broadcasting where one standard is applied 

to pronunciation, timing, and speech rate. Also, 

there is a vast difference in controllers’ mastery of 

the English language. When a controller’s accent 

is notably strong and speech production is poor, 

all pilots in the cockpit listen intently to what is 

being said to understand what ATC wants them 

to do. Add to that a fast speech rate and there is 

a greater probability that the pilot will miss a part 

of the message content. Furthermore, controllers 

who speak before depressing the microphone key 

or release it before they are finished talking transmit 

partial messages. These examples of poor delivery 

technique result in a failure to receive the entire 

message on the flight deck, which can change 

the entire meaning of a phrase. Also, many pilots 

reported that controllers with high-pitched voices 

are difficult to understand.

EXECUTIVE SUMMARY
viii 

4. Poor radios and transmission quality in some areas 

of the globe contribute to the unintelligibility of 

controllers. Transmissions from ATC might be weak 

and sound scratchy, hollow, or distorted. Some radios 

might be 60 yrs old or older. When controllers use 

these radios, it sounds like they are using a carbon 

or poor-quality microphone because of the hollow 

sound and background echo.

5. Differences associated with U.S. and ICAO phraseology and procedural ambiguities need to be resolved 

for pilots and controllers to reach a common ground 

of understanding. The pilots provided examples to 

support their feeling that not all words and phrases 

universally convey the same meaning for pilots and 

controllers. The most common examples provided by 

the discussants involved the interpretation of cleared 

direct and runway surface operations. Phrases such as 

“after the arriving aircraft” and “after aircraft of the 

moment” appended to “line up and wait,” and “into 

position and hold,” although intelligible, understood, 

and read back correctly, are difficult instructions to 

follow, as the pilot cannot determine when to safely 

execute the procedure. Several complained that different phrases were used to indicate the same action, the 

two most frequently mentioned being “into position 

and hold” and “line up and wait.” A single, global 

phraseology standard should be adopted.

6. Language and procedure familiarization training is 

essential for flight crews lacking operational recency 

and multiple trips into a foreign country. Flying into 

a country with a check airman is not enough with 

the variability in ATC procedures, airspace structure, 

airport operations, geography, languages, cultures, and 

communications. Classroom instruction and experience in simulators provide pilots with added knowledge for international flights. With ever-increasing 

international flights, training in ICAO phraseology 

and procedures that differ from domestic ones becomes essential. Pilots should know the meaning of 

various words and phrases before leaving the U.S. 

Unfortunately, many pilots learn these things while 

on the job. 

7. The number of fights, coupled with recency of flight 

time in the geographical area (i.e., theater), is critical 

to understanding accented English, and will influence 

how easily controllers from different countries are 

understood. The more often pilots fly to a particular 

international airport, the greater their knowledge 

and skill set become. Associations between how 

a word appears in print and its pronunciation are 

formed based on experience listening to accentedEnglish pronunciation of these words. Pilots expect 

particular words and phrases and understand their 

meanings. When other words are substituted, pilots 

may not understand and may question the meaning 

and controller intent. All of this knowledge is then 

applied each time the pilot flies to that airport. Prior 

knowledge allows for more flexibility when abnormal 

situations arise. 

8. Technological advancements such as digital communications (CPDLC and ADS) may mitigate problems 

associated with accent, pronunciation, and speech 

rate, especially when reprogramming the FMS. Pilots 

who have access to datalink applications report their 

benefits and encourage their expansion. Receiving 

clearances, reroutes, radio frequencies, clearances, 

instructions, radio frequencies, and other information 

via a datalink as text (or synthesized voice) would 

bypass language barriers associated with a lack of 

English language proficiency. 

Finally, we present 10 recommendations derived from 

the pilots’ responses to the interview questions and discussions. They are: (1) Adopt and adhere to the phraseologies 

contained in Doc4444 by all of the ICAO member states 

and the aviation community. Lack of standardization in 

phraseologies, procedure execution, and inconsistencies 

in language proficiency can lead to misunderstandings 

and unsafe acts. (2) Resolve the disparities that currently 

exist in the intentions (meaning) expressed by some 

words and phrases (e.g., cleared direct clearance, prepare 

to overshoot). (3) Develop additional phraseologies for 

inclusion into Doc4444 if the existing phraseologies cannot explain adequately an event involving the safety of an 

aircraft, provide actions, or offer solutions. (4) Develop 

one standard order for the presentation and delivery of 

ATC phraseology1

 by ATC, and require that ATC personnel adhere to it. For example, “cleared for approach, 

maintain your altitude” may violate pilot expectations to 

descend and lead to confusion. (5) Transmit no more than 

two speech acts in an ATC message (excluding speaker 

and receiver identifiers). Analysis of ATC voice tapes 

have repeatedly demonstrated that messages containing 

more than two speech acts (e.g., clearances, instructions, request, or their combination) can lead to radio 

frequency congestion and the production of readback 

errors. (6) Develop and implement one universally accepted and agreed upon standard accent, dialect, speech 

rate, cadence, and pronunciation for aviation telephony. 

Inherent differences between speakers’ and listeners’ 

languages impede decoding ATC Communication. (7) 

Develop aviation training courses that address plain language proficiency, cultural differences, and appropriate 

phraseology to declare an emergency, indicate the degree 

of emergency, assisted handling requests, and assistance 

during unexpected or unusual situations or events. (8) 

Adopt standardized testing standards, instruments, and 

testing procedures by all of the ICAO member states. This 

would help assure better global communication standards. 

(9) Require at least a Level 4 Language Proficiency in 

1 The words, phrases, and clauses used to deliver clearance items, requests for 

information, issue reports, etc. and the order in which these communication 

elements appear in the transmission.
ix 

Common English, as defined by ICAO in Doc9835 for 

ATC personnel and crews involved in flight operations. 

ATC personnel and flight crews will/must demonstrate 

more than a limited understanding of the concepts of 

“emergency fuel,” “minimum fuel,” “expedited handling” 

because of low fuel and other safety-related phraseologies 

to retain their certification. Although the interviews and 

discussions focused on pilot and controller communications, some of the examples provided by the pilots also 

involved safety personnel (e.g., firefighters, emergency 

rescue technicians). Pilots and controllers must demonstrate the ability to extract and relay the words necessary 

to indicate the extent of the emergency, i.e., “declare an 

emergency” (Doc4444) in minimum fuel, emergency 

fuel, or requests for expedited handling. (10) Adopt 

minimum ICAO hardware/software standards that assure appropriate voice/data communication quality and 

coverage to enhance the safety of ATS operations now 

and into the future. ICAO member states should be 

encouraged to cooperate in upgrading their hardware, 

software, and communications equipment for the benefit 

of global aviation.

1 

United States Airline Transport Pilot

International Flight Language Experiences

First learn the meaning of what you say, and then speak.

— Epictetus

INTRODUCTION

In a report released by the National Bureau of Economic 

Research (NBER, 2008), the United States economy has 

been in recession since December 2007. Since then, other 

countries have reported economic downturns, indicating 

the existence of a global recession. The U.S. is working 

diligently with other countries to limit its effects both 

within the U.S. and internationally. In light of this recession, the Federal Aviation Administration (FAA) updated 

its projections in the number of passengers arriving into, 

and departing from, the U.S. through the year 2025 

(FAA 2008a). That report notes, “The worldwide recession drives international passengers down 0.9 percent 

in 2009, but a rebound in economic growth leads to a 

4.2 percent growth in passengers in 2010. For the balance of the forecast period, stable worldwide economic 

growth leads to international passenger growth averaging 

4.6 percent a year and totaling 310.0 million in 2025” 

(p35). As shown in Figure 1, the largest percentage of 

growth will involve the Asia/Pacific area, followed by the 

Latin America. 

As the volume of U.S. and foreign flagship carriers increases, so too will the number of transmissions necessary 

to provide air traffic control (ATC) services. These services 

include clearances and instructions, as well as traffic and 

weather advisories, reports, and requests. Given that the 

present air-ground communications system is reaching 

pre-9/11 saturation levels during peak traffic periods, it 

is common for some controllers to send longer and more 

complex messages to reduce the number of times they 

need to communicate with individual aircraft (Prinzo, 

Hendrix, & Hendrix, 2006) and to use nonstandard 

phraseology to decrease the amount of time on frequency 

(e.g., go fast). The ability to quickly decode, understand, 

read back, and comply with these messages can be a 

problem for all pilots, especially those who are unfamiliar 

with how ATC services are delivered by controllers in a 

particular region. 

Airline transport pilots (ATPs) who have English as 

their second or third language may have difficulty understanding local nuances and lengthy clearances delivered at 

rapid rates. Likewise, native English-speaking pilots may 

encounter difficulties understanding the English spoken 

by English-speaking controllers or by non-native speakers 

of English. Reports from Brazil (Associated Press, Feb. 

19, 2007) in recent months have pointed increasingly at 

controller error as the leading likely cause of an accident 

involving a Legacy business jet and a Boeing 737 that 

resulted in the deaths of 154 people in 2006. Accident 

transcripts revealed that the business jet pilots apparently 

had trouble understanding the English spoken by the 

Brazilian controllers. On three separate occasions, they 

asked for clarification without receiving a satisfactory 

response. The final accident report issued by Centro 

de Investigação e Prevenção de Acidentes Aeronáuticos 

(CENIPA) and National Transportation Safety Board 

(NTSB) concur with each other on many of the basic facts 

and findings, but they disagree in their interpretations 

of these facts and offer different conclusions. Whereas 

U.S. & FOREIGN FLAG CARRIERS

 PASSENGER TO/FROM THE U.S. 

2008 - 2025

4 4.3

5.2

3.2

0.0

2.0

4.0

6.0

Atlantic Latin America Asia/Pacific Canada

Transborder

Average Annual Percent Growth

Figure 1. Projected Average Annual Growth in Passengers 
2 

CENIPA attributes the accident to mistakes made by 

the pilots and controllers, NTSB places the fault upon 

the controllers and the ATC system. Appendix 1 of that 

report contains the following probable causes issued by 

NTSB (CENIPA, 2008).

The evidence collected during this investigation 

strongly supports the conclusion that this accident 

was caused by N600XL and GLO1907 following 

ATC clearances which directed them to operate in 

opposite directions on the same airway at the same 

altitude resulting in a midair collision.

The loss of effective air traffic control was not 

the result of a single error, but of a combination of 

numerous individual and institutional ATC factors, 

which reflected systemic shortcomings in emphasis 

on positive air traffic control concepts.

Contributing to this accident was the undetected 

loss of functionality of the airborne collision avoidance system technology as a result of the inadvertent 

inactivation of the transponder on board N600XL.

Further contributing to the accident was inadequate 

communication between ATC and the N600XL 

flight crew.

These findings are relevant to a recent content analysis 

of the communication between Thai controllers and local 

Thai pilots, native English (e.g., U.S., British) and non–

native English- (e.g., Korean, Japanese) speaking pilots 

(Tiewtrakul, 2007). The results of that study found that 

the local Thai ATC accent affected pilot understanding. 

In particular, there were more communication problems 

(readback errors, requests for repeats, and no responses) 

among the non–native English pilots, followed by native 

English pilots, and the least problems occurred among 

the Thai/local pilots. Tiewtrakul concluded that the Thai 

controllers’ native language may have influenced their 

English pronunciation to the point that non–native Thaispeaking pilots were at a disadvantage in understanding 

what was spoken.

Likewise, controllers may have difficulty understanding 

the English spoken by native and non-native Englishspeaking pilots. For example, Kanu Gohain, Director 

General of Civil Aviation (DCGA) in India, told reporters that in 2006 India ‘sent home’ between 20-25 pilots 

(mainly from the Commonwealth of Independent States 

and Eastern Europe) because their English posed safety 

concerns (Reuters, Feb. 15, 2007). The DGCA did not 

clear these foreign pilots to fly in India because they did 

not demonstrate proficiency in English on the oral exams.

A content analysis of U.S. ATC en route communications performed by Prinzo, Hendrix, and Hendrix (2008) 

revealed that when an aircraft was registered to a foreign 

airline with a language other than English as its primary or 

official language, not only did the pilots spend more time 

on the radio communicating with ATC, but also more 

transmissions were exchanged, and more communication 

problems were present within their transactions. In these 

situations, the pilots’ English proficiency — especially their 

accents — often resulted in the controller not being able 

to completely understand what the pilot was attempting 

to say. Rarely did the U.S. controllers express difficulty 

understanding a native English-speaking pilot.

Lack of proficiency in the English language among 

pilots and controllers who are non-native English speakers has resulted in fatalities,1

 mishaps and unsafe acts. In 

response, the International Civil Aviation Organization 

(ICAO), an agency of the United Nations, published 

Manual on the Implementation of ICAO Language Proficiency Requirements (ICAO, 2004). The implementation 

of the ICAO language proficiency requirement was slated 

for March 2008.2

 Specifically, ‘Aeroplane and helicopter 

pilots and those flight navigators who are required to use 

the radio aboard an aircraft shall demonstrate the ability 

to speak and understand the language used for radiotelephony communications.’3

 Similarly, ‘Air traffic controllers 

and aeronautical station operators shall demonstrate the 

ability to speak and understand the language used for 

radiotelephony communications.’4

English language proficiency educational materials, 

training programs, and testing programs are being developed and implemented to meet the ICAO mandate. 

Clearly, the concern for aviation safety continues to 

be a global concern. Given that what is known about 

language-based communication problems is derived from 

accident, incident, and mishap reports, what is absent is 

an understanding of how prevalent these problems are 

during normal air traffic operations.

The available reports that describe operational communications between pilots and U.S. controllers were 

derived from voice tapes provided by tower (Cardosi, 

1994; Burki-Cohen, 1995), terminal radar approach 

control (Cardosi, Brett, & Han, 1996; Prinzo, 1996), and 

air route traffic control centers (Cardosi, 1993). Unfortunately, the existing reports (written a decade ago) do not 

provide any indication as to the magnitude or severity 

of communication problems that involve non-native 

English-speaking pilots who fly international flagships 

into the U.S. or by U.S. pilots who fly to international 

destinations. Consequently, an operational shortfall exists 

in our understanding of international operational communications as it occurs within the National Airspace 

System (NAS), in foreign countries, and its perceived 

impact on safety by airline transport pilots.

Likewise, there is a lack of baseline data regarding 

the flight experiences of pilots who fly internationally. 

It comes as no surprise then, that research is needed to 

identify and fill the gaps in communications data that 

1 As an example, in 1990, Avianca Flight 51 was making its third approach into 

JFK Airport and failed to inform air traffic control they had a fuel emergency 

and crashed.

2 In November 2007, the Assembly of ICAO drafted a resolution to precede 

Resolution A32-16 that would urge up to a 3-yr extension of the provisions 

in A32-16 and Article 40 of the Convention.

3 Appendix A, Manual on the implementation of ICAO language proficiency 

requirements.

4 Ibid.
3 

would contribute to the understanding of some of the 

language issues, communication problems, and procedural 

differences airline transport pilots encounter when flying 

internationally. Also, as digital voice communications 

systems and their applications emerge, it is important to 

know which messages may present a problem for nonnative English-speaking pilots.

Therefore, the purpose of this study was to identify 

language issues that can become barriers to efficient and 

effective communication between the airline transport 

pilots (one group of native English-speaking pilots, one 

group of non-native English-speaking pilots) and air 

traffic controllers (who may or may not be fluent in English). A total of 64 international airline transport pilots 

participated in small focus group meetings to discuss 

the types of communication problems they encounter 

during international flights. There were 48 pilots who 

flew for four U.S. air carriers and 16 pilots who flew for 

four foreign air carriers. The U.S. pilots were interviewed 

separately from the foreign pilots.

We attempted to preserve the richness and breadth of 

the information given during the interviews in a series 

of reports. The first report (Prinzo & Campbell, 2008) 

provided an analysis of the first two sections of the structured interview: 1) Background Information related to 

the recency of international flight experiences among the 

pilot-participants and 2) General/Preflight Preparation. 

It covered the U.S. pilots’ responses and discussions of 

questions 1-23.

This second report provides a continuation of the 

analysis of the U.S. pilots’ flight experiences during 

times when they experienced language issues that became a barrier to efficient and effective communication 

between themselves and air traffic control. It covers the 

pilots’ responses and discussion for questions 24-30. 

These questions ask about 1) the frequency with which 

they experience problems related to word meanings, 

2) problems related to how words are pronounced, 3) 

problems that affect them the most that are related to 

the differences in the word(s) used to describe clearances, 

instructions, advisories, and requests, 4) problems related 

to the same word(s) used to describe different actions, 

5) problems related to accents or dialects, 6) the extent 

to which nonstandard terminology was confusing, and 

7) the extent to which they experienced language-related 

difficulties when programming their FMS to comply 

with ATC. When possible, the content was tabulated 

and presented in tables. Their verbal discussions are 

combined, condensed, edited, and presented as a narrative from the perspective of a hypothetical, albeit typical 

ATP-rated pilot.

RESULTS

Section 4: Word Meaning and Pronunciation (how

words are spoken)

24. How often during a flight do you experience problems 

related to word meanings? 

As shown in Table 1, 58% of the pilots reported they 

“rarely” experienced problems related to word meanings, 

while another 33% reported they “occasionally” experienced problems. Only 8% indicated they “frequently” 

experienced problems. Approximately 40% of the respondents provided examples of the types of problems 

they experienced. 

Rarely Do I Experience Problems Related to 

Word Meanings Explanation

Of the 28 pilots who reported less than 10% of their 

interactions with controllers involved problems related 

to word meanings, 36% provided comments (written, 

oral, or both). Presented below is a compilation of their 

experiences.

Accent

For me, the three big-ticket items are: (1) transmissions going too fast; (2) transmissions being clipped; 

and (3) heavy accent being transmitted across the 

airwaves. It happens when we’re trying to understand 

what we’re supposed to be doing. I’ve had times 

when I’ve had to ask for a repeat four or five times; 

and we’re in the cockpit listening intently and trying 

to, word-by-word, figure out what our departure is. 

But generally, it’s because of accents, and it rarely 

happens. Maybe it’s because I grew up in New York 

and heard a lot of eclectic voices, which allows me 

to pretty much understand what ATC wants.

Table 1. Frequency of Problems During Flights Resulting from Word Meanings. 

Frequency of In-flight Problems 

Resulting from Word Meanings 

Number 

of Pilots Issues Discussed 

Rarely (less than 10% of my interactions 

with controllers) 28 

Accent; Pronunciation; Radio Technique; Speech Rate; 

Variability in Language Proficiency; Word Meanings 

Occasionally (between 10-24% of my 

interactions with controllers) 16 

Culture; Pronunciation; Radio; Speech Rate; Word 

Meanings 

Frequently (between 25-74% of my 

interactions with controllers) 4 Pronunciation 

Often (between 75-90% of my interactions 

with controllers) 0 

Without fail (more than 90% of my 

interactions with controllers) 0 
4 

Pronunciation

As far as the pronunciation, it rarely is a problem. 

