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

HCS Consulting Services

Roswell, NM 88201

August 2010

Final Report

U.S. Airline Transport Pilot International 

Flight Language Experiences, Report 4: 

Non-Native English-Speaking Controllers 

Communicating With Native 

English-Speaking Pilots

DOT/FAA/AM-10/12

Office of Aerospace Medicine

Washington, DC 20591

OK-10-0077-JAH

Federal Aviation

Administration
NOTICE

This document is disseminated under the sponsorship 

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

of information exchange. The United States Government 

assumes no liability for the contents thereof.

___________

This publication and all Office of Aerospace Medicine 

technical reports are available in full-text from the Civil 

Aerospace Medical Institute’s publications Web site: 

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

Technical Report Documentation Page 

1. Report No. 2. Government Accession No. 3. Recipient's Catalog No. 

DOT/FAA/AM-10/12 

4. Title and Subtitle 5. Report Date 

August 2010 

6. Performing Organization Code 

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

Report 4: Non-Native English-Speaking Controllers Communication With 

Native English-Speaking Pilots 

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

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

1

FAA CAMI 

P.O. Box 25082 

Oklahoma City, OK 73125 

2

Capt. A Campbell 

Johns Creek, GA 

30022

3

Hendrix & Hendrix 

Consulting Services 

Roswell, NM 88201 

 

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

FAA Civil Aerospace Medical Institute 

P.O. Box 25082 11. Contract or Grant No. 

Oklahoma City, OK 73125 

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. 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. This report is a compilation of 

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

their difficulties in international operations. In this report, their responses to questions 39-45 are presented as a 

compiled narrative. We derived six major thrusts: (1) The English language proficiency of non-native Englishspeaking controllers may be inadequate for high workload conditions; (2) Pilots develop and use different 

strategies to improve ATC communications once they determine the controller’s language proficiency; (3) Pilots 

describe ATC communications between users of the same and different languages; (4) Language switching 

distracts pilots and limits understanding, adversely affects situational awareness, leaves them with feelings of 

uncertainty, and increases their workload; (5) Language barriers most affect situational awareness just prior to 

top-of- descent and during taxi; and (6) How pilots compensate for reductions in situational awareness. We offer 

16 recommendations to improve communication practices ranging from developing standardized and secure 

English language testing for use by all ICAO member states, to realistic emergency and nonroutine scenarios and 

simulations demonstrating use of conversational English to enhance datalink for surveillance and 

communications.

 

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 38 

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

iii

Acknowledgments

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

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

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

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

Division (AAM-500) of the Civil Aerospace Medical Institute. 

We thank all the people at American, Continental, Delta, and United Airlines who were instrumental in the 

success of this project – especially the 48 U.S. pilots who participated in the interviews. Among these pilots were 

several who participated in the discussions either shortly after returning from international flights, left immediately 

after the interview to be part of international flight crews, or 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, and Theresa While and Audrey Thomson (AMA-800) for their 

expertise in coding pilot data. 

Finally, we thank the staff at Xyant Technologies for transcribing the many hours of voice tapes and written responses into Excel© spreadsheets.

v

Contents

RESULTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Section 6: Non-Native English-Speaking Controllers Communicating With Native English-Speaking 

Pilots. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Q39. How would you characterize voice communications between international non-native Englishspeaking controllers and native English-speaking pilots?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Q39a. When you hear international non-native English-speaking controllers, what tells you whether 

they are high or low in English language proficiency?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Q39b. If you suspect an international non-native English-speaking controller’s English language 

proficiency is low, what do you do to improve understanding?. . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Q40. How might native English-speaking pilots’ communications with international non-native 

English-speaking controllers differ from that of pilots and controllers who speak the same 

language?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Q41. During a typical international flight, about how much time do native English-speaking pilots 

and international non-native English-speaking controllers spend talking as compared with 

pilots and controllers who speak the same language?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Q42. Do international non-native English-speaking controllers have to communicate differently with 

native English-speaking pilots than pilots who speak their local (native) language?. . . . . . . . . . . 12

Q43. To what extent has hearing a non-native English-speaking controller switch between languages 

posed a problem for you?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Q44. Describe how your situational awareness is affected by changes in your ability to understand 

the language(s) being spoken over your communications system.. . . . . . . . . . . . . . . . . . . . . . . . 17

Q44a. When do changes in your ability to understand the language(s) being spoken over your 

communications system most affect your situational awareness?. . . . . . . . . . . . . . . . . . . . . . . . . 19

Q45. What do you do to compensate for any reduction in situational awareness?. . . . . . . . . . . . . . . . 21

DISCUSSION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

vii

EXECUTIVE SUMMARY

This is the fourth report from a series of reports that 

presents the findings from in-depth interviews with 48 

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

A second series of reports used the same format and questions with pilots who fly for Aeroflot, Alitalia, China Air, 

and LAN Chile airlines.

English language proficiency is a safety concern as 

noted by the International Civil Aviation Organization 

(ICAO 2004). Given that international flight operations 

are increasing, it is important to know more about the 

language experiences U.S. pilots encounter when flying 

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

traffic controllers, and pilots. 

Several major U.S. airline companies were asked to 

solicit volunteers from among their international pilots 

to serve as paid subject matter experts in a structured interview constructed to assess the language difficulties they 

encounter during international flights. There were 12 pilots 

from each airline, representing American, Continental, 

Delta, and United Airlines, for a total of 48 airline transport 

pilots (ATPs). These pilots were assumed to be representative of typical U.S. airline pilots flying internationally as 

to English language proficiency, familiarity with ICAO 

and aviation procedures, terminology, and standard air 

traffic phraseology. We limited the size of each interview 

to include no more than four pilots. There were morning 

and afternoon sessions that took place over several days 

at each company’s preferred location. 

The structured interview was divided into 10 sections: 

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

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

Meaning and Pronunciation , (5) Language Experiences 

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

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

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

(9) Communication Problems, and (10) Technological 

Intervention. A copy of the interview questions appears 

in Prinzo and Campbell (2008).

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

written responses to the questions contained in Sections 

1-3, the second report continued with Section 4, and the 

third report summarized the pilots’ responses to questions 

in Section 5. This report continues with the U.S. pilots’ 

responses to questions found in Section 6. It provides a 

wealth of information related to their flight experiences 

when communicating with controllers who speak English 

as a foreign language. It provides an overall description 

of how these communication exchanges affected their 

perceptions of safety, communications, workload, and 

situational awareness.

The pilots’ answers to the questions and discussions 

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

and some were relayed in third person. The analyses of 

those discussions and written responses are summarized 

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

compendium of flight experiences. This was done to 

preserve the richness and integrity of the information 

given during the interviews.

The pilots listed 21 different non-native English languages that they heard during their international flights, 

with Spanish and French listed 22.60% and 19.86%, 

respectively. When asked about their overall non-native 

English-speaking language experiences, 21% reported 

their language experiences with controllers who spoke 

English as a foreign language could use some changes, 

and 31% said their experiences were not good enough 

for extreme conditions such as an emergency or avoiding 

weather. None of the pilots reported communications as 

extremely poor.

The pilots’ responses had six major thrusts: 

(1) Some non-native English-speaking controllers’ 

English language proficiency may be inadequate for high 

workload conditions. The controller’s English language 

proficiency becomes readily apparent during periods 

of adverse weather, heavy traffic, or when unexpected 

circumstances arise. Pilots had difficulty with some 

tower controllers’ inability to understand that either 

their aircraft or another aircraft required emergency 

services. Likewise, when faced with adverse weather or 

volcanic activity, some pilots reported en route controllers could not communicate effectively with native 

English-speaking pilots (lacked English language skills). 

The added time-pressure, anxiety, and stressors during 

these times led some pilots to use Common English in 

an attempt to be understood. In the absence of complete 

bilingualism, some controllers’ utterances became prone 

to errors and misunderstandings occurred. This in turn 

led to requests to have the message retransmitted, which 

also added more workload.

(2) Pilots develop and use different strategies to improve 

ATC communications once they determine the controller’s language proficiency. They listen to the controllers’ 

pronunciation and fluency to determine how proficient 

they are in speaking and understanding English. They 

also consider comprehension, grammar, vocabulary, 

and the controller’s projected confidence (although 

to a lesser degree). When responding, pilots said they 

speak slower, more distinctly, clearly, and sometimes 

louder. All crewmembers listen closely to all messages, 

and they may turn up the volume. When the message 

is for them, the crew will say what they thought ATC 

said. If there is a lack of agreement, they transmit either 
viii 

“Please repeat” or “Say again.” Rarely do they ask for a 

confirmation or verification of a specific element.

(3) Pilots describe ATC communications between users 

of the same and different languages. When pilots and 

controllers share the same language, communication 

exchanges seem more relaxed with very little lag time 

from the end of one message to the onset of a reply. 

They use shortened call signs, exchange salutations and 

pleasantries, and you hear occasional laughter. Some 

pilots thought more information was relayed between 

speakers of the same language in the same amount of 

time than between a native and non-native speaker.

Some U.S. pilots perceived non-native Englishspeaking controllers took longer to answer their questions because they were taking calls from local pilots 

first. Both the English-speaking pilot and non-native 

English-speaking controller slowed down their speech 

rates and kept their transmissions brief and concise, 

using ICAO phraseology. Radio discipline was the rule, 

rather than the exception. Controllers might be more 

inclined to ask local pilots to deviate from their route 

than foreign pilots. Talking to a foreign pilot in English 

could take more time and effort, create stress, and still 

result in miscommunication. 

(4) Language switching distracts pilots and limits 

understanding, adversely affects situational awareness, 

creates uncertainty, and increases workload. When pilots 

enter into a foreign country’s airspace, they may hear 

the controller speaking in English and then communicate with a local pilot in their native language. This 

language-switching poses a problem for any pilot unfamiliar with the local language – a disadvantage because 

it is not easy to identify the controller from among the 

other speakers; when one speaker begins and another 

ends, it is often difficult to recognize words, phrases, 

or relevant information. More attention is diverted to 

listening to the radio than “aviating,” navigating, or 

performing station-keeping tasks. The pilots need to 

listen to the radio to understand how the conditions 

outside their aircraft may affect their flights.

By listening to ATC instructions, clearances, reports, 

and other information broadcast over their radios, pilots 

learn about the weather and traffic in their vicinity and 

develop expectations regarding their own communications with that controller. Failure to understand leads to 

a feeling of uncertainty. If one pilot is 30 miles in front 

of another aircraft and reports turbulence at 35,000 feet, 

then the pilots following may not want to remain at that 

same altitude. Knowing what is ahead allows them to 

request adjustments to their flights. Since the pilots do 

not understand the language, they can neither anticipate 

the turbulence nor request an altitude change to avoid a 

rough ride for their passengers.

(5) Language barriers most affect situational awareness 

just prior to top-of-descent and during taxi.1

 When pilots 

were asked to rank-order different phases of flight most 

affected by language barriers, their viewpoint involved 

threats to safety first and, for some, loss of employment 

second. It is during the top-of-descent that pilots are 

most dependent upon timely communications from 

ATC. It is at this time they receive their clearance and 

begin planning their arrival to the destination airport. 

They need to be fully cognizant of events that may impact their arrival, and communicating with controllers 

whose language skills are inadequate or who provide 

ATC services in multiple languages may jeopardize their 

situational awareness. When on the airport surface, in 

addition to scanning their instruments, completing 

safety checklists, and observing other aircraft movement, they might be copying a clearance from a heavily 

accented or less-proficient controller or listening to the 

controllers as they talk in their native language, both 

of which add to the workload and limit situational 

awareness.

(6) How pilots compensate for reductions in situational awareness. When we asked pilots what they do 

to compensate for any reduction in situational awareness, they said they conduct a complete and thorough 

ground and pre-flight preparation and review, increase 

their vigilance and attention, and apply their best 

practices to operational communication with ATC. 

All flight crewmembers are expected to draw on their 

experiences and help disambiguate ATC transmissions 

and contribute to situational awareness. Traffic collision avoidance system (TCAS) is an enhancement to 

situational awareness – pilots correlate ATC communications with other aircraft with the targets on their 

display and alert the controller, should any become a 

threat.

Finally, we present 15 recommendations derived from 

the pilots’ responses to the interview questions and discussions. They are: (1) Support standardized, consistent, 

and secure English language-testing standards for use by 

ICAO member states; (2) Develop realistic emergency and 

nonroutine scenarios and simulations that require controllers (and pilots) to demonstrate their use of conversational 

English. These scenarios and simulations should be added 

to existing or new instructional and training programs, 

as well as to refresher training; (3) Provide pilots with the 

opportunity to listen to ATC messages and conversational 

English spoken by non-native English-speaking controllers in English. Priming the pilots in the languages they 

will be hearing over their radios may facilitate decoding 

1 Pilots were asked to determine when changes in their ability to understand 

the language(s) spoken over their communications system most affected their 

situation awareness by rank ordering a list of 12 phases of flight from 1= 

most affected to 12 = least affected. The list was derived from Phases of Flight 

Definitions and Usage Notes developed by Commercial Aviation Safety Team 

(CAST)/International Civil Aviation Organization (ICAO, 2006). Although 

the phrase top-of-descent was not included, the phrase when preparing for 

descent – from cruise to either initial approach fix or VFR pattern entry was.
ix

and comprehension; (4) Expand ICAO Emergency ATC 

vocabulary and phraseology and create datalink messages 

beyond “PAN-PAN, PAN-PAN, PAN-PAN,” “MAYDAY, MAYDAY, MAYDAY” or “CONDITION RED 

MAYDAY, MAYDAY, MAYDAY.” When pilots declare 

emergency situations, they need a set of phraseology to adequately express to controllers what they need for ensuring 

a safe, efficient, and effective outcome; (5) Publish a common, universally accepted, and comprehensive aviation 

thesaurus by CAST/ICAO. It would include definitions 

of standardized concepts, vocabulary, phraseology, and 

procedures; (6) Provide Notices to Airmen (NOTAMs) 

in the native language and in English in a standard and 

consistent format for use by all ICAO member states; 

(7) Exploit datalink capabilities to provide pilots with 

enhanced situational awareness. In particular, instructions 

and clearances conveyed in the native language can be 

correlated with that aircraft’s flight identifier transmitted 

by automatic dependent surveillence (ADS) broadcast 

technology and displayed graphically and in real time 

using cockpit displays of traffic information (CDTI); 

(8) Develop a digital datacom message repository that 

pilots can access to review recent messages sent to other 

aircraft within a defined distance (to be determined). It 

would provide the same information currently available 

over their radiotelephony party-line communications, 

but it would be presented as text in English. This information could replace the information lost by language 

switching, help maintain situational awareness, and allow pilots to anticipate future clearances, instructions, 

weather, turbulence, traffic, and other developing events; 

(9) Develop new ICAO phraseology for pilot requests for 

ride reports. Pilot reports (PIREPS)2

 provide ATC with 

valuable weather information experienced by pilots during 

their flights that is relayed to ground weather stations. In 

the U.S., some of this information is shared with pilots 

who request a “ride report.” Ride reports do not exist in 

China and may not exist in other countries. Requests for 

ride reports are common in the U.S. Since there is no 

required phraseology, non-native English controllers are 

at a disadvantage understanding what information U.S. 

pilots are requesting. 

2 PIREPs include reports of strong frontal activity, squall lines, thunderstorms, 

light-to-severe icing, wind shear and turbulence (including clear air turbulence) 

of moderate or greater intensity, volcanic eruptions and volcanic ash clouds, 

and other conditions pertinent to flight safety.

Examples of some requests include, “How’s the ride 

sound today?” and “What kind of ride reports have you had 

on climb outs?” (10) Develop structured ATC phraseology for providing pilots with ride report information. In 

response to pilot-requested ride reports, U.S. controllers 

use a combination of aviation and Common English. 

Presently, if weather is not a factor, some controllers might 

convey that information using the following examples, 

“No complaints,” “Some deviations along your route,” and 

“It should be okay.” Again, non-native English-speaking 

pilots would be at a disadvantage understanding what 

was said over the party line. Any information related to 

a ride report should have a predictable format and structure; (11) Develop new ICAO phraseology for use when 

normal operations are disrupted. In particular, controllers 

need to know what the pilots need during these times. A 

review of off-nominal events may shed light for crafting 

standardized pilot requests; (12) Develop a universal 

dialect for spoken messages. Location names should have 

one agreed-upon pronunciation; (13) DataCom messages 

should be non-ambiguous to all pilots and controllers; 

(14) DataCom spoken and written messages should 

contain no more than two communication elements; and 

(15) Research studies are needed to determine whether 

issues exist in the interpretation and execution of spoken 

or written clearances and instructions. In particular, the 

following questions should be answered:

a) Should pilots and controllers be provided with 

displays that present ATC messages in English only or 

English and their primary language?

b) Should ATC messages be presented orally or visually as text/graphics, or both?

c) How should ATC messages be presented to best 

capture the intent of the message to controllers and 

pilots? 

d) What is the best approach to convey the finesse 

of a flight operation (e.g., management of flow)?

e) How do we test messages to ensure the intended 

action is executed by pilots and controllers who share 

the same, as compared with different languages, cultures, 

or both? 

1

United States Airline Transport Pilot International

Flight Language Experiences

To effectively communicate, we must realize that we are all different in the way we perceive the world and 

use this understanding as a guide to our communication with others.

