How do you pronounce…?

17 Jul 20 11 Comments

This is a very interesting article by Allen Amsbaugh which was originally published in NASA’s ASRS Directline about the issues of navigational fixes which sound or look similar. The ASRS is the Aviation Safety Reporting System which collects reports anonymously and then analyses the data in order to share important information to the aviation community. This is why the reports below are referenced only by number and not by the name of the person who sent it in.

The article is an intriguing intersection of aviation and language which shows just how important it is to consider the human factor, even for something simple like naming airspace fixes.

The FAA’s National Flight Data Center is in charge of naming airspace fixes. When a new fix is needed by an FAA region or facility, a request is made with a choice of names. The center will then check to see that the proposed name:

a) is pronounceable,
b) does not duplicate another spelling,
c) is not profane in several of the major languages, and
d) is unique to the entire world.

Then the new fix is put into use.

Although the ASRA article is a bit dated and some of these waypoints may have been renamed in the meantime, I found it very helpful to understand the types of problems that could come up.

I’m off camping for the weekend (wish for sunshine for me!) but I would like to thank NASA and ASRS for allowing me to reprint the piece.

How do you spell…? How do you pronounce…?

by Allen Amsbaugh

Over the years, the ASRS has received many reports regarding navigational identifiers that sound similar to other fixes, or are not spelled in a logical fashion. Two caught my eye recently and were the impetus for this article. The first incident was reported by two crew members. One of these reporters stated:

“Enroute to PDX from DEN. Near BOI cleared direct DUFUR, direct PDX. Inadvertently spelled DUFER into the FMC. Note: DUFER is 14 DME, ILS 16R Seattle. Since the course seemed reasonable, I did not double-check for route deviation DUFER to PDX. A lesson learned! I am surprised that two intersections would be so close with similar names.” (# 258559, 258669)

SEA is about 50 miles farther from BOI than PDX, and about 17 degrees farther to the north. The ARTCC Controller rectified the situation by a gentle, “Where are you going?” The ASRS has issued a For Your Information Notice to the appropriate agencies and FAA offices in an attempt to rectify this problem. It was recommended that the name be changed on one of the intersections. We all hope that one of the spellings will not be changed to DOOFR!

More Waypoint Problems

Another air carrier crew had a problem entering the Charlotte, NC, area:

“We mistook Barretts Mountain (BZM) to LINCO intersection. Instead we started BZM to LYNNO intersection. LINCO is 203 degree radial off BZM, and LYNNO is 115 degree radial off BZM, both about 25 miles. It is suggested that intersections which sound so similar not be used in such a close area to another.” (# 108815, 108919) The ASRS issued an Alert Bulletin to the appropriate FAA offices with a recommendation that the name of one of the intersections be changed. This is exactly what has been done—LYNNO is now PLUMM on the MAJIC SEVEN arrival to Charlotte (MAJIC.MAJIC7). The system works!

International Events

The system also works in international airspace, as seen in the following report:

“On R22 between Alaska and Japan (the ‘N’ route). We requested Tokyo Radio to obtain clearance from FL330 to FL290 after NOGAL. HF communication was spotty, but I read back the clearance twice. Each time, Tokyo acknowledged by reading back the whole clearance. (I assumed he did this because of HF. Perhaps he was trying to clarify the fix.) Passing NOGAL, I called, ‘Departing FL330 for FL290.’ When we called ‘reaching FL290,’ Tokyo told us we should be at FL330 until NOGAR (a fix 493 miles down track). It’s interesting to note that it took about three minutes before he could pronounce the two fixes differently, and then we realized there was a similar sounding fix on the same route. Japanese pronounce ‘L’ and ‘R’ [similarly], making the words [sound] the same when pronounced by Tokyo Radio. Tokyo immediately amended our clearance to FL290. An immediate review of related fix names for similar sounding names, as pronounced by local speaker’s language, is essential. Not every nation or language can or does speak English the same way native English speakers do. Japanese phonetic differences should be taken into account, especially in Japanese airspace. At a minimum, NOGAL should be changed. (# 242971)

ASRS issued a For Your Information Notice to the FAA with the recommendation that NOGAL intersection be renamed to minimize confusion. The latest charts show that NOGAL has been renamed NYTIM. But, how does one pronounce NYTIM? Is it as “nighttime,” or possibly “nit tim,” or even “nee tim”? Even native English speakers will have to guess about this one.