I know the words when they say them. I do have a 

problem with pronunciation, mostly in one country 

in Asia. When we’re starting down, that’s my danger 

zone. They’ll say, “Cleared to so and so,” and in the 

cockpit I will say, “Cleared to so and so” because 

I want the other pilots’ opinions – “Is that what he 

really said, go to so and so?” It’s hard sometimes 

for me to understand what fix we’re supposed to 

go to. But once we’ve deciphered the word, rarely 

does the meaning call into question what you’re 

supposed to do. The problem is in understanding 

what the word is.

Radio Technique

Transmissions that are clipped can change the 

whole meaning of a phrase.

Speech Rate

Well, with the word meanings, it’s just a matter 

of the transmission going too fast. A lot of the real 

hard stuff is down in Central and South America, 

and I speak the language so it’s not greatly different. 

Every now and then, I’m not sure what he’s talking 

about if I’m not looking at the guide. It’s hard to 

understand because to me they talk fast.

Variability in Language Proficiency

It’s interesting that in one city in South America, it 

seems that the clearance delivery person is the most 

difficult person of everyone, at least in my experience down there, to understand. It’s not the tower 

controller or the ground controller or the approach 

or departure person. We wonder why.

Word Meaning

Take the whole MAYDAY5 thing that is pounded 

into us. I don’t think that an emergency means the 

same thing to some foreign controllers as it does to 

me. We’re going to say MAYDAY, and use the ICAO 

phraseology. It may just be that it’s a word spoken 

that another person doesn’t understand. I’ve never 

had a situation where I say one thing, and they know 

exactly what I said, and yet they think I’m going to 

do something completely different. 

There was a problem when a controller said, “Line 

up and wait after the arriving aircraft.” That’s not used 

at all domestically in the States. Lufthansa is on final 

approach and the controller clears us to line up and 

wait after the landing airplane. You’d better make 

sure you hear after the landing airplane; because, if 

all you hear is line up and wait, you’ve just taxied 

out in front of Lufthansa. In the U.S., the arriving 

airplane is on the ground before you’re cleared into 

position using the phrase position and hold.

5 Implied lack of understanding the meaning of MAYDAY (distress).

Occasionally I Experience Problems Related to 

Word Meanings Explanation

Sixteen respondents reported they occasionally experience problems related to word meanings. Approximately 

62% of them provided comments (written and interview) 

that were edited, compiled, grouped, and are presented 

alphabetically.

Culture

Declaring an emergency in one country in South 

America doesn’t get the adrenaline flowing in them 

like it does us, even if we use the ICAO code word.

Pronunciation

In Europe and South and Central American, pronunciation is much more of an issue for me. What 

will happen is that I will understand completely or 

not at all. I think the controllers in one country in 

Asia are very predictable once my ears get used to 

their pronunciation of “R’s” and “L’s.” I occasionally have to ask them to “say again” for the word 

meaning, but it’s not a biggie.

And sometimes, when I used to fly the triple seven 

in South America, if we had a Spanish speaker onboard, he could almost always pick up what they 

were saying the first time because his ear was tuned 

to the rolling R’s and any other thing that we weren’t 

tuned to. By the time we came back, we would be 

picking it up too. But the person’s pronunciation, 

diction and enunciation, the way they do it, along 

with the speaking rate, make understanding more 

difficult for me.

Going to one city in South America, one night they 

wanted us to hold at, and his words were “Tango 

Romeo Mike;” 6

 and we couldn’t find “Tango Romeo 

Mike” anywhere. I think it is the Thermal VOR to 

be honest with you; but we put it in there7

 and it’s 

thousands of miles away. And so we kept asking 

him, “Where do you want us to hold?” and he kept 

saying, “Tango Romeo Mike.” We finally gave up 

after six tries. We told the controller, “We’ll go to a 

place called Romax and hold.” The next morning, 

we asked the on-duty controller what “Tango Romeo Mike” was, and he goes, “Oh that’s the TORIM 

intersection – That’s T, O, R, I, M.” That is probably 

the only time I had a problem with something that 

was said that turned out to actually be a problem. 

So it does happen.

Radio

Part of the issue is with the equipment the other 

person’s using – bad radios. That compounds a 

problem.

Speech Rate

To me, some controllers speak to fast and I’ll miss 

some things. My perception is that they expect us 

6 It may be that the controller used the fix name TORIM, that sounded like 

T, R, M (instead of the phonetic Tango Romeo Mike).

7 Aircraft Flight Management System (FMS).
5 

to know exactly what their plan is because of how 

they do it every day. But, I get up there once every 

two years. I can be farther behind in the Northeast 

Corridor than I can be in one city in Central America.

Word Meaning

In the approach clearances, my experience has 

been that cleared approach means one thing in one 

area and something else in another area. Some of 

the differences are subtle nuances, but they exist. 

Even going to another country in North America, 

there are some small differences. It may be that ATC 

uses the terminology radar identify in one area and 

radar contact in another.

In one city in South America, you’re cleared to 

line up and wait after the arriving airline. We watch 

the airplane touching down, as the guy told us this. 

That is not the arriving airplane. It’s the airplane 

out there on a nine-mile final. How do we know 

which airplane the controller is referring to? Through 

experience, we learn to ask, “You mean I can go 

on the runway after the guy who just landed?” And 

they’ll say, “Oh no, no, no, after the one out there 

on final,” which we can’t see because of the clouds.

Frequently, I Experience Problems Related to Word 

Meanings Explanation

Four respondents reported that they frequently experience problems related to word meanings. Although all 

of these respondents made comments, one did not fully 

understand the question and reported that he experienced 

problems more frequently because he doesn’t fly as many 

trips. For the three remaining pilots, their comments from 

both the written and interview portions of the questionnaire were edited, compiled, and are presented below.

Pronunciation

It is a problem for me in one country in Asia, while 

in Europe there are definite, different dialects that can 

really cause us to say, “What was that he’s saying?” 

Words that are similar can be confusing. I can look 

at my chart and know what I’m expecting when I’m 

told, “You’re cleared direct Patoka.” But, I have to 

verify that he means proceed present position direct 

Patoka; and sometimes there are several waypoints 

that are close to each other that sound very similar. 

In some cases, I have to ask multiple times to make 

sure that we’re going to Onvost and not Harvest, or 

was that Léon or Dijon? The same problem happened 

in the U.S. a couple of years ago with the arrivals. 

The names had to be changed because they sounded 

too similar on different corner posts.

25. How often during a flight do you experience problems 

related to how words are pronounced?

Of the 48 U.S. pilots who participated in the interviews, 21% rarely experienced problems with how 

words were pronounced, 42% occasionally experienced 

problems, 31% frequently experienced problems, and 

6% often experienced problems. The distribution of 

their response selections is presented in Table 2, along 

with a list of the issues they discussed. Fifty-six percent 

provided comments. 

Rarely Do I Experience Problems Resulting From 

How Words are Pronounced

Ten pilots reported that they rarely experience problems 

related to how words were pronounced. Sixty percent 

provided comments from the written and interview portions of the questionnaire.

Culture

I only have trouble understanding the controllers 

in one country in Europe. My experience has been 

that they expect us to understand their dialect and 

know what fixes they’re talking about, even though 

the names are pronounced differently than I expect. 

To me they speak quickly, and they’re going from 

their language to speaking English, and it’s kind of 

tough for me to mesh.

Pronunciation

To an extent, the pronunciation detracts from the 

primary task. The first experience with pronunciation problems might be an initial inconvenience to 

try to figure out the word; and I might have to ask 

them a couple of times to repeat what was said. 

Or, we go to the FMS to find it and it’ll be another 

transmission to verify we got the right one. I may 

go back to spelling phonetically to make sure that 

we have the right understanding. Sometimes I get 

the feeling that because I couldn’t understand what 

was said, they get disgusted. But we usually end up 

getting what they want us to do.

It would be ideal, if we got our clearance via 

ACARS;8

 it’s really nice – the clearance just pops 

8 Aircraft Communications Addressing and Reporting System.

Table 2. Frequency of Problems During Flights Resulting From Pronunciation. 

Frequency of In-flight Problems Resulting From 

Pronunciation 

Number 

of Pilots Issues Discussed 

Rarely (less than 10% of my interactions with controllers) 10 Culture; Pronunciation 

Occasionally (between 10-24% of my interactions with controllers) 20 Pronunciation; Radio 

Frequently (between 25-74% of my interactions with controllers) 15 Accent; Culture; Pronunciation 

Often (between 75-90% of my interactions with controllers) 3 Pronunciation 

Without fail (more than 90% of my interactions with controllers) 0 
6 

up. I’d say the majority of the time – 90% plus – 

overseas we get our clearance via the radio. And 

depending where we are, it can be a challenge. If 

we can understand the words that are said in one 

city in Asia, we usually understand the clearance.

Occasionally I Experience Problems Resulting 

From How Words Are Pronounced Explanation

Twenty respondents reported that they occasionally 

experience problems related to how words are pronounced. 

Of these pilots, 55% provided comments that were edited, compiled, and grouped alphabetically according to 

common themes.

Pronunciation

The difficulty I have experienced is increased by 

accent, dialect and the way it’s presented. The most 

common examples would be the names of intersections. The controller will say it, and I look down and 

try to find the routing, I read all the words to try to 

figure out what word it was that was just said – the 

position that we were cleared to. 

It seems that for me reading, hearing, and pronouncing French words and/or names are very different 

from how the appear in our English. I end up asking 

for verification after every clearance. Many French 

controllers seem to know that we don’t understand 

their English well; so, they’ll say the word, and then 

spell it out phonetically. I had one, just coming out 

of Tel Aviv yesterday. He cleared me to [VESAN]. 

I said, “Where?” He said, “VESAN, Victor Echo 

Sierra Alpha November.” OK, it’s VESAN; I see that 

on the map. 

But for me, again, I have trouble with pronunciation 

in Southeast Asia – Korea, Vietnam, and sometimes 

Japan – accents are troublesome. For me, the AsianEnglish is not very clear, so when words are clipped, 

or run together, it becomes a problem. My perception is that when I talk with an Asian controller, all 

the words will be put together; and it’s very difficult 

for me to determine just what was said. It’s a very 

common thing throughout Asia. 

Japan tends to have some very excellent Englishspeaking controllers. When I find one that isn’t, it 

falls right into the category of very difficult to understand. Many male Japanese controllers add an 

“Oh” to a phrase. Our call sign might be [Airline 

name] eight four six and it becomes [Airline name] 

eight Oh four six; and unless my ears are tuned in to 

that, I’m going to miss the call. Also, when Japanese 

controllers say the number “seven” I just don’t hear 

it very clearly. I’m not quite sure what I heard.

Radio

The signal quality, the quality of the English being 

spoken, whether it’s an accent or just dialect – and 

then, I would also chalk up part of it to hearing 

issues. As I’m getting older,9

 I’m beginning to have a 

difficult time understanding some Asian controllers 

who have very high, nasally voices. I do know that 

I have partial hearing loss in certain frequencies. 

Sometimes it’s difficult to determine what word 

was said.

I have more of a problem with the quality of the 

radios flying the Caribbean and South America, 

than I do understanding the words. We just can’t 

understand anything they’re saying, not because of 

the way they talk but because it doesn’t get to the 

airplane very well. I don’t know if it’s more static 

or just poor quality. It [sounds] like it’s coming 

through a wire between two cans – some of it is 

really, really bad.

Frequently I Experience Problems Resulting From 

How Words Are Pronounced Explanation

Fifteen respondents reported that they frequently experienced problems related to how words are pronounced. 

Seventy-three percent provided additional information 

that was arranged by common topics. 

Accent

I find it very difficult hearing what controllers are 

saying to me in a Spanish and occasionally French 

accent. I have to stop what I’m doing, look at the 

chart, and make sure that the fix they name is the one 

I want to go to. I have to remember that English may 

be their second language and I have to understand 

their accents when they speak English. 

You ask is it more than just the language, is it 

the phraseology and being unfamiliar with the 

phraseology? It’s also being unfamiliar with the 

middle accents. The first part of the word might be 

emphasized and the last part of the word faded out; 

they pronounce it differently than we do.

Culture

I think the French are very proud of their language, 

and rightfully so. When we are cleared to a position or a waypoint, the names are pronounced in 

French as if delivered to a French pilot. If it is an 

off-airways waypoint, we might not know where 

we’re cleared to. So, we need to look at our chart 

and have a good idea where the controller is sending us, so we can interpret what we hear correctly. 

Otherwise, we might have to ask for a repeat and 

he will spell it phonetically. 

And I want to explain that when we experience 

problems, it’s not that this has necessarily caused 

me to make a wrong turn or do something incorrectly; the problem that I feel it has caused is the 

communication and the deciphering of what it is 

exactly that they want us to do, which takes a little 

bit of time and puts us behind the aircraft. On most 

9 Presbycusis is a loss of hearing ability due to aging. Higher frequencies 

are more susceptible to hearing loss than lower frequencies. It occurs more 

frequently among older men.
7 

of these flights, there is some kind of verbal interaction that breaks down.

Pronunciation

I have trouble understanding what is said – especially when European controllers pronounce fixes 

and waypoints. I just don’t hear the subtle differences 

and it causes the names of fixes to sound similar 

to me. I have to ask for verification, like one out of 

every three or four transmissions, to make sure I 

understand exactly what they want me to do.

I also have trouble with accents and pronunciation 

in South America. I think my problem understanding Brazilians is the influence of the Portuguese 

language. In Brazil and Chile, the letter “E” is added 

to words and it takes some getting used to. In Peru 

and Ecuador, it’s difficult for me to understand everything spoken in English with a Spanish accent 

particularly when the letter “V” is pronounced like 

our letter “B.” “Victor” is “Bictor.” 

In the Caribbean, the Jamaican influence is apparent and I experience a language barrier when 

communicating with controllers there; and then, 

Havana’s pretty straightforward. Haiti can be a little 

problematic for me at times – Port au Prince, and the 

French influence into the Haitian culture so that’s 

a double whammy.

Some other areas I’ve noticed are Southeast Asia 

– Korea, Vietnam, China, and occasionally Japan. 

Japan tends to have some excellent English-speaking 

controllers.

Often I Experience Problems Resulting From How 

Words Are Pronounced Explanation

Three respondents reported that they often experience 

problems that were related to how words are pronounced. 

Comments from the written and interview portions of 

the questionnaire are included below.

Pronunciation

Since native English speakers emphasize the first 

syllable and Hispanic speakers emphasize the second syllable in their words, it causes me to have 

to shift gears. For English-speaking and -hearing 

people, there are many fixes that sound and look 

very similar to us but to them, are different. I can’t 

figure out exactly what they’re saying. I feel lucky if 

I understand what is said, but I cringe when I hear 

my call sign. I’m like, “I hope I can understand this 

time” – I might let down the guys in the cockpit 

because it seems like I always have trouble getting 

it the first time.

When I’m in Europe, around Sicily and some Southern parts of Italy, it gets pretty colorful. I’ve found 

the pronunciation can be varied and emotional.

26. What problems affect you most related to differences 

in the word(s) used to describe a clearance, instruction, 

advisory, or request? Please list some examples.

The pilot responses included differences in phrases, 

as well as words. Forty-three of them provided examples 

and comments that were organized according to reoccurring themes: Communications, Procedural Ambiguities, 

Training and Differences Between U.S. and ICAO/

International Flights, and Word Meaning in Different 

Parts of the World.

Communications

We identified seven different issues that are reported 

repeatedly throughout all discussions. They are presented 

in Table 3 and discussed separately.

Call Signs

A lot of times, in places like China, India, or Japan, 

if the numbers are the same or similar, controllers 

use phonetics and not the name of our company. 

For example, “Continental ninety-nine” was “Charlie 

Oscar Alpha” and before, when I was going over 

Turkey, they would use “Continental Airlines Charlie 

Oscar Alpha” versus “Continental.” I’m tuned to 

hearing “Continental” not “Charlie Oscar Alpha.”

Another thing is the use of heavy. The way controllers are expected to say call signs is definitely a 

problem. Every country has its own way of doing it 

– the FAA, only on the first transmission (except if the 

controller doesn’t want to respond that we’re a heavy 

jet). With the Canadians, it is every transmission.

Line Up and Wait

Line up and wait is an ICAO procedure,10 while 

the U.S. procedure is position and hold.

11 What I’m 

referring to is differences in words, not differences 

in what they want us to do. In Santo Domingo, we 

are cleared to “line up and wait” or “line up and 

wait after arrival Airbus.” If we ask, “Do you mean 

after the aircraft that just passed?” they say “No, no, 

after the one [that is] six miles out.” Line up and 

wait is a big problem. We pretty much ironed that 

out. I just wish every country said it the same way.

Non-Routine Request

I’ve found that the pronunciation of off-route 

10 Line up and wait is a grouping of ICAO phraseologies (3.4.11). 11 U.S. phraseology (ATP 7110, par. 3-9-4).

Table 3. Communications Issues Identified by 

U.S. ATP Pilots. 

Communication Issues 

Call Signs 

Line Up and Wait 

Non-Routine Requests 

Pronunciation 

Radio 

Speech Rate 

The Number of Instructions 

Transfer of Communications and Conditional Clearances 
8 

waypoints, instructions, and explanation of unexpected events is difficult to understand from the 

cockpit to the controller and from the controller to 

the cockpit. In other words, if I call up Rome and 

ask for a different routing into Fiumicino,12 because 

of weather or volcanic activity – it’s very difficult 

for him to understand what I’m saying. Conversely, 

when he comes back and gives me a routing that 

I’m not anticipating I must spend time deciphering 

and analyzing what he said while looking for it as 

we’re traveling at 250 miles an hour. So, both of 

us have trouble if it’s outside the spectrum of what 

we’re anticipating to hear.

Pronunciation

The pronunciations of words that are different from 

what I have been hearing are difficult for me to understand. Sometimes I won’t catch the numbers in 

a frequency change, the name of a fix, or off-route 

waypoints because they might be pronounced differently. I’ve found that the arrival fixes, “MELON” 

and “AIRES,” spoken by some Asian controllers in 

English can be very difficult for me to decipher. 

There are nearly 100 different SIDs13/Transitions 

and STARs14/Transitions at Charles De Gaulle Airport 

(CDG) often distinguishable by only one letter or 

number. Even though I’ve been there many times, 

sometimes I have to re-verify what ATC tells me 

because I have a difficult time hearing the difference. I think it’s more familiarity and frequency of 

flying into an area that overcomes the problems 

on understanding the pronunciation and accent. 

I can lose my experience level by not flying there 

often enough.

Speech Rate

My experience has been that when controllers get 

tongue-tied and frustrated, they start speaking very 

fast and we know we’re in trouble. When that happens, I ask them to just slow down a little bit for me. 

Like a band, if the singer can’t sing, the band just 

plays really loud, and no one knows the difference. 

The Number of Instructions

I expect, and can handle easily, three instructions. 

And what kind of chaps me is, many times over in 

one Asian country, I get a heading, turn, descent, 

and frequency change. We’re always heading west 

and the controller says, “Two five zero two six zero 

two seven zero.” Heading 250 and slow to 260; or 

was it turn to 260 and slow to 250? So to me, it’s 

the amount of information given; it’s not a problem 

with differences in words.

12 Location of Leonardo da Vinci Airport, which serves Rome, Italy. 13 Standard Instrument Departures. 14 Standard Terminal Arrival Route.