— Anthony Robbins (American advisor to leaders) 

This is the fourth in a series of reports derived from 

the responses made by 48 U.S. pilots about their international flight experiences during small, structured focus 

group interviews. It continues with question 39 and ends 

with question 45. These questions asked pilots about 

their language experiences with controllers who spoke 

English as a foreign language. The pilots were asked to 

imagine flying into a country where a language other than 

English was the primary language. Although controllers 

would speak English to them, they might speak to local 

pilots in their country’s primary language. As a result, 

the U.S. pilots might hear several different languages on 

any given frequency.

The first report (Prinzo & Campbell, 2008) provided 

an analysis of the first three sections of the structured 

interview: 1) Background Information related to the 

recency of international flight experiences among the 

pilot-participants; 2) General/Preflight Preparation; 

and 3) Air Traffic Control (ATC) Procedures. It covered 

the U.S. pilots’ responses and discussions of questions 

1-23. The second report (Prinzo, Campbell, Hendrix, 

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

experiences when word meanings and pronunciation became barriers to efficient and effective communication. It 

covered the pilots’ responses and discussions to questions 

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

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

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

It addressed their language experiences in non-native 

English-speaking airspace and airports. 

Some of the questions asked pilots to select from 

among a list of alternatives that best reflected an aspect 

of their flight experiences and information to support 

their selection, while other questions asked them to 

provide examples or describe a particular event. When 

possible, the content was tabulated and presented in tables. 

Likewise, when their discussions of a particular question 

appeared to address similar topics with a shared issue or 

concern, we grouped them together and its core issue, 

or concern, was extracted and labeled. Topics within an 

issue, or concern, are presented alphabetically, as is the 

issue or concern. 

The pilots’ responses were combined, condensed, 

edited, and presented in the form of a narrative from the 

perspective of a hypothetical, albeit typical airline pilot 

with an ATP1

 certificate; redundancies were removed to 

1 An Airline Transport Pilot 

improve readability. As various times during the interviews, one or more of the pilots might be asked for additional information or to clarify some point during the 

discussions. In most cases, the question was asked of an 

individual pilot, but there were times when all the pilots 

in a group were asked, and it is duly notated in the text. 

RESULTS

Section 6: Non-Native English-Speaking 

Controllers Communicating With Native EnglishSpeaking Pilots

The questions in this section of the interview focused 

on the English language proficiency of non-native Englishspeaking controllers and how well they communicated 

with pilots who were native speakers of English. For 

example, a controller in Mexico might speak in Spanish 

to Aero México pilots and English to pilots flying for 

British Airways or Qantas Airways. We explored how the 

controllers’ communications affected pilots’ perceptions 

of safety, the communication process, and situational 

awareness.

39. How would you characterize voice communications 

between international non-native English-speaking 

controllers and native English-speaking pilots?

As shown in Table 1, only 48% of the respondents 

indicated voice communications were either “excellent” 

(4%) or “very good” (44%), while 52% perceived it 

either “could use some minor changes” (21%) or was 

“not good enough for extreme conditions” (31%) such 

as an emergency or avoiding weather. None of the pilots reported communications with these controllers as 

“extremely poor.”

Communication Is Excellent Explanation

It Depends on the Area

The controllers I deal with in Europe and in the 

North Atlantic are excellent. In fact, most non-native 

English-speaking controllers are excellent; but that 

can be attributed to the airports our Company flies to.

Very Good In Most Respects Explanation

Of the 21 respondents, 62% provided a rationale for 

their response selection. Those who did not indicated 

they had nothing new to contribute.
2 

Controllers Make Effort to Communicate

I find that most controllers try hard to speak English intelligibly. I really think they want to do the 

very best they can and really try to adhere to ICAO 

phraseology, and it doesn’t present a problem. When 

asked to “say again,” the repeat is usually slower and 

more intelligible.

It Depends Upon the Situation – Routine or Unusual

All controllers are very good during routine communications. It’s only when nonroutine events 

occur that we have problems getting controllers to 

understand that we may have to make a missed approach because our cabin crew is not ready to land, 

etc. Certainly, they don’t deal with these situations 

every day; we don’t deal with them everyday either. 

Occasionally, when things get really tense, our 

excitement level may be higher, and we may lend 

ourselves to slang or nonstandard terminologies. 

That’s when communication goes out the window. I 

think sometimes ATC does not understand we need 

to divert or must declare an emergency, and they’d 

probably rather hear us say “Mayday.”

Multi-Language Frequencies

Radio protocol lost

An English-speaking pilot can ask a controller a 

question, and a lot of times another local carrier will 

interfere – just jumps right in – so we have to wait, 

and wait, and wait, and finally get an answer. That 

happens quite a bit; controllers will answer native 

pilots several times while English-speaking ones go 

unanswered.

Everyone gets stepped-on

The controllers do get “stepped on” a lot; and when 

there is a lot of conversation going on, that causes a 

little bit of a problem.

Some Places Are Better Than Others

The international controllers are very good in most 

respects. But how well they understand English depends on where it is – some places are better than 

others. Going into Canadian and Caribbean airspace 

is pretty good. Some areas we go through in South 

and Central America, maybe not quite as much.

We Complain Although It’s Really Very Good

We fly to about 10 international destinations, use the 

same routes, and the same pilots tend to fly them, so 

it tends to be fairly standard. [The] same routes lead 

to few surprises. Routine communications are very 

good in most respects. I have never felt in jeopardy 

due to a language difficulty. 

Because we live in a jaded world, we complain. 

I just don’t see any issues in radio communication. 

We get the job done; we don’t declare too many 

emergencies due to communications problems, and 

there certainly aren’t any accidents most of the time. 

Using datalink for weather deviations

Interviewer: How often in a 6-month period have you 

heard other crews use, or have you had to think about 

using emergency authority to get a clearance because of 

language difficulties?

That is a good question. I talked to a crew last week 

returning from Beijing that had to do exactly that. 

And I agree that the Datalink is a non-ambiguous 

way of communicating; it is in some ways slower. 

Table 1. Perceptions of Voice Communications Between Non-Native English-Speaking Controllers and 

Native English-Speaking Pilots

Voice 

Communications 

Number of 

Pilots Issues Discussed 

Excellent 2 It Depends on the Area 

Very good in most 

respects 21 

Controllers Make Effort To Communicate 

It Depends Upon the Situation – Routine or Unusual 

Multi-Language Frequencies 

Some Places Are Better Than Others 

We Complain, But It’s Really Very Good 

Could use some 

minor changes 10 

Different Dialects and Language Proficiency Affect Understanding 

It Depends Upon the Country and the Situation 

Universal Phraseology Is Lacking 

Not good enough for 

extreme conditions 15 

Controllers Lack Concept of Avoiding Weather 

Controller Workload Increases 

In Heavy Traffic, Forget Smooth Communication 

Normal Situations Okay – Distress Situations May Not Be Understood 

Situational Awareness Decreases 

Extremely poor 0 
3

When you have a weather deviation, you put in 

a request; and then you’re sitting there waiting for 

something to happen. And if it doesn’t happen quickly 

enough, you have to make a move and hope if you 

eventually have to declare an emergency, you will. 

If you’re actually speaking with someone, you can 

say, “I’ve got to turn now.”

Interviewer: But you have use of emergency authority, 

for example; because of communications problems, it’s 

not used all that often.

No, but I would caveat that statement with the fact 

that the deviation is occurring without a clearance, 

and the backup is, “I’m going to say I’m using my 

emergency authority.” But you’re not using the word, 

declaring it over the radio, until someone requests, 

“Why are you where you’re at?” Then you explain, 

“I had an emergency, I was getting too close to 

dangerous weather.” 

You don’t typically throw the word emergency out 

when you’re deviating from what you’re doing without the clearance until you’re questioned about it. If 

procedures were applied by the book properly, pilots 

would state the fact they are using an emergency 

authority to deviate from their current flight track. I 

think it would be documented much more frequently 

if it was done in that order, where the pilot declares 

an emergency before starting the deviation.

Interviewer:I have a question about using the datalink 

for weather requests. If there is a weather condition, what 

is an acceptable delay period for getting that information 

and what would exceed it?

It depends, probably about a minute. Your radar 

looks out pretty far, and you’re using it to make these 

kinds of decisions. Sometimes weather changes 

quickly, or when you get in closer, you realize it is 

not giving you an accurate painting of the weather2

– it’s worse than you thought.

Could Use Some Minor Changes Explanation

Different Dialects and Language Proficiency 

Affect Understanding

We’re all speaking the same language; we’re just 

speaking different dialects of it and with different 

levels of proficiency. The degree to which we understand one another is going to determine how effective 

communications are. If both people are proficient 

and speak the same dialect, the level of understanding is going to be high; and safety enhanced. If they 

speak different dialects or a native English-speaking 

person speaks with a non-native English-speaking 

person, their dialects are probably different. The 

chance that they are going to get something wrong 

or misunderstand something becomes much higher.

It Depends Upon the Country and Situation

Not all controllers speak English well. We’ll be talking to a Panamanian controller who speaks English 

2 The reader should also consider the possibility that inaccuracies may occur 

when pilots only receive limited instruction on the proper use of weather radar 

or make faulty inferences (see www.cad.gov.hk/reports/main3.pdf).

as though from the States – it’s real clear that he 

understands us. 

Sometimes we hear a controller who just doesn’t 

say [a phrase] right, or has an accent that differs from 

the one from Panama, and that’s okay, but does he 

understand? It’s hard to know until we ask something 

out of the ordinary and then judge it from the response 

we get or don’t get – we just have to be careful and 

resolve ambiguity. 

But let’s face it – when it’s time critical or out of 

the ordinary, I’m not sure the message gets through. 

If ATC could expand vocabulary outside the ICAO 

ATC phraseology to include conversational English, 

then when we ask a question that’s outside the norm, 

controllers might better understand our situation. 

Universal Phraseology Is Lacking

There needs to be more of a common universal 

phraseology in ICAO. Just as Chicago and the Northeast Corridor have their own procedures and way 

to do things – every country has its own nuances as 

well. Some use ICAO, some use ICAO with some 

parts of TERPS,3

 some use PANS-OPS.4 It would be 

nice if they all used the same standard. 

We need standard phraseology for all communications; terminology needs to be the same. I’d like a fix 

to be called a “fix.” We’re after the same thing in all 

languages. The French way of pronouncing versus 

the American, which is best? Just tell me how you 

want it pronounced, and I’ll adapt to the standard.

Not Good Enough for Extreme Conditions 

Explanation

Controllers Lack Concept of Deviation for Weather

I’ve found that when the operation becomes nonstandard or the weather gets bad, some controllers 

cannot communicate effectively with native Englishspeaking pilots. Last year, I had a lot of problems 

trying to get around hurricanes and thunderstorms. 

The controller did not really understand exactly where 

we were and that there were other aircraft dealing 

with the same problem – and at one point I was 

concerned that maybe he mixed up who was who.

Interviewer: How were you getting a sense he was not 

getting what you needed? What did he do that would 

be evidence of that?

He was calling another flight back instead of us. 

And I don’t know if he was just misunderstanding or 

something else; we really got the impression that he 

did not understand our location. We had just given 

a position report, and he had us in radar contact; it 

must have been radar contact because that made it 

even more a concern for us that he did not understand 

which aircraft was which. And deviations – in one 

3 Terminal Instrument Procedures

4 Flight Procedures (PANS-OPS, Doc 8168; ICAO, 2006) and the Procedures 

for Air Navigation Services – Air Traffic Management (PANS-ATM, Doc 

4444; ICAO, 2007).
4 

minute he would say we couldn’t and then the next 

minute he would clear us; but he would clear us in 

the opposite direction of where we wanted to go.

That’s another case where TCAS is very valuable – 

to verify that you aren’t interfering with offset traffic. 

Weather issues often are very challenging in foreign 

airspace.

Controller Workload Increases

When there are only two airplanes it’s not a problem. 

However, if there is a storm or something special going 

on and the controller is talking in the native language 

to local aircraft in the approach control corridor and 

everybody’s maneuvering around the weather, it’ll be 

really frustrating not knowing what is being said to 

the other airplanes. We’re out there trying to figure 

out what’s going on, “Am I going to be able to get to 

the airport? If there’s weather, where is everybody else 

going?” We can’t ask because we don’t know what’s 

happening and don’t speak the local language.

An example is an arrival to Lima, Peru. Their radar 

was not very good; one aircraft is coming out from 

Lima on the same airway we’re on coming in. They 

had to wait. ATC kept calling him for DME5

 – “What’s 

your DME from Lima VOR?”6

 And we’re coming in – 

“What’s your DME from the Lima VOR?” We’re not 

going to be able to descend until his DME is more 

than our DME. 

That is not a problem if you can understand it in 

English; but if ATC is speaking Spanish to this guy and 

we’re 68 miles from the airport and still at 33,000 

feet – we’re in for trouble. We know that because 

we see this guy on the TCAS.

In Heavy Traffic, Forget Smooth Communication

Significant traffic volume, maintaining an arrival 

or departure, with significant weather requiring 

deviations around a standard path, is more than 

many foreign controllers can handle. The time delay between a request and a response sometimes is 

unacceptable. So, we declare over the frequency for 

everybody to hear – “We’re coming left heading so 

and so to go around some weather; and we’re at this 

altitude.” The delay from completion of a transmission to comprehension of meaning can be significant 

during high tempo ops. 

Unacceptable lag times

Interviewer: When you talk about the time being 

unacceptable, what timeframe? 

It depends, a lot of times it has to do with frequency 

congestion. The non-radar environment is where 

it has become necessary to do exactly that. In the 

Eastern Caribbean and Saint Lucia, where they’re nonradar and there are build-ups, airplanes are moving 

around; ATC has us on a 41⁄2-degree flight path at a 

steep descent angle to the runway, and we haven’t 

5 Distance Measuring Equipment

6 VHF Omnidirectional Range

started the descent. In those types of situations, we’re 

literally being blocked by other transmissions. Or, if 

we put the request in and have not gotten a response 

back in a minute or so, then it becomes an issue. 

We declare what we’re doing at that point; we have 

a legitimate emergency.

Normal Situations Okay – Distress Situations 

May Not Be Understood

I do not deviate from the flight plan with any nonnative English-speaking controller unless it is an urgent 

situation. In normal situations – and that is 99.9% of 

the time – everybody’s pretty happy; everybody gets 

what they want. 

If we had an emergency and needed certain services, 

it would be difficult to communicate that in certain 

parts of the world. I would anticipate tons of trouble 

because there could be some pieces missing in the 

communication that could cause a serious problem. 

I had an emergency in Mexico and it took 15 minutes to get it explained. We had hot brakes after an 

abort. A fire truck showed up but didn’t see any fire, 

so it was leaving and we’re telling the controller, 

“No, get them back here.” We couldn’t get across 

to him why we needed it to stay. We finally got our 

company operation personnel to call and explain in 

Spanish why they had to be there.

Interviewer: Was it the ground personnel that didn’t 

understand or the tower controller as well?

The tower controller knew we had an emergency; but 

we weren’t going up in flames so why did we need a 

fire truck? We couldn’t explain the precaution to him.

In extreme conditions where the task loading is such 

that we have to do what we have to do – listening 

and trying to decipher communications is going to be 

low on my priority list. The higher priorities are flying 

the airplane, what we’re going to do, and clearing 

everybody out of the way.

Situational Awareness Decreases

It’s not good enough for extreme conditions; when 

things break out of the normal ICAO structure nonnative English-speaking controllers don’t do very 

well. When they talk in their own language to local 

aircraft, English-speaking pilots lose the “big picture.”

39a. When you hear international non-native Englishspeaking controllers, what tells you whether they are 

high or low in English language proficiency?

Two subject matter experts7

 (SMEs) and the first author (Coder 1) independently coded the pilots’ responses 

using Doc 9835 Manual on the Implementation of ICAO 

Language Proficiency Requirements (ICAO, 2004). Key 

words served to filter pilots’ comments and remarks. For 

7 One SME is an instructor at the FAA International Training Office, and the 

other provides aviation English training to controllers and flight personnel. All 

of the coders are very familiar with the language proficiency scales.
5

example, one pilot reported using how controllers pronounced words, while another pilot considered the verb 

tense and grammar of the controller’s utterance. The key 

words “pronounced words” was coded Pronunciation, 

while “verb tense and grammar” was coded Structure. This 

process was performed on 94 pilot comments.

Coder 1 was unable to categorize seven of the comments 

into any of the six categories and added two more categories: Projected Confidence and Language-Switching. 

Coder 2 was not able to categorize two comments, while 

Coder 3 categorized all 94 comments. Presented in Table 

2 are the percentages of agreement between the coders. 

Krippendorf’s alpha (Hayes & Krippendorff, 2007) was 

computed to measure the agreement among the coders 

and it was α = .81, indicating a high degree of reliability 

among them.

The eight different ways pilots tell whether a controller 

is high or low in English language proficiency, along with 

several examples of key words, are presented in Table 3. 

A chi-square test of goodness-of-fit revealed Pronunciation and Fluency were cited more often to determine if a 

controller was high or low in English language Proficiency, 

χ2(7) = 80.83, p <.05.