The Perils of English Pronunciation

English is a wonderful tongue, and is the official language of the air. Every time that I flew abroad, I thanked my lucky stars that the Wright brothers were American! But the English language has several deficiencies—the biggest one being that there are no iron-clad rules for the pronunciation of vowels and combinations of vowels. Several consonants, in combination or singly, also can be pronounced more than one way.

The English language has come a long way from its Latin roots wherein pronunciation has very strong rules, but aviation makes tough demands on English. One member of the ASRS staff suggested using the Klingon language, which has no vowels; another suggested creating more vowels just for naming navigational fixes!

The United States airspace fixes also include many names of Native American, Spanish, and French origin. Very near the ASRS office is the compass locator for the ILS Runway 30L approach to the San José International Airport—JORGE, the Spanish name equivalent to the English “George.” I have heard it pronounced “George,” and more properly, “Hor-Hay,” as it would be pronounced in Spanish. Many others come to mind, including DOWNE on the ILS Runway 25L at Los Angeles. Is it pronounced “Down,” or “Downey” as is the city beneath it? You will hear this both ways too.

When expert help is proffered, it is a good idea to accept it—as the following example shows:

“Controller gave route change ‘Direct PERRI intersection, J8 OTT, OTT 3 arrival KBWI.’ He spelled out the intersection. The Captain began programming the FMS while we both reached for enroute charts. The Captain loaded ‘Direct PERRY,’ and the course indicated about 140° which was reasonable from the assigned 090° heading. The FMS would not accept J8, and we began to analyze why. TCAS II indicated traffic which was descending through our altitude and a potential conflict. The Captain initiated a left turn to avoid the traffic. Center issued a ‘Left turn immediately!’ and then assigned 100° [heading]. The conflict could have been averted by my verifying PERRI versus PERRY as the FMS entry. The Controller spelled out P-E-R-R-I, and I wrote it down correctly, but did not verify the Captain’s input…” (# 264927)

This error resulted in a traffic conflict because of the wrong heading. The Controller wanted the reporter to go to PERRI, a fix east of Charleston, WV, while the Captain entered PERRY, a fix southeast of Puerto Rico in the Caribbean! The FMS would not take J8 from PERRY because PERRY is not on J8, but PERRI is. Both man (the Controller) and machine (the FMS) tried to help this crew—to no avail.

5, 4, 3…

These problems are not restricted to five letter fixes. They also crop up in three letter VORs, as evidenced in this report:

“The original flight plan from SFODFW included Las Vegas, NM, as part of the filed route. A re-file was requested airborne, “Direct Beatty [BTY], Las Vegas, [LVS] Wichita Falls [SPS], on course.” We were requesting BTY, LVS and SPS VORs. LAX Center cleared us “direct LIDAT, Beatty, Las Vegas, Wichita Falls.” Just east of BTY VOR, LAX Center gave us a right turn to a 180 degree heading and said that we were getting close to a hot restricted area. LAX Center said that our clearance was over Las Vegas [LAS], NV…I realize that there are many navigation fixes around the world that have the same name…” (# 81977)

The reporter is right. There are many fixes with the same name, but no five-letter airspace fixes have the same name, only VORs and NDBs. For example, VORs with the same name but different letter designators include Springfield (SGF), MO, and Springfield (SPI), IL; Las Vegas (LAS), NV, and Las Vegas (LVS), NM; Bradford (BDF), IL, and Bradford (BFD), PA; and Danville (DNV), IL, and Danville (DAN), VA. All these examples are in United States airspace, and there are many more throughout the world.

Common Problems

As you might surmise, all of the above incidents happened in modern aircraft with Omega Navigation Systems or Inertial Navigation Systems. The same problems will be encountered by those pilots flying with Global Positioning Systems or LORAN. This is not to imply that the flight crew with the more modern navigation systems are more careless, it just means that they have new problems to solve. They must be more careful with their long distance leg requests to ensure that ARTCC understands that they want to go to Farmington, NM, (FMN) not Farmington, MO, (FAM) or Farmington, MN, (FGT). Flight crews must be very careful when they type a fix into their FMCs so that they go to CLEAT, MD, not CLETE, OH. There are many examples similar to CLEAT/CLETE—such as AANTS/ ANNTS, BRIJJ/BRIDG, etc. If you’d like to play a little game, go to FAA Publication 7350.6, “Location Identifiers,” and turn to the Airspace fixes section. See how many pairs you can find in one minute. You’ll find many are listed consecutively, such as DUMPE/ DUMPI.