Transfer of Communications and 

Conditional Clearances

I have the most problems with frequency changes. A 

controller may give me a frequency to change over to and 

has enough of an accent or speaks too rapidly so I can’t 

catch all of it. You know, 33 or 23, and now we have 

the additional 23.5 frequencies; and so I think, “What 

was that that he wanted exactly?” I mean, “Say again 

the frequency.” Just yesterday, the same thing happened 

on a flight.

When I get a conditional clearance like, “Cleared for 

the ILS15 at the marker contact tower” why can’t I contact the tower now? Why tell me to do something five 

minutes from now in a very high workload environment? 

I’m liable to forget it 99% of the time because there’s no 

buzzer to remind us to do that five minutes from now. I 

would be shocked if landing without a clearance was not 

preceded by some conditional clearance, because when 

you tell me to do something, I do it now. I don’t wait 

five to ten minutes.

Procedural Ambiguities

Presented in Table 4 is a list of the pilots’ issues related 

to the procedural ambiguities they experienced. These 

problems are all related to the differences in the words 

that describe a clearance, instruction, advisory, or request 

speech act16 and when they are used.

Altitude Assignments

Altitude assignments vary with the country and 

controller. Words such as climb and maintain and 

maintain are used in a different context by foreign 

controllers. It is common for them to say level two 

five, and in the U.S., the controllers always say flight 

level [e.g., flight level two five zero].

High Speed

High speed means going more than 250 knots 

below 10,000 feet, and that’s generally over the 

water; so, we are technically in approach airspace. 

Sometimes on departure I hear, “cleared high 

speed.” Does that mean I can go up to the aircraft 

limit speed at low altitude? Or, am I restricted to the 

15 Instrument Landing System. 16 A speech act is a particular type of communication element (fundamental 

unit of meaningful verbal language) which is defined by its purpose, operation, or action.

Table 4. List of Procedural Ambiguities. 

Procedural Ambiguities due to Word Usage 

Altitude Assignment 

High Speed 

Pre-Departure Clearance (PDC) 

Restricted or Unrestricted Climb 

Runway Separation 

Transition Level 
9 

maneuvering speed 283 knots as opposed to 360 

knots? These are some of the questions in my mind.

Pre-Departure Clearance (PDC)

The real questions are, who do I call, and how far 

can I expect them to clear me? Do I call clearance 

delivery? Do I call tower? Do I call approach? Do I 

put in a request and have them call me back? 

The biggest thing I’ve seen in Europe is it’s regimented. They’ve got an apron, a ramp, a company 

frequency and they want us, at particular times, 

to step through those particular frequencies in a 

particular sequence for specific purposes. If we 

don’t do it that way, it messes up the whole wheel 

turning. We take two gears off the machine and it’s 

going to strip itself if we don’t start at the beginning 

and work through the process. 

Some parts of South America are very good about 

providing the clearance or ground control on the 

pre-clearance frequencies. But some aren’t. In one 

country in South America, we get the clearance 

request going, then we get pushback engine start

clearance; and when we’re on the taxi out, once 

they see us pointed toward the runway, they know 

that we’re, no kidding, going to go flying. It’s almost 

like, “Oh, he’s really serious.” Now they start reading it to us. 

In some cases, we hear folks on another frequency 

reporting overhead, and doing an arc back in and 

things like that; it’s nice to be able to sit there and 

think, “Okay, I’ve got one guy landing, one guy 

reporting in, and one guy up here.” I don’t get that 

luxury if I have to copy a clearance, and get to the 

end of the runway, complete a takeoff checklist, 

and then start down a runway. Once they get us on 

a runway, they want us out of there.

And other places, getting the clearance on taxi out 

is difficult for me because it makes me that much 

more distracted when they’re trying to get us to a 

particular end of a runway, or to take a particular 

route. In some cases, they’ll clear us to our taxi to 

position, and holding position, for runway “humptycratts.” As we’re taxiing out I look up, and the runway 

is completely clear; I start to copy the clearance and 

look back up, and here comes this airplane back 

out, just as Ground is saying, “Hold position for 

pushing back seven six seven,” or something like 

that. And they’re allowing somebody else to come 

out in front of us.

Restricted or Unrestricted Climb

Restricted or unrestricted climb is one of those differences I find in other countries. In Santo Domingo, 

we are cleared to filed altitude then given initial level 

off, “cleared to climb flight level one two zero,” as 

opposed to expect altitude. They still require pilots to 

make the restrictions on whatever SID17 that they’re 

on. “Cleared high-speed climb,” [brings about the 

17 Standard Instrument Departure.

same concerns] when Tel Aviv clears you. I have the 

same questions with the restrictions on the arrival. 

Canada uses something else.

Runway Separation

Runway separation is scary at some places. We 

could be at 500 feet and hear “you’re cleared to 

land.” You see them18 just pulling off but not clear. 

Do they mean, “You’re cleared to land now?” A lot 

of times in one city in Asia, we’ll see that. I don’t find 

it very comfortable. I want to ask, but we’re afraid 

that he’s going to yell at us when I ask, “Have you 

forgotten about us?” But I’ve seen it below 500 feet 

as well. All the time I’m sitting there thinking, “Get 

ready for a go-around because that aircraft will not 

clear before I touch down.” Other than the U.S., 

when we switch over to tower we’re told to continue. 

In the U.S., we can be number five and they’ll 

clear us to land. But we won’t be cleared to land 

until the runway is positively cleared and vacant for 

us alone. It’s something that’s peculiar to the U.S. 

I’m surprised I don’t know what a U.S. controller 

has to have to clear us to land, even though we’re 

number four or five in line. Of course, he can always 

cancel our landing clearance. In other parts of the 

world – we’ll get “continue” until the runway’s all 

ours. That’s one difference, and I prefer the U.S. 

In Santo Domingo, we are cleared “line up and 

wait” or “line up and wait after arrival Airbus.” A 

line up and wait after arrival aircraft clearance to 

me is a bogus clearance. Why not wait until the arriving – whatever it is – has landed, then clear me 

to line up and wait. In a broad sense, conditional 

clearances have always bothered me.

Sometimes the verbiage they use like “you’re not 

cleared for takeoff,” “you’re not cleared for landing,” can be misinterpreted very easily. I realize that 

they’re translating from their language to English, 

but they’re thinking in their language; and if we 

step up to the bar a little bit here, I think it’s going 

to make it a lot safer. In the U.S., we never hear not 

cleared for takeoff or not cleared for landing. But 

it’s commonplace in Central and South America, 

and Mexico.

Transition Level

Transition level is assigned by ATC. When they 

clear us below what we think their transition level 

will be, I always ask them, “What is the transition 

level?” There needs to be an easier way to handle 

the transition levels. 

In the U.S., everything below 18,000 is reported 

in thousand feet, and in Europe everything above 

5,000 or 6,000 or whatever is reported in flight level, 

for example, “flight level five zero.” In a romance 

language, transition level is said as level of transition. So when I ask them, “What’s the transition 

level?” they don’t get it even though the words are 

18 Aircraft on the runway.
10 

the same. But when I ask in Portuguese or Spanish, 

then they get it completely. 

It is very frustrating switching from 298, to 1013, to 

a local altimeter. In one South American city, 6,000 

feet is the transition altitude. So the transition level is 

above that at some point. If I ask what the transition 

level is in English, they say, “Yeah, you’re cleared 

500 feet.” Although it doesn’t vary by more than a 

few hundred feet, the point is we want to be sure 

that we don’t leave the standard Pressure Altitude 

of 1013 hPa19/29.92 InHg20 before it’s time. 

When you’re saying the transition level at 6,000 

feet, they just told us to maintain 6,000, and, “Wait 

a minute, you just told me the transition level’s at 

six zero.” Am I flying with pressure set at 1013 

hPa, or what do you want me to set? We have a 

high barometer out there like 3020 InHg, so that’s 

a pretty big discrepancy in altitude (about 256 feet) 

– especially at the lower altitude, where everybody’s 

flying within 1,000 feet of each other, or whatever.

Beijing Approach will issue a clearance to descend 

to an altitude, for example, 4,000 meters, and then 

they’ll add the words on standard. And it took me the 

longest time to figure out what on standard meant. 

And what he was doing, because the transition level 

may vary, he was adding that to say, “I don’t want 

you to change to local altimeter here.” But that’s 

something peculiar to Beijing; I don’t even think it’s 

written anywhere, but they use it. In Santos, they’ve 

started throwing that on a regular basis.

Training and Differences Between U.S. and ICAO/

International Flights

There were two over-reaching issues the pilots discussed 

in response to interviewer questions regarding attaining a 

desired comfort level for international flights. One issue 

pertained to training and the other to differences between 

the U.S. and ICAO/Foreign terminology and phraseology. 

Training

I don’t recall specifically training in ICAO terminology. We were thrust into the environment and 

learned it as we went along. We learned from “the 

school of hard knocks.” Give international pilots a 

half-day class in what ICAO terminology means. 

For example, maintain radar heading means fly 

heading to one eight zero, or to fly our assigned or 

present heading.

For new crews going into a foreign country, training is a must. There are several things we get before 

going south – speed control and things like the 

15,000-foot restriction. On the charts in Mexico, it 

talks about 200 knots when we’re 10,000 feet AGL21

or below. So flying into Mexico City, we’re used to 

250 knots at 17,000 feet; whereas, usually here in 

the U.S., we’re used to it at 10,000 feet. These are 

19 Hectopascal - a unit of the metric system, which is the same as millibar. 

(Used Internationally)

20 Inches of mercury (U.S. standard). 21 Above ground level.

little things that we have to try to read through the 

charts multiple times. 

When we’re within 30 miles, below 10,000 feet 

above the airport, we’re supposed to be at 250 knots. 

When we’re at 17,000 feet and slowing down, I’m 

finding out that I have to wait awhile to make sure 

that my speed is slow enough, if I need to put the 

slats out that I’m still high enough that I may have 

a mach number that’s almost up to the point where 

I can’t get them out. So there are other things you 

have to watch out for.

Modules

You were asking about the modules.22 I think the 

modules are a great tool that absolutely needs to be 

provided. The modules are good for a review, but 

they don’t replace a first time with the check airman, 

or if you haven’t been down there in awhile. I think 

that’s where our airline is trying to go to reduced 

manpower – not to send check airmen. The modules 

do not replace a check airman. 

We used to have little booklets on the particular 

airports, like the type of modules that they’ve built 

for some of these airports – San Jose, Guadalajara, 

Mexico City. They used to give us these little informational books so check airmen could train new 

pilots. It was great stuff. But these modules are replacing that, and that’s good. The modules are very 

good. There are some airports that I do not want to 

go into the first time by myself. 

Check Rides

Our airlines still requires a check airman on certain 

airports. But they’ve relieved some of the necessity 

for a check airman on a first flight into certain other 

airports. That’s probably not necessarily evil; we may 

not need it for every airport. For ones that are really 

tough – they still require one. I don’t see them taking 

that away. If they did, I’d raise a red flag.

Check airmen are needed because of the geography, procedures, and communications. St. Thomas 

is in the middle of a bunch of mountains, and its 

approach is very steep. It has a short runway, and 

there’s a mountain at the end. Guatemala has a short, 

slick runway with cliffs on each end. 

As far as I know, Mexico City is the only place 

left in Mexico that requires a check airman on the 

first flight. There are pilots that will not bid Mexico 

City. It’s like going out to New York or La Guardia; 

it demands your full attention. There is very little 

room for error, there are many ways to mess up, 

and it’s just that you have to be careful. The airport 

elevation is over 7,300 feet. When intercepting the 

ILS we may get or are warned that we may get sidestepped to the other runway; there are high-speed 

turns; we’re almost at the tire limit speed for takeoff 

and landing. 

22 The modules are “computer based training” that teach pilots local differences 

and procedures about a particular city before ever leaving the U.S.
11 

Differences Between the U.S. and ICAO/

International Terminology/Phraseology

Different theaters use different words for the same 

thing, or at least their pronunciation is different. 

The difference is between our terms and the rest 

of the world. 

The United States does not subscribe to ICAO 

terminologies, internally here. For instance, I hear 

foreign pilots having problems coming to NewYork, 

all the time. They’re used to ICAO, and they don’t 

get that here; they get Common English. 

Sometimes verbiage controllers’ use like, you’re not 

cleared for takeoff or you’re not cleared for landing

is strange. That type of thing can be misinterpreted 

very easily. I realize that they’re translating from 

their language to English; but they’re thinking in 

their language, and if we step up the bar a little bit 

here, I think it’s going to make it a lot safer. Then I 

think we’re definitely on the right track. 

In the U.S., you never hear not cleared for takeoff or not cleared for landing, which could easily 

be confused with cleared for takeoff, or cleared 

to land. In the States, if ATC wants us to get on a 

runway and get ready to go, its position and hold; 

whereas in Australia and Europe, it’s line up and 

wait. We have to adapt a little bit, but we can usually understand; and I think they have to adapt to 

some of our way of saying things. A cleared direct 

[FIX] may mean cleared direct via flight plan route 

in foreign countries.

I think the bulk of this came from training in the 

U.S., and our ICAO compliance has never been 

very good in the first place. And we're looking at 

it from the perspective of where we came from, 

and thinking they’re nonstandard, but the fact of 

the matter is we were nonstandard all along – both 

pilots and controllers. 

Also, this deal about holding position, well it’s 

always been that way. If we had used ICAO terminology in the first place, we wouldn’t have had years 

of experience knowing what we expect. Cleared 

into position and hold means what we know it to 

mean; but using the same words in a different order 

makes it mean [something] entirely different in ICAO 

standards. So that’s why I say, it’s to their credit that 

they have actually been a lot more standard in areas 

than we have been. And that’s what we’re citing, 

as though they’re messing us up, but it’s really us 

that’s messed up in our comprehension. Oh yeah. 

There’s that “Americanism,” if you want to call it 

that. We have an U.S. ATC system, which we all 

grew up in, and the minute we went international, 

we adapted, and so forth. 

The word clearance is used quite often. We get 

clearance to push;taxi clearance, maybe an apron, a 

ramp, a company, a ground free; and an ATC clearance with many different interpretations.

It seems to me that few controllers seem to understand what is expected with distress calls. I had an 

emergency condition in one Asian country where 

we had to shut an engine down on the triple;23 and 

their handling of that emergency condition – they 

didn’t quite understand that everything was under 

control. And every time we went to a new controller, 

he wanted to do everything for us; and we’re trying 

to calm him down and he’s getting more excited.

Another example is minimum fuel versus emergency fuel. Our FARs24 provide a very clear definition of emergency fuel. My experience in the Asian 

countries is that they have no concept of emergency 

fuel, minimum fuel and expedited handling because 

we are getting short of fuel. We avoid trying to get 

too descriptive, because they’re not going to be able 

to follow what we’re saying. 

Word Meaning in Different Parts of the World

Presented in Table 5 are some examples pilots gave of 

words and phrases they thought had different meanings 

from country-to-country and from controller-to-controller.

The first three are general statements. We attempted to 

arrange the remaining 11 according to phase of flight. 

Some of these words and phrases were discussed during 

the small focus group meetings.

27. There are problems related to the same word(s) used 

to describe different actions. Just to get you thinking, 

consider the difference between “hold point” used in 

the air versus “hold point” used on the ground or “taxi 

into position and hold” versus “line up and wait.” Can 

you think of any other examples? Please list a few.

Of the 48 pilots, 62% cited examples of problems 

related to the same word(s) used to describe different 

actions, and different word(s) used to describe the same 

action. As shown in Table 6, their examples reside within 

four different themes: Communication Problems, Same 

Words Used to Describe Different Actions and Different 

Words Used to Describe Same Actions, The Development of an ATC System, and Words/Phrases That May 

Cause Problems.

Communication Problems

Accent

The accents in Asia and the U.K. can be difficult 

to get. The accents in Scotland and Ireland, coupled 

with the worst radios in the aviation world, lead to 

misunderstandings.

Omission of Descriptive Word(s) to Identify Action

How many times have I been instructed to do 

something, and the controller does not say what 

he is referring to, like “maintain two five zero.” Is 

that a speed, altitude, or heading? Last week, going 

down to the Caribbean, we were told to “maintain 

two five zero;” and we were at 33,000 feet, and 

we didn’t know if that was knots or flight level. 

23 The Boeing 777 aircraft is referred to as the “triple.” 24 Federal Aviation Regulations.
12 

Table 5. ATP Examples of Word and Phrase Disparities. 

General Statements 

Altitude assignment on a SID/STAR that requires you to make the restrictions stated on the SID/STAR.a 

Maintain radar heading is used in some countries.

Phonetic spelling of fixes, words, and call signs before pronouncing the word is sometimes confusing. 

Word and Phrase Disparities Presented by Phase of Flight

Line up and wait in foreign countries and position hold in the U.S. 

You’re not cleared for takeoff; you’re not cleared for landing. In the U.S., you will never hear these phrases 

because they are easily confused with cleared for takeoff or cleared to land. 

Cleared high speed while below altitude requiring 250k.b 

Word and Phrase Disparities Presented by Phase of Flight (continued)

Direct route clearances mean direct to fix via flight plan route in foreign countries and direct to fix in the U.S. 

Cleared via versus cleared by (procedure) is not a real problem. But when you’re cleared via a procedure 

versus cleared by the procedure itself, what is the difference?c 

Flight versus flight level, when assigned an altitude. 

Cleared to climb level one two zero versus flight level. 

We say, transition level; they say, level of transition. 

Pilot’s discretion descent has a different meaning in foreign countries. 

Speed, heading, altitude, etc., without the word describing which is referred to, i.e., maintain 250. 

Overshootd is a term they used in Canada, England, and some other European countries. It means that you 

turn, that you stay on the localizer or something; it really means that they’re getting ready to send you 

around. a If you have a published crossing altitude, you are required to make that altitude as shown on the SID/STAR. 

b This could occur during departure or arrival, but outside of the United States, such as in Canada. The U.S. has a 

mandatory limit of 250 KIAS below 10,000 ft. c Usually the pilot would be cleared to the destination airport via a point depicted on, for example a STAR, and 

then the routing and altitudes depicted on that procedure. d The respondents did not clarify their understanding of the meaning of the word.

Table 6. Themes and Examples of Problems Related to the Same Word Describing Different Actions. 

Communication Problems 

Accent 

Omission of Descriptive Word(s) to Identify Action

Pronunciation 

Same Words Used to Describe Different Actions and Different Words Used 

to Describe Same Actions 

Altitude Assignment 

Altitude Restriction 

Bearing Versus Radial 

Cleared Approach 

Cleared to Push 

Direct Route Clearance 

Overshoot 

Pilot’s Discretion 

The Development of an ATC System 

Each Country/Controller Differs 

Pilot Training 

Words/Phrases That May Cause Problems 

ATC Waits for Pilot Request 

Cleared to Offset vs. Deviate 

Follow Versus Follow Behind 

Holding Instructions 

Landing Instructions 

Line Up and Take Off

Line Up and Wait After Aircraft of the Moment 

Line Up and Wait Versus Position Hold 

Parking Bay 

Unclear Taxi Instructions 

Visual Approach Versus ILS Approach 

a Anchor words attach meaning to the numbers present in speech acts. For example, “degrees” is associated with 

heading, “knots” with speed, and “descend”/”climb” with altitude.

b The pilot is responsible for spacing. 
13 

We were pretty sure it wasn’t a heading because it 

wasn’t anywhere near to an appropriate heading. 