ICAO Language Proficiency Categories

Comprehension

When ATC is questioned by an English-speaking 

pilot, I listen to whether or not the controller continues to repeat the same words and rigidly sticks 

to ICAO standard terms; if so, I know that we’re 

going to have a problem. Also, how they reply to 

not-so-usual requests from the pilots and their ability 

to comprehend nonstandard jargon are indicators. 

Fluency

We listen to the cadence of their transmissions as 

well as the number of pauses in their transmissions, 

whether there is halting speech. Other aspects include 

timbre, inflection, emphasis, and speech rate. Typically, they speak very slowly and distinctly. 

Interaction

The amount of time it takes for ATC to answer an 

inquiry or whether we’re just handed-off. If he says, 

“Standby,” and asks his buddy what I just said – the 

time lag in responding is a good way of telling, and 

so is how quickly he understands what I just said. If 

we ask them a question and they can respond very 

quickly, then I usually know that they know exactly 

what I’m talking about. 

Pronunciation

I can tell by their ability to properly pronounce 

English names and words, as well as their diction, 

accent, and the clarity of their spoken word. Another 

factor is how clearly they communicate their message. 

If I can understand without having to ask for a repeat, 

they probably are pretty good English speakers.

Structure

Phraseology is another tip, as are correctness, 

sentence structure, and the use of proper English.

Vocabulary

Whether or not controllers can change their answer and their ability to communicate outside of a 

standard clearance – that is, can they deviate from 

the canned radio calls?

What does “next” mean?

One pilot provided an example using the phrase “next 

taxiway.” In his example, he used the analogy of a calendar. 

Figure 1 illustrates the ambiguity with the word “next” 

regarding a meeting next Thursday.

Today is Monday, the 7th. If I tell you I’m going to 

meet you next Thursday, am I going to meet you on 

the 10th or the 17th? 

Likewise, the same ambiguity can occur with instructions for the pilot to exit a runway. As shown in Figure 

2, which taxiway should the pilot use when issued an 

instruction to exit the runway via the next available 

taxiway or to turn [right, left] next taxiway? Would it be 

the nearest taxiway or the one after that – the next one?

Other Categories of Language Proficiency

Projected Confidence Speaking In English

I listen for the confidence in their voices and the 

deliberateness of enunciation and pronunciation. 

Some controllers don’t speak as forcefully, are 

uncomfortable with where they emphasize words, 

Table 2. Inter-Coder Agreement Classifying Pilot Judgments of Controller Language Proficiency 

Percent Agreement ICAO Categories of 

Language Proficiency Coder 1 & 2 Coder 1 & 3 Coder 2 & 3 

Comprehension 50% 100% 71% 

Fluency 91% 96% 96% 

Interaction 71% 43% 25% 

Pronunciation 94% 100% 94% 

Structure 63% 88% 67% 

Vocabulary 83% 100% 100% 
6 

Table 3. How Pilots Determine Non-Native English-Speaking Controllers’ Language Proficiency 

ICAO Categories of 

Language Proficiency 

Percentage of 

Instances 

ICAO Descriptors 

(Level 6, Expert and Level 3 Pre-Operational) 

Comprehension 6.32% 

L6 Comprehension is consistently accurate in nearly all contexts and 

includes comprehension of linguistic and cultural subtleties. 

L3 Comprehension is often accurate on common, concrete, and workrelated topics when the accent or variety used is sufficiently intelligible 

for an international community of users. May fail to understand a 

linguistic or situational complication or an unexpected turn of events. 

Fluency 25.26% 

L6 Able to speak at length with a natural, effortless flow. Varies speech 

flow for stylistic effect, e.g., to emphasize a point. Uses appropriate 

discourse markers and connectors spontaneously. 

L3 Produces stretches of language, but phrasing and pausing are 

often inappropriate. Hesitations or slowness in language processing 

may prevent effective communication. Fillers are sometimes 

distracting. 

Interaction 7.37% 

L6 Interacts with ease in nearly all situations. Is sensitive to verbal and 

non-verbal cues and responds to them appropriately. 

L3 Responses are sometimes immediate, appropriate, and 

informative. Can initiate and maintain exchanges with reasonable ease 

on familiar topics and in predictable situations. Generally inadequate 

when dealing with an unexpected turn of events. 

Pronunciation 36.84% 

L6 Pronunciation, stress, rhythm, and intonation, though possibly 

influenced by the first language or regional variation, almost never 

interfere with ease of understanding. 

L3 Pronunciation, stress, rhythm, and intonation are influenced by the 

first language or regional variation and frequently interfere with ease of 

understanding. 

Structure 6.32% 

L6 Both basic and complex grammatical structures and sentence 

patterns are consistently well controlled. 

L3 Basic grammatical structures and sentence patterns associated 

with predictable situations are not always well controlled. Errors 

frequently interfere with meaning. 

Vocabulary 8.42% 

L6 Vocabulary range and accuracy are sufficient to communicate 

effectively on a wide variety of familiar and unfamiliar topics. 

Vocabulary is idiomatic, nuanced, and sensitive to register. 

L3 Vocabulary range and accuracy are often sufficient to communicate 

on common, concrete, or work-related topics, but range is limited and 

the word choice often inappropriate. Is often unable to paraphrase 

successfully when lacking vocabulary. 

Other Categories of Language Proficiency 

Projected Confidence 7.37% Their comfort-level speaking English 

Language-switching 2.11% How often they speak their native language 

Today is Monday, the 7th. If I tell you I’m going to meet you next Thursday, am 

I going to meet you on the 10th or the 17th? 

S M T W TH F S 

6 7 8 9 10 11 12 

13 14 15 16 17 18 19 

Figure 1. When is Next Thursday? 
7

and what words they stress. They don’t speak loud 

enough when they are uncomfortable with what 

they’re saying. It is an effort for them to say things, 

and we know they are working to put their sentences 

together. We hear anxiety in their voice. 

Language-Switching

I also listen to the way the controller is talking to the 

other aircraft either in English to all of them or in his 

native tongue. Also, how often they use their native 

language and hearing them effectively control nonnative English-speaking pilots from other countries. 

39b. If you suspect an international non-native Englishspeaking controller’s English language proficiency is 

low, what do you do to improve understanding?

Respondents’ responses to interviewers’ questions and 

compiled comments from the written and interview portions of the questionnaire were grouped into four major 

categories: (1) Message Reception on the Flight Deck, (2) 

Message Production From the Flight Deck, (3) Resolving 

Ambiguities/Doubts, Requests (4), and Contributions 

From Prior Knowledge. One respondent made no comments. The list of pilot actions is presented in Table 4. 

An examination of these categories revealed 46% of the 

pilot actions centered on Message Production From the 

Flight Deck, 22% on Message Reception on the Flight 

Deck, slightly more than 20% on Resolve Ambiguities/

Doubts, and 5.75% each on Requests and Contributions 

From Prior Knowledge. 

Message Reception on the Flight Deck

I make sure everybody’s on a headset or an earpiece 

to begin with, through the departure and the arrival 

phase. (An earpiece helps me understand better. It 

takes out any technical static or anything that might 

be there.) Then, during the enroute phase, the speaker 

is always on so the other pilots can hear ATC too. 

I’ll turn the radio up and concentrate on what ATC’s 

saying, make sure we’re both listening and hearing 

and have it repeated if we don’t understand.

Message Production From the Flight Deck

It’s funny how sometimes we’ll actually get louder 

and speak slower. Speaking louder does not reduce 

repeats. It’s not as if they’re deaf; but [everyone] has 

a tendency to do that, “Well you can’t hear me, that’s 

one reason why you can’t understand me.” 

I may say my readbacks slower, more distinctly, 

and make them more easily understood than might 

be necessary if I was talking to New York or Boston 

Center. By saying it that way, I give him the opportunity to detect if I don’t understand exactly what 

it was that he wanted to convey; so we check it on 

both fronts: I read back what I think he gave me; and 

if he verifies it, it’s okay.

We speak Common English in the States, and everybody understands; so I think, “Okay, speak only 

in ICAO terms that they will understand because they 

are limited [in English proficiency].” They know air 

traffic control and they know ATC English; so speak 

ATC English slowly, clearly, and make sure they 

repeat it if there’s any doubt at all. 

Interviewer: You’re saying be aware if they only speak 

very limited Aviation English?

Right, I’ve found that [non-native English-speaking 

controllers] know about “cleared for takeoff.” They 

know about “climb and maintain.” They may be 

unsure about “radar contact.” They may not be able 

to speak to us about a unique occurrence. So, I just 

speak slowly and make sure I enunciate my words. I 

keep the questions very short and to the point. When 

Figure 2. Where Is the Next Taxiway? 
8 

Table 4. List and Frequency of Pilot’s Actions to Improve Understanding a Non-Native English-Speaking 

Controller Whose English Language Proficiency is Low 

List of Pilot Actions Frequency Reported 

Message Reception on the Flight Deck 

Crew Resource Management 

Make sure every crewmember listens attentively 4 

Confer with pilots on the flight deck about their understanding of the message 4 

Sensory and Attentional Resources 

Listen more closely; Pay stronger attention; Listen attentively using headset 7 

Turn up the volume 5 

Wear an earpiece or headset 3 

Message Production From the Flight Deck 

Speech Production 

Enunciate, remove tension from my voice; speak clearly 8 

Speak slowly 13 

Word Production 

Spell out fixes, waypoints 2 

Use the phonetic alphabet to spell fixes, waypoints, intersection names 6 

Phraseology 

Use only ICAO phrases, vocabulary, terms. Avoid slang, jargon 10 

Be succinct 5 

Give full readbacks 2 

Readback what he said so his response is only affirmative or negative 2 

Resolve Ambiguities/Doubts 

Ask for another controller, if necessary 3 

Ask for clarification or verification 3 

Make sure ATC repeats slowly fixes, clearances, transmissions 13 

Obtain confirmation of a repeated transmission or clearance 2 

Requests 

Make your requests and questions short, standard, and simple 3 

Do not ask for direct routing, ride reports, or PIREPsa 3 

Contributions From Prior Knowledge 

Anticipate the clearance 1 

Be aware that they only speak ATC [ICAO] English 1 

Hope there’s no emergency 1 

Make no assumptions 1 

Stay on expected route 1 

Try to comply exactly 1 

a Pilot Weather Report. A pilot report to FAA air traffic facilities of meteorological phenomena encountered by aircraft in flight. See the 

Aeronautical Information Manual § 7-1-20, (FAA 2009). 
9

I get an answer then I go to the next point. And then 

I use only ICAO ATC vocabulary.

Resolve Ambiguities/Doubts

If I think the controller is having a problem, I 

listen more intently, slow down my speech, speak 

clearly, concisely, distinctly, and use standard ICAO 

terminology. I do not use the local name but use the 

phonetic spelling of the fix. And I don’t add any extra 

information. We stay on the expected routing and 

accept that we’re stuck on that route.

[If I’m not sure] I’ll ask the guys sitting next to me 

what they thought the controller said. We ask for 

repeats until everybody understands the clearance. 

Occasionally we’ll hear another pilot trying to comment on what the controller is trying to tell us.

Interviewer: Does that usually work after a couple of 

times?

Yes, it does. The controller will either slow down, 

speak more clearly, or we will. However, the bottom 

line is we all have to be on the same page about 

what it is we’re supposed to be doing. I repeat his 

instructions back to him and allow him to interpret 

his instructions. “Do you want me to go here?” “Yes.” 

“Do you want me to go there from right here, or do 

you want me to stay on route to go there?” I get to 

be more exact – “What do you want me to do?”

Interviewer: So, you’re using conversational English 

for the clarification phrase?

I ask questions – not very in-depth ones. I try to 

use ICAO language. I talk slower and try to take any 

kind of tension out of my voice and ask for repeats, 

or “say agains,” as necessary.

Interviewer: Generally, in the U.S., you’ll say, “Say 

again,” or “Verify heading,” or “Was that ...,” and you’ll 

give a particular heading if that’s what it is. Do you say the 

same type of phrase with a non-native English-speaking 

controller, or do you find a different way to get that 

point across?

I try to just use two words, like “Please repeat” 

or “Say again.” If we try to elaborate, “Would you 

please say that again, or I didn’t understand that,” it 

is too much Common English. 

Interviewer: If you read back incorrectly, would they 

assume, because you are the pilot, that it’s okay – or 

would they correct you?

Domestically, I expect ATC to correct me if it is 

wrong; but outside the U.S., I wouldn’t take that 

chance. In South America a lot of times, what a pilot 

says is golden and controllers pretty much let us do 

what we ask even if it’s incorrect. I think some of it 

is their culture. That has caused a lot of accidents 

because I think pilots are asking for something 

sometimes that isn’t safe, and ATC is not going to 

question our judgment.

Requests 

I’ve found it best not to ask for PIREPs or ride reports. That would be the kiss of death trying to say, 

“What kind of ride reports do you have southbound 

on upper amber funkycratz?” Controllers are not 

going to understand.

40. How might native English-speaking pilots’ communications with international non-native English-speaking 

controllers differ from that of pilots and controllers who 

speak the same language?

The responses from 46 pilots to the written questions 

appear in Table 5. Two pilots left the question blank 

and had nothing more to offer during the discussions. 

Approximately 35% reported Radio Communication 

Protocol Differs in a Multi-Linguistic Environment 

when compared with the communications between pilots 

and controllers who speak the same language. Another 

20% mentioned differences in Speech Production. The 

responses of the remaining pilots were equally represented 

in Cognitive Aspects of Cross-Linguistic Communication (15%), Pilot Controller Interactions (15%), and 

Verification/Confirmation of Messages (15%).

Cognitive Aspects of Cross-Linguistic Communication

The speed of communication and understanding 

is probably a comfortable pace for [pilots and controllers in their native language]; but then it seems 

like they really slow down when they speak English.

Interviewer: They have awareness then?

Right, it’s fairly noticeable when they switch back 

from Chinese to English, that they slow down and 

speak a little bit differently, depending on their skill 

level.

It’s always easier if the controllers are speaking their 

first language, as opposed to their second language. 

If two Spanish people are speaking English, they’re 

going to understand each other better because they 

understand the dialect and accent better than a 

Spanish person who is speaking English to an English 

person. Same-language pilots and controllers tend to 

relax; they rapid-fire spit out the clearances. It takes 

more time for the non-native speaking controller to 

convert to English. 

Pilot Controller Interactions

Characterizing the difference between me talking 

to a Chicago controller and a non-native Englishspeaking controller – I can’t freelance, which is very 

applicable to unusual situations, unusual clearances 

and requests. I must stick to ICAO communication 

standards in that situation where communication 

is difficult. 

When pilots and controllers speak the same [nonEnglish] language, we tend to hear shortened call 

signs. I’ll hear the Spanish controllers talking to other 

Spanish-speaking pilots using jargon just as we do, 

rather than standard ICAO phraseology, and their 

tone is more casual and familiar.

If accent and terminology are the same – and some 

assumptions are understood such as, if a pilot and 
10 

controller speak the same language, they’re probably 

from the same culture and from their upbringing, will 

know culturally what is meant. I think the assumptions sometimes [between pilots and controllers] 

from countries are really different; it can be kind 

of a barrier. 

Radio Communication Protocol Differs in MultiLanguage Environments

Radio discipline is maintained more with mixed 

languages, while pilots and controllers who speak 

the same language will add greetings like, “Good 

morning,” or “So long.” They will use slang and offthe-cuff remarks like, “Hey, who’s winning the World 

Cup?” If we say, “Bon jour” in France, controllers 

will come back and say something in French. The 

more you say, the more there is a chance for error.

There’s Trouble Outside of Standard Phraseology

How much trouble do you want to create for yourself? If we’re getting a few bumps at our altitude, we’ll 

probably wait it out. We’ll keep nonstandard or nonrequired communications to an absolute minimum. 

In the U.S., we tend towards slang sometimes; and 

that cannot enter into the arena when everybody 

speaks a different language. We really need to use 

the standard terms, the standard phraseology, give 

them in the same order, and speak slowly and clearly 

to make the communications work. 

Jargon, Slang, and Buzz Words

We’re warned against using slang or jargon in any 

country. When communicating with international 

controllers, we’re told to carefully choose our wording; use nothing that can be misconstrued, avoid 

words like “emergency” and “burn.” Watch our 

speech rate; don’t use slang or nonstandard ICAO 

terms; don’t say “oh” for “zero” or “point” for “decimal.” Use standard ICAO terms (something they are 

trained in; and, hopefully, the U.S. will be [ICAO] 

someday).

Speech Production

An example – we hear “American ten sixty-four” 

call-in to a U.S. controller, but it is “American one 

zero six four” to the Mexican controller. We hear 

Aero Mexico call-in as “Aero Mexico eight sixty-four” 

to the same controller. So obviously, it’s easier for 

those who are native to the same language, and it 

takes more time if one is a non-native English-speaker 

because they use more words and speak slower.

Table 5. Perceived Differences in Communication Between Native and Non-Native English-Speaking 

Pilots and Controllers 

Categorical Differences Items 

Cognitive Aspects of Cross-Linguistic 

Communication (7) 

Awareness and attention. Speed of communication and 

understanding. Easier for controllers to speak in their native 

language. Easier when both speak the same language and the 

level of understanding between them is better. It’s much easier to 

get their points across with minimal transmission time. 