Entering the Fix

If there are any questions in your mind, whether you are a pilot or a controller, you must ask immediately to clarify the situation, of course. We also have a few suggestions to help you avoid Waypoint Identifier Woes:

  • Pilots flying the aircraft with the new navigation systems should have their charts on hand at all times to ensure that spelling mistakes are not made.

  • Charts and flight plans should be consulted often to ensure that direct routings seem reasonable, and that the map presentation has no strange “spikes” or turns.

Common sense precautions and special care will prevent any of the navigation errors we’ve discussed.

Again, thanks to ASRS Directline for allowing me to reprint the article. I hope you found it as interesting as I did.

You might be interested in reading about TWA flight 514 on Wikipedia or the 40-page final report. TWA flight 514 crashed into a mountain on final approach in 1974 and the accident investigation board ended up split as to whether the flight crew or Air Traffic Control were responsible for the error which led to a controlled flight into terrain. The investigators also found that six weeks before the accident, another commercial flight had almost ended up in the same situation. At the time, there was no means for this flight crew to report what had happened without risk of reprisals or blame. In a case such as this, it meant that flight crew and controllers did not report a possibly confusing situation if there was the risk of making them look bad. The results was that a known issue might not get attention until an aircraft actually crashed, which is exactly what happened with TWA flight 514. If the other flight crew had felt safe enough to report their confusion at that location, the fatal crash might have been avoided. After this investigation, the ASRS was created in order to facilitate anonymous reporting for flight crew and controllers without fear of reprisals.

My favourite airspace fix, by the way, is coming into Mannheim in Germany. For an approach from the south, the waypoint is called MANEM, which is what Mannheim is called in the local dialect (Mannemerisch), which I learned as a child. A small thing but it made me smile.

See you next week.

Category: Demystifying,


  • I think they should all end in “OUGH”

    as in ‘through’
    as in ‘enough’
    as in ‘cough’
    as in ‘plough’
    as in ‘rough’

    and ‘lough’. ;-)

  • Yes, use of words and pronunciation is very important, especially in aviation. With the greatest generosity of spirit, America is included in the worlds English speaking nations. Spellcheck tried its best to get me to change “aeroplane” to “airplane”. I over-rode it. In the same vein, it seems they are constructed of something called “aloominum”, whatever that may be. I haven’t been asked by spellcheck to make that an alternative. I suppose “aerobatics” are on spellchecks list to “airbatics”. Being an amateur writer of short stories I am aware that our language is a dynamic, living organism, with words added and removed constantly. I try not to be a “prosephobe”. (made that up!) but there is some mangling of English (Manglish?) that really grate though. Can others think of some?