I think the controller is not speaking in his native 

tongue; and it just didn’t come out complete when 

he utilized English. So, of course, we just asked to 

repeat; but that’s what frequently happens – we end 

up asking for repeat clearances a lot.

Pronunciation

Flying over South America, we check in, and the 

controller might utter a few things, and it sounds 

like “maintain three nine zero,” except he leaves 

out maintain. “I didn’t know you were at three 

nine zero, I didn’t tell you to maintain.” So, it’s the 

experience of knowing when I check on, this guy’s 

probably going to say this, that, and the other thing. 

[Kan trá ver se (Kán trav er se)] If it’s a word that 

kind of rhymes with an English word, that’s where the 

problem is. If I missed a word or two, I’ll say to the 

guy next to me, “Did you catch that?” Even though 

he doesn’t speak [the local language of the controller], he’s been there enough that he goes, “Oh yeah, 

what he said was, we’re going to transition over to 

Upper Bravo 3-19.” The controller sounded like he 

said, “pour me a martini” or, I don’t know what. It’s 

the rhyming type things that aggravate me at times. 

I hear something that may rhyme with a fix down 

route; and he’s saying something that has no relevance to that at all, because his accent’s so severe. 

It’s not a wording thing; it goes back to the written 

thing. It doesn’t seem like many of these places 

diverge from the actual written procedure; it’s, did 

we get the right procedure in the first place? If I’m 

flying with a guy that’s doing this all the time, he 

could help by saying that they’re going to give us 

the, AVASU 3, with a deep, deep accent. If I’m 

listening for that, “Oh yeah, okay,” now it’s written 

down, everything’s just fine.

And we’re cleared for takeoff – No, we’re not. 

We have to dig through the 42 pages of charts and 

gouges, 25 and, it’s either the rhyming or the sounds 

are alike. If we’re geared to listen for what we think 

were going to get, suddenly that guy’s speaking pretty 

clear to us. If I go in there just completely blind, fat, 

dumb, and happy, he may be speaking English but 

his accent may be so severe to me that things that 

are pretty commonplace, just aren’t coming through. 

And I’m thinking, “Now what did that sound like?” 

I encountered some real problems that could have 

become operational problems. We have to ask him 

again. I talk about it with my flight crew and say, 

“Better check on that.” Okay, real common in the 

cockpit, “Did you get that?” We’ll hear a transmission before saying “Roger,” or ask to confirm it. Then 

say, “[Airline name] one two three is cleared to xyz 

flight level abc.”

If they phonetically spell a three-letter fix, I get it 

real quick. If there’s a particular departure, or ar25 A “gouge” is a collection of personal notes of a pilot that provides information about previous flights that serve as memory joggers.

rival, that is a native language word, like “BUCOS” 

becomes “BULOS” – real simple – and if I hear about 

the “BUCOS Two Alpha,” then I look in my charts 

and there’s only a “BULOS One Charlie,” and here’s 

a “BUCOS Two Alpha,” that can help differentiate 

[between what he said and what was heard]. 

When we get what I perceive to be rapid fire Brits 

who have such staccato to their voices at times, it’s 

“What did he say?” Was it “South Hampton” or 

“South Park?” And the Scots, I get transfixed by their 

language. If I listen to what they say, and have an 

idea of what they’re expected to say, it’s very easy. 

But numbers and letters, and alphanumeric designation [that appear] at the end of a native language 

fix name, make it much easier to understand what 

they’re trying to say.

Same Words Used to Describe Different Actions and 

Different Words Used to Describe Same Actions

During the discussions, pilots spent differing amounts 

of time talking about their flight experiences related to 

Altitude Assignment, Altitude Restriction, Bearing vs. 

Radial, Cleared Approach, Cleared to Push, Direct Route 

Clearance, Overshoot, and Pilot’s Discretion.

Altitude Assignment

A phrase that comes to mind is descend to, rather 

than descend and maintain. Just the difference in 

phraseology can really catch us off guard, if we’re 

not used to it.

Altitude Restriction

Altitude restrictions are different while on a procedure of being cleared both lateral and vertical, or just 

the lateral – so that’s the biggest one while airborne. 

Clearances out of MEX26 will give a high altitude, 

i.e., 350, as our original clearance. The actual hold 

down is much lower – we are expected to know 

this. I’m on a SID and the controller will say, “Climb 

and maintain flight level three five zero;” he doesn’t 

mention any restrictions, but I am expected to meet 

them. I don’t think there’s a big problem in Europe 

or Japan. I think it is just as they expect – the three 

dimensions – not just the two dimensions.

Bearing Versus Radial

Sometime ago, I ran into a controller who uses 

bearing when radial is meant. That happened a long 

time ago, when the radio range and ADF27 were used 

for navigation. We’re talking about VOR28 where we 

fly radials. The bearing and VOR don’t go together. 

Bearing and ADF are together. I haven’t heard it 

recently, but it was another example of a word that 

has two different meanings – what they said versus 

what they meant.

26 3-Letter Identifier for Mexico City Airport. 27 Automatic Direction Finder. 28 VOR stands for very high frequency omnidirectional radio range.
14 

Cleared Approach

France is the only country where I have run into 

this – cleared to intercept loc. It means, cleared 

for approach. It is kind of like no clearance; just 

proceed on.

Cleared to Push

In many places clearance to push means you’re 

cleared to push and start engines. In other places, 

clearance to push is separate from clearance to start.

Direct Route Clearance

An example of a phrase or a word having two 

different meanings that I have run into is cleared 

direct. In Europe and Central and South America, 

it can mean direct to fix via flight plan route. In the 

U.S., it means direct track from present position to 

fix, and direct from one point to another.

Figure 2 depicts a flight plan route (Points A, B, C, D, 

and E) and a direct route (Point A, Point E). The solid 

line represents what an international controller may expect 

with a similar cleared direct clearance. This can lead to 

U.S. pilot uncertainty. The dotted line indicates the route 

that both the U.S. pilot and U.S. controller expect to be 

flown, when cleared “Point A direct Point E,” eliminating 

the route over Points B, C, and D.

Overshoot

The term, overshoot is used in the U.K., Canada, and 

other places. They may direct us to overshoot versus go 

around. It means the same thing; it’s a classic. I think that 

when you hear it the first time, it’s going to be confusing. 

You’ve heard the one about the L101129 pilot? It’s 

an old war story. Supposedly, the L1011 was going 

into Gatwick and was told to overshoot because 

there was a guy on position and hold, or line up 

and wait there. He said, “Yeah it’s no problem; I’ll 

overshoot that guy and land just past him.” I don’t 

know if it’s true or not. Most countries use go around

or cleared missed approach in this situation.

Pilot’s Discretion

I hear plot’s discretion, and it means we can do 

things at our discretion. Or I hear, descend when 

ready. They mean the same, but are termed differently.

The Development of an ATC System

There were two underlying issues that surfaced. One 

issue involves the differences between how countries 

provide their air traffic control services and the other 

talks to training.

29 Lockheed aircraft.

Each Country/Controller Differs

Where the controller learned English ATC telephony is a big thing. In Panama, it’s as though we 

never left the United States. But in Colombia, it’s a 

whole new world, same in Bogota, everywhere else 

in South America. It’s just different.

When I fly to London, I know what I’m [probably] 

going to hear from the tower. I know anywhere 

else that I fly internationally I’m going to be told to 

“continue” by the tower before I can land. I’ve got 

to remember to get the landing clearance.

The hold point concept for taxiing is used more 

widely in Europe than in the U.S. I hear it in some 

places in Asia – like Hong Kong, where the controllers are British-trained.

The speed limit point is used in some places in 

Europe. It’s another restriction not really used in the 

U.S. In the U.S., they will spell it out on a chart, 

“250 knots and 10,000 feet at this point.” In the 

U.K. chart, they’ll just have this little, shaded box, 

and we have got to go somewhere else in the chart 

to find out what that means. If we fly past that point 

at a high speed, we’ve violated our clearance. It’s a 

bit of a problem, simply because they use it in other 

countries, and they don’t use that concept here. I 

think it’s probably more generic to the U.K. There 

are just some things on their charts that are less 

clear to us than they could be. I actually think, in 

this issue, they ought to be doing it the way we do 

it in the United States; just put it on the chart next 

to the box – how fast you want me to be going, and 

what altitude you want. If it’s important, put it all in 

there. I’ve been up all night.

We need to talk about hold points on the ground, 

hold points in the air, taxi into position and hold. I 

wish everybody would use the same standard ICAO 

terminology. It would make things easier. Hold points 

in the air don’t usually create a problem – unless 

Figure 2. Incongruent Expectations Involving 

a Cleared Direct Clearance. 

Point A

Point C

Point D

Point E

Point B

Flight plan route 

Direct route ------------- 
15 

the instructions are nonstandard, like hold different 

from how you get to the fix: Northeast and it’s not 

published on the charts. Sometimes, we don’t know 

if we’re supposed to hold or not; we’re just cleared 

to a fix and nothing else.

We have all had this happen in France, “cleared to 

intercept loc” with no approach clearance. In France 

cleared to intercept the loc, is cleared for approach.

Pilot Training

Most of the examples in question 27, and the ones 

we have talked about, are illustrated in our Part 2, 

which is part of the FARs we carry in the airplane. If 

you study it and go to an international ground school, 

you should pick up on most of this. There’s always 

something that is not quite in the same context, 

order, the radio is scratchy, their English language 

skills seem to be butchered, or their accent is so 

strong. But as far as the different phraseology, most 

of it is spelled out, if we look for it ahead of time.

At our airline, I know in the training that I’ve received, some of the more common terms like overshoot and line up and wait, are briefed extensively. 

When you first go there, it’s not the first time you’ve 

heard these kinds of expressions.

Domestic guys are sent to Mexico City without 

international ground school. They may not be diligent enough to look in Part 2 and some of the other 

places to find the nuances of international flying, 

which are illustrated in international ground school. 

I am a domestic captain, but domestic as far as that’s 

concerned includes Canada and at least most of 

Mexico. It doesn’t include going across the Gulf to 

Cancun or something like that; but I’m still hitting 

Monterrey, Mexico City, Puerto Vallarta, Acapulco, 

and all of those places down there that’s considered 

domestic flying. There are a lot of nuances that I 

really have to look at, and be familiar with, and 

experience raises my comfort level.

Words/Phrases That May Cause Problems

In this part of the interviews, the pilots discuss the 

words/phases that may lead to incorrect actions. 

ATC Waits for Pilot Request

In one country in South America, on the descent, 

we check in and the controller may say, “You tell 

me when you want to start down, okay?” Basically, 

that’s what they’ll say. Go to other places and they 

won’t say anything; they’ll fly you overhead three 

five oh. In the States, controllers would never say, 

“Let me know when you want to start down.” They 

say, “Descend pilot’s discretion” or “Cross humpty 

at flight level so and so.” Sometimes the South 

American way feels better.

Cleared to Offset Versus Deviate

When I ask for a deviation for weather, or something, the controller might say, “Cleared to offset.” 

It was really a clearance to deviate around the 

weather. It is a term that I’m aware of; but I’d like to 

hear what I’m used to in my comfort zone. If you’re 

not experienced in the area you’re flying, it could 

really mess you up.

Follow Versus Follow Behind

In one city in Europe, when I was given the clearance cleared to follow behind I challenged it. I 

said, “I understand that I am cleared to follow.” 

That would have answered them in the affirmative; 

but it still did not convey the meaning of what he 

meant, and what I mistook the meaning to do – a 

most dangerous situation, I think. 

Tower thinks you understand; you think you 

understand; you proceed according to that understanding; and you’re wrong. I don’t know how you 

would rectify that particular situation. If you have 

a question, and you think you might be wrong, be 

very careful. If you think you’re right, you proceed 

on to the next problem, and file that one away. You 

don’t even think about it anymore.

Holding Instructions

It is probable that the U.S. is more standard in 

issuing holding clearances than other places. We 

all know that going into the London area, if we’re 

going to have to delay at a fix, it won’t sound like 

it does here. In the London area, we’ll be told to 

“take up the hold at Willow.” It’s not “enter this” or 

“enter that.” Another controller may say, “Enter the 

hold.” Well, that makes a little more sense; but the 

first time I heard “take up the hold,” I had to stop 

and think for a second; and then I was distracted.

Nuances are as varied as individuals are. Cleared 

the racetrack is confusing. It’s published on the 

charts – and I don’t have a specific for it – but I 

don’t think you’ll see racetrack listed as an ICAO 

word, but you’ll hear it in Britain occasionally. The 

intent is holding, in a racetrack [pattern] at this so 

and so waypoint. 

There are places in Central and South America 

that are not using standard ICAO terminology in 

holding. In some cities, there’s a fix on part of the 

approach, close to the initial approach, or at the 

initial approach point, and the controller will say, 

“Report that point outbound.” It’s along your route 

of flight, down into the approach and landing. What 

they really mean is, “Report that fix outbound and 

enter holding.” If no one ever told me that, I could 

look at that and say, “I’ll report it outbound as I 

continue on the approach.” What it really means is 

you’re going into holding. That’s my clue to query 

and say, “Okay understand we’re going to hold at 

this point.” And they say, “Yes, OK,” and so that’s it.

Holding on the ground is different. I will hear 

hold point different ways – in a Runway 35 hold 

position, hold line, position hold, hold short, line 

up and wait – they all are understandable, if heard 
16 

at the right time. Last week, I was told to “take the 

runway.” Now what the heck does that mean? Hold 

short is not one I particularly like. Which is better 

–taxi into position and hold or line up and wait? It 

would make things easier if everybody would use 

the same standard ICAO terminology.

Landing Instructions

In the U.S., we can be 15 miles out, behind several airplanes, check onto the tower frequency and 

told we’re cleared to land. Not in other countries 

– when I contact the tower, I’m going to be told to 

continue before I can land. I’ve got to remember to 

get the landing clearance. They’ll give it to you, but 

not until all the other airplanes in front of you have 

landed and are clear. 

Line Up and Take Off

At least two times each I have gotten the clearance, 

“line up and takeoff Runway 9,” or “Runway 2.” 

That’s totally bizarre. I know what line up and wait

is, and I know what takeoff is; but I don’t know what 

line up and takeoff is. I’ve always gotten clarification, “What do you want us to do exactly?” That is 

very nasty, and I wrote a report on that. I’ve only 

heard it in two places – in Cancun, Mexico and in 

Sao Paulo, Brazil.

Line Up and Wait After Aircraft of the Moment

My first time to England, I got the clearance, “I 

want you to line up and wait after the aircraft of 

the moment.” What he told me to do was to take 

my position after the guy does a go-around. It’s 

English, but not English I’m used to. I sat there and 

went, “Wow, if this happens in English, then I can 

just imagine what will happen in other countries.”

Line Up and Wait Versus Position and Hold

Line up and wait versus position and hold can be 

confusing. They mean the same thing, but one is 

used in Europe, Central and South America, and 

the other in the U.S.

Visual Versus ILS Approach

Many times in the domestic, we’re used to hearing, “Cleared for the visual approach.” In some 

European countries, we’re waiting for that clearance 

and will have to ask them specifically. Then they’ll 

come back with, “Yes, you are cleared for the ILS 

runway” or whatever. There’s ambiguity in a critical 

environment like that. We want to know that we are 

cleared for the approach.

Parking Bay

Parking bay is a term I only heard in China. When 

we’re cleared to push back and start, they’ll say, 

“Cleared to Parking Bay 15” – it’s a spot. Unless you 

heard that before, you don’t know what it means. 

They say, parking bay, or papa bravo sometimes. 

That’s even worse. Papa bravo means nothing to me. 

In the States, they would say, “Spot 11.”

Unclear Taxi Instructions

When taxi instructions are not in the expected 

sequence, as in “‘Cleared to Runway 22” instead of 

“taxi to Runway 22 via Echo,” I always ask, “What 

taxiway am I to go to?” I like taxi instructions that 

are given in the expected sequence. Of course, we’re 

listening to instructions in their native language. Until 

we ask in English and we’re expecting a certain taxi 

clearance, and then we get a different sequence. 

We have to ask, “What is the taxi limit?” “Can I go 

any route to Runway 22, or take the shortest route, 

or taxiway Echo?” In Canada, you can get, “Taxi to 

runway XX.” The Canadian terminology of your clearance to taxi to a runway for departure does not have 

the same meaning as it does in the United States.

28. Have you experienced problems related to how words 

are pronounced (e.g., accents or dialects)? Please explain.

The respondents’ compiled comments from the written and interview portions of the questionnaire are listed 

alphabetically in Table 7, followed by their abridged 

responses. In addition to the seven identified problems 

related to pronunciation, they also presented radio, 

technology, and unfamiliar words as associated problems. 

Problems Related to How Words Are Pronounced

Accent

The biggest problem I have is rapid-fire talking with 

heavy accents transmitted over weak radios. When 

they’re speaking English, more of my brain cells go 

into concentrating, pulling away from whatever else 

I might be doing in a multitask environment, like 

flying. For me, accents may be difficult in Scotland, 

France, most of South and Central America, New 

Table 7. Problems Pilots Experienced Related to how Words are Pronounced. 

Problems Related to How Words Are Pronounced Associated Problems 

Accent 

Dialect 

Pronunciation – Enunciation 

Pronunciation of Fixes 

Pronouncing Phonetically 

Speech Rate 

Voice Pitch 

Radio 

Technology 

Unfamiliar Words 
17 

Zealand, China, and Japan. Sometimes, in Australia 

and Great Britain, it really depends. On the other 

hand, controllers I’ve dealt with in the Hong Kong 

or Singapore, seem easier to understand.

I understand a lot of the Asian language is so verbal; 

and they place a lot of their emphasis on the sound 

of the word and that can totally change the meaning. 

The Dutch are very good, usually. But, every once 

in a while, their words sound too guttural and the 

accent too heavy for me to understand what was 

said. When I call them up and ask for a repeat, they 

do it very well.

In South America, it’s very common that the transmissions are of poor quality; and that just compounds 

my problem with accents. Many times, we have to 

make clarification calls to get corrected instructions.

We have our own accents in the U.S.; when in the 

Southern part, I wonder if we’re speaking the same 

language. Someone pointed out that female French 

controllers are the most difficult to understand, due 

to their heavy accents. Even in India, some of it is 

very difficult for me.

Dialect

When controllers speak, it’s a different dialect, like 

the Scottish, every word is hard for me to understand. 

In Japan, South America, and France it depends on 

the controller and the dialect usage.

Pronunciation of Fixes

Every country has its own way of pronouncing 

words that may not sound like we say them. They’re 

pronouncing the names of intersections, VORs, and 

procedures as they would in their native language, 

not how we would in English. If we’re cleared to a 

fix and I’m familiar with its pronunciation; it’s no 

problem. But, when it’s different, I get the charts out 

and try to find a name that matches. 

The Russian pronunciation of some fixes can be 

pronounced about seven or eight different ways. 