Pilot Controller Interactions (7) More formal. Less nonessential communications. Extraneous 

conversations don’t exist with different languages. Can’t freelance 

in unusual situations/clearances/requests. There may be some 

reluctance to ask for clearances that may be hard to understand. 

Tone more casual and familiar in the same non-native English 

environment – lots of chatter and some laughing – I don’t 

understand it, but it seems casual. 

Radio Communication Protocol Differs In 

Multi-Linguistic Environments(16) 

Native speakers [of English] will normally speak more slowly and 

try to enunciate clearly any transmissions, eliminating jargon 

foreign to non-native English-speaking controllers. Speak in ICAO 

standard terminology, in a clear, concise tone without additional 

comments, short and to the point. Less use of slang, off the cuff 

remarks, no pleasantries. Most languages do not translate exactly 

word-for-word. Subtle differences in meaning can creep in. Samelanguage pilots and controllers will use “slang,” but others will use 

standard. Shortened call signs, more use of jargon. 

Speech Production (9) Difference in accents and phraseology used. Speaking rate is 

slower. Speak more clearly and deliberately. Say each number – 

Delta one two three vs. Delta one twenty-three. 

Verification/Confirmation Of Messages (7) We ask short and precise questions. More frequent repeats, 

speak more slowly. Don’t make out of normal requests. More 

need for repeat and clarification. We, as native English-speaking 

pilots, can cause the same difficulties for controllers/pilots as they 

do for us. 
11

Verification/Confirmation of Messages

Interviewer: You said it’s easier for controllers to speak 

their native language than English; but in terms of how 

you handle it, you speak in a slow, clear, standard manner. Is that more or less what you do?

That’s more or less what we do. I always ask a question if I’m not completely sure of what he wants; I 

always ask, “What do you want, where?” 

41. During a typical international flight, about how much 

time do native English-speaking pilots and international 

non-native English-speaking controllers spend talking 

as compared with pilots and controllers who speak the 

same language?

Respondents’ compiled comments from the written 

and interview portions of the questionnaire are included 

below. As shown in Table 6, only one pilot reported 

English-speaking pilots spent “considerably more time” 

communicating with non-native English-speaking controllers, compared with pilots and controllers who spoke 

the same language. Another 33% reported that “more 

time” was spent, 33% reported it as “less time,” and 

15% as “considerably less time.” The remaining 17% 

reported the time to be “about the same” regardless of 

language pairing. 

More Time Spent Communicating Explanation

Twelve of the 16 respondents (75%) provided comments, of which four either misunderstood or misread 

the question. One pilot reported he was not sure what 

they talk about, and another said that although he did 

not time them, it seems more time occurred between 

non-native and native.

Repeats and Slowed Cadence

It takes more time between the native Englishspeaking pilot and the non-native English-speaking 

controllers than between the pilots and controllers 

of the same language because the native English 

speakers are constantly asking them to say again and 

repeat. The frequent requests for repeated transmissions and complex clearances take probably twice 

as much time. Short clearances with one instruction 

– an altitude assignment or heading – take about the 

same amount of time for all. 

Same Language-Many Transmissions/ Native EnglishOne Transmission

When I’m hearing Spanish-to-Spanish clearances, 

voice communications tend to be multiple clearances 

or multiple transmissions in the same amount of time 

that it takes us to make one transmission and receive 

one transmission. They might have two, three, or four 

go back and fourth to our one, because it’s easier for 

them to talk in the same language. And then we have 

all the repeated radio calls to clarify a transmission; 

that’s just the nature of the beast.

We do not fly into high-traffic environments. I could 

be on a frequency with only one or two other airplanes, and it’s not uncommon to hear them speaking 

in Spanish. There are times when we’d like to get a 

word in but can’t get on the frequency.

About the Same Time Spent Communicating 

Explanation

Of the eight respondents who selected this response, 

87.5% commented.

Radio Traffic Too Heavy for Chatting With Anyone

It’s just too busy up there and too much going on, 

so the chitchat among two native speakers versus a 

non-native speaker and an English-speaking controller has diminished over the years to more or 

less pure business communications. There are the 

same number of regular transmissions going from a 

Continental flight inbound as for a Lufthansa flight 

inbound. As long as they’re speaking English to other 

foreign carriers, whether it’s Lufthansa or United, 

they spend about the same amount of time talking 

to each airplane. It is about the same as long as the 

transmission is understood. If there is a long pause 

after a transmission, then it’s going to take some time.

Table 6. Pilots’ Perceptions of Time on Frequency Communicating Between Native and Non-Native 

English-Speaking Pilots and Controllers 

Time Spent 

Communicating 

Number of 

Pilots Issues 

Considerably more time 1 No Comment 

More time 16 Repeats and Slowed Cadence 

Same Language-Many Transmissions/Native English-One Transmission 

About the same 8 Radio Traffic Too Heavy for Chatting With Anyone 

Less time 16 

Native English-Speaking Pilots Make More “Say Agains” 

One Language May Require More Words Than Another 

Same-Language Speakers Communicate More 

Considerably less time 7 Native English Speakers Check-In, Check-Out 

Same-Language Speakers Communicate More 
12 

Less Time Spent Communicating Explanation

Approximately 81.25% of the 16 respondents offered 

explanations for their selections. 

Native-English Speaking Pilots Make More 

“Say Agains”

It probably takes more time with native Englishspeaking pilots to non-native English controllers 

because we’re asking for repeats and trying to be 

accurate. I’ll typically hear non-native Englishspeaking controllers carry on conversations with 

native non-English speaking pilots and will have no 

idea what they’re talking about.

One Language May Require More Words 

Than Another

Maybe their language uses more words to express 

the same thought. Long running conversations with 

pilots and controllers speaking the same language 

is not common with English-speaking pilots. With 

us, non-native English-speaking controllers mainly 

stick to canned and necessary communications for 

air traffic control.

Same-Language Speakers May Communicate More

If [a controller] gives what I think might be the same 

clearance given to us to a local pilot, it seems to last 

about three times longer. I don’t know if they are more 

verbose or more nonstandard. I can’t really tell, but 

it’s just the time the transmitter is keyed sounds like 

less time is spent with me than with him.

It appears that there are more communications 

among native-language speaking [controllers] to their 

native language cohorts. They speak to each other 

in their native language maybe about the nuances 

of the weather and may be more inclined to add a 

greeting, a goodbye, or a comment – “Is Joe working 

the other sector today?”

Non-native English-speaking controllers have to 

really keep it simple [with us]. We do not usually 

discuss complex nuances of weather, etc. There is 

less jargon, greetings, and “chit-chat” when I’m 

talking to them. 

Considerably Less Time Spent Communicating 

Explanation

Of the seven respondents who thought non-native 

English-speaking controllers spent considerably less time 

communicating with native English-speaking pilots, 71% 

provided comments. 

Native English Speakers Check In, Check Out

I check in, check out – end of story. I make my point 

quickly and receive my clearances. It’s less fatiguing 

for me. No “chit-chat” means less fatigue.

Same-Language Speakers May Communicate More

When language is a barrier, I interact less with the 

non-native English-speaking controllers and rely more 

on weather radar, company dispatch, or ear-to-ear 

with other aircraft. I’m not able to get the same type 

of information as I do from native English-speaking 

controllers. I think when they’re speaking with their 

own pilots, they have a familiar way of speaking and 

may add some colloquialisms.

If I speak the local language, many times I add 

something to break the ice. I’ll say, “Bon jour [Air 

Carrier] zero eight six one level three seven zero.” 

And they’ll come back with “Merci.” Maybe it’s not 

a good thing to do; but it seems like they talk more 

to their own pilots and very little with us. If language 

proficiency is minimal, extraneous conversation 

adds confusion. 

Flying over the Arabian Peninsula, we hear one of 

the PATCO8

 guys on the radio, so we relax and can 

communicate more with him. There’s no misunderstanding. That’s not the case when we’re talking with 

a non-native English-speaking controller.

42. Do international non-native English-speaking controllers have to communicate differently with native 

English-speaking pilots than pilots who speak their local 

(native) language?

As shown in Table 7, 48% of the pilots reported “yes,” 

there were differences in how international non-native 

English-speaking controllers communicated based on the 

language spoken by the pilot, 6% agreed but limited their 

responses to “sometimes” differences occur. Another 23% 

were either “uncertain” or said “no,” they did not believe 

there were differences. The remaining 23%, although they 

left the question blank, from their discussions it appeared 

that they agreed with the pilots who reported differences. 

Yes, International Non-Native English-Speaking 

Controllers Have to Communicate Differently 

Twenty-three pilots reported differences occurred at 

least sometimes in the communication process. 

Brief and Concise to Us – Longer and Faster to Natives

I think controllers use slang, accents, and speed 

when speaking to local pilots in their native language. 

It would be easier for the pilots to understand. I think 

communicating is different because of the length of 

their communication and the amount of time they talk.

I found that controllers do not answer our questions. They must speak more slowly, concisely and 

deliberately to an international group that is flying 

through their country just as we do with them. The 

communication process is different between what 

you’re accustomed to hearing and saying, versus 

being able to converse in a foreign language. 

8 Professional Air Traffic Controllers Organization – The Union representing 

U.S. air traffic controllers during the 1981 strike from which President Reagan 

fired the striking controllers who failed to return to work – many went to 

work for non-U.S. air traffic services.
13

No Common Accent, Dialect, Slang, or Jargon

A controller cannot use local slang or jargon with 

native English-speaking pilots because we won’t 

understand what the controller said. Also, since we 

don’t share a common accent or dialect, I don’t understand a word I just heard quite as clearly as from 

a controller who says that word the same way as me. 

Slower Speech Rate

I find that controllers whose speech rate is slower 

understand that to speak fast to us will lend itself to 

confusion. They want it done right the first time, so 

they speak slower to me in English than they would 

to a native pilot in their own language. Controllers 

who speak more slowly and enunciate will not have 

to make repeated radio calls and be challenged with 

pilots who ask, “What did you just tell me?” 

They Can Speak Their Common Language

I can tell a Chicago controller, “The captain tells me 

I have 10 minutes and we’re going to have to proceed 

elsewhere; am I going to make it by then?” If we ask 

that question to Magadan control,9

 we’re not going 

to get the same kind of answer. So, if a French pilot 

is talking to a French controller, I would guess the 

same off-the-page type of communication can occur 

that I have in Chicago. Then the French controller 

would have to use ICAO standard terminology for 

me to understand, but the fine details will not be 

communicated.

They Put Us on Different Frequencies

Going to Europe, I think they actually put non-native 

English-speaking pilots on different frequencies than 

the English-speaking pilots. We’re all going to one 

frequency, and we’re all going to hear each other. 

I think they do that for a reason, and I’m not sure 

what that reason is.

9 Magadan is located in Northeastern Siberia.

Sometimes International Non-Native EnglishSpeaking Controllers Communicate Differently

Three respondents reported Sometimes. All of them 

provided comments during the interviews.

It Depends on the Local Pilot’s English Skills

Sometimes there are differences that we need to 

clear up, but it’s not something that’s a real problem. When English is a problem [for a local pilot], 

controllers revert to their native language. It seems 

like they speak quickly to get it done, but they have 

to communicate in English with us.

I’m Uncertain Whether International Non-Native 

English-Speaking Controllers Communicate 

Differently 

Three respondents reported that the controllers probably communicated differently with pilots who spoke their 

language compared with how they communicated with 

native English-speaking pilots. Although initially unsure, 

during the discussions they also identified differences.

I Think They Limit Communications to 

Essentials Only

The reason that I was kind of wishy-washy about 

my response was because I do not know what they’re 

saying to each other, since it’s not in English. But I 

would assume it’s about the same [as between an 

English-speaking controller and pilot]. 

When speaking to us, it does change to just essential communications. They probably would be 

less inclined to ask me, as a non-native language 

pilot in their country, to deviate, or to go out of my 

way with a nonstandard clearance, than they would 

with pilots they knew could communicate clearly 

with them. They would have to think about how to 

say it perfectly to us, versus to a pilot who speaks 

their language. 

Table 7. Pilots’ Perceptions of Communications Between Native and Non-Native English-Speaking Pilots 

and Controllers 

Response Number of Pilots Differences in Communication Practices 

Yes 23 

Brief and Concise to Us – Longer and Faster to Natives 

No Common Accent, Dialect, Slang or Jargon 

Slower Speech Rate 

They Can Speak Their Common Language 

They Put Us on Different Frequencies 

Sometimes 3 It Depends on the Local Pilot’s English Skills 

Uncertain 6 I Think They Limit Communication to Essentials Only 

No 5 It Should be the Same as What They Say to Us, Just Easier 

No Written Response 11 

Comfort In Your Native Language 

Higher Workload Requires More Effort 

Speech Rate Slower 

Translation Takes Time 
14 

No, Do Not Believe International Non-Native 

English-Speaking Controllers Communicate 

Differently 

Of the five respondents who did not believe there were 

differences, two said we should ask the controller, while 

the others did not know what their languages entailed or 

what they were saying in their native languages. Although 

it appeared to be easier for them to communicate in their 

native language, the pilots did not believe there should 

be anything different in how they communicate.

No Written Response to the Question

Although 11 respondents did not provide a written 

response, they did discuss their experiences. Based on their 

discussions, it would appear they perceived differences in 

the communication practices between international nonnative English-speaking controllers and native Englishspeaking pilots, as compared with pilots who spoke the 

local language.

Comfort in Your Native Language

Non-native English-speaking controllers ask us [questions] if they have to; and I would say that if they don’t 

have to, they won’t. It’s just a matter of comfort using 

one’s own language.

Higher Workload Requires More Effort

I’ve found that it is harder for non-native Englishspeaking controllers to communicate in English, 

especially during times of higher workloads because 

they have to concentrate on slowing down their rate 

of speech and making sure that we understand. Their 

pilots would have the same problem coming into 

our airspace as we do going into theirs. We do try to 

make sure we understand and do what they expect 

us to do. I think it is hard for them to deal with us. 

I think non-native English-speaking controllers 

communicate in their native language when they 

deem it to be appropriate. But in most of the highdensity international arrivals and departures, they 

try to speak the same [to us as they do local pilots]. 

If I can’t understand the language being used, it’s a 

safety of flight issue. 

Speech Rate Slower

Well, now that I think about it, maybe they do tend 

to speak English slower and more clearly to the nonEnglish speaking pilots. The differences are real subtle, 

but they exist. Maybe it’s more of an effort for them 

to speak English, since it is their second language. 

We’ve got to realize that they’re speaking English 

now, but may not be used to it. We need to slow it 

down, and make sure the pronunciation is there. 

Translation Takes Time

I tend to think non-native English speakers have 

to talk more slowly and think about the clearances 

because now they have to think, translate, and speak 

in English and then hear, translate, and understand 

what we said. So, I think it takes more time to do 

that. If they are disciplined, they will attempt English 

with all the pilots. If not, the only English spoken will 

be to English-speaking pilots.

43. To what extent has hearing a non-native Englishspeaking controller switch between languages posed a 

problem for you?

As seen in Table 8, only 6% of the pilots reported 

language-switching as not being a problem for them, 

while 40% reported it as a problem to a “moderate” or 

“greater extent.” The remaining 54% said it was a problem 

“to a limited extent.” Their discussions focused on issues 

ranging from “it’s annoying” to reductions in situation 

awareness where safety degrades.

To a Great Extent Explanation

I consider the situation more severe than my colleagues 

do. I think it really decreases situational awareness.

To a Considerable Extent Explanation

Radio Protocol Lost

The fact that we don’t know when [pilots and controllers who speak the same non-English language] 

are done with a conversation can result in everybody 

stepping on each other.

Reduces Situational Awareness

When I hear non-native English-speaking controllers speaking in their native language, it reduces my 

situational awareness because I don’t know when 

the communication begins and when it ends. I know 

when they say, “[Air Carrier] one two three” that 

they’re talking to me and when they say, “[Othership] 

one two three” that they’re talking to someone else. 

But, if I hear a non-English language being spoken, 

I don’t know what they’re saying, so I must listen 

because it may come back to me. 

To a Moderate Extent Explanation

Of the 16 respondents, 94% participated in the 

discussions.

Mixed Languages – Spanglish

When controllers start switching between languages, it’s hard for them to make the change completely because many times, I hear what comes out 

as “Spanglish.10” Then I have to guess. Is he talking 

to me? If he switched to his native language due to 

stress – that is not good.

10 Spangish is the transformation of English words into Spanish ones among 

bilinguals. For example, “norsa” for “nurse,” instead of the standard Spanish 

“enfermera.” 
15

Situational Awareness Lessened

When controllers speak to pilots in their native 

language, they’re not offering us an important piece 

of the equation when they switch back and forth 

between languages. When they issue a clearance in 

their own language, we don’t know if they just issued 

a heading or an altitude, and I cannot use what I’ve 

heard for traffic avoidance and traffic awareness. 

Our situational awareness is degraded, or may be 

compromised. It’s not a comfortable feeling – I like 

to know where everybody is and how our flight is 

situated.

I don’t think it makes my job any less safe, but we 

can’t get an inference from what they’re doing to 

know how they’re going to handle us, especially 

if they’re speaking in their native language to the 

aircraft that’s in front of us, behind us, or next to us. 