  • The language used in aviation communications is primarily the English language. However, as Sylvia’s narrative demonstrates, this can lead to confusing, and even very dangerous situations. The pronunciation of the English language can differ when spoken by people whose native tongue is a different one. The fact that in quite a few countries the national language may be used as well can be the cause of other complications. But even when properly pronounced, there still can be unexpected situations arising from the interpretation. At many airports an aircraft may be cleared to “line up behind departing…” What ATC means is: “AFTER the departing aircraft…”, in other words when the departing aircraft has commenced its take-off roll. I once witnessed a funny incident, luckily without serious consequences.
    Maybe the procedure has changed, but in the ‘seventies when this happened it was not unusual at Brussels for an approaching aircraft to get its landing clearance from the approach controller.
    An aircraft was waiting for take-off, I was no. 3. The aircraft ahead of me was a DH Dominie, the Royal Navy designation of a four-engined De Havilland Heron. He was cleared “to line up behind departing”. Which he did, quite literally. So now there were two aircraft at the beginning of the runway when ATC decided that there was not enough free airspace to clear the first waiting airliner for take-off, and another one was on short final but still on the approach frequency. We were on the tower frequency. The first aircraft was told to clear the runway. He was unable to, he did not have enough room to manoeuvre past the Royal Navy Dominie.
    The pilot was asked what he was doing on the runway. The reply, in “the Queen’s English” was “You told me to line up behind, and so I did.” Most English pilots would have made the correct interpretation, but a military pilot would exactly, literally, do as told.
    It led to a flurry of overshoots and a controller who suddenly had to give instructions to pilots that were sending them in directions that did not correspond to the standard missed approach procedure, but the controller handled it superbly.
    I have also been confronted with a French controller mixing up his English when I was “cleared position and ‘old”. Fortunately I scanned the approach before lining up and saw the landing aircrat in time. My protest was met with “I told you ‘old position”. I also witnessed what could have been a collission between a landing aircraft and another one waiting for take-off from a mid-runway postition at CDG. It was dark, with low clouds. The pilots of the landing landing aircraft spoke French. Fortunately the waiting aircraft understood French, realised that an aircraft was landing behind him and alerted ATC who cleared him for “immediate take-off expedite.”
    Now already many years ago a group of pilots were discussing a new potential technological solution. The proposal was to develop a system that would allow ATC to send instructions directly to the autopilot of an aircraft. Under this proposal, the crew would be informed by messages or even a schematic picture on their navigation screen to inform them of the inputs that ATC were giving to their autopilot.
    This was never officially formulated, it was mooted between a group of pilots with some inputs from a technical expert who was quite adamant that such a system was well within the technical possibilities, even at the time.
    This was immediately vetoed by the pilots’ unions. It never even featured in any official discussion. There were several reasons why this was deemed undesirable. One captain who also had a law degree was of the opinion that it would be a breach of the command structure and would obscure who would be in charge if anything would go wrong. It was also feared that it could be used to interfere with aircraft, lead to confusion when pilots were no longer in full control and would lose the overall picture. It also was feared that it could lead to accidents in case of a malfuntioning system.
    I think that secretly the pilots just did not like the idea of becoming glorified passengers. Anyway, it never got beyond a very informal discussion between a small group of pilots.
    BTW: In the Middle East where religion forbids the use of alcohol many devout Muslim pilots substitute “Whiskey” by “Water” in their R/T conversations. It does not cause any confusion so in my opinion this should be respected. Even so, the word “whiskey” (gaelic “uisge”) means….. WATER! The full “uisge beatha” means “water of life”, just like aquavit, and in that particular context yes, it is an alcoholic drink.
    Don’t use it when flying your ‘plane !

  • SEA is 1.86 degrees north of PDX (~112nm, ~128sm) not 17; I wonder where that error came from? Nice to hear ARTCC was gentle with the pilot, as they were when I mistook some random light for IAD on a nighttime approach back when IAD was so underused that it only turned on non-statutory lights on request.

    It’s not that Japanese pronounce ‘r’ and ‘l’ similarly; it’s that the language has only one liquid (see, whose pronunciation is not consistent to ears raised on two liquids — watch Tampopo (whose titular heroine is trying to make a go of a noodle shop) and notice how many ways the Japanese word for a thin noodle is pronounced. But the point is still valid; somebody may have thought that the terminal ‘r’ (which is not a liquid in English) would be distinguishable from a terminal ‘l’, or may not have thought at all about who would be pronouncing the intersection.

    The author is also too confident in how fixed Latin pronunciation is; from the combination of a British teacher at a US school, and singing choral works by composers of several nationalities for a very particular conductor, I know at ~5 ~standard pronunciations — not counting the way Steeleye Span mutilate it in “Gaudete”!

    ISTM that problems like the first two (and maybe the 4th?) should be fixed en masse, before there are any more issues; a simple computer program could compare all pairs of names that are within some hundreds of miles of each other. Issues like JORGE or DOWNE are harder, but making sure names don’t get mixed up is basic.

    I’m not surprised that there are two Springfield VORs; VORs tend to carry town names (or airport names, which are derived from towns), and Springfield is the most common town name in the US. (Among other random facts, that’s why the Simpsons live there.) I’m also not surprised names haven’t been changed for simplicity, especially if a name change would involve a town from a different Congressional district (cf Illinois rep Hastert making a fuss a proposal to eliminate the penny because its obverse has a profile of Lincoln and Illinois nicknames itself “Land of Lincoln”). Maybe a VOR Realignment Commission is needed — although it would have a tough time with on-airport VORs like the ones in this example.