We’re looking at the fix TEVVA – Is that Teva, TBAY, 

or Tivva? In Japan, we go to Nippi Nupta Nango;

we know all of them in our mind, but occasionally 

I’m surprised. The fixes are different enough that 

we’re not going to confuse Nippi with Nupta; but 

if we hear Nippi and that’s all we have, and it comes 

up on the screen Nippi – we know we’re good.

I find it very hard to understand Latin American 

and Caribbean controllers, unless we fly the routes 

frequently and can name the fix or NAVAIDs30 that 

are Spanish, or in the local language. An example 

is Charlie, Delta, Oscar at Santo Domingo, which is 

pronounced “Cacho;” but looking at the spelling, 

you would never get that. Maybe skip the name and 

just use the phonetics, “Cleared Cacho, Charlie, 

Delta, Oscar” spoken very slowly would be great. 

I think controllers probably get a lot more train30 Navigational Aid.

ing than we do. It comes down to controller and 

pilot training. We know the rule to pronounce the 

five-letter fixes – It’s supposed to be a hard syllable 

and then the soft one. And yet, there is a way we’re 

supposed to hear, hard and soft syllables, and it’s 

confusing. 

For NAVAIDs, phonetics is enough, but for FIR31

boundaries, if they would speak slowly, clearly, and 

give the fix name and then phonetics afterwards. I 

can’t write that fast, and I can’t process the information up here. If we ask for phonetics and then they 

give it to us, it causes extra wordage, extra congestion on the frequency. The solution might be to send 

the data digitally. Read it on your screen and – oh, 

yes, it’s accepted.

Pronunciation – Enunciation

I have to include Russian with Spanish and Chinese 

as languages that I’ve had the most significant amount 

of problems. I also have trouble when Portuguesespeaking controllers add an “E” to words, and when 

Chileans and some Spanish-speaking countries use 

the Spanish rather than English pronunciation of 

words. When we’re looking at our route of flight and 

have two similar sounding fixes, I spell it back to 

make sure we’re going to the right one. It happens 

when we’re about to be transferred, especially from 

one major ARTCC32 to another.

It may be my hearing of what they’re trying to say, 

because I think they’re doing their best to give me 

a good English clearance; but sometimes when I’m 

hearing their accent, I find myself having to ask for 

it to be repeated – sometimes two or three times. I 

hope it doesn’t make the guys frustrated, but I want 

to make sure I go where he’s expecting me to go. 

But there are times, no matter what country, that 

the accent, or the dialect, is so pronounced that 

we can’t understand the controller. I can have that 

same problem in New York, the Northeast Corridor, 

or Chicago.

Another problem is translation. There are many 

English words that do not exist in other languages. 

Sometimes, things may be lost in the translation. I 

don’t have an example, but I’ve seen it many times; 

that’s why we standard [phraseology]. 

Well the “R words” are really tough for some nonSpanish speakers; it seems like Spanish speakers roll 

their R’s. I’m sure that it’s difficult for some Asian 

controllers to learn English. I’ve spoken to some 

whose English is perfect; but for the most part, a 

lot of them still have the problems with words with 

“R” and “L.” And some Asian controllers pronounce 

English words quite differently.

The Japanese pronunciation of numbers such as 

“two” and “three” sound very similar to me. Because of their high-pitched voices, I miss a lot of 

numbers. In any clearance, there’s going to be a lot 

of altitudes and frequencies with these numbers in 

31 Flight Information Region. 32 Air Route Traffic Control Center.
18 

them. We might be cleared to flight level 320, but 

to me it sounds like 330; and sometimes it takes 

a couple of transmissions to get across. Also, they 

insert the “Oh” sound in their speech, making 846 

into “eight-oh-four-six.” 

The French controllers’ pronunciation, when they 

slow down, emphasize “L,” “J,” and “K” for some 

reason. You got me to thinking that it is absolutely 

true, they talk too fast, and like he33 said, you ask 

them to repeat, and they talk at least as fast again. 

Which words are the most difficult to understand? 

Definitely the numbers in frequency changes “two,” 

“three,” “one,” “six,” and “seven.” When we go to 

Europe, there are three digits past the decimal point 

in radio frequencies – and we’re used to just using 

two digits in the States.34 When they say “one two 

three decimal six one five,” I think there’s too many 

numbers and then I remember that six one five is right.

I think the hardest people for me to understand 

are the female Taiwanese controllers; and I think 

they speak Mandarin, or Cantonese. But they have 

sibilant – they make “S’s” and they almost lisp their 

English pronunciation, and it’s very difficult to hear 

over the radio. And I’m always saying to them, “Say 

again, say again.” 

I find that the British-trained controllers tend to have 

very good enunciation, especially when they speak 

slower, and their English tends to be pretty easy to 

understand; but when we hear a Scottish or Welsh 

accent, sometimes it can sound like a completely 

different language. In some ways, I can understand 

what the British controllers are saying better than 

many of the North American controllers – other 

than the terminology being slightly different. For 

the most part, I’ve had very good luck with Indian 

or Pakistani controllers. 

I find it challenging interpreting intersection names 

when there is an accent. Local accents make it almost 

impossible for me to determine the correct name. 

The words in standard ATC are easier to understand. 

When they ask me to do something in nonstandard 

ATC, I have a hard time trying to decode it.

Pronouncing Phonetically

There is a vast difference in controllers’ mastery 

of English. My biggest problem is when a controller tries to use the phonetic alphabet for fixes that I 

don’t know. I have a hard time with how they pronounce some words that aren’t used much or are 

pronounced differently in their language. That has 

led to controller-pilot frustration because of having 

to ask for the name of the fix three times and still not 

quite getting one of the letters in it. If they’re trying to 

get us off our route, and spell a phonetic point that 

we have to find on the map and put into an FMS, 

we don’t want to put in the wrong point because it’ll 

send us some place that we’re not supposed to be. 

33 The pilot who commented earlier in the discussions. 34 In the U.S., standard phraseology is two digits to the right of the decimal; 

other areas use three digits to the right of the decimal.

Using the phonetic alphabet saves me. I use it a 

lot. When I can’t understand what he’s saying, I tell 

him to just spell it, and then I usually get it.

Speech Rate

The speed of conversation can hinder understanding. I have trouble when I fly the Northeast Corridor. 

It seems that they talk so fast and expect everyone 

to know all the nuances to their operations. When 

a controller speaks too fast with an accent, I ask for 

a repeat, congesting the frequency. 

In some instances, the controller is extremely busy. 

If the weather’s bad, they tend to talk much faster; 

and sometimes confirming the clearance can be 

difficult because of other transmissions. So, it’s not 

just that they talk fast, the conversation is very fast. 

Clearances are read very quickly, and they don’t 

wait for an answer.

Voice Pitch

I don’t want this to be interpreted as a sexist remark, 

but women’s voices in general, don’t transfer easily 

over the radio. Poor equipment and background 

noise add to the shrillness, which masks what they’re 

saying. The pitch on some female controllers, when 

they start with my call sign, at that point where I’m 

concentrating on the shrillness of it, I’m missing the 

words. It divides my attention and makes it harder 

for me to understand.

Radio

Almost anywhere in South America, the distances 

are so vast that the radios don’t seem to have coverage. I’ve found that accents are worse if the radios 

are weak. Sometimes it’s really disconcerting. The 

natural reaction is to turn up the volume; then another airplane transmits, “WOOO OH” and blows 

us out of the cockpit because they transmit OK. It’s 

very annoying and compounds everything. 

In many places of the world, it sounds as though 

the equipment is World War II vintage. It sounds 

like a tin can at the end of a string. In one Western 

European city, talking with approach control is 

terrible. I think they are working from 60-year-old 

transmitters because there is a shrill in the background that masks what they’re saying.

There is hollowness in the sounds of many of the 

controllers in one country in Eastern Europe. It 

sounds like their equipment is poor – maybe they 

were never taught how to speak into a microphone. 

When I hear the echo background, they’re using a 

carbon [microphone]. Oftentimes, it sounds as if 

the controller is not using a headset, even though 

they are available, especially in some countries in 

South America.

A cockpit procedure I like is to require pilots to wear 

the full headset below 18,000 feet. Communication 
19 

and understanding is clarified, whether between 

crewmembers, on the cockpit voice recorder, or 

somebody on the ground.

Technology

The technology that is coming and how we operate in some of the areas of operation, obviously the 

CPDLC35 and ADS36 environment is entirely different 

when flying in Latin America, where you’re speaking, 

making position reports, and talking to controllers 

on a limited basis. I’m hoping that is where the 

technology is leading us in the future.

Unfamiliar Words

Some of the words used are kind of a miscommunication, for lack of a better term. One word they 

use is pre-direct. In the U.S., we get cleared from 

Point A to Point B as a direct routing. Over there, 

we can be direct to here, now they want us to go 

down to a route fix, and they’ll say, “Pre-direct to 

xyz.”’ Exactly what is pre-direct? What we want to 

know is, “Are we cleared direct?” 

28a. Which words are more difficult for you to understand?

The words provided by the respondents’ written portion 

of question 28a are presented in Table 8. Their compiled 

comments involved issues related to fixes, numbers, and 

procedures.

Fixes, Procedures, and Numbers

Fixes and procedures that have very similar spellings or pronunciations are problems for me. English 

spoken with a heavy local accent sometimes gets a 

puzzled look from pilots. Look at ACINA and EXANI. 

Another one – and they’re about six centimeters 

apart – SIGMA is the boundary between America 

and Mexico, and SEGMA is out towards Panama. 

They’re both given as part of direct clearances. Am 

I going to SIGMA or SEGMA? On readback, I must 

spell it to be clear. I can’t even recall how they pronounce “X” down there. Keep in mind that it really 

depends on what word is being pronounced, and 

by which controller – a Swedish controller trying 

to say “R” or a Mexican saying “J.”

There are so many fix names – they’re all limited to 

five characters – and if we were in an airspace system 

that had such long distances between NAVAIDs here 

in the U.S., we might have more of that issue. We 

understand the context in which those five letters 

were stuck together and that it’s supposed to be 

pronounceable (e.g., LUVLY, PANZE). But down 

there, maybe the five letters they put together don’t 

make sense to us but may say something to them 

(e.g., DONIS, MANEM). 

Coming out of Scotland, crossing PIKIL I learned 

to say, “Pike Hill;”37 they call it “Pickle.” Whether 

35 Controller Pilot Datalink Communication. 36 Automatic Dependent Surveillance. 37 That is what PIKIL sounds like to the pilot.

colloquial or local pronunciation, not the phonetic, 

it’s not by the letters – like “Pike Hill” versus “Pickle.” 

It’s what they call it; once you get used to it, it’s fine. 

Numbers, especially in frequencies, flight levels, 

and call signs, are a big problem for me in Japanese airspace; they’ll say a frequency, and I’ll read 

back what I thought was the frequency; I’m off by 

a couple of numbers. Then there are the numbers 

“one,” “two,” and “six.” It seems to me that a “six” 

in Spanish doesn’t roll off the tongue, or maybe 

I’m not hearing it very well. It seems like Spanish 

numbers are spoken too fast. 

The proper names of the facilities within a country, 

waypoints, and intersections are the ones that are 

the most difficult for me. What is its relationship to 

the 2,000-character Chinese language? They came 

up with a sound, and somebody at Jeppesen had 

to come up with the way it is spelled in an English 

language. What does tiajqm sound like together? 

I don’t know. When one camera manufacturer was 

coming up with a name, they selected “Kodak” because it’s pronounced the same in every language.

Ground controllers and clearance delivery, oddly 

enough, seem to have the worst English language 

skills. Tower controllers are better, and approach is 

even better; then, as we get farther away from the 

airport, it starts to get worse. The approach controllers are the “hot” English speakers.

28b.Do you perceive a difference in clarity of information 

provided when a native English speaker uses “Indian 

English” versus “Hong Kong English” versus “British 

English” versus “North American English?”

Some written responses included a specifically stated 

“yes” or “no,” while others were implied. The responses 

were incorporated and appear in Table 9 according to (1) 

Perceived Difference; (2) Variety of English Language; 

and (3) Response Type (Positive, Negative, Comments). 

One respondent did not provide any information, since 

he was not familiar with the other English dialects. 

Cannot Answer

With the whole native/non-native English speaker, 

I am not sure how to approach that. If a non-native 

Korean pilot comes on the radio talking with a Hong 

Kong approach controller, I couldn’t tell you that he 

was Korean. I could probably tell you he was Oriental, but I wouldn’t be able to tell you from where. 

Other non-native speakers – a French person, sure, 

I think I could tell that a French person was trying 

to speak English to a Hong Kong controller. But in 

the Oriental [languages], I wouldn’t be able to tell 

you if the person was Korean, Japanese, or Chinese. 

It all boils down to the individual controller’s proficiency in English. It’s all about training – how far 

are they going to let him go before they put him on 

the mic?
20 

Table 8. List of Words and Issues That Impede Pilot Understanding. 

Accents, Speech Rate 

Not pinpointing actual words but a heavy local accent may be challenging at times 

Short words can easily become abbreviated and sound completely different especially when spoken fast 

Nearly any word in “Pidgin English” of the Eastern Caribbean 

French 

Not words but languages/Controller – French 

French women controllers sending us to off route waypoints 

Local fix pronounced in French versus my “American” 

Spanish 

Spanish-based fixes, NAVAIDs, and some words, unless one knows Spanish 

Spanish numbers 

Clearances/Procedures

Clearances that you are not expecting 

Clearances to fixes

Procedures (STARS/SIDS) 

Speed changes/restrictions/altitude restrictions; i.e., crossings, waypoint names 

Direct (in Japan) 

Fix Names, Waypoints, Intersections, NAVAIDs, STARs/SIDs

Fix names 

The proper names of navigational facilities or intersection names on charts 

Many waypoints and intersections are difficult to understand if you haven’t had a chance to see them first 

Unfamiliar NAVAIDs 

When VORs are referenced using full names versus 3-letter identifiers 

Letters 

“R,” “L,” “J” and “W” words 

Numbers 

Numbers in frequencies, flight levels, call signs 

The numbers two, three, five, six, eight seem to be difficult 

Most foreign countries do not use niner for nine 

Unexpected words, clearances, etc 

Clearances that you are not expecting 

Unexpected words, clearances, charted points 

Unusual or unfamiliar words 

Words (i.e., names) that are native to the particular country 
21 

Table 9. U.S. Pilots’ Perceptions in Information Clarity as Spoken by Native English-Speaking Controllers. 

There is a Difference Among Native Speakers of English 

Indian English 

Positive 

– Indian is probably the clearest. 

Negative 

– Indian English would be the most difficult. The others do not present a problem. 

– Indian controllers are impossible to understand. 

– Indian English is the hardest to understand. 

Hong Kong English 

Positive 

– Hong Kong English is the easiest. 

 British English 

Positive 

– I find English spoken by English natives (U.S., U.K.) very easy to understand. 

– British and North American English are the easiest to comprehend. 

– British-trained controllers are very easy because the words are clearly separated. 

Negative 

– British English is the hardest to understand. 

North American English 

Positive 

– British and North American English are the easiest to comprehend. 

Negative 

– Indian, Hong Kong, or British English when spoken at a normal rate seem to be more precise and 

understandable than some North American English. 

– Some domestic, New England controllers are tough. 

– When I fly the NE corridor, they talk fast and expect us to know all their nuances to their operations. 

Non-specific 

– (1) North American (2) British (3) Hong Kong. 

– I've never heard Hong Kong English but remember there were differences in the other three. 

Cited No Specific Variations of the English Language 

Negative 

– Accents other than U.S. and U.K can be very difficult. 

– Heavy accents can slow down the conversation. 

– To unfamiliar pilots there is sometimes a puzzled look of “What did they just say?” 

Cited Other Than Specified Option 

Negative 

– Certainly, heavy accent and English (e.g., Scottish version of English) can be hard to understand. 

– Japanese is hard to understand. 

– Scottish controllers are impossible to understand. 

There is no Difference Among Native Speakers of English

Positive 

– Results are generally quite good. 

– Not to the “tuned ear.” 

Conditional (Non-specific) 

– Somewhat; To a degree; A minor one; Very little; Very little if any; Not specifically; Not a problem. 

– Not normally, however, some native English speakers have a wider vocabulary. I was recently told, “Go 

around Airbus ensconced on Pad B.” 
22 

Don’t Perceive a Difference

I haven’t had significant experience to say that it’s 

been a problem. When I’m hearing people who 

have grown up with English, British, Australian, and 

the U.S., even with their accents, I’m more able to 

pick up what they’re trying to say than Spanish and 

French; but it has gotten better. Sometimes their 

pronunciation and my hearing can cause difficulties.

Perceive a Difference

There’s quite a bit of difference between Indian 

English or Hong Kong English, British English, and 

North American English. There are different terminologies, accents, and speeds [speech rates]. It’s 

funny because the British have so much of an influence, both in Hong Kong and India. But because of 

the native speakers there, the way they pronounce 

English is quite noticeable. The differences are 

subtle, and native words do creep in, but I can tell 

they were brought up with British English. 

If it’s an English speaker in any of those countries, 

I pretty much can “tune my ear” to anything that 

the British taught – whether it’s Indian, Hong Kong, 

or what have you. It’s when we get the non-native 

English speakers who put accents on words that 

we don’t expect; but it just doesn’t flow to the ear 

from what I’ve heard, because the syntax may not 

be correct to my ear or where they emphasized.

U.S. English Versus British English

There is a difference in clarity in British English; I 

can’t put my finger on exactly what it is, other than 

they speak pure English and we speak American. 

They may have a more exacting form of English. We 

have a lot of slang. I’m used to Northeast English, 

which is basically very fast, as opposed to a little 

slower, but clipped English in the British Isles. And 

each group has a slight accent. The British English 

speakers are more standard, and usually very easy 

to understand.

Indian English Versus Hong Kong English

You know you’re on the same page with a native 

English speaker, and there’s rarely a need to have 

them “say again;” and invariably you will, if they’re 

non-native. When speaking English, an Indian 

speaker is a little singsong, while the Hong Kong, 

with the Chinese inflections over it, is very precise.

North America

My trouble is in the North American regional dialects, similar to the New York area. Or occasionally 

I’ll get somebody in Georgia, and that’s a little harder 

for me to interpret. Yeah, let’s talk about Northeast 

English versus Southeast English. 

The controllers in the Northeast think nothing of 

seeing how fast they can possibly talk to us, and 

give so much information at the same time that we 

can’t possibly write it all down and understand. In 

the South, they wait until we say, “Go ahead, I’m 

writing some more information down here.” 

A Follow-on Question

Interviewer: If there was one universal English language 

that could be broadcast synthetically or otherwise, which 

one would you want it to be?

I think Australia is better at proper phraseology, or 

Hong Kong. They are also very good with proper 

phraseology. There are an awful lot of Australian 

controllers working in Hong Kong and they are really on top of that over there.

28c. Do you perceive a difference in clarity of information provided when a non-native English-speaker uses 

“Indian English” versus “Hong Kong English” versus 

“British English” versus “North American English?”

For this question, pilots were to consider that controllers might not have English as their primary language. 

The controllers may have learned English in school or 

privately. The pilots may hear non-native English-speaking 

controllers provide ATC services in the English taught by 

native speakers from English-speaking countries. Because 

some of the pilots’ remarks directly related to Question 

28b, they were moved into that section of the report. 