The Frankfurt Incident

I originally said “not at all,” but because of something that transpired the other day, I realized that 

[language switching] did cause a problem when controllers spoke English to us and their native language 

to another carrier. Coming into Frankfurt the other 

morning, we were cleared to intercept the localizer 

at 8,000 feet. The controller was talking to everybody 

in English and cleared another aircraft to 4,000 feet 

before glide slope intercept. I’m watching the glide 

slope come down and we’re not getting cleared to 

4,000. All of a sudden, he’s talking to Lufthansa air 

cargo in German – they’re not speaking English. I 

look at the TCAS and realize that he is talking in 

German because I’ve got an MD1111 underneath me. 

The pilot was supposed to go to the right runway, 

but he overshot to the left runway. The controller 

came back and asked us if were able to get down 

11 Type aircraft.

from there because the MD11 is below us. So, it’s 

gear and flaps for us to slow down; he’s speeding up 

and sliding over, back to the right runway. Had the 

controller continued to speak in English to that pilot 

instead of switching to German, we’d have known 

the position we were in earlier and could have been 

better prepared. 

In fact I’m unhappy and wondering why they aren’t 

letting me down. So that did cause us a problem, 

at 8,000 feet, throwing out gear, flaps, and slowing 

down to 160 knots to try to keep the separation. The 

runways in Frankfurt are close together, so aircraft 

can’t be wingtip-to-wingtip on parallel approaches. 

I think you’ve got to have aircraft staggered by three 

miles. It happens rarely but that’s why when they 

switch from English to speaking in their native tongue 

to somebody; I’m looking for somebody who did 

something wrong.

Interviewer: At 8,000 feet, did you intentionally 

slow down to 160 knots, or were you told to slow?

We were told to slow. ATC wanted more separation. 

If we couldn’t slow, since he was lower, he would 

get to land, and we would go around. So we slowed 

to 160 knots, and then they came back and said we 

could accelerate back to 170 knots. So we went from 

flaps 20 to flaps five – less drag on the airplane at 

that point. But, it was at that point we not only had 

to slow down, we still had to get down to 4,000 feet 

to catch the glide slope, which had already gone by.

Interviewer: And that added to your workload at the 

same time?

Yes, everybody was really working together, and 

the cargo guy was trying to do what he could do. 

The controller was trying, too. If he had continued 

to speak in English, we would have known about the 

traffic. If the guy had said, “Okay cleared to intercept 

Table 8. The Extent to Which Language-Switching Poses a Problem for Pilots 

Alternative Number of 

Pilots Issues 

To a great extent 1 Really Decreases Situational Awareness 

To a considerable extent 2 Radio Protocol Lost 

Reduces Situational Awareness 

To a moderate extent 16 

Mixed Languages – Spanglish 

Situational Awareness Lessened 

The Frankfurt Incident 

There Is a Communication Barrier 

 To a limited extent 26 

It’s Annoying 

Knowing a Little of the Language Helps 

Languages You Don’t Know Are Distracting 

Low English Proficiency May Impact ATC Duties 

Reduced Situational Awareness – Degraded Safety 

Requires Increased Attention 

Not at all 3 

It’s a Minimal Impact Proficiency 

Know the Language or Blank It Out 

Linguistic Ability Equals ATC 
16 

runway seven left,” I could have said, “I thought you 

cleared him to seven right” – and it’s “oops.” But by 

that time, he’d already gotten over there – because I 

didn’t understand what they were saying in German 

– he had either overshot or misread the instructions 

and the controller thought he said left when he said 

right, or vice versa. But he was where he shouldn’t 

have been.

Interviewer: And without TCAS would you have stayed 

at 8,000 feet?

Yes, they would not have cleared us. They did not 

clear us until we intercepted the glide slope; and they 

had cleared us to intercept the localizer, which was 

the horizontal path, but not the vertical path. They 

hadn’t cleared us for the approach, only to intercept. 

Had they cleared us for the approach, we would have 

started down and been on top of the other aircraft. If I 

misinterpreted what he said as cleared for the approach, 

we would have armed the glide slope. When it locks 

in, we would have started down – which would have 

caused a big problem. And a lot of times, they clear 

pilots for the ILS12 approach in two separate transmissions. First, we intercept the localizer then they clear 

us to intercept the glide slope – as opposed to how we 

do it in the States. Under these circumstances, it could 

have gotten nasty. Without the TCAS, we wouldn’t have 

known he was out there. We had lost contact with the 

other aircraft; we heard it report ahead of us, but once 

he spoke German, we didn’t know where he was going.

There Is a Communication Barrier

It’s not a problem, per se, that he’s speaking in two 

different languages, but it is a concern that I’m not 

aware of clearances given to other aircraft regarding 

altitudes, aircraft ride reports for turbulence, and 

frequency changes. It’s a communication barrier. I’m 

not even sure they will understand if I ask for a ride 

report. Pilots generally ask other pilots for ride reports, but it eventually lessens situational awareness.

To a Limited Extent Explanation

Approximately 77% of the 26 pilots discussed their 

responses.

Accents

I’ve noticed that the controllers’ accents become 

thicker when switching back to English after they’ve 

spoken their native language to somebody else.

It’s Annoying

From a communication standpoint, I find it annoying, but not really a significant factor.

Knowing a Little of the Language Helps

There was one incident I was involved in while in 

the Air Force. We were dumping fuel in an emergency, 

and the controller cleared a Spanish airline into our 

airspace and our altitude – in Spanish. I caught it 

12 Instrument Landing System

and said, “Hey, do you realize that we’re over here?” 

“Oh yeah, we’ll go somewhere else.” So that was a 

case where, with my limited Spanish, I understood 

what he was saying and stopped an incident. Not 

understanding what a controller says in his native 

language could be a hazard to flight.

Languages You Don’t Know Are Distracting

It’s moderately distracting since I do have to listen to 

that conversation even though I do not understand. If 

he’s talking, I’ve got to listen or I could miss a call that 

is actually for us because it’s the same voice, same 

pitch, and accent. But in a high workload environment, 

it might cause us to not pay attention to the checklist, 

the configuration, or the FMC13 programming. 

Low English Proficiency May Impact ATC Duties

Controllers who switch from their own language to 

English and back again have to switch gears, and a lot 

of times they have to start thinking about what they’re 

going to say if they’re not terribly proficient in English. 

So there might be a delay in a clearance, an assignment of heading, or something like that. Generally, it 

is not too much of a problem in a normal traffic flow.

Reduced Situational Awareness – Degraded Safety

Being left out of the loop gives me an uncomfortable 

feeling, especially in terminal areas. We need to understand what’s in front, around, and behind us in English. 

So, it does decrease situational awareness in regards 

to other aircraft – their clearances and requests. When 

controllers and pilots talk to each other in their own 

language, it can cause a breakdown in communication 

and in the safety net because if there was a mistake in 

their conversation, I would not know if it affects us.

I heard a story of a guy catching something where 

there would have been a conflict. It’s pretty rare now 

with TCAS; however, an increase of situational awareness is a good thing any way you look at it. Without 

TCAS, it gives you less situational awareness and that 

can degrade safety.

Requires Increased Attention

I find that I use a little more attention if controllers 

talk in their own language and then skip right away 

to our call sign. Sometimes we might actually think a 

different controller is talking as he switches languages 

or that it is two non-English speaking pilots talking 

to each other over the radio. It can be hard for us to 

identify who’s actually speaking. 

Not at All Explanation

Linguistic Ability Equals ATC Proficiency

I’m just in awe of anybody who can think that fast. 

It helps with situational awareness in the terminal 

area, especially if he’s talking to [a pilot] who can 

pick out a particular altitude or fix that they are at. 

So it helps if the controller can shift back and forth. 

13 Flight Management Computer
17

It gives me confidence in his level of proficiency if 

he can think and speak that quickly.

Know the Language or Blank It Out

Because of my language ability, I understand almost 

all the controllers everywhere I go; it doesn’t present 

a problem for me. But by the same token, if they 

start speaking in a language I don’t know, I blank 

it out because I know I can’t understand what he’s 

saying and I don’t care, because it doesn’t apply to 

me. Actually, it presents more of a problem for me 

when I understand what he’s telling the other guy 

because it just automatically registers, but when they 

switch to a language I don’t understand, it is not a 

problem at all.

Minimal Impact

It doesn’t really impact me. I can’t understand what 

he says. He just finished speaking to a pilot in the 

native language, and now he’s speaking English to 

me. Do I need to be let in on their conversation? The 

only question is – where’s the other aircraft?

44. Describe how your situational awareness is affected by 

changes in your ability to understand the language(s) 

being spoken over your communications system.

The pilots’ responses from the written and interview 

portions of the questionnaire are summarized below. As 

shown in Table 9, their contributions were organized 

into 10 different, albeit related, themes, ranging from it 

being a non-issue to a hazard to flight.

Decrease in Normal Operation

When we don’t understand, there is a decrease in 

the normal operation of the airplane because we have 

to take time to make repeated radio calls – “I call you 

back.” We sit there waiting when we should have 

begun our descent 10 miles ago. Now our airspace is 

compressed, and we’re getting into a problem. These 

types of difficulties take time away from duties that 

help maintain our situational awareness, especially 

during descent to landing when we need to brief 

approaches and calculate descent profiles.

Hazard to Flight Reported in Local Language Instead 

of in English

A pilot may report a hazard to flight in a foreign 

language, and the controller may not pass it on in 

English. That is information that I’m not privy to. I 

could be missing important data relative to the location of that aircraft or reports by other pilots that 

might be nice to know but I can’t understand – such 

as a plane slid off the runway. We all incorporate that 

information to build the bubble of airspace around 

the airplane we’re operating. Things like that should 

definitely be stated in a manner where everyone can 

understand exactly what’s being said.

High Workload Times Affects Situational 

Awareness the Most

It’s been my experience that it is a considerable distraction. Sometimes the pilot not flying can’t understand 

the controller, so the pilot flying has to answer for 

him, and that increases workload. Situational awareness goes down because we’re spending more time 

concentrating on when they’re going to switch from 

speaking their native language to English. 

It’s obviously the high-workload environment where 

more communication problems are taking place than 

need to take place. For me, it’s when we’re taxiing out 

and taxiing in because both the pilot and controller 

have a high workload. There’s more aircraft on the 

frequency and more direct contact with the controller 

than during preflight, so there’s a higher chance of error.

The times most affecting our situational awareness 

are the high-workload times that crowd out the time to 

deliberately listen to any controller – and that would 

be takeoff and departure for me. It takes my attention 

away from my primary duties of what I want to do, 

and I have to focus it all on what they’re trying to say.

It seems to me that the highest chance for error in 

communications is when I’m starting with my descent 

through approach. There’s so much going on during 

that time such as having to make more responses and 

having direct contact with the controller. Also, there 

is more traffic and that causes more communication 

on the frequency.

Table 9. Changes in Pilot Situational Awareness Due to Changes in Language Understanding 

Ways Situational Awareness Is Affected by Changes in Language Understanding 

Decrease in Normal Operation 

Hazard to Flight Reported in Local Language Instead of in English 

High Workload Times Affect Situational Awareness the Most 

It’s Not a Problem 

Loss of Clarity of Language 

Multi-Language ATC Is Confusing 

Multi-Language Crewmember Can Help or Hinder 

Situational Awareness and Cockpit Duties 

Taxiing Amid Airplanes Without Knowing Where They’re Going 

TCAS and Technology Aid Situational Awareness 
18 

It Is Not a Problem

It would be huge distraction if we heard somebody 

was cleared across our runway. It is not affected so 

long as we ascertain that the communication was 

correct. In other words, if we’re comfortable with 

what we just heard, it’s generally not a problem. If we 

doubt what we heard, we need to have it clarified.

Interviewer: If the instruction was spoken in a different 

language, you wouldn’t know anyway.

Right, and quite honestly, at that point we’re not 

really listening to the controller. We are flaring and 

unless we hear the words go around or overshoot, 

nothing is going to change what we’re about to do 

at that point. Landing is a relatively low workload 

time; there’s really not that much to do except physically manipulate the controls and land the airplane.

Loss of Clarity of Language 

I am much less complacent overseas due to language comprehension problems and getting a consensus in the cockpit as to what the controller said. 

Situational awareness is directly proportional to the 

clarity of the language – all the languages spoken 

on the frequency. If we can hear it and understand 

it, our situational awareness is great; and if we can’t, 

[it may be nonexistent].

Multi-Language ATC Confusing

To get the proper separation in [name city], sometimes controllers give short vectors on a tight turn to 

runway zero five. We don’t know if that is what he’s 

doing to the guy in front of us or not. If controllers 

are talking to a local aircraft in their own language, 

we have no idea if it is on the ground, in the air, or 

departing. Where is the weather? So, multi-language 

ATC is a very dangerous situation, and I think it 

should be outlawed. 

Multi-Language Crewmembers Can Help or Hinder

If we’re the only English-speaking airplane and there 

are a whole bunch of airplanes out there, situational 

awareness can deteriorate to almost zero when we 

don’t understand what’s going on. If we’re lucky, we 

might pick up some local language or have a multilanguage co-pilot who can interpret for us. There is 

a benefit if one of us has even a limited knowledge 

of the local language – it augments our situational 

awareness. Going into Mexico once, a controller 

gave holding instructions to me in English and to 

an Avianca in Spanish – to the same fix at the same 

altitude. I was able to pick that out.

The problem with that is there is only one pilot 

interpreting the clearance instead of two pilots. I 

don’t want my co-pilot speaking the local language 

for that reason.

Situational Awareness and Cockpit Duties

It’s as if we’re in a dark room and having somebody 

turn on a light. If we understand where the other 

people are, what they’re doing, or where they’re 

expected to be, that’s the answer to the test. Being 

in the dark, we only get bits and pieces instead of 

the full picture of the situation that we need [to 

maintain a safe flight]. 

For example, an aircraft is on the same frequency 

as me, doing the same approach, coming into the 

same airport except I’m not going to know what he 

is doing because I don’t understand the language. 

Whereas if it’s in English, I know the call signs of the 

two guys in front of me because I just heard that guy 

get doglegged, and this guy’s on base, and I’m right 

behind him. So, I have more situational awareness 

of aircraft that are around me that could be a factor 

for our flight. 

Also, somebody might report in seeing volcanic 

smoke and we could fly right through that area unless that information is broadcast in English. So, I 

have to concentrate more on listening, which can 

certainly distract me from doing my cockpit duties. 

We all like to think ahead and anticipate what the 

next thing is going to be so we can be ready for it. 

When we don’t know, it increases our nervousness; 

it’s just a little less comfortable.

Taxiing Amid Airplanes Without Knowing 

Where They’re Going

Ground operations can be very confusing; everybody’s speaking the local language except us. I have 

no idea if another airplane is sitting there waiting for 

me or where he’s going, and that’s a very frustrating 

[situation] to be in – and dangerous. 

I’m a first officer on a narrow-body aircraft; that is a 

busy seat. In the Caribbean, when we’re taxiing, ATC 

issues us a new clearance and we’re trying to start 

engines, and get everything done. We either have 

to stop and decide whether to copy the clearance 

now or complete our airplane stuff.

During these times, the captain’s more focused on 

what the controller is saying, as opposed to a first 

officer who’s moving switches and starting engines 

when clearances are being issued. That might be a 

little bit of an overload for me. But along the same 

lines, part of the reason my situational awareness 

is greatly affected is because I tend not to listen as 

intently since I don’t understand what is being said 

in non-English. Since I can’t tell the beginning and 

the ending [of the transmission], I don’t know when 

ATC will come back to me because I don’t know the 

flow sequence that they’re going through.

TCAS and Technology Aid Situational Awareness

When a pilot and controller are speaking in a 

foreign language, it doesn’t give us the ability to 

be aware of whether they’re talking about weather, 

airport conditions, clearances, or whatever. I tend to 
19

depend on my instincts concerning who’s in my immediate area, and we have technology on our planes 

that help us be aware of other airplanes’ positions, 

terrain considerations, things of that nature; but I 

also like to hear what is being said between the pilot 

and controller. TCAS helps us maintain situational 

awareness. We try to figure out what controllers are 

having other airplanes do. We can watch them on our 

cockpit display. I think I lose situational awareness 

to some extent, but I’d be really worried if we didn’t 

have TCAS. That would be a nightmare.

Interviewer: I have a question on situational awareness. Do you visualize traffic climbing and descending 

and speeding up and slowing down, relative to yourself, 

under most situations?

I have a picture in my head based on the transmissions being given. Basically, I visualize the airplanes 

that are the highest threat, closest to us, in front of us, 

and behind us. When the weather, thunderstorms, 

etc. develop and they are deviating around weather, 

I get a feel for it, and a lot of times I can transpose 

that onto the TCAS; and based on our TCAS picture, 

I know where they are.

44a. When do changes in your ability to understand the 

language(s) being spoken over your communications 

system most affect your situational awareness? 

The pilots were provided with a list of 12 phases of 

flight to rank order. The list was derived from Phases of 

Flight Definitions and Usage Notes (CAST/ICAO Common 

Taxonomy Team,14 2006). The pilots’ assigned values for 

each phase of flight were tabulated by frequency of occurrence. The results are presented in Table 10, followed by 

the philosophy the pilots used when assigning values to 

14 Commercial Aviation Safety Team (CAST)/International Civil Aviation 

Organization (ICAO)

each phase of flight, and discussions of their two highest ranks. Two phases of flight were tied for being most 

affected by language barriers (Rank 1): Preparing for 

descent and preparing for final approach. Tied for being 

the next most affected phase of flight (Rank 2): Aircraft 

taxiing on the airport surface either to the runway or to 

the gate, ramp, or parking area. The phases of flight least 

affected generally involved tasks in which the pilot had 

little to no direct involvement with tower controllers.