    @J: Cute! I learned “enough” and “rough” as rhymes — how do you pronounce them? — but the demonstration sentence I was taught added “though” (long ‘o’) but didn’t include “lough”, which I first heard when a Celtic band showed up at my college.

    Silvia: interesting point on the ASRS; I knew of the crash — it happened near where I grew up and not long before I started learning instrument flying — but I hadn’t known until recently of the near-miss.

    • Vaguely aviation-related: Two brothers came to the USA and founded an aircraft company that is still quite well-known to this day. Their family name was “Loughheid”. ;-)

  • @me, on the stairstep: 17 degrees looks like a bearing rather than a distance. Never Mind….

    @Rudy: that’s quite a collection of gaffes; I’m not surprised a French controller wasn’t taught an English voiced ‘h’ rather than the stop in “Le Havre”, but the confusion between “behind” and “after” sounds like the sort of thing that should have been ironed out a long time ago. I remember hearing about proposals for machine-to-machine transmission of directions. It sounds like a better system in some ways, especially if the initial entry involved controllers marking the path on touch screens, and I wouldn’t be surprised if the opposition included irrational factors. OTOH, given several discussions here concerning the need for pilots to have skills sharp when the inevitable unusual happens — not to mention the issues with MCAS, especially the lack of dual sensors/reports — I wonder whether the mossbacks had something of a point. I was taught ANC — “Aviate, Navigate, Communicate”; do you see those as discrete, or do they blur into each other? I suspect that there’s no fits-all solution; would such a system be useful to give pilots fewer threads to attend to on arrival and departure, without leaving them to become inattentive during cruise?

  • Chip, R/T confusion can have its origins not only in the way people of different nationalities pronounce the same (English) language. Even if English is their mother tongue: There are differences in the way the language sounds when spoken by American, English, Scottish or Irish people. And to make matters worse there are local peculiarities, not necessarily in the language. For instance, the controller at German airports will say “Cleared for take-off, tschuss (bye).” The pilots are expected to know that they must switch to the departure frequency. This frequency is listed on their SID charts and may even differ between the different standard departures.
    A local variation on standard procedures actually was the cause of a demotion from captain to F/O – and it was me!
    We operated frequently out of a small Italian airport. With our take-off clearance ATC used to give us a higher level than the prescribed one in the SID and we were allowed to climb straight to that level. I was on my annual simulator check ride with a new, and as it turned out rather rigid check captain. For our check, this particular airport was programmed into the simulator. The chief pilot operated the simulator and acted as ATC, the check pilot was in the jump seat. I got the usual clearance, first of course with an engine failure after V-1 and a single-engine ILS. The next take-off again: “cleared for take-off, cleared FL 160”. We took off for the second time and this time I continued direct to the cleared level.
    Well, the check pilot failed me: I should have levelled off at the level as specified in the SID until the SID exit point before continuing to the higher level. For two miserable weeks I was put back as F/O before the chief pilot, who was well aware of the local peculiarity, got another simulator slot, and gave me another check ride which I passed (of course).
    The very next rotation brought me again to this Italian airport. The same again: “Cleared for take-off, cleared FL 160.”
    I had learned my lesson: I levelled off at the initial SID level. This provoked a puzzled response from ATC: “(our call sign) I see you level at five tousand why you not climb to your cleared level?”