The responses were incorporated and appear in Table 

10 according to (1) Perceived Difference (Yes or No); (2) 

Variety of English Language; and (3) Response Type (Positive, Negative, Comments). There were two respondents 

who did not provide any information. They reported that 

they were not familiar with the other varieties of English 

spoken by non-native English speakers. The respondents’ 

compiled comments from the written and interview portions of the questionnaire follow. 

Perceived Differences

The Differences Vary From Subtle to Pronounced

The difference is subtle, most of the time; at others, 

it is pronounced. There is always a problem listening 

to a non-native speaker use different English dialects; 

maybe it’s my familiarity with the language. Going 

into Great Britain versus Delhi, India, or Hong Kong, 

China, it’s just the nuances of what they say, what 

they do, and different words. 

The Influence of American Television on English 

Spoken in Non-English Airspace

It’s funny when a non-English speaking person tries 

to use the American slang heard on TV. (American 

programs are shown around the world). They may 

not understand the context in which it was said 

but will repeat it, and we wonder how they come 

up with that.
23 

Table 10. U.S. Pilots’ Perceptions in Information Clarity as Spoken by Non-Native English-Speaking 

Controllers Using Different Varieties of the English Language. 

There is a Difference Among Non-native English Speakers 

Indian English 

Non-specific 

– I’ve never heard Hong Kong English but remember there were differences in the other three. 

Hong Kong English 

Positive 

– I prefer Hong Kong English, then North American, British and Indian. 

British English 

Negative 

– British English harder to understand vs. North American English. 

– The Brits are the worst. 

North American English 

(See comments under Hong Kong English and British English.) 

Not Definitive (Cited No Specific Option) 

Positive 

– Most definitely; Very much so; Yes; Yes, but not as much difference. 

Negative 

– More difficult to understand, repeats necessary. 

Conditional (non-specific) 

– Sometimes. 

– Maybe a slight accent, but these “English” speakers are very standard and usually easy to understand. 

– The non-native accent, inflection and emphasis can outweigh the normal precision and make 

understanding difficult. 

– Rule for normal conversation, or lack of rule-slang, can impact radio traffic. 

There is a Difference Among Non-native English Speakers 

Cited Other Than Specified Option 

Negative 

– Almost same as Q28b. A non-native with yet another accent can distract from understanding clearly. 

[Certainly, heavy accent and English (i.e., Scottish version of English) can be hard to understand.] 

– Chinese’s and Russian Controllers do not speak confidently and seem to slur words together. 

– Japanese voices pitched high and grate. 

There is no Difference Among Non-native English Speakers 

Indian English 

– Unknown term, “Indian English.”

Hong Kong English 

– No issue Hong Kong.

Not Definitive (Cited No Specific Option) 

– Again, quite satisfactory; Not really; No; None. 

Conditional (non-specific) 

– Not normally, except due to slight vocabulary differences. 
24 

English Spoken by Controllers in Mexico and France

I have heard some British accents once or twice 

in Mexico that surprised me. For me, the French are 

the absolute worst to understand because of the way 

they draw out words and run syllables together. If 

we say, “Say that again,” in a slower cadence and 

lower tone, they’ll come back to us that way. But, if 

there are more than about four or five guys trying to 

get direct from one place to another, they’re using 

rapid-fire French; and then switch over to English, 

but it “Ain’t no kind of American English I know.”

English Spoken by Controllers in China 

I’ve noticed that Chinese controllers have a problem enunciating certain numbers correctly. A large 

percentage of clearances have numbers – frequencies, altitudes, headings, airspace, and things like 

that. Add to that a nasal tone when they speak, 

their volume tends to be rather forced, and it’s 

almost like a staccato sort of a pitch. When they’re 

issuing a frequency, it can be very difficult for me 

to understand. 

Limited Experience

I have flown a bit in New Zealand and Australia, 

but I’ve only been to Hong Kong once. Think about 

Northern Canada, where you have the Frenchspeaking controllers using English. It’s not so much 

of a problem for me if they use standard terms.

India, for instance – If you’re going off the page, 

and you want to start talking to someone, it’s going to go over a lot of non-native English speakers’ 

heads. If you’re sticking to a normal clearance and 

ICAO stuff, I think they tend to stick to it a little bit 

better because it’s what they know.

29. To what extent have you found nonstandard terminology confusing? 

The data in Table 11 show only one pilot found 

nonstandard terminology to be a non-issue, while at 

least 62.5% reported to it to be confusing to a limited 

extent. The remaining pilots indicated nonstandard terminology was confusing, at least to a moderate (12.5%), 

considerable (19%), or great extent (4%). Their compiled 

comments are presented below according to the extent 

they found it confusing.

To a Great Extent I Found Nonstandard Terminology Confusing Explanation

Both of the pilots who selected this response on the 

written questionnaire provided comments during the 

oral interviews.

Line Up and Wait

During my first flight into Latin America, the use of 

nonstandard phraseology was extremely confusing. 

The first time I heard a line up and wait clearance or 

you’re cleared to three two zero and after departure 

maintain 2,000 feet, was hugely confusing to me. 

Now that I’ve operated in these areas for a number 

of years, it’s not so much of a problem anymore, 

but it could be a big problem for someone on their 

first flight there.

Table 11. Extent Pilots Found Nonstandard Terminology Confusing. 

Extent Nonstandard 

Terminology is Confusing 

Number 

of Pilots Issues Discussed 

To a great extent 2 

Line up and Wait 

Partial Call Sign 

Use of Roger 

To a considerable extent 9 

Initial Contact 

Japanese Accent and Pronunciation 

Line Up and Wait and Stand By 

Nonstandard Altitude Restriction 

Pilot Expectation 

TCAS 

U.S. Lack of ICAO Standardization 

To a moderate extent 6 

(Amended) Full Route Clearance 

Different Taxi and Approach Clearances 

Terms With Multiple or Different Meanings 

To a limited extent 30 

Did Not Fully Understand Question 

Different Terminology for Emergency, Weather, Delays, etc 

Each Airport/Country has Different Procedures for Issuing PreDeparture Clearances (PDC) 

Must Get Around Pronunciation 

Terminology Is Not Standard to Any Country 

Not at all 1 It is Not an Issue 
25 

Partial Call Sign

Leaving off a call sign or just reading back a number causes me to stop and think, “Who is he talking 

about?” If I knew, I might be able to track where this 

guy was. During the most intense part of the flight 

[the approach phase], is where I try to figure out 

where we are in the sequence. If I’ve been on the 

radio hearing all the call signs answering clearances, 

I can build a mental map of where everyone is. If a 

pilot comes on and uses only a number [or partial 

call sign], I lose my situational awareness. This use 

of numbers only in call signs is true even in the U.S.

Use of Roger

The acknowledgment of a clearance by “Roger” 

isn’t used much. I hear controllers say, “I need a 

readback on that.” I’m glad to see that is happening because it helps my situational awareness if the 

nonstandard types of things are avoided. 

To a Considerable Extent I Found Nonstandard 

Terminology Confusing Explanation

Eight of the nine respondents who selected this response 

provided comments. 

Initial Contact

With pilot fatigue being involved, initial contact 

with an ATC facility with different dialects, hearing words we’re not expecting is confusing when 

nonstandard. The most obvious one occurs coasting 

in off the North Atlantic Track, when we switch to 

Scottish [control] at 20 West. Before our first contact, there is a bunch of airplanes checking in; we 

can’t get a word in edgewise so we’re a little antsy. 

When we call in, he says, “[Airline name] stand by, 

[Airline name] stand by.” Then it’s, “[Airline name] 

Scottish control da-da-da” – he’s giving instructions 

immediately but we’re not ready. 

Japanese Accent and Pronunciation

When we fly to Japan, there are some words that 

are not easy to understand, because some of the 

letters are difficult for Japanese controllers to pronounce. However, they’re absolutely stringent on 

their phraseology and the order that they deliver a 

clearance. It’s always the same, probably down to 

the pause between instructions. I have never flown 

there when there’s been a big weather system or 

an emergency. I can’t say how that would work out 

once things degrade, but the common phraseology 

is good.

Line Up and Wait and Stand By

Hearing the controller say, “line up and takeoff 

on twenty-seven” really caught my attention. It is 

totally nonstandard. I’ve never heard anything like 

that. When we request a direct route, or ask when 

to begin a descent, French controllers say, “I call 

you back.” We use standby. The use of nonstandard 

terminology, different accents, and other conditions 

we’ve talked about, make it very confusing and 

dangerous. 

Nonstandard Altitude Restriction

The nonstandard use of, climb with/without restrict, and climb and maintain on a SID. There are 

also some descents and taxi clearances that include 

nonstandard terminology, or are given in an order 

that we don’t expect, that have caused confusion. In 

some places, published restrictions are to be intact 

or waived, airspeeds, and when to slow. 

It is more challenging and difficult when there’s 

weather, when there’s a hold up on the airport, or we 

have to hold some place because they’ve got reduced 

routing into the airport. When we’re cleared off our 

expected routing, verification is imperative because 

it’s difficult when the phraseology and verbiage gets 

nonstandard, gets away from what we’re expecting, 

and their pronunciation sometimes makes it more 

difficult for us to understand. It increases our workload when we have to make multiple transmissions.

Pilot Expectation

I expect a certain clearance at a certain time to a 

certain place. I expect certain instructions at various 

times in my flight and different instructions can be 

confusing until we can get everything decoded and 

this goes right into the front of the program. When 

we get something that’s not on our route, we can 

have FMS programming issues.38 We may have to 

break out the maps and look for it. If we can’t find 

it, we have to ask, “Say that again” or, “can you spell 

that?” After a few times the controller gets a little 

frustrated with the spelling and he’ll say, “Cleared 

your destination.” 

My biggest nightmare on the ground is a nonstandard transmission from a controller asking me 

to pull in behind a different kind of airplane and a 

different taxiway – trying to figure out what airline 

he’s talking about, did he mean line up behind 

him, or what was he saying? And I usually ask for 

a retransmission.

Let’s face it, if controllers move things out of the 

order that we expect to hear them, it makes understanding more difficult. We expect to hear these 

things; and as long as they come in the right order 

with the right phraseology, it’s all clear. The biggest 

offenders are down in South America.

TCAS39

TCAS is a great tool; the other great tool is GPWS40

– enhanced GPWS with the terrain mapping – what 

a godsend that is. My situational awareness goes 

way up with TCAS – knowing other traffic, seeing 

the weather, mountains and all displayed on our 

map; it provides a lot of necessary information. 

38 Making FMS inputs. 39 Terminal Collision and Avoidance System. 40 Ground Proximity Warning System.
26 

Before we started bringing some of that stuff into 

the F100,41 I had a check airman go with me to Lyon 

at night. The check airman told me that when we 

come in on this runway expect to go out and make 

a big teardrop approach. I’ll need to slow down; 

otherwise, we may be really wide of our approach. 

The next day, I see that we flew right over the top of 

a 10,800-foot mountain. To have a display showing 

this10,800 foot piece of terrain, allows me to know 

why I’m at 12 [thousand feet]; up to this point, a lot 

of that stuff has been additional information – that is 

really critical. Situational awareness is a lot better.

U.S. Lack of ICAO Standardization

With the examples that have been covered, the 

way we differ in the States from ICAO terminology 

and phraseology is one of the biggest problems we 

have. The lack of standardization is the issue. We 

are nonstandard compared to the world.

To a Moderate Extent I Found Nonstandard Terminology Confusing Explanation

Five of six respondents provided comments. Their 

comments have been condensed and combined to remove 

redundancies.

(Amended) Full Route Clearance

In an international setting, I expect to hear standard 

terminology. Otherwise, I must question the intent 

of any clearance/communication. Let’s start with 

full route clearance, because it’s what we typically 

get” but they don’t tell us it is a reroute. Knowing 

that we’re going to get a reroute would really help; 

otherwise, it adds confusion. 

Receiving our initial clearance in pre-flight preparation is probably one of the weakest links in the 

process when flying internationally. The procedures 

used domestically are probably the clearest and 

most succinct, where the communication is not a 

barrier. When they change our clearance in preflight preparation they say, “Contact XXX on this 

frequency.” Then we can compare our printed version 

with the new clearance. If it doesn’t match, we can 

see the changes and ask for a new flight plan with 

those changes. If we’re getting a verbal clearance 

domestically, they will say, “Be prepared to copy a 

full route clearance,” or “We have an amendment 

to your clearance.” 

We don’t get this benefit internationally. I have to 

say, “Hey can you clarify that? That wasn’t ICAO 

standard phraseology.” “What do you want me to 

do?” If it’s just “[Airline name] triple seven heavy 

descend and maintain flight level two nine zero,” 

that’s standard ICAO communication. 

Is there ICAO standard terminology that would 

give us that same route clearance? They give me, 

as part of our paperwork, a printed sheet that says, 

41 Fokker 100 airliner.

“Hey, 15 minutes prior to departure, do this, 10 

minutes prior do that” They’ll even have the verbiage expected for that call, and what we should 

say specifically to the controller at that point. It’s 

a cheat sheet. When we have alternate altitudes, 

alternate speeds, or something, we might expect 

to call for clearance prior to push back, but expect 

our clearance on the taxi out.

Different Taxi and Approach Clearances

All countries are different. In Shanghai, he says, 

“Expect your clearance on taxi out.” The other day, 

I got it before I pushed. Another place that they use 

nonstandard terminology is Beijing. What does this 

mean, “cleared for approach maintain your altitude?” 

It’s not “maintain your altitude until established,” 

or “maintain your altitude until you’re on the glide 

slope.” It’s just maintain your altitude. They wanted 

me to fly the approach but stay at [my present] altitude. When I got this clearance, I stated my altitude 

and prepared for a slam-dunk.

42 I liken that situation 

to the level of maturity of the aviation environment 

over there. Every time we go to Beijing, it gets better 

because they’re training more people and getting 

more sophisticated with less nonstandard terminology. But for now, “cleared for approach, maintain 

XXX altitude” is typical in Beijing.

Terms With Multiple or Different Meanings

Look at our 10-7 page, which is the ground 

operations page, and the 10-9 pages – put these 

two together. There are many differences in ground 

operations and how things are called. The terms 

we hear are gate hold, ramp tower, apron (apron 

means different things in different places), terminal 

ramp, hold line, hold point, critical areas, but it’s 

not standard across the ICAO system. So, at some 

places, for push, you’ll call Ramp Control; other 

places we’ll call Terminal Ramp; other places we’ll 

call Ramp Tower; and hopefully it’s depicted on our 

10-7 pages on how to do that.

Nonstandard terminology in the South American 

arena can be difficult. It confuses me only from 

the standpoint that I want to be absolutely and 

completely sure what the clearance is and what 

they are saying. So, it increases my workload and 

the controller’s because if I’m not absolutely sure, 

I have to ask for clarification. 

In normal flight, it’s not a problem. If there is a 

problem with the aircraft or there’s weather, our 

focus is not necessarily going to follow the communications. If we are dealing with an aircraft with 

a non-normal situation, it can greatly elevate our 

workload because we’re trying to convey something 

in nonstandard terminology. Nonstandard phraseology will require me to clarify.

42 A slam dunk is a rapid descent when an aircraft is on a short final.
27 

To a Limited Extent I Found Nonstandard Terminology Confusing Explanation

Of the 30 respondents who reported to a “limited 

extent,” 13% provided no comments, and another 13% 

indicated they did not understand the question. Once the 

question was clarified, two pilots reported “infrequently,” 

one to a “limited extent,” and one reported “not at all.”

Did Not Fully Understand Question

They usually give us standard information. It would 

be very confusing whenever it’s nonstandard – depending on the phase of flight. We expect them to 

be clear and concise telling us what they want us to 

do. I think this is what he wants me to do; I go back 

and recheck it, because this is the point where they 

usually ask me to do this. They did that last week; 

they’ll probably do it next week. So I need to go 

back and clarify it. I would probably press him to 

state it again in proper ICAO standards.

From what I’ve seen, the foreign pilots have more 

trouble with our nonstandard terminology than I 

think we do with theirs. To the inexperienced international pilot terms such as line up and wait or

cleared direct, with those local accents, would make 

that nonstandard terminology confusing.

Different Terminology for Emergency, Weather, Delays, etc.

Everything we’ve talked about, and what really accentuates it is, when there’s a nonstandard operation, 

in other words – an aircraft emergency, weather, 

delays, other traffic, and an influx of additional 

traffic. Now, ATC gives us something different – a 

hold off of an airway or slow down, do this or do 

that, and turns and vectors. That’s where experience 

level comes in again. The problem is the confusion 

that comes when there is a nonstandard operation.43

We’ve all heard “your transmissions are stuck on” 

versus “blocked,” or “position and hold,” for “line 

up and wait.” “We’re going five hundred, make it 

quick.” It really makes me chuckle when I hear the 

controller say something like, “I’ll get to you in a 

little bit,” instead of “stand by,” or “wait one,” or 

something a little more succinct. 

In Brazil, we have a procedure to warn pilots – 

descend on anything in an arrival, or descend via 

an arrival. In the morning, it’s very difficult to catch 

the nuance; we have to be very specific because one 

controller will give a clearance to go to particular 

altitudes, while another will feed us the altitudes, 

and we do the lateral math ourselves. We can really hose ourselves if we don’t ask very specifically, 

“Now is this on or via?”

If you have a plan when you call them, most often 

they’ll concur and accept the plan. I find that is the 

easiest way to straighten out what I’m expected to 

do sometimes.

43 The pilots reported emergency, weather, delays, etc. as being nonstandard.

Each Airport/Country Has Different Procedures for 

Issuing Pre-Departure Clearances (PDC)

The excitement begins when we get our clearance. 

In the U.S., our clearance comes up printed – I can’t 

think of anywhere that happens internationally. So, 

when outside the U.S., everybody has to really pay 

attention, so we stop what we’re doing and listen 

to the clearance. Pre-departure clearances may be 

given in sequences that we’re not used to getting. 

I’ve noticed that a lot in South and Central American countries. It seems random to me but I know 

what to expect as far as nonstandard terminology. 

I try to become aware of some of the waypoints, so 

I know what they’re telling me. Then I go over all 

the departures. There could have one departure for 

every runway. There are probably 20 in Germany. 

Whoever is in the right seat says, “Okay, guys, I’m 

getting ready for the clearance,” and everyone listens. 

I have my written clearance out to see if it’s going 

to follow. They might say, “You’re cleared as filed 

to San Francisco,” or “Your destination,” or “You’re 

cleared,” or they might give us a bunch of fixes 

that are on our route to the destination. If it doesn’t 

match what I’ve got written down, I’m scrambling 

around saying, “Did they say this departure?” “Did 

they say that departure?” 

Expect Clearance on Taxi Out

In the United States, we really never taxi without 

a clearance. But internationally, every airport has 

different procedures as far as when we get our 

clearance, when we push back, and when we can 

start the engines. We call for clearance prior to 

push back, but we expect it on the taxi out. Some 

of the procedures are so convoluted that our operations people made us a printed sheet as part of our 

international paperwork. It helps us go through the 

procedure. It may say, “15 minutes prior to departure 

do this, 10 minutes prior make the 10-minute call, 

at 5 minutes prior....” For example, in Shanghai it 

says, “Expect your clearance on taxi out.” The other 

day, I got it before I pushed.