Rank 1

When Preparing for the Descent – From Cruise to 

Either Initial Approach Fix or VFR Pattern

Ranking philosophy

My overall philosophy for selecting the priority was 

the speed of the aircraft, the danger of the environment it is in, and the sterility of the environment in 

which I’m communicating. If I’m the only aircraft 

being controlled as a primary for that controller, it’s 

usually less of a problem. The impact of situations 

as they threaten our aircraft is proportional to the 

complexity of the phase of flight. The threats seem 

to follow workload – where we are the busiest and 

preparing for the busiest time [is] when it would be 

the most distracting to hear clearances that I can’t 

understand.

Constricted airspace

The point where ATC is taking many airplanes and 

putting them into a confined space versus taking 

many airplanes and taking them out of a confined 

space – it’s a higher risk factor going in than it is 

going out. When flying, we want our situational 

awareness to be the best when we’re in the most 

congested area. We have to descend on time, and 

then, as we get in the lower altitude structure, there 

Table 10. Effects of Language Understanding on Situational Awareness by Phase of Flight 

Rank Phase of Flight 

1 When preparing for descent – from cruise to either initial approach fix or VFR pattern entry. 

1 When preparing for final approach – from the final approach fix to the beginning of the landing flare. 

2 When taxiing – the aircraft is moving under its own power and terminates upon reaching the runway. 

2 When taxiing – the aircraft has exited the landing runway moving to the gate, ramp, or parking area. 

4 When preparing for take-off – aircraft is on the runway surface in take-off position. 

5 When in climb to cruise – from completion of initial climb to initial assigned cruise altitude. 

6 & 10 b When in the en route phase in international airspace. 

7 When in the en route phase under the control of en route centers. 

9 When take-off power is applied, through rotation and to an altitude of 35 feet above the runway 

elevation or gear-up selection, whichever comes first. 

10 When preparing for landing - transition from nose-low to nose-up attitude just before landing 

touchdown. 

11 When moving in the gate, ramp, or parking area - assisted by a tow vehicle (tug) moving to the 

taxiway. 

12 When preparing for departure - aircraft is stationary. 

bThis phase of flight was ranked 6th and 10th by the same number of pilots. 
20 

is another set of problems – can ATC fit us into the 

flow? The native language can throw everything out 

of whack. If there is weather in the area, it changes 

everyday operations.

Increased workload

In preparation for descent, there are a lot of things 

happening, obviously, with the aircraft, checklists, 

ATC, and other aircraft. It is a very busy time when 

we are trying to get a lot of communications completed. If the amount of communications is increased, 

the amount of workload is increased. The amount 

of awareness during these phases of flight is also 

increased. To me, that’s where the most problems 

in communications occur.

Multiple languages on frequency

Usually, communications are rapid-fire, especially 

going into a real busy airport. We do not want to 

miss one [transmission]. Hearing a different language 

that’s being spoken is a distraction. The hardest thing 

to prepare for is when we first receive our clearance 

at initial descent. That is when we are figuring out 

exactly what the approach is, the arrival; and that’s 

when communication barriers can get problematic 

– subtle miscommunications can be life-threatening. 

Controllers speak in their native language to the guy 

ahead of us. If I knew what he was given, I could 

prepare to maybe slow down or speed up.

When Preparing for Final Approach – From the Final 

Approach Fix to the Beginning of the Landing Flare

Aviating and navigating can be complicated 

by language barriers

The arrivals and descents are our highest concerns 

and priorities. Getting around to the final and being vectored in can be difficult. We’re low on fuel 

coming in, trying to get on the localizer, making 

sure that we’re on the correct runway. We could be 

dealing with weather. We’re tired and it is vital that 

we understand what controllers are saying.

Broken English is a distraction

The hardest time is when we’re concentrating very 

intently on what we’re going to do, and, suddenly, 

somebody comes up in broken English and now it 

is much more difficult.

Lack of understanding is uncomfortable during 

off-nominal situations

If something happens when the airplane is in a critical phase, a light comes on, or an abort procedure 

is pronounced; that’s when we don’t want to hear 

a foreign language or have difficulty understanding 

exactly what the controller wants us to do. I want 

to be able to say – “Hey [Air Carrier] seven one’s 

aborting on three five.” I want to feel comfortable 

knowing that they know what I’m saying too.

Multi-linguistic communications detracts 

situational awareness

What airplanes are on approach, are landing, are 

being cleared for takeoff on that runway, or opposing 

runways – I need to have the big picture. But I don’t 

have information that is being conveyed in [another 

language] and things are moving along. That would 

be most distracting. 

Rank 2 

When Taxiing: The Aircraft Is Moving Under Its Own 

Power and Terminates Upon Reaching the Runway/

The Aircraft Has Exited the Landing Runway Moving 

to the Gate, Ramp

Ranking philosophy

The overall philosophy for my ranking of the situations was asking the question, “Are they a threat to 

our aircraft?” The threats seem to follow workload. 

In terminal areas, there are more radio transmissions 

and if there is a language barrier, it’s going to be a lot 

harder to follow. Where we are the busiest is when 

it would be the most distracting to hear clearances 

that I can’t understand.

I compartmentalized the items to areas where I could 

lose my job and on [the] likelihood of a change occurring. I looked for the ticket item for me and went 

to number 2 and 3. Then I looked for the least threat 

times, and put those next to the bottom. 

Divided attention

Ground operations are definitely high on the list 

because we are either going to ding something pretty 

quickly or get on the wrong runway or taxiway if we 

are not really paying attention. In my mind’s eye, a 

heavily accented controller giving us instructions, a 

little bit of weather and traffic involved, and we’re 

trying to make it to the end of the runway while 

copying a clearance accurately. Either we are going 

to listen to the clearance or going to taxi – we are 

not able to do both at the same time. 

Domestic compared with international operations

Domestically, we know what we’re going to get 

and where we’re going to go; but internationally, I 

invariably have to use a lot more mental capacity to 

figure out where we’re going and what we’re doing. 

Sometimes, to be honest, I assume that the guy in the 

left seat knows where he’s going and what he’s doing.

Ground operations are less predictable

I find my situational awareness is definitely the 

lowest on the ground – taxiing around, getting taxi 

clearances, understanding the taxi clearances. Taxiing 

out is difficult sometimes because there is less time 

to develop a plan because we don’t always know 

what runway we’re going to get until the controller 
21

says taxi to this runway. Sometimes the communications really affect us because there’s ambiguity 

about where we’re going. And then, as we move 

toward the runway, we can have problems with 

communications, where we’re not sure about what 

needs to happen. We’re changing controllers and the 

levels of proficiency change, depending on where 

we are from the departure runway. We get most of 

the taxi incursions taxiing out to the runway. It’s a 

high-workload environment.

Increased activity level on the ground and on frequency

Mainly on taxiing in a non-English speaking arena 

– whether it’s after departing the runway upon landing or after push-back trying to get to the departure 

runway. ATC could be talking to somebody on the 

other side of the field and we wouldn’t know, because 

we don’t have full situational awareness. There are 

a lot of ground vehicles and other airplanes moving 

through the same aircraft movement area in close 

proximity to each other with the possibility of a runway incursion. Runway incursions are an important 

thing and if that information is not given in English, 

it is a problem.

Unusual clearances

The most affected was taxiing around and getting 

unusual clearances, which weren’t necessarily critical but were sometimes hard to understand. If we’re 

having trouble understanding the taxi directions, our 

workload goes up; we can sit there and say, “Well 

we’re probably going to turn off this way and go to 

this location.” There are more nonstandard things that 

happen on the ground than when enroute. 

45. What do you do to compensate for any reduction in 

situational awareness?

The pilots’ oral and written responses were grouped 

into 13 common themes, as shown in Table 11. Each 

theme follows, and, in some cases, the interviewer asked 

additional questions. Their responses ranged from individual preparedness to the use of aircraft equipment.

Be Prepared

As pilots, we really need to be prepared for what 

we’re going to do. I study ahead of time, which is much 

more of a player in the international arena than it is 

in domestic operations. I review the STARs,15 SIDs,16

approach plates, airport diagrams, and possible taxi 

routes. Mountains are here; water is here; routes are 

here; fixes are this; planned is this; optional is this. I 

focus on what’s going on both on the ground and in 

the air, how we might be cleared, what we can expect 

the route will be on the ground and in the air – the 

arrival and the departure we can expect to be given.

If I am going somewhere that I’ve been to before, 

I talk to the co-pilot about all the possible things 

I’ve ever experienced. Usually, somebody has been 

there a number of times, and that can make all the 

difference. If we lose situational awareness, we’ve 

got to do something pretty quick. Experienced pilots 

know what’s coming and do more ground or preflight preparation. Pay attention to what’s being said 

on the radio, and monitor the instruments for what 

is going on.

Challenge Unclear Clearances

Challenge dubious clearances. A dubious clearance is one that is not accurate or not clear. We do 

15 Standard Terminal Arrival Route 16 Standard Instrument Departure

Table 11. What Pilots Do to Compensate for Reductions in Situational Awareness 

Ways to Counteract Reductions in Situational Awareness 

Be Prepared 

Challenge Unclear Clearances 

Clarify 

Check the NOTAMs 

Cockpit Resource Management (CRM) 

Employ Aircraft Equipment and CRM 

Increase Attention and Listen Intently 

Know Your Clearance and Fly Your Own Airplane 

Local Language NOTAMsc can Be Difficult 

Recognize There Is Reduced Situational Awareness 

Request Slower Speech 

Slow Down and Use Standard Communication 

TCAS as a Tool to Compensate 

Use Headset 

c Notice to Airmen 
22 

have situations where we get different phraseology 

for cleared for the approach. The controller may 

clear us to an altitude and then clear us to intercept 

the localizer; and here comes the glide slope, and 

it’s time to descend, but we don’t think we have a 

clearance to descend. We can’t get a word in because ATC is talking in the local language, and all 

of sudden, we have to throw it all out and get back 

to the glide slope. 

Somewhere, in some statement, we may have been 

cleared for the approach, but the words did not click 

with us, so we did not descend on the glide slope 

because we didn’t think we got the approach clearance. That happens in Russia and South Poland a lot. 

The best maneuver the airlines teach is a properly 

executed go around.

We increase our vigilance of what is going on out 

there and review the procedures before we get there. 

We stop if we’re on the ground, ask ATC to repeat 

what’s going on, or tell the controller that we don’t 

understand the clearance. We may have to ask for 

a vector to get us going to where we need to be.

Check the NOTAMs

I check the NOTAMs and accomplish briefings during times of low workload – such as in-cruise flight, 

where my situational awareness is not as needed. 

Last year in Santiago, Chile, they closed one of the 

runways they normally use. It was only NOTAM’d in 

Spanish and I was the only one [of our flight crew] 

that understood it because I spoke Spanish. I thought 

that to be bizarre because half of the NOTAMs are 

in Spanish, and half are in English. The ones that 

we needed (all of them in English) were in Spanish. 

Interviewer: You mean it was not translated?

No [it was not translated].

Clarify

We ask for clarifications as necessary with the controller and will repeat our request as often as required. 

We also confirm instructions with the captain before 

it is read back. We will use the phonetic alphabet 

to clarify and cross-reference maps or publications.

Cockpit Resource Management (CRM)

I make sure all crewmembers are listening and get 

everybody involved. I read someplace that 72% of all 

runway incursions happen on the first day and on the 

first leg, because crewmembers are afraid to call out 

stuff. So that’s part of my briefing – Does everybody 

have their airport pages out? We review procedures 

and taxi diagrams ahead of time. I want progressive 

taxi instructions from everybody.

We use all the tools that we’ve been trained to use, 

which is use CRM resources and make sure everybody’s 

briefed on being totally aware of radios and clearances. 

And sometimes I embarrass the guys. They think I’m 

an old guy who can’t hear. But I will ask a guy about 

what the clearance was or what our descent is. 

Employ Aircraft Equipment and CRM

I will ask for a repeat of any clearance or altitude – 

anything I have a question on – and I will use other 

pilots in the cockpit. We use our aircraft’s equipment, 

and an example of that would be TCAS. We really 

spend a lot more time looking at the TCAS display 

and range, trying to identify the competition, per 

se, especially in the arrival area where everyone is 

converging and where the sequences are coming in. 

With TCAS, we almost become backup controllers. 

We can guess what they’re doing and what to expect, 

based on what we’re seeing with altitudes and turns, 

headings from other aircraft. If we cannot get through 

the language barrier, we still see the picture that’s 

developing on the TCAS.

Increase Attention and Listen Intently

I use all my pilots, so there are no assets being 

wasted. We listen intently, eliminate some tasks, and 

ensure the cockpit light is on to limit the distractions 

in the cockpit. We heighten our awareness and really pay closer attention than we probably would 

domestically. We wear our headsets so that we’re 

able to hear what’s being said. And then finally, if 

there are any questions, we’ll verify them as to what 

we’ve been instructed to do. It’s very cheap insurance. 

Know Your Clearance and Fly Your Own Airplane

All we can do is take care of what we can control 

– knowing our own clearance and flying our own 

airplane. I’ve learned a lesson early on – I don’t have 

to know everything, so I don’t pretend to. I’ll ask. 

We always have three people in the cockpit, and I 

make sure everybody knows what the plan is. When 

we’re taxiing, my situational awareness is the lowest; 

I’ll be looking around, checking the taxi diagrams. It 

comes down mainly to resolving ambiguity – having 

charts available while utilizing my relief pilots, not 

overloading them to the point that I’m the only one 

taxiing the airplane, and no one else is monitoring me.

Recognize There Is Reduced Situational Awareness

The very first thing I have to do is recognize that 

I have a reduction of situational awareness and 

then customize the resolution to what’s causing 

the problem. To do that, I try to discover why it has 

been reduced. It could be a simple thing such as I’m 

fatigued and need coffee to wake me up. It could be 

a variety of things.

I’ll alert the other pilots on duty to increase their 

situational awareness as well. We do a thorough 

brief again, especially for both the departure and the 

arrival. We’ll think about our situational awareness 

because a pilot never really knows it is lost until it 

is back. Never forget what we’ve always been taught 

– aviate, navigate, communicate.
23

Request Slower Speech

When I can’t understand, I ask the controller to 

go a little bit slower. I verify everything including 

opinions until I am sure I understand. We agree this 

is the altitude we are going to, we agree we are going to this fix. I verify a match for everything before 

it goes into the computer.

Slow Down and Use Standard Communication

We slow down our normal operation to be a lot 

more deliberate in what we are doing because we’re 

trying to pay attention to what could be a threat. 

We are trying to do everything we can to increase 

our situational awareness and compensate for not 

understanding the language being spoken. We stick 

to standard communication. 

Even when controllers and pilots are speaking in 

their native tongue, frequently we can understand 

their call signs. We may not know where they’re going, but at least we know who’s out there. We just 

have to listen very intently and try to correlate TCAS 

data to what the controllers are saying.

TCAS as a Tool to Compensate

During the enroute phases, TCAS is golden. The 

route knowledge, knowing what to expect, and why 

we are expecting that, and what a possible Change 

1 or Change 2 might be – that’s spectacular. We find 

that kind of knowledge to be valuable from the guy 

who has been there before.

Interviewer:17 Do any of you use your TCAS to 

compensate?

Absolutely, that’s one reason why it’s a piece of 

required equipment going into South America.

Interviewer: Can you use it to get a sense of where a 

plane is and where it is going?

Absolutely. I just said, we can question the controller 

and find out what we don’t know [when we don’t 

know what they are saying in their own language]. 

That’s the only recourse we have. 

Use Headset

Everybody is listening to what’s going on using their 

headsets because, hopefully, somebody will catch 

what everybody else misses. 

Interviewer: In what environment do you normally 

wear headsets?

Headsets are required below 18,000 feet. I wear 

them all the time when I’m operating in European 

airspace. It helps me to understand what’s being said. 

We sit there and wear it for two and a half hours, so 

you’re happy to take the thing off.

17 This question was asked of a group that had not mentioned TCAS as a 

compensatory tool.

DISCUSSION

This report focuses on the communication between 

non-native English-speaking controllers and how well 

they communicate with native English-speaking pilots. It 

provides an overall perception among 48 U.S. ATP pilots 

of how these communication exchanges affect safety, the 

communication process, workload, and situational awareness. The interviewers took the pilots’ comments and 

opinions at face value and occasionally asked additional 

questions but did not challenge any of their statements 

or comments.

Language production is generally thought to involve 

four steps: first, you have an idea of what you want to say; 

second, you organize that idea into an acceptable linguistic 

form containing a grammar, vocabulary, cadence, and 

phonetic segments (Fromkin, 1971); third, you develop a 

set of motor commands in your brain that are sent to the 

respiratory, laryngeal, and articulatory systems necessary 

for speech production (e.g., MacNeilage & Ladefoged, 

1976); and fourth, you execute these motor commands 

(e.g., Broca’s area for articulation, Dronkers, Plaisant, 

Iba-Zizen, & Cabanis, 2007). 