  • Yes, Sylvia points to a problem that with the increased memory capactiy of modern navigation systems can have unwanted and potentially nasty – meaning dangerous – consequences.
    The first computerised nav systems that I learned to work with were Loran, Decca and VLF-Omega (GNS). Decca most probably is no longer in use. Loran probably went the same way. Are VLF-Omega stations still operational? I don’t know but in 1981 the GNS was “the bees’ knees.’
    We could fly from waypoint to waypoint and it gave a lot of extra information too. It could calculate remaining endurance, optimum cruise speed, wind speed and -direction, drift and drift angle, etc.
    The desired operational mode was selected using a rotary selector switch and it could store 9 (yes: nine) waypoints in its working memory.
    With some waypoints having the same or very similar names, and with modern systems having the capacity to hold a very large number in its memory, the crew must be careful when making manual inputs. And check that they have the correct waypoint. With the sophistication of the latest systems that should be a thing of the past. Navigation plans can be stored, perhaps more applicable to airlines with a number of fixed routes than to executive jets that can expect to operate where the boss wants to go.
    The limited waypoints held in the old systems could also lead to embarrassing situations. With the autopilot coupled to the nav system, (the old Carrousel IV INS was one of them, the GNS was programmed in a similar way) the aircraft would fly from waypoint 1 to 2, 3, etc. The waypoints that were behind were redundant, so the crew would input the coordinates for “10” in waypoint 1, 2 “11”, etc. So when passing waypoint “9”, the last one, the autopilot would fly to no 1, 2, 3 and so on.
    On one transatlantic flight the crew dozed off. Oceanic ATC is not nearly as busy as over densely populated continental areas, the crew would be expected to call for the occasional position report.
    Unfortunately, they did not re-program the computer. So waypoint “1” was still the… airport of departure. And after passing waypoint “9” the aircraft did not proceed to the next intended position, that had not yet been programmed in the system.
    And so the 747 made a gentle 180 turn and returned to the airport of departure. When finally the crew, probably woken up by ATC, realised what had happened, they had already gone too far back, they did not have the endurance to turn around once more. So the captain made up a fib about a technical problem, they did not have much choice.
    What happened to the crew after? I don’t know.
    But we – if we are pilots – must be aware not only of the errors that can arise from spoken R/T, confusion about waypoints with similar identifiers, but also be aware that a minor typo in the inputs can bring the aircraft on a substantially different track from the one on the flight plan.
    Are there still systems in use that require in-flight updating of the waypoints? Maybe that hazard is something of the past.

  • Macine-to-machine transmission’s strength is also its greatest weakness: because this protocol must be standardized, it’s unambiguous, but may also fail to perform well in nonstandard situations!

    That said, having flight plans or clearances in a digital, machine-readable format probably helps things; I assume ATC already have that?

  • Mendel,
    In my early days we worked out the nav. plan and filed the flight plan with ATC ourselves.
    Of course, in commercial airline operations this is all done by Flight Ops.
    When I returned to executive jets, things had changed dramatically.
    Gone were “luxuriy extras” like INS, Loran, Decca and VLF-Omega. Even the FMS systems that some ten to fifteen years ago received their inputs from VOR-DME now operated on GPS. GPS had become the standard and in fact was q requirement.
    But more had changed: Before I moved to turbo-props like ATR-42, Shorts 3-60, Fokker 50, Fairchild FH227 and F27 the flight levels above FL 280 had a 2000 dft vertical separation, so FL 280, next (opposite) was FL 310, then FL 330 (a,gain in opposite direction), FL 350 and so on. But later air data computers were more accurate than the purely barometric ones, and so “RVSM”, reduced vertical sepatation minima was introduced. So now FL 280, 290, 300, 310, etc in alternating directions. The aircraft had to be RVSM equipped and certificated, the crew had to be RVSM approved. The operator also had to hold an RVSM certificate.
    Together with the near-limitless number of waypoints and the very much increased air trafffic, the old way had become a thing of the past. With our executive jets we had to engage one of the professional services that would file our flight plan and get our ATC slots. There were many waypoints, and the ATC computer would decide which route we would be allocated. Usually close enough, but not always exactly the same plan if we flew the same route again.
    So, Mendel, ATC not only have the flight plans, they are computer-generated BY ATC and sent to the crew via their handling agent.
    Above FL 420 the RVSM rules did not apply. We often flew a “Stallion”, an updated Ce500. It was able to climb directly to FL 430 and, supposing that ATC allowed a climb through RVSM airspace, we then were able to cruise at that altitude before the operator had fulfilled all requirenments for RVSM approval.

  • The article says:

    “For example, VORs with the same name but different letter designators include Springfield (SGF), MO, and Springfield (SPI), IL;”

    Thisis an interesting assertion. SPI is “Spinner”, not “Springfield”, and to my knowledge it was known as “Capital” before that (I don’t know how long it was “Capital”, but long enough that the overlying Kansas City ARTCC sector is known as the “Capital Sector” to this day). I wonder when the article was published.

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