Must Get Around Pronunciation

Every nonstandard term/phrase is generally not a 

factor in understanding instructions once pronunciation is understood. Pronunciation aside – for the 

most part, controllers do a pretty good job using 

standard terminology. There are a thousand fixes on 

a Caribbean map. There’s no way we can remember 

how a particular fix or waypoint is pronounced. 

When we’re actually there, it’s a dynamic situation, 

especially if we don’t figure out the name of where 

we’re going to go. A perfect example – I was flying 

into Savannah last week and there’s an outer marker 

named MAVIS. I pronounced it “mā-vəs,” and the 

guy I was flying with pronounced it “mā’vĭs.” 

Terminology Is Not Standard to Any Country

What is nonstandard terminology? For example, 
28 

we know we’re going to get line up and wait and 

we know what it means; it’s not standard to the 

U.S., but for them, it is. The first time we go in and 

hear nonstandard terminology, it’s confusing. After 

that, it seems to be a lot less so. The reason being, 

once we’ve been to a particular airport, we expect 

the nonstandard and it becomes the standard at 

that airport. We learn quickly what we have to do 

to survive. 

Anytime I talk in plain English with a foreign 

controller, it becomes very interesting. They seem 

to recognize something off the beaten track is going 

to confuse us. For example, the flight attendants set 

the watch to the wrong time and just completed 

serving breakfast as I was preparing the aircraft for 

landing. There was no way they could collect trays 

and prepare the airplane in time for landing. I had 

to call the controller and ask for a delay. I wasn’t 

sure if I was going to be able to convey that to him. 

I said, “We are not ready to land, and we need to 

delay. Could I make a 360 or do a holding pattern?” 

Fortunately, he figured it out. 

Not at All Have I Found Nonstandard Terminology 

Confusing Explanation

Only one respondent reported no difficulty.

It Is Not an Issue

I don’t get that much nonstandard terminology, 

and if it’s a little different from what we expect, it’s 

not really confusing. We just clarify it if we need to.

30. To what extent do you experience language-related 

difficulties when programming the FMS to comply 

with ATC? 

As shown in Table 12, 54% of the pilots reported 

that they experienced language-related difficulties “to a 

limited extent” when programming the FMS to comply 

with ATC. An additional 37% “had not experienced 

any difficulties.” (The pilots who reported “no difficulties” embellished upon their written responses and their 

oral remarks appear under issues discussed.) Language 

presented itself as a difficulty “to a moderate extent” to 

6% of the pilots and “a considerable extent” to one pilot. 

During the interviews, 34 pilots discussed their issues, 

14 had nothing to add, and two did not understand the 

question. 

To a Considerable Extent I Experience LanguageRelated Difficulties When Programming the FMS

to Comply With ATC

Dialect and Accent – Cuba and Lima

For me, Cuba, Lima, and North Lima are good; 

South Lima is worse. Their dialect and accent can 

confuse me. I have more problems with spelling 

there. Even when I try to spell phonetically, I have 

trouble understanding exactly where they’re going 

with it. 

Table 12. Extent Pilots Experienced Language-Related Difficulties When 

Programming FMS to Comply With ATC. 

Extent Language-related 

Difficulties Experienced 

Number 

of Pilots Issues Discussed 

To a great extent 0 

To a considerable extent 1 Dialect and Accent – Cuba and Lima 

To a moderate extent 3 Inputting 1- or 2-Letter Codes 

To a limited extent 26 

British vs. South American Clearances 

Cultural Differences 

Inputting Altitude 

NAVAID Designators Not Recognized 

Phonetics Aid In Input and Punctuation 

Problems With Similar-Sounding Names 

Routings Differ From PDC and Company 

FMS 

Translations Confused Programming 

Verifying Verbal Fix/Waypoint With FMS 

Not at all 18 

ATC Words 

Communication Difficulties Limit Use 

Datalink and FMS May Not Match 

Did Not Understand Question 

Familiarity Aids In Input 

Similar Names Confuse Input 
29 

To a Moderate Extent I Experience Languagerelated Difficulties When Programming the FMS to 

Comply With ATC

Inputting One- or Two-Letter Codes

It’s been my experience that some countries are 

better than others. Obviously, language has nothing 

to do with the box, but it’s the information that we’re 

getting to input into the box. To program the FMS 

properly, I have to understand exactly what my 

route is. So, the problem is in pronunciation of the 

fix/waypoint, etc. If I enter a NDB44 with a one- or 

two-letter code for a particular NAVAID, 45 I have 

to be sure that we heard exactly the point that they 

want us to go to, and that I input the correct point 

into our navigational system; otherwise, we’ll go to 

the wrong place. 

To a Limited Extent I Experience Language-related 

Difficulties When Programming the FMS to Comply With ATC

Of the 26 pilots, 23% made no comments. The comments of the other 16 pilots are presented alphabetically, 

according to identified issues.

British Versus South American Clearances

When we receive clearances, it’s getting the spelling right or else get the full route including the fixes. 

The Brits are really good. When we enter British 

airspace and start getting clearances, we pull up 

the route page as we come off the tracks. We look 

at it and know he’s going to give us “cleared to 

London airport.” If it’s not there, we catch it, and 

know what to expect. 

South America is a different story. We get a change 

within a route, or something out of the blue when 

we’re not ready and least expecting it. It’s usually 

not with a strong English-speaking person, or else 

the radios are bad. We’ll say, “Say again; say again.” 

We have the technology to eliminate this issue by 

the use of Datalink.

Cultural Differences

It’s a cultural difference again. There’s almost a 

point of pride among South American controllers 

to get the clearance to us on the first pass. In Latin 

America, it seems like half the time they spell out the 

name of the fix before we ask to go direct [FIX]. In 

some places in Europe, it seems that controllers are 

pretty uppity about it. “Why should I spell? I’m using 

the King’s English.” I’ve seen it where we may get a 

penalty if I ask, “Please read back,” after getting a 

clearance to leave Paris. He’ll say, “I call you back.” 

Then four or five other guys get their clearance – we 

just went to the back of the line. 

44 Non-Directional Radio Beacon.

45 Navigational Aid.

Inputting Altitude

I have an example of a British ATC clearance to 

climb, “Cleared to level two seven zero.” That’s 

a new clearance that has to be input. And this is 

separate from the restriction; it’s not really a cruise 

level change, so the way you program it into the 

FMC varies. It’s not just changing the cruise level; it’s 

actually putting in the whole thing. If the guy said, 

“Cleared to two seven zero,” – with restrictions – 

and I just entered the cruise level change, I may not 

make the restriction. British ATC clearance, “Cleared 

to flight level two seven zero, level by GIBSO” is a 

crossing restriction, not merely a cruise level change 

so FMS programming varies.

NAVAID Designators Not Recognized

Assuming there’s a 3-letter designator – well, it’s 

in our FMC as a 3-letter designator, and it gives a 

name for it that doesn’t even relate to the 3-letter 

designator – that’s a big one so we must look at all 

our charts. If it’s a 5-letter word, then it gets a little 

strange. Our airline reduced the number of tailored 

charts that made navigation very easy in regions like 

South America. We had one chart with all of South 

America on it. But it’s gone, so now it’s all standard 

Jeppesen-issued. The lack of tailored charts has made 

it a little more difficult.

Phonetics46 Aids Input and Pronunciation

Spelling of a fix or waypoint phonetically by 

non-English [speaking controllers] is sometimes 

impossible if it’s not on the flight plan or known. If 

I have difficulty locating it, I ask for it to be spelled 

phonetically. It may take more time to clear up, and 

it’s frustrating for the controller and pilot when it 

happens. Once I understand where they want me 

to go, I don’t have much trouble. Most of the time, 

the FMS is a godsend because it has the arcing approach to Mexico City; it makes that approach a 

lot easier and safer. 

Problems With Similar-Sounding Names

A heavy accent makes it very difficult to figure out 

which fix they want when two of them sound very 

similar in English. I have the same problem with 

similar-titled STARs and SIDs. It gets confusing at 

times. In Narita, we get the ARIES North and the 

ARIES South departure.

In some of the Southeast Asia airspaces, they may 

pronounce the word perfectly – properly – in their 

language, using English. It’s similar to “garage” [guh 

-rahzh, -rahj, in American English] versus “garage,” 

[gar – ij, -ahzh, in British English]. It’s the same word, 

but our pronunciations differ.

Routings Differ From PDC and Company FMS

I experience the most impact when it’s not a 

46 The international radiotelephony spelling alphabet created by ICAO. It is 

referred to as ICAO phonetics in FAA Order JO 7110.65.
30 

familiar routing, or it differs from the flight plan/

original PDC. Changes to what I have to program 

in the FMS are a problem. If we’re cleared as filed, 

it’s easy; we have less pronunciation to decipher. 

If we get a full-route clearance verbally by a nonnative English speaker, it can be a true handful. It’s 

an invitation to a violation somewhere.

When we get initial clearance at our coast-in 

point, we check not only the flight plan we check 

the programming in the FMS, ascertaining that we 

have exactly what we’re supposed to be getting. It’s 

analogous of placing your order with McDonalds, 

once we get the order we check the bag to make 

sure we got what we ordered.

The FMS routing is from our company, written in 

plain English. We program it in, and invariably, it’s the 

one we get when we coast in. We can look at the list 

of intersections and clearance points and understand 

what he’s going to say by just reading it off our screen. 

Once we come back into the radar environment, on 

both ends – on the Canadian side and on the European 

side, they’re named intersections; after we go over one 

of the points, we’re in normal VHF communications, 

radar contact, and normal operations.

Translations Confused Programming

The FMC is a great asset and help. It’s very smart. It 

takes simple instructions and only goes one place after another. Programming isn’t a universal language. 

Some transitions, like in China, have little logical 

order. In the FMS, I might select a departure, and 

then I’ll have four or five transitions. The departures, 

or transitions might all have the same name, but 

with a different prefix or a suffix letter attached to 

them. I have to select each one and determine where 

it goes; it’s not very clear. I’m not quite sure who 

programs that; I’m not sure if it’s language-related, 

or country-specific issue.

Verifying Verbal Fix/Waypoint Names With FMS

A verbal clearance is much more challenging 

when I have to verify a waypoint name. When 

I’m programming my FMS, I’m looking for a word 

match, “Oh that’s what I heard, because that’s the 

only one that sounds like what was said.” If I’m not 

sure, I use the FMS printed word to verify it verbally 

over the radio. 

Europe has many fixes in a small area. There are 

five NAVAIDs along a 40-mile segment of our jet 

way. I’m looking at our chart and half the time, 

I can’t find some of them because they’re just so 

crammed. There are boxes off to the side with an 

arrow pointing over an intersection that is 2 inches 

away, and I’m looking for the name off to the right.

Not at All Do I Experience Language-related Difficulties When Programming the FMS to Comply 

With ATC

Twelve of the 18 pilots who selected this response 

commented. Two did not understand the question. 

Communication Difficulties Limit Use

I won’t touch the FMS unless I know what I’m going 

to put in there. I check with my crew, “Am I hearing 

right? We’re going direct to BUCLOS as opposed to 

BUCLAS?” Going into Japan, I’m told, “Cleared to 

MERIN.” We know it’s supposed to be MELON, but 

they cannot pronounce MELON. [Because some 

names are pronounced differently than what pilots 

expect], we almost had an airplane run out of gas 

in South America a couple of months ago.

So, the difficulty is in the communication, not the 

programming. If there are language barriers, the FMC 

is very difficult to program. We have to understand 

what the controller said if I’m to input it correctly; 

otherwise, it never comes up on the FMC.

The person that puts the fix on a screen so it doesn’t 

have to be spelled phonetically should have a winner’s placard. We could spell a fix phonetically, but 

they’re going Alfa, Delta, Charlie – it comes up with 

three – oh, we’re going to ANCHO, then BOWLEGS, 

then, whatever – it could take out situational awareness and cause slight confusion.

Datalink and FMS May Not Match ATC Words

We can get a complete route of flight 99% of the 

time by Datalink. We ask for it, and they send us the 

whole flight, short of the arrival or departure. The 

FMC47 “speaks” English. It’s easier than listening to 

unfamiliar words.

May Not Understand Question

Having the FMS off or on doesn’t make any difference. We have that capability, but I don’t know if 

you’re talking about the stored routes. The clearance 

is a verification of what you can expect. I still have 

to navigate from what I understood, in the interpretation of the clearance. Now all I have to do is push 

one button – I’ve got a whole list of legs up there. 

When the controller says, “[Airline call sign] direct 

to TUBIE.” “What did he say?” “I don’t know?” “Oh, 

did he say ATUBIE?” “Oh yeah, we got it there.”

If the controller uses unfamiliar fixes and talks 

fast, I would not use the FMS. When the language 

barrier is deciphered, the route written down, I’ve 

identified it on the map, and we know where we’re 

going is safe then, I’ll reprogram the FMS. Some 

pilots put fixes in the FMS on the fly, but that’s not 

procedurally correct. When procedures aren’t followed, pilots get in trouble. 

Similar Names Confuse Input

I make sure common departures that sound alike 

are completely resolved, before I put anything in 

47 Flight Management Computer.
31 

the box. At de Gaulle,48 they have two departures 

that are spelled almost identically. They both begin 

with an “A,” and there are only two letter differences; 

it’s easy to confuse them. The two departures are 

spelled really similar and sound very similar, but 

they’re totally different – clearances, departures, 

departure procedures. The taxiway markings are 

horrible on the north complex. It’s hard to know 

what taxi directions they want you to go to if they 

don’t speak clearly.

DISCUSSION

International Flight Experiences Among Participants

In the three months preceding the interviews, the 48 

U.S. pilots listed 74 geographical areas they had flown 

through, with Canada, England and Mexico frequented 

by at least 33% of the pilots. They landed in 47 different 

countries or regions during that time period. Within the 

30 days preceding the interviews, 83% flew an average 

of five international flights, including multiple flights 

to Costa Rica, Guatemala, and Venezuela. Clearly, as a 

group, the pilots had diverse flight experiences.

English Language Acquisition and Usage

All of the U.S. pilots listed English as their first language and learned it informally at home prior to entering 

elementary school. Also, they reported English as the 

language spoken most frequently at home. Approximately 

60% neither spoke nor understood any languages other 

than English. For the remaining pilots, many indicated 

they spoke/understood some French, Spanish, or both. 

In addition to Spanish, one pilot spoke/understood 

German, and one spoke/understood Spanish, French, 

and Portuguese. When asked about their listening and 

speaking skills, nearly 80% reported no dominance of 

one skill over the other.

Word Meaning and Pronunciation (how words are 

spoken)

Factors Influencing Decoding ATC Communication

The U.S. pilots’ responses on the written component 

of the interview indicated problems related to word 

meanings occurred occasionally; but they did not perceive 

word meanings as an obstacle during their flights. In fact, 

58% reported they rarely experienced problems related 

to word meanings, 33% reported occasional problems, 

and 8% indicated they frequently experienced problems. 

Regardless of how frequently they experienced problems with word meanings, for them, accent, speech rate, 

and pronunciation adversely affected their ability to 

understand word meanings to a greater extent than radio 

technique and the quality of ATC radio equipment. All 

of these components have an effect on a pilot’s ability 

to decode the voice stream to get to the next stages of 

48 Charles de Gaulle International Airport resides outside of Paris, France.

information processing — comprehension, selection, and 

execution of an action sequence.

When a controller’s accent is notably strong, the 

captains frequently ask all pilots in the cockpit to listen 

intently to what is being said to understand what ATC 

wants them to do. Add to the accent the perception of a 

rapid speaking rate, and the pilots will, more likely than 

not, miss part of the clearance, instruction, advisory or 

other information. Furthermore, controllers who speak 

before depressing the microphone key clip the beginning 

of their messages. Poor delivery technique may result 

in a failure to receive the entire message on the flight 

deck, which can change the entire meaning of a phrase. 

Finally, poor radio equipment weakens and distorts voice 

characteristics, rendering some aspects unintelligible. 

To aid decoding, pilots may refer to their charts, 

gouges (i.e., personal notes), and other reference materials 

as they talk among themselves to reach consensus as to 

what the controller said. Under these situations, they may 

request a “say again” or confirmation of the transmission. 

Otherwise, they read back what they thought was said, 

expecting the controller to correct a faulty readback. To 

successfully decode the message, the pilot collaborates 

with other crewmembers to reach consensus. The question that emerged was, “What does ATC want us to do?”

Successfully decoding an ATC message does not ensure they understood what to do. Unfortunately, not all 

words and phrases universally convey the same meaning 

for pilots and controllers. The most common examples 

provided by the discussants involved runway surface 

operations. They noted that in some parts of the world, 

ATC does not use the phrase “position and hold” as is 

done in the U.S. Instead, the controller may say, “Line up 

and wait.” Also, the message “Line up and wait after the 

arriving aircraft” creates confusion. The arriving aircraft 

may not necessarily be the aircraft preparing to land but 

is nine miles or more from the threshold. By talking to 

other pilots or relying on their previous experiences, pilots 

learn to ask the controller which aircraft will trigger their 

movement onto the runway surface. Although there may 

be an implied lack of knowing when to take the runway, 

it may be that the pilot does not want to taxi onto the 

runway when he cannot know for certain which aircraft 

he is to separate himself from, or if he will be on the 

runway for an extended period of time.

If the controller said, “Line up and wait after the landing airplane,” but prematurely released the microphone 

key, or the pilot diverted attention to prepare to taxi 

onto the runway, the pilot may hear only, “Line up and 

wait.” This may result in the pilot selecting an action 

sequence resulting in taxiing-out in front of an aircraft 

preparing to land.

Another example is related to differences in perceptions 

that may be cultural rather than language-based. In the 

U.S., if a pilot says “mayday” to convey an emergency, 

the controller assists the pilot to bring the aircraft to a 

safe landing if possible. This might involve clearing other 
32 

aircraft away from the area and notifying supervisory and 

emergency personnel (e.g., fire, rescue). In some parts of 

the world, mayday may not have the same meaning for 

controllers as it does for pilots, and their controllers may 

not react like U.S. controllers or provide expected services.

Being Able to Discriminate Between Similar-Sounding 

NAVAIDs Is a Problem

It would seem from the written component of the interviews that pronunciation was a more frequent problem 

among the U.S. pilots than word meanings, primarily because of the controllers’ accents. In fact, only 20% reported 

they “rarely” experienced problems with how words were 

pronounced, 40% “occasionally” experienced problems, 

31% “frequently” experienced problems, and 6% “often” 

experienced problems. Sixty-five percent of the pilots discussed the problems with controller pronunciation. 

One encompassing problem was with similar-sounding 

names of fixes, waypoints, and intersections. Non-native 

English-speaking controllers pronounce these words using 

the accents, dialects, emphasis on syllables, etc., consistent 

with their native language. Pilots unable to successfully 

discriminate a similar-sounding word from another often 

asked other crewmembers for assistance. The additional 

effort pilots have to put forth parsing the controller’s voice 

stream correctly to decipher ATC instructions and advisories takes time. That may put them behind the aircraft.

The question that emerged was, “What did ATC say?” 