For listeners, speech perception occurs when a spoken 

message is heard and understood (Wernicke’s area for 

understanding receptive language, Beeman, 2005). It 

entails four general levels of language processing. First, 

speech sounds are identified and categorized (sensory 

and phonological encoding processes); second, the lexical 

representations of words are retrieved from the mental 

lexicon (lexical processes); third, the syntactic structure of 

the sentence is determined, and the gist of the sentence 

is stored in working memory (sentential processes); and 

fourth, contextual cues are used to integrate the gist of 

the sentence with the context in which it is embedded 

(discourse processes).

When the listener is proficient in the language, discourse processes serve to facilitate speech perception, 

allowing the listener to generate strong expectations as 

to what words will be spoken next. For example, English 

grammar follows a subject – verb – object (S-V-O) sentence 

structure, where both the subject (S) and object (O) are 

nouns. Thus, the listener comes to expect a verb (V) will 

follow the subject of the utterance prior to the object.

When a language uses a different grammar structure, 

such as subject – object – verb (S-O-V, e.g., Japanese 

and Hungarian), a listener unfamiliar with that sentence 

structure will not be able to use discourse processes to 

the same extent as the person proficient in that language 

and may have difficulty extracting the meaning of the 

sentence. As an example, languages with an S-O-V structure generally place a person’s title (e.g., Jane Captain) 

after their name, while S-V-O languages place it before 

the name (e.g., Captain Jane). In air traffic control, when 

“descend and maintain twelve thousand” was put into an 

on-line translator, it appeared as “Lower 12,000, maintain” in Japanese and “The drop maintains 12,000” in 
24 

Korean. In an S-V-O translation from English to Arabic 

(Modern Standard), the same instruction was translated 

as “Descended and kept 12 thousand.”

Although Aviation English involves making statements, 

asking questions, issuing commands, giving reports, and 

warnings, it does not follow the conventional grammar 

structure or rules of ordinary English languages. Generally, it does not pose a problem for pilots and controllers 

when they follow the rules contained in documents such 

as Order 7110.65 The Handbook of Air Traffic Control 

(FAA, 2010) or Procedures for Air Navigation Services - Air 

Traffic Management Doc4444 (ICAO, 2007). 

However, problems can arise when pilots and controllers stray from the phraseology developed specifically for 

aviation and replace it with Common (or plain) English. 

For example, “Can you accept runway 05” is the equivalent 

for “Expect runway 05.” The unsuspecting, non-native 

English-speaking pilots receiving the request, “Can you 

accept runway 05?” may not understand it since that 

phrase is not found in either Order 7110.65 or Doc4444. 

If pilots and controllers limit themselves to the approved 

phraseology, communication problems might diminish 

(Prinzo, Hendrix, & Hendrix, 2008). 

Unfortunately, absent from these documents is 

phraseology beyond that used to declare an emergency. 

Non-native English-speaking pilots and controllers are 

at a disadvantage when faced with a possible emergency 

because they must rely on their Common (or plain) 

English skills. Pilots must adequately convey the nature 

of their emergency, their intentions, and requests for 

any assistance. Likewise, controllers must be able to 

interpret the information and decide the best course of 

action. Being able to communicate effectively during an 

emergency is difficult using a native language and can 

become completely unmanageable if it must occur in a 

language where proficiency is limited.

As pointed out by Prinzo et al. (e.g., Report 3, 2010b), 

pilots’ perceptions regarding the English language proficiency of international controllers often is dependent upon 

where they fly, with some places perceived as better than 

other places. For example, Canadian, Cuban, and German 

controllers who provide ATC services in their respective 

airspaces were perceived as being very good, whereas the 

Chinese, Russian, and South American controllers had 

greater difficulty understanding requests made by pilots 

in English. In fact, many of the U.S. pilots reported that 

all controllers were very good communicators during 

routine and expected situations. Another important factor was experience – there may be fewer surprises among 

pilots who repeatedly fly the same routes than pilots less 

familiar with these routes.

Inadequacies in Controllers’ English Language 

Proficiency During High Workload Conditions

How proficient a bilingual controller is in English 

becomes apparent as they encounter problems. During 

these times, pilots may be faced with time-critical events 

requiring quick decisions, actions, and responses from 

ATC. Although ICAO phraseology exists for distress calls 

(MAYDAY, MAYDAY, MAYDAY) and urgency messages 

(PAN-PAN, PAN-PAN, PAN-PAN), no phraseology currently exists to convey the pilot’s precise circumstances or 

to tell the controller what is needed. In fact, phrases such 

as “fuel emergency” and “fuel priority” are not recognized 

terms after making a distress call or transmitting an urgency message. Flight crews short of fuel must declare a 

Pan or Mayday to be sure of being given the appropriate 

priority (Eurocontrol, 2007). 

It may be that representatives from the aviation community who develop aviation phraseologies assume pilots’ 

and controllers’ English skills are sufficiently adequate 

for emergency, unusual, or unanticipated operations. 

Should these events occur, the pilot and controller would 

simply communicate in conversational English to reach a 

common ground of understanding of the situation as it 

unfolds. Controllers would provide the needed services 

and obtain any specialized assistance for the pilot. Hence, 

there was no need to built phraseologies to explain the 

situation or convey what services were needed.

Unfortunately, this assumption is false, as documented 

in Doc 9835 (ICAO, 2004) regarding the implementation of English language proficiency requirements and 

confirmed by several pilots who participated in these 

interviews. They told of their difficulties with some tower 

controllers who were unable to understand that either 

their aircraft or another aircraft was distressed (e.g., hot 

brakes, disabled aircraft on the runway) and required 

emergency vehicle services. Likewise, when faced with 

adverse weather such as hurricanes, thunderstorms, or 

volcanic activity, some pilots reported some en route 

controllers could not communicate properly with native 

English-speaking pilots. During these circumstances, it 

can become cognitively challenging for less proficient 

controllers to decode, translate, interpret, and understand 

from English to their native language and back again to 

English. The added pressure, anxiety, and stressors pilots 

experience during these times may find them using Common English or even slang in an attempt to be understood. 

Unfortunately, it is at this precise moment that the 

controllers’ command of the English language may be 

inadequate. They may not grasp completely the complexities of the situation from the English spoken by 

the pilots. For controllers to correctly infer an accurate 

understanding of the situation as told to them by the 

pilots requires a successful mapping of the pilots’ words 

and concepts with theirs. In the absence of complete bilingualism, their utterances may become prone to errors 

and misunderstandings (Varella, 2006). This also holds 

true for pilots who attempt to apply their best guesses. 

For example, although birds exist in most countries, 

and a robin is a very typical bird in the United State, 

there are no robins in Poland. Consequently, talking to a 

native of Poland about robins would be baffling for that 

person. Likewise, explaining the concept of watching a 
25

movie to members of rural nomadic tribes living in the 

Middle East will result in puzzled expressions.18 The 

point is, just as there are some words and concepts that 

are comparable across languages and cultures (e.g., birds) 

some words and concepts have no equivalence in another 

language or culture (e.g., watching a movie). Thus, effective communication results from the extent to which 

pilots and controllers can construct a common ground 

of understanding – a shared mental representation of 

the events of the moment. Incomplete understanding 

diminishes situational awareness, can threaten safety, and 

adds another layer of complexity to an already stressful 

situation.

During adverse weather, heavy traffic, and unexpected 

circumstances, several U.S. pilots reported hearing some 

pilots and controllers revert to their native language during 

the course of their interactions. Consequently, pilots who 

are unfamiliar with the local language experience frustration and uncertainty since they no longer can anticipate 

unfolding events. If they ask the controller what is happening, there may be unacceptably long delays between 

the end of their questions and the onset of a response 

as the cognitive demands placed on controllers become 

unmanageable. As noted by a pilot “Significant traffic 

volume, maintaining both arrival/departure [traffic flow], 

with significant weather that requires deviations around 

a standard path, is more than many foreign controllers 

can handle.” And by another, “They need to use the 

standard phraseology with me for me to understand. If I 

can’t understand the language, it’s a safety of flight issue.”

Strategies Pilots Use to Improve ATC Communication

While monitoring their radios, pilots listen to how well 

controllers talk to other pilots. The pilots in our study 

tended to rely primarily on the controllers’ pronunciation and fluency to determine how proficient they were 

in speaking and understanding English. The pilots also 

considered comprehension, grammar, vocabulary, and 

interactions with other pilots as well as the controller’s 

projected confidence, although to a lesser degree.

Once pilots decided a particular controller exhibited 

low-level skills, they altered the way they spoke to that 

controller and listened more attentively to what was said. In 

particular, pilots said they deliberately spoke slower, more 

distinctly, clearly enunciated words, and sometimes spoke 

louder. If on the ground, sometimes they stopped their 

aircraft and only moved once the problem was resolved.

When anticipating a call from ATC, their strategies 

revolved around having all crewmembers listen closely 

to all the messages and possibly turning up the radio volume. Some crews wear headsets. Likewise, they listened 

closely to messages designated for them and compared 

what each one thought they heard. If there was a lack 

of consensus among the flight crew, then a request for 

18 Personal communication from an Army chaplain serving U.S. troops in 

Iraq, Kuwait, Afghanistan, and Qatar.

repeat occurred either in the form of “Please repeat”19 or 

“Say again.” This is unlike their communications with 

U.S. en route controllers where pilots may say, “Confirm 

heading two four zero” or ask, “Was that down to one 

eight oh?” (Prinzo et al., 2008).

A Description of Same-Language Pilot Controller 

Communications

When pilots and controllers share the same language, 

the speed of communication and understanding is effortless and unconscious (same-language participants 

generally do not think about what processes are active 

because understanding appears to be automatic, rather 

than controlled). They apply top-down higher-order 

language processes in anticipation of each other’s utterances. Consequently, they are probably more relaxed, 

and communication progresses at a comfortable pace; 

likewise with speech production. Generally, speech progresses automatically, requiring very little forethought, 

thus allowing the controllers to formulate and produce 

their clearances rapidly.

The pilots’ perceptions of the information flow between speakers of the same native language seemed more 

casual and relaxed. It contained occasional laughter, lots 

of chatter, shortened call signs, and some jargon – with 

less reliance on ICAO phraseology. There appeared to 

be a degree of familiarity between the pilot and controller, possibly due to a shared dialect, accent, grammar, 

vocabulary, and probably culture, all of which contribute 

to the ease of understanding (Al-Hasnawi, 2007). There 

might be salutations during initial call-up and again when 

handed-off, as is done in the U.S. Local slang and jargon is 

understood, but only by those who share (or understand) 

these socio-linguistic-cultural features.

Some pilots thought controllers and pilots who shared 

the same language spent more total time on frequency. 

Controllers could chain together several instructions at 

a time, offer multiple clearances, or make several transmissions in the same amount of time it took them to 

complete a transaction with a native English-speaking 

pilot. Thus, more information could be relayed between 

speakers of the same, as opposed to different languages, 

in about the same amount of time.

A Description of Different-Language Pilot 

Controller Communications

Unlike communication between speakers and listeners 

of the same language, the English-speaking pilots perceived 

non-native English-speaking controllers answered questions from local pilots promptly, while they often had to 

wait. While waiting they heard the controller take calls 

from other local pilots.

The pilots noted that controllers slowed down their 

speech rate when switching from their primary language 

19 Although the pilot used the word “please,” discussions with several controllers indicated they had never heard any pilot use “please” during radio 

communications.
26 

to English. Clearly, it takes longer to mentally translate 

from one language to that of another, especially if less 

proficient in one of those languages. 

When communicating with non-native speakers, radio 

discipline was maintained to a higher degree in a multilingual environment, with nonessential communication 

kept to a minimum. In particular, informal communication and the exchange of pleasantries were avoided. Pilots 

thought the controllers might be less inclined to ask a 

native English-speaking pilot to deviate from their route 

than a local pilot with whom they could communicate 

more easily. Trying to explain to a native English-speaking 

pilot would take more time, could result in miscommunication, more effort, and stress than calling up a pilot 

who spoke their language. 

Pilots also limited their utterances to ICAO standard 

terms and phraseology, said them in the same order, and 

spoke more slowly than they would if talking to a native 

English-speaking controller. Just as the S-V-O sentence 

structure facilitates lexical access among English languages, 

knowing that a pilot’s readback is recited in the order in 

which instructions were given may help the controller 

process and confirm the accuracy of the readback more 

quickly. Slower readbacks provide controllers with more 

time to execute bottom-up language processes to extract 

and identify meaningful syllables from the speech stream, 

combine them into words, phrases, clauses, etc. until 

the meaning of the utterance is determined. Although 

it is common for pilots in the U.S. to substitute “oh” for 

“zero” or “point” for “decimal,” substituting one word 

with that of another could result in confusion among 

less proficient non-native English-speaking controllers. 

Therefore, common U.S. word usage was avoided among 

pilots who knew it was important to choose their words 

carefully to prevent possible misunderstandings. If pilots 

needed clarification, their questions were concise and 

well controlled.

Some pilots thought more time was spent communicating between native English-speaking pilots and non-native 

English-speaking controllers, but others expressed the 

opposite opinion. The perceptions of the former group 

were that the added time on frequency resulted from 

more requests by pilots speaking English to have either 

the entire message or part of it repeated, confirmed, or 

verified. These additional transmissions would increase the 

total time on frequency. Also, during the communication 

process, native English-speaking pilots and non- native 

English-speaking controllers may slow down their speech 

rate to make it easier for the listener to understand them.

For the U.S. pilots with the opposing viewpoint, they 

thought less time was spent communicating between 

native English-speaking pilots and non-native Englishspeaking controllers because controllers’ transmissions 

were limited to simple ATC clearances and instructions 

devoid of pleasantries, and the pilots also were brief and 

to the point. Shorter messages with limited words take 

less time to transmit.

Human Factors Considerations in Language 

Switching

At some time or another, many of us have participated 

in a conference call and attempted to identify who the 

speaker of the moment was from among the many people 

participating in that call. If we try to identify who the 

speaker is, we might miss some of what is being said, as 

more of our attention is dedicated to bottom-up processing of acoustic information. We listen in on these 

party line conversations to obtain information and also 

provide some when it is our turn to talk. We listen for 

our name to be called before we enter the conversation. 

We also listen for a drop in pitch and longer pauses to 

signal the end of an utterance and possibly a dialogue 

(Ford & Thompson, 1996). 

When pilots enter into a foreign country’s airspace, 

they may hear the controller speaking in English and 

then in the local language. This language switching poses 

a problem for any pilot unfamiliar with the language. 

Language-Switching Distracts Pilots 

and Limits Understanding

Hearing non-native English-speaking controllers 

switch between languages serves as a distraction to pilots 

as they give more of their attention to listening to other 

pilots talk than to performing station-keeping tasks (e.g., 

completing a checklist, configuring the aircraft, programming the FMC). Identifying and then isolating the 

controller’s voice from that of other pilots is not a trivial 

task, especially when pilots cannot use the content of the 

transmissions to distinguish between a controller issuing 

an instruction and the pilot reading it back. Pilots, like 

others who are proficient in English-only (monolingual), 

are at a disadvantage when hearing foreign languages because they cannot use these same signaling cues to identify 

turn-taking, speaker identification, word recognition, or 

relevant information (Marian & Spivey, 2003; Weber & 

Cutler, 2004). At best, they may be able to map some 

familiar sound patterns and guess at what is being said.

Language Switching Adversely Affects 

Situation Awareness

Party line communications present an anomaly to 

flight operations. Interview data gathered by Pritchett 

and Hansman (1993), like the interview data presented 

here, suggest party line communication provides pilots 

with useful weather and traffic information that affects 

their situational awareness. However, a simulation study 

conducted by Hodgetts et al. (2005) suggest party line 

communication increased the perceived workload among 

the pilots in their study, as well as the time pilots took to 

complete their descent checklist, when compared with the 

absence of a party line. Like the pilots in the Hodgetts 

et al. study, our interview data also indicated perceived 

increases in workload, but the increases were attributed 

to focused attention on non-English communications.
27

Language Switching Leaves Pilots With 

Feelings of Uncertainty

The more relevant and accessible the information, the 

better pilots can do their job. There are two sources of 

auditory-presented information – direct communication 

between the pilot and controller and indirect information 

obtained by listening to the communications between a 

controller and all other pilots on the same frequency via 

the party line. When all communications are in English, 

pilots know how their flights are situated as events unfold around them. So, they listen for traffic avoidance 

and traffic awareness, clearances and requests, and ride 

reports for turbulence. The clearances and instructions 

issued to other aircraft may have a direct impact on their 

flight path. 

However, when multiple languages are spoken, pilots 

unfamiliar with these languages do not know what is 

occurring. It limits their situational awareness about the 

big picture and the status of the protected zone around 

them. Pilots want to know who is in front of them, 

what they may be flying into (e.g., weather, volcanic 

ash), as well as what is behind them. Without complete 

and accurate information, they cannot develop useful 

strategies, contingency plans, or expectations. This, in 

turn, can restrict situational awareness, degrade safety, 

and leave them feeling uncomfortable – especially in 

busy terminal areas. 

An example provided by a bilingual pilot illustrates the 

problem well. He was given the same holding instructions 

in English that another pilot received in Spanish. Both 

pilots were given the same fix and altitude. Had the U.S. 

pilot not understood Spanish and queried the controller, 

the outcome could have been catastrophic.

Language-Switching Increases Pilot Workload

Difficulties in understanding take time away from performing other duties that help pilots maintain situational 

awareness, especially during the descent to landing phase 

of flight. It is during this time when they calculate their 

descent profiles and begin their approach briefings. This 

is supported by Hodgetts et al. (2005), who reported the 

pilots in their study only took longer to complete their 

descent checklists. Having to factor in additional cognitive demands due to language barriers may increase the 

workloads of both the pilot flying and non-flying pilot. 

As pilots enter terminal airspace, there is more traffic 

and communication, a decrease in separation minima, 

and less time to initiate and execute procedures. Language-switching adds another layer of complexity to 

communications, especially among pilots unfamiliar 

with the languages spoken over their communications 

system. The added wait times by controllers who are 

slow in responding to pilot requests and questions can 

result in pilots rushing to perform tasks and maneuvers 

at a faster pace to maintain their descent profile. Failure 

to maintain the descent profile may result in having to 

execute a missed approach.

Language Barriers Most Affect Situational 

Awareness Just Prior to Top-of-Descent and Taxiing 

When pilots were asked to rank-order 12 phases of 

flight from most to least affected by language barriers, 

their philosophy involved threats to safety first and loss of 

employment second. Having a high workload, more radio 

communications, and low second-language proficiency 

can overburden working memory and lead to distractions, lapses in attention, interference, and disruptions 

(see Resnick, 2006).

As noted by the Flight Safety Foundation (Flight Safety 

Digest, 2000), “Incorrect management of the descentand-approach profile and/or aircraft energy condition 

may result in a loss in situational awareness; and/or an 

unstable approach” (p. 71). Although the Flight Safety 

Foundation recommends that pilots complete the descent 

preparation and approach briefing 10 minutes before 

reaching the top-of-descent point, whether pilots can do 

so is dependent upon how well they can communicate 

with controllers who are less proficient in English.

As noted by several pilots, they may be at a disadvantage if ATC delays providing them with the information 

necessary to complete these tasks. It is during this phase 

of flight that pilots receive their clearance and begin to 

plan their arrival. Failure to provide English-speaking 

pilots with the same information provided to other pilots 

in their native language may create an incomplete or 

inaccurate assessment of the situation. Not being fully 

cognizant of the situation may impose a threat to safety.

While on the airport surface, pilots again face uncertainty while performing a range of tasks – scanning their 

instruments, taxiing the aircraft to/from the runway, 

monitoring the radio, scanning out the window, completing checklists, and so on. They also might be copying 

their clearance instructions from heavily accented or less 

proficient controllers or listening to them as they talk in 

their native language, both of which add to workload, and 

limit situational awareness. Pilots may find themselves 

either landing on or taking off from the wrong runway.

Unlike domestic operations, U.S. pilots indicated 

higher cognitive workloads during international operations. What caused the added workload? All the pilots 

were ATP certificated and knew how to operate their 

aircraft, as demonstrated by their pilot ratings and 

certificates. A review of their discussions revealed that 

uncertainty with local procedures, language barriers, 

incomplete information, and feelings of isolation made 

the upcoming events less predictable and contributed to 

their sense of diminished situational awareness or loss of 

the “big picture.” 

Compensating for Reductions in Situational Awareness

When we asked pilots about what they do to compensate for any reduction in situational awareness, they said 

they conduct a complete and thorough ground and preflight preparation and review. Also, during their flights, 

they increase their vigilance and attention, and apply their 
28 

best practices to operational communication with ATC. 

That is, they listen attentively, use standard phraseology, 

apply a proper delivery technique (speak clearly, slowly, 

deliberately, concisely, and pause momentarily between 

each element in a readback), and if uncertainty presents 

itself, they clarify, verify, challenge, or restate the problem 

until any remaining ambiguity is resolved. 

They also rely on their own past experiences and 

that of other crewmembers, especially when situation 

awareness is limited or sketchy. That is, all members 

of the crew are active participants – from the moment 

they arrive in the cockpit until they leave the aircraft at 

its destination. Each crewmember is vital and expected 

to help disambiguate ATC transmissions and contribute 

to situational awareness.

In fact, some pilots viewed TCAS as an additional 

crewmember that was responsible for traffic awareness. 

Some pilots attempt to correlate what ATC is saying to 

other pilots with the targets displayed on TCAS. Using 

the other aircraft’s call signs, they develop expectancies 

involving the other aircraft’s locations, and possible maneuvers (changes in altitude, heading, speed, etc.). Pilots 

who watch other aircraft on their TCAS display can see 

if an aircraft may encroach into their protected zone and 

alert ATC about a potential conflict. 

In summary, the pilots provided much discussion about 

their experiences flying into non-native English-speaking 

countries and how communicating with the controllers 

there affected their situational awareness and workload. 

The differences in the pilots’ opinions resulted from 

where they generally flew and their experiences flying to 

particular areas of the world. Pilots flying into an area for 

the first time might have different opinions than a pilot 

who has been there many times before. Also, a pilot new 

to international flying would have a different opinion 

than a pilot with many years of diverse international 

flight experiences.

Generally, non-native English-speaking controllers 

did their jobs well, and language was not reported to be 

an issue during routine, non-eventful situations. However, during periods of high workload, heavy traffic, and 

weather, many of the pilots did not believe the controllers’ 

English was adequate. Also, when controllers reverted 

to their native languages, pilots who did not know these 

languages experienced discomfort and uncertainty as their 

situational awareness eroded. During times of uncertainty, 

pilots use their established strategies to compensate and 

mitigate against losses in situational awareness brought 

on by language switching. For example, some pilots attempted to infer what was said by ATC with changes 

made to aircraft targets on their TCAS displays.

We offer the following eight recommendations. They 

were derived from the information provided by the pilots 

during the interviews.

Recommendations

1. Support standardized, consistent, and secure English 

language-testing standards for use by ICAO member 

states.

2. Develop realistic emergency and nonroutine scenarios 

and simulations that require controllers (and pilots) to 

demonstrate their use of conversational English. These 

scenarios and simulations should be added to existing or 

new instructional and training programs, as well as to 

refresher training.

3. Provide pilots with the opportunity to listen to ATC 

messages and conversational English spoken by nonnative English-speaking controllers in English. Priming 

the pilots in the languages they will be hearing over their 

radios may facilitate decoding and comprehension.

4. Expand ICAO Emergency ATC vocabulary and 

phraseology and create datalink messages beyond “PANPAN, PAN-PAN, PAN-PAN,” “MAYDAY, MAYDAY, 

MAYDAY” or “CONDITION RED MAYDAY, 

MAYDAY, MAYDAY.” When pilots declare emergency 

situations, they need a set of phraseology to adequately 

express to controllers what they need for ensuring a safe, 

efficient, and effective outcome.

5. Publish a common, universally accepted, and comprehensive aviation thesaurus by CAST/ICAO. It would 

include definitions of standardized concepts, vocabulary, 

phraseology, and procedures. 

6. Provide NOTAMs in the native language and in 

English in a standard and consistent format for use by 

all ICAO member states. 

7. Exploit datalink capabilities to provide pilots with 

enhanced situational awareness. In particular, instructions 

and clearances conveyed in non-English can be correlated 

with that aircraft’s flight identifier transmitted by automatic dependent (ADS) broadcast technology, displayed 

graphically and in real time using cockpit displays of 

traffic information (CDTI). 

8. Develop a digital datacom message repository that 

pilots can access to review recent messages sent to other 

aircraft within a defined distance (to be determined). It 

would provide the same information currently available 

over their radiotelephony party-line communications, but 

it would be presented as text in English. This information 

could replace the information lost by language-switching, 

help maintain situational awareness, and allow pilots 

to anticipate future clearances, instructions, weather, 

turbulence, traffic, and other developing events. 

9. Develop new ICAO phraseology for pilot requests 

for “ride reports.” Pilot reports (PIREPS)20 provide ATC 

with valuable weather information experienced by pilots 

during their flights that is relayed to ground weather stations. In the U.S., some of this information is shared with 

pilots who request a ride report. Ride reports do not exist 

20 PIREPs include reports of strong frontal activity, squall lines, thunderstorms, 

light to severe icing, wind shear and turbulence (including clear air turbulence) 

of moderate or greater intensity, volcanic eruptions and volcanic ash clouds, 

and other conditions pertinent to flight safety.
29

in China and may not exist in other countries. Requests 

for ride reports are common in the U.S. Since there is no 

required phraseology, non-native English controllers are 

at a disadvantage understanding what information U.S. 

pilots are requesting. Examples of some requests include, 

“How’s the ride sound today?” and “What kind of ride 

reports have you had on climb outs?”

10. Develop structured ATC phraseology for providing 

pilots with ride report information. In response to pilotrequested ride reports, U.S. controllers use a combination 

of aviation and Common English. Presently, if weather 

is not a factor, some controllers might convey that information using the following examples, “No complaints,” 

“Some deviations along your route,” and “It should be 

okay.” Again, non-native English-speaking pilots would 

be at a disadvantage understanding what was said over 

the party line. Any information related to a ride report 

should have a predictable format and structure, possibility 

in the form presented in the following examples. 

{Light Turbulence}THROUGH Flight Level 

{three one five} 

{Light Chop} AT Flight Level {three one zero} 

‘TIL {Location} AREA THEN {Smooth}

11. Develop new ICAO phraseology for use when normal 

operations are disrupted. In particular, controllers need 

to know what pilots need during these times. A review of 

off-nominal events may shed light for crafting standardized pilot requests. Some examples are provided below 

for illustrative purposes only.

REQUEST {Fire Rescue} {Smoke in Cabin}

REQUEST {Ambulance} {Medical Emergency}

REQUEST {Alternate airport} {Weather, Closest 

Hospital, Aircraft Malfunction}

REQUEST {Police} {Unruly Passenger}

13. Develop a universal dialect for spoken messages. Location names should have one agreed-upon pronunciation.

14. DataCom messages should be non-ambiguous to all 

pilots and controllers.

15. DataCom spoken and written messages should 

contain no more than two communication elements.

16. Research studies are needed to determine whether 

issues exist in the interpretation and execution of spoken 

or written clearances and instructions. In particular, the 

following questions should be answered:

a) Should pilots and controllers be provided with 

displays that present ATC messages in English only or 

English and their primary language?

b) Should ATC messages be presented orally or 

visually as text/graphics, or both?

c) How should ATC messages be presented to best 

capture the intent of the message to controllers and pilots? 

 d) What is the best approach to convey the finesse 

of a flight operation (e.g., management of flow)?

 e) How do we test messages to ensure the intended 

action is executed by pilots and controllers who share the 

same, as compared with different languages, cultures, 

or both? 

References

Al-Hasnawi, A.R. (July 2007). A cognitive approach 

to translating metaphors. Translation Journal, 

11(3). Retrieved from http://accurapid.com/

journal/41metaphor.htm. Accessed 04 May 2010.

Beeman, M. (November 2005). Bilateral brain processes 

for comprehending natural language. Trends in 

Cognitive Sciences, 9, 512-518.

CAST/ICAO Common Taxonomy Team. (Feb, 2006). 

Phases of flight definitions and usage notes version 

1.0.1. Retrieved from http://www.intlaviationstandards.org/Documents/PhaseofFlightDefinitions.

pdf. Assessed 04 May 2010.

Clark, H. H. (2001). Conversation: Linguistic Aspects. 

In N. J. Smelser & P. B. Baltes (Eds.), International 

Encyclopedia of Social and Behavioral Sciences 

(pp. 2744-2747). London: Elsevier. Retrieved from 

http://www-psych.stanford.edu/~herb/2000s/

Clark.iesbs.Conv.pdf. Accessed 4 May 2010.

Dronkers, N.F., Plaisant, O., Iba-Zizen, M.T., & Cabanis, E.A. (2007). Paul Broca’s historic cases: high 

resolution MR imaging of the brains of Leborgne 

and Lelong. Brain, 130, 1432-1441. Retrieved 

from http://brain.oxfordjournals.org/cgi/reprint/

130/5/1432?maxtoshow=&hits=10&RESULTF

ORMAT=&fulltext=Dronkers&searchid=1&FIR

STINDEX=0&resourcetype=HWCIT. Accessed 

4 May 2010.

Eurocontrol. (Aug 20, 2007). ICAO standard phraseology: A quick reference guide for commercial air 

transport pilots. Retrieved from www.skybrary.aero/

bookshelf/books/115.pdf. Accessed 4 May 2010.

Federal Aviation Administration. (Feb 2010). Order 

7110.65 The Handbook of Air Traffic Control. 

Washington, DC: Author. Retrieved from faa.gov/

documentLibrary/media/Order/ATC.pdf. Accessed 

4 May 2010. 

Federal Aviation Administration. (Feb 2010). Aeronautical Information Manual. Washington, DC: Author. 

Retrieved from faa.gov/air_traffic/publications/

ATPubs/AIM/aim.pdf. Accessed 4 May 2010.

Flight Safety Foundation (Aug - Nov 2000). ALAR Tool 

Kit. FSF ALAR Brief Note 4.1 – Descent-andapproach profile management. Retrieved from 

Flight Safety Digest pp. 71-74. flightsafety.org/alar/

alar_bn4-1-profilemgmt.pdf. Accessed 4 May 2010.
30 

Ford, C. & Thompson, S.A. (1996). Interactional units 

in conversation: Syntactic, intonational, and pragmatic resources for turn management. In E. Ochs, 

E. Schegloff, & S. A. Thompson, (Eds.), Interaction and Grammar, (pp.134-184). New York, NY: 

Cambridge University Press. mendota.english.wisc.

edu/~ceford/documents/Ford_UnitsinConversation.pdf. Accessed 16 July 2009.

Fromkin, V. A. (1971). The non-anomalous nature of 

anomalous utterances. Language, 47(1), 27-52.

Hayes, A. F., & Krippendorff, K. (2007). Answering the 

call for a standard reliability measure for coding data. 

Communication Methods and Measures, 1, 77-89.

Hodgetts, H., Farmer, E., Joose, M., Parmentier, F., Schaefer, D., Hoogeboom, P., ..., Jones, D. (2005). The 

effects of party line communication on flight task 

performance. In D. de Waard, K.A. Brookhuis, R. 

van Egmond, & T. Boersema (Eds.), Human Factors in Design, Safety, and Management (pp. 1 - 12). 

Maastricht, the Netherlands: Shaker Publishing.

International Civil Aviation Organization. (2004). 

Manual on the implementation of ICAO language 

proficiency requirements. (ICAO Doc 9835/

AN453). Montreal, Quebec, Canada: Author.

International Civil Aviation Organization (2006). Procedures for Air Navigation Services - Operations 

(PANS-OPS), Vol. I Flight Procedures. (ICAO 

Doc. 8168). Fifth Edition. Montreal, Quebec, 

Canada: Author.

International Civil Aviation Organization (2007). Air 

traffic management – Procedures for Air Navigation 

Services (ATM-PANS), Doc 4444. 15th Edition. 

Montreal, Quebec, Canada: Author.

MacNeilage, P. & Ladefoged, P. (1976). The production 

of speech and language. In E.C. Carterette and M. 

P. Friedman (Eds.), Handbook of Perception (Vol. 

7, pp. 75-120). New York: Academic Press.

Marian, V. & Spivey, M. (2003). Bilingual and monolingual processing of competing lexical items. Applied Psycholinguistics (Psychological Studies of 

Language Processes) 24(2), 173-193. doi:10.1017/

S0142716403000092.

Prinzo, O. V., Campbell, A. Hendrix, A. M., & Hendrix, 

R. (2010b). U.S. airline transport pilot international 

flight language experiences report 3: Language experiences in non-native English-speaking airspace/

airports. (Technical Report DOT/FAA/AM-10/9). 

Washington, DC: Federal Aviation Administration, 

Office of Aerospace Medicine.

Prinzo, O. V., Campbell, A. Hendrix, A. M., & Hendrix, 

R. (2010a). U.S. airline transport pilot international 

flight language experiences report 2: Word meanings and pronunciation. (Technical Report DOT/

FAA/AM-10/7). Washington, DC: Federal Aviation 

Administration, Office of Aerospace Medicine.

Prinzo, O.V., Hendrix, A.M., & Hendrix, R. (2008). Pilot 

English language proficiency and the prevalence 

of communication problems at five U.S. air route 

traffic control centers. (Technical Report DOT/

FAA/AM-08/21). Washington, DC: Federal Aviation Administration, Office of Aerospace Medicine.

Pritchett, A., & Hansman, R.J. (1993, April). Preliminary 

analysis of pilot rankings of ‘party line’ information 

importance. In R.S. Jensen and D. Neumeister 

(Eds.), Seventh International Symposium on Aviation Psychology (Vol. 1, pp. 360-366). Columbus, 

OH: Ohio State University. 

Resnick, M. (2006). Human Factors. In Badiru, A.B. (Ed.) 

Handbook of industrial and systems engineering 

(pp. 1-20). Boca Raton, FL: CRC Press.

Varella, S. (2006). Lexical relations in a cross-linguistic 

context. Babel, 52 (2), 172-182.

Weber, A., & A. Cutler. (2004). Lexical competition in 

non-native spoken-word recognition. Journal of 

Memory and Language, 50 (1), 1-25.