The problem partially arises from differences in accents, 

pronunciation, and dialect, as well as the quality of the 

broadcasting equipment on the ground. When ATC clears 

pilots to a fix, waypoint, or intersection, the controllers 

pronounce these words in their native language as if to 

a local pilot. It makes it difficult for many U.S. pilots to 

really decipher what ATC is saying – especially if they 

are on their first or second flight into that area. It is not 

uncommon for pilots to delay other duties to look at the 

chart to determine the fix ATC gave them.

There are differences in how syllables are pronounced 

by speakers of different languages, e.g., U.S. English, 

Mex•i•co Pronunciation: (mek’si-kō”); Mexican, Mé•xi•co 

Pronunciation: (me’hē-kô”). In particular is the time lag 

between pronouncing the first consonant and the voicing 

of the vowel in a consonant-vowel cluster (category group). 

That is, /p/ followed by /a/ to create /pa/ varies for English 

and Spanish. Also, the location of syllabic stress affects how 

words are pronounced. The differences hinder language 

decoding by the listener. Individuals learn to associate 

words and word meanings to sounds in their native language; until pilots learn to associate particular words with 

specific sounds of foreign languages, there will be difficulty.

Lack of Standardization in Phraseologies and 

Inconsistencies in Language Proficiency

Air traffic operations are highly standardized – aircraft 

arrive at a particular time and location at a set altitude, 

heading, and speed. Controllers develop expectancies 

based on these traffic patterns and follow localized written 

procedures and standard phraseology for communications. 

Likewise, pilots develop similar expectations. Phraseologies were constructed to standardize the utterances spoken 

by controllers and pilots to build a shared understanding. 

Unfortunately, there are variations to that standard that 

can affect safety. When coupled with differences in language proficiency, the affect on aviation safety may erode.

Some of the variances from prescribed phraseology 

involve how an air carrier’s name, flight number, and 

weight designator (e.g., use of heavy) are spoken by 

controllers. Other examples include the words “you’re 

not” as part of an utterance from ATC (e.g., “you’re 

not cleared for takeoff;” “you’re not cleared to land”). A 

practice of issuing instructions at different points created 

angst in the cockpit. It may be that one controller may 

say, “Cleared to land” to a pilot who is number 15 in line, 

while another controller may wait until that same pilot is 

number one before saying, “You’re cleared to land.” Also, 

one controller may use line up and wait, while another 

position and hold. Pilot use of emergency fuel versus minimum fuel versus expedited handling because of low fuel 

does not always convey the level of the emergency. The 

procedure of authorizing the pilot to establish separation, as in line up and wait after the arriving aircraft, was 

extremely troubling, as the pilot could not determine 

which of the arriving aircraft to follow.

Lengthy clearances, especially those containing latitude 

and longitude, can be a problem for pilots as can the order 

in which instructions are given. Based on a comprehensive 

analysis of enroute operational communications, Prinzo, 

Hendrix, and Hendrix (2009) recommend that controllers 

include three of fewer instructions/clearances in a transmission, and this corresponds to what pilots said during 

their interviews. Memory becomes taxed once this upper 

limit is reached. Controllers who exclude anchor words 

(e.g., heading, speed, flight level, etc.) create problems for 

pilots. As noted by one pilot, “Many times, they’ll give 

you a heading, a turn, a descent to, and a freq change. 

We’re always heading west and the controller says, ‘two 

five zero two six zero two seven zero.’ Heading 250 and 

slow to 260; or was it turn at 260 and slow to 250?”

When unexpected events occur that have the potential 

to create a problem, controllers and pilots cannot always 

rely on these phraseologies to explain their situations, 

provide actions, or offer solutions. During these times, 

pronunciation of the off-route waypoints, instructions, 

numbers, and nonstandard phraseology often become 

difficult to understand. When uncertainty exists, pilots 

ask for clarification, confirmation, and verification – especially when controllers’ accented English and pronunciation impedes understanding. As pilots gain familiarity 

with these languages, the controllers’ utterances become 

easier to decode, understand, and execute because pilots 

are developing mental representations that correspond 

to these words. However, these associations decay if not 

practiced and heard frequently.
33 

The pilots provided examples related to some of the 

procedural ambiguities they experienced. With altitude 

clearances, U.S. controllers use the words flight level, followed by three discrete numbers; outside the U.S., controllers use level followed by two discrete numbers. Thus, pilots 

assigned an altitude of 25,000 feet will hear this spoken by 

the U.S. controllers as, “flight level two fife zero;”49 and 

the controller outside the U.S. will say, “level two fife.” 

Same Words Used for Different Actions 

Create Confusion

During the discussions, pilots spent differing amounts 

of time talking about their flight experiences related to altitudes and altitude restriction, bearing vs. radial, clearances, 

and pilot’s discretion. For example, cleared to intercept loc

is an approach clearance, while overshoot and go around are 

missed approach clearances. Of the 48 pilots, 62% cited 

examples of problems related to the same word(s) used 

to describe different actions, where the words themselves 

have caused confusion.

Pilots need to be particularly sensitive to the disparities 

in the intentions expressed by some words and phrases 

spoken by controllers outside of the U.S. One often-cited 

example was the direct route clearance. Although the same 

words are delivered to the pilots, in the U.S., the controller 

wants the pilot to fly direct to the fix just given; whereas, 

the non-U.S. controller may want the pilot to fly direct to 

the fix according to the flight plan route. 

The U.S. pilots reported that when outside U.S. controlled airspace, the same clearance “cleared direct Point E” 

(see Figure 2) issued by a non-U.S. controller frequently 

has an additional phrase “cleared direct flight plan route,” 

causing confusion. In particular, the question pilots ask 

themselves is, “What is the route I’m expected to fly when 

given the clearance ‘cleared direct Point E flight plan route?’” 

And what is expected when the additional phrase flight 

plan route is omitted in a foreign country? Do they fly the 

clearance as they would if in the U.S., or do they cross all 

of the fixes from Point A to Point E? This is especially true 

when the controller uses “cleared direct point E” twice, 

followed by “cleared direct Point E flight plan route.” The 

direct clearance becomes a point of confusion because the 

direct part of the clearance may be used by some foreign 

controllers as a non-ATC (common language) phrase. 

In one reported incident, the pilot was cleared “direct to 

DME mileage VOR radial” and then questioned by the 

controller when he flew direct and not via an arc. While 

the Aeronautical Information Manual (FAA, 2008b) and 

the ICAO (2007) explain the direct route as direct point 

to point, some non-U.S. controllers may be adding the 

extra phrase, causing confusion. The reported method for 

handling this clearance was to keep asking for clarification. 

At some airports, clearance to push instructs the pilot 

that the aircraft can be towed away from the gate, and the 

pilot may start the aircraft’s engines; while at other airports, 

clearance to push instructs the pilot that the aircraft can be 

49 The number five is pronounced fife in ICAO phonetics.

moved away from the gate. The pilot must wait to start 

engines until issued the clearance to start. These examples 

make it clear that pilots must be fully aware and vigilant 

in understanding the full intent behind the words used 

by ATC. 

Some countries use phraseology that is not used in the 

U.S. One example is speed limit point and another is cleared 

to offset. The former refers to a speed restriction listed on 

charts, while the latter is a course deviation. Often, airline 

training programs offer courses to their international pilots 

that will include some briefings on phraseology and procedures that differ from those used in the U.S. Training, 

coupled with simulator experiences, a check airman, and 

an experienced crew, should assist the inexperienced pilot 

when making a first flight into an unfamiliar airspace and 

possibly mitigate the effects of fatigue associated with a 

long flight across several different time zones.

Developing One Standard for Pronunciation and 

Delivery Technique Are Key Factors

Attempting to make sense out of what they heard diverted 

the pilots’ attention away from the primary task of flying 

their aircraft. Accented English, spoken quickly, required 

greater pilot concentration on what was being said and 

made understanding notably difficult. In particular, the 

pilots indicated that the names of intersections, navigational 

aids, and procedures were pronounced by controllers in 

their native languages, and these pronunciations were quite 

varied. The pronunciation and spelling of some NAVAIDs 

can be quite similar and lead to problems for the pilots. 

Also, the influence of the controllers’ primary languages 

was evident as they pronounced the numbers “one,” “two,” 

“three,” and “six,” and words with “J,” “L,” “R,” and “W” 

sounds. The importance of the pronunciation of numbers 

cannot be overstated because they appear in clearances, 

instructions, advisories, call signs, and procedures. 

It became particularly difficult when controllers broadcast over weak radios with poor signal quality and when 

air-ground communications reached saturation levels. 

Transmissions might sound hollow and distorted; if the 

controllers spoke at a higher pitch, their voice might be 

masked by signal noise at higher frequencies. Also, controllers speaking at a fast pace left little time for pilots to 

ask for clarification.

When asked if they perceived a difference in clarity of 

information provided by native English-speaking controllers, some pilots reported that training was the key element. 

If all controllers received proper training that included 

broadcasting techniques and instruction in English language 

skills, then clarity would not be an issue. Among pilots 

who perceived a difference between U.S., British, Indian, 

Hong Kong, and Australian controllers, they noted subtle 

differences in dialects, terminologies, accents, and speech 

rates as distinguishing characteristics. When asked if one 

universal standard could be broadcast, precision and proper 

phraseology were key factors.
34 

The same question was put to them about non-native, 

English-speaking controllers. Among the pilots who perceived differences, the differences ranged from subtle to 

obvious. The differences reside in the accents, cadence, tone, 

speech rate, and knowledge of plain English. As long as 

standard ICAO phraseology was adhered to and flight conditions were routine, communicating was straightforward.

Expectancies Facilitate Pilot Action but 

May Create Problems

Ninety-eight percent of the pilots reported nonstandard 

terminology as confusing to a limited or greater extent; 

approximately 75% discussed their experiences, offered 

examples, or both. There were two common threads to 

their responses: The first dealt with the timing of clearances 

(taxi, approach, full route) and the second with the negative 

affect nonstandard terminology had on understanding.

As pilots fly into a particular airspace, they develop 

memories of their flight experiences. These memories have a 

structure and contain a series of episodes with explicit begin 

and end sequences. As noted in the first report (Prinzo & 

Campbell, 2008), pilots spend time reviewing their flight 

plan, charts, gouges, as well as talking with their flight crew 

about previous missions. All of this information is used to 

develop their schemata (Bartlett, 1932), which are general 

knowledge units used during comprehension. 

One particular type of schema is the script (Schank 

& Abelson, 1977). Scripts are causally-linked memory 

representations of action sequences. Speech acts activate 

them, and the quality of a script is based on expertise. 

That is, skilled pilots who often fly to a particular airport 

have clear and distinct expectations about the appropriate order in which they perform action sequences – they 

develop scripted action sequences. In comparison, less 

skilled pilots and pilots who are relatively unfamiliar with 

that same airport have weaker scripts and may perform 

the same actions unsystematically. When nonstandard 

phraseology is used, activating the appropriate script, its 

associated action sequence, or both may not occur or is 

delayed until the pilot understands what the controller is 

attempting to say. This happens when pilots request either 

a “say again,” “confirm,” or “verify” of all or some of the 

ATC transmission.

The extent to which a particular speech act matches 

the script for a given action sequence, the less time it will 

take the pilot to understand it. As noted by the pilots, all 

countries are different as to when they issue clearances. 

Some clearances are given before pushback while the 

aircraft is at the gate and sometimes when taxiing to the 

runway. There also are temporal differences when pilots 

are to make position reports, what to include in these reports, and whether the controller wants a position report. 

Consequently, pilots must have access to different scripts 

for each country’s airspace they enter so as to comply with 

its rules and procedures. 

There are disparities between the procedures used in 

the U.S. and other countries in the delivery of full and 

amended route clearances. In the U.S., ATC will provide 

the pilot with a warning to expect a verbal clearance or 

an amendment to a clearance previously issued. In other 

countries, pilots do not receive advance notice of a forthcoming change, it just arrives and they have to figure it 

out on their own. The differences between what is stored 

in pilots’ memories as scripts and actual events can create 

confusion, erode understanding, and add stress. 

Receiving clearances that appear nonsensical add to 

uncertainty as do receiving instructions out of an expected 

order. For example, “cleared for approach, maintain your 

altitude” may violate the pilot’s expectations that when 

coming in on an approach, there is the expectation of 

descending and slowing the aircraft. The pilot may apply 

an approach script, infer a rapid descent at some point of 

the approach corridor, and build an expectation to receive 

that instruction from ATC before a go around is necessary. 

The important point is pilots develop scripts as part 

of their pre-flight preparation. These scripts form their 

expectations during the various phases of flight. They lay 

out these scripts from beginning to end with slots (frames) 

ready to receive particular terms so they can initiate the 

appropriate procedures. They expect to receive instructions, clearances, and other ATC speech acts in a particular 

sequence, beginning with their call sign. Sometimes the 

foreign controller’s English-language proficiency impedes 

the delivery of these messages, making comprehension difficult for the pilot. Other factors that can either facilitate 

or interfere with understanding include the order of ATC 

speech acts in a message, the timing of ATC messages, 

and whether or not the contents of ATC messages are in 

agreement with the pilot’s expectations.

Language-Related Difficulties Slow 

Reprogramming the FMS

Approximately 63% of the pilots reported no problems 

programming the FMS once they were able to understand 

what the controller said and wanted them to do. Consequently the difficulty resided in the communication, not 

the programming. There were several factors that impeded 

the pilots from communicating effectively with controllers – faulty ground-radio equipment, signal strength that 

interfered with the intelligibility of the voice stream, and 

language barriers. High pitch shrills, white noise (static), 

and weak signals can mask, distort, and otherwise make 

the voice stream partially, or completely, unintelligible. 

When this happens, pilots rely on previous experience to 

infer what might have been said, may turn up their radios, 

confer with other crewmembers, or ask the controller to 

repeat, confirm, or verify all or part of the message.

Hearing a language other than one’s native language takes 

time because some sounds are difficult to detect and may 

be perceived as a non-word sound sequence. For example, 

the sound of \p\ in the words “spin” and “pin” are heard as 

being the same when in fact they are differently produced; 

“pin” is aspirated (a puff of air is felt on the back of the 

hand) whereas “spin” is not (Cummings, 2004). This may 
35 

be one reason that non-native English-speaking controllers 

mispronounce some names and numbers – if they cannot 

detect the subtle differences, they may not be able to create 

them during phonation. 

Failure to detect differences in basic sounds creates 

problems for pilots because they, like controllers, may not 

hear the subtleties or put them together meaningfully to 

create words. As a result, pilots frequently ask controllers 

to either say the word again or spell it phonetically. Still, 

the controllers’ dialect and accent make deciphering difficult. Once the voice stream is decoded successfully into 

meaningful sounds, word recognition proceeds rapidly. In 

fact, native speakers can recognize a word spoken in their 

language within 200 or fewer ms and reject a non-word 

sound sequence in 500 ms (Aitchison, 2003).

During this phase, pilots may be reading along or writing down what they heard (or thought they heard) as it is 

delivered by the controller. If the controller was reciting the 

filed flight plan route, the pilots did not perceive language 

as a barrier because they just followed along using the 

previously received clearance or FMS routing. However, 

the names of STARs, SIDs, and other changes to the flight 

plan route (e.g., a reroute) may exacerbate programming 

the FMS. The pilots noted the following language barriers 

to programming the FMS: (1) Although some fixes sound 

similar when spoken in English, they have different spellings, (homophones; e.g., their and there); (2) The name of 

a fix may be the same in print but is pronounced differently 

(heterophones; e.g., tear – cry and tear – rip); (3) Strong 

accents make it difficult to determine which of several fixes 

ATC wants them to go to; and (4) Unfamiliar fixes spoken 

quickly. It behooves pilots to ensure they input exactly what 

ATC transmits over the radio, or, the route of flight may 

deviate from the intended route, and the aircraft will go 

to the wrong place. Pilots should never second-guess the 

pronunciation of route information. When in doubt, they 

should ask ATC to spell fixes phonetically using the ICAO 

phonetic alphabet before putting them into the FMS.

Generally, pilots followed a practice for reprogramming 

the FMS: (1) Understand and verify what ATC said; (2) 

Write it down; (3) Identify it on the map; (4) Confirm it 

with other crewmembers; and (5) Enter the reroute into 

the FMS. One pilot had the practice of mentally flying the 

aircraft to establish a reroute and then entering the data 

into the FMS. In summary, once a verbal understanding is 

acknowledged, there is no problem with the FMS.

Recommendations

1. Adopt and adhere to the phraseologies contained in 

Doc4444 by all of the ICAO member states and the 

aviation community. Lack of standardization in phraseologies, procedure execution, and inconsistencies in 

language proficiency can led to misunderstandings and 

unsafe acts.

2. Resolve the disparities that currently exist in the intentions (meaning) expressed by some words and phrases 

(e.g., cleared direct clearance, prepare to overshoot). 

3. Develop additional phraseologies for inclusion into 

Doc4444 if the existing phraseologies cannot explain 

adequately an event involving the safety of an aircraft, 

provide actions, or offer solutions. 

4. Develop one standard order for the presentation and 

delivery of ATC phraseology by ATC, and require that 

ATC personnel adhere to it. For example, “cleared for 

approach, maintain your altitude” may violate pilot 

expectations to descend and lead to confusion.

5. Transmit no more than two speech acts in an ATC message (excluding speaker and receiver identifiers). Analysis 

of ATC voice tapes have repeatedly demonstrated that 

messages containing more than two speech acts (e.g., 

clearances, instructions, request, or their combination) 

lead to radio frequency congestion and the production 

of readback errors.

6. Develop and implement one universally accepted and 

agreed upon standard accent, dialect, speech rate, cadence, and pronunciation for aviation telephony. Inherent differences between speakers’ and listeners’ languages 

impede decoding ATC communication. 

7. Develop aviation training courses that address plain language proficiency, cultural differences, and appropriate 

phraseology to declare an emergency, indicate the degree 

of emergency, assisted handling requests, and assistance 

during unexpected or unusual situations or events.

8. Adopt standardized language-proficiency testing standards, instruments and testing procedures by all of the 

ICAO member states. This would help assure better 

global communication standards.

9. Require at least a Level 4 Language Proficiency in Common English as defined by ICAO in Doc9835 for ATC 

personnel and flight crews involved in flight operations. 

To retain their certification, ATC personnel and flight 

crews will/must demonstrate more than a limited understanding of the concepts of “emergency fuel,” “minimum 

fuel,” “expedited handling” because of low fuel and other 

safety-related phraseologies. 

10. Although the interviews and discussions focused on pilot 

and controller communications, some of the examples 

provided by the pilots also involved safety personnel 

(e.g., firefighters, emergency rescue technicians). Pilots 

and controllers must demonstrate the ability to extract 

and relay the words necessary to indicate the extent of 

the emergency, i.e., “declare an emergency” (Doc4444) 

in minimum fuel, emergency fuel, or requests for expedited handling. 

11. Adopt minimum ICAO hardware/software standards 

that assure appropriate voice/data communication 

quality and coverage to enhance the safety of ATS operations now and into the future. ICAO member states 

should be encouraged to cooperate in upgrading their 

hardware, software, and communications equipment 

for the benefit of global aviation.
36 

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