Aviation Alphabet and Numbers; NATO Phonetic Alphabet

Aviation alphabet and numbers are the international phonetic alphabet, numbers, flags, and signs created by NATO in 1953 and are still used today.

Aviation Phonetic Alphabet

The aviation alphabet is the international phonetic alphabet created by the North Atlantic Treaty Association (NATO). The aviation alphabet is called the International Radiotelephony Spelling alphabet, which evolved into the present day alphabet. Several organizations have adopted the alphabet for their organizations, such as the North Atlantic Treaty Organization (NATO) and the International Civil Aviation Organizations (ICAO). This is also the alphabet used by the United States military.  

The aviation alphabet is actually a spelling alphabet. Each letter is pronounced as a word, which standardizes communication regardless of the language or location of the speaker.

Aviation Phonetic Numbers

The aviation number system is also a phonetic number pronunciation and is the international phonetic numbers system. When the North Atlantic Treaty Organization (NATO) and the International Association Organization (ICAO) adopted the alphabet, the numbering system was also adopted.  

Why is the phonetic aviation alphabet and numbers used?

The purpose of the aviation alphabet is to make communication simple.  Letters can sound the same when stated, such as ‘b’ and ‘p’, ‘d’ and ‘g’, or ‘t’ and ‘v’.  When calling out a fix, an airport or a tail number, the difference in one letter is huge. 

Imagine flying IFR (instrument flight rules), coming from New York heading to Miami.  You receive a clearance instructing you to fly directly to a GPS fix called ACERB, in South Carolina. You hear ACERE, which happens to be in Miami, where you are heading. There is a huge possibility for confusion between the ‘B’ and ‘E’.  Based on the destination no red flags are raised, but the difference in one letter is 559 miles away from where the controller sent you. 

The one-letter error could cause air traffic control (ATC) to report you as the pilot and a lot of explaining as to your deviation.  Reports from air traffic control are not a fun thing to deal with, as they can affect your pilot’s license and your insurance. Thus, the phonetic alphabet is used to help prevent such an error. 

Numbers do not have quite the same similarities but can easily be misunderstood as other words.  The number three in English is difficult for some speakers as the ‘th’ sound is uncommon in most languages. The number nine in English is pronounced the same as ’nein’ in German, which means no.  Thus the numbering system is used to ensure clearer communication.

Imagine flying on a crappy cloudy day with minimal visibility in busy airspace and radio full of static. You receive a clearance to cross a fix at 9,000 but you hear 5,000.  That one number error can put you in grave danger.  Both are odd numbers, which correlates to a proper altitude for your direction of flight.  However, in busy airspace, another plane could be traveling at the same altitude and you could be the cause of a collision. The best-case scenario is a report filed against you for a pilot deviation. 

Understanding radio communications can be more difficult based on the multitude of accents and dialects. I speak southern and my pilot speaks Yankee. Members of our aviation family speak Spanish and German, as their first languages. My pilot has taught other pilots from all over the world who speak a dozens of different languages and some with different dialects.  The use of the phonetic alphabet and numbers aids in clear communication regardless of the speakers primary language. 

In addition to the verbal differences, other issues such as radio interference or background noise can interfere with communication and the phonetic aviation alphabet and numbers assist in clarifying the content of the transmission.

Have you ever listened to a static-filled radio, barely able to make out the words of the controller? The ability to transmit information without confusion is absolutely necessary to ensure safety of flight.  The use of a uniform phonetic aviation alphabet and numbers helps with communication.  

The current Pilot-Controller Glossary has over 1,300 words, which a licensed pilot must understand, but the basic commands come in the form of letters and numbers.  

Is the use of the phonetic aviation alphabet and numbers required in aviation?

The use of the phonetic aviation alphabet and numbers is stated in the Aeronautical Information Manual (AIM), which is guidance to a pilot to comply with the applicable Federal Aviation Regulations regarding communications procedures.  

In the AIM, Chapter 4- Air Traffic Control: Section 4-2 Radio Communications Phraseology and Techniques; Paragraph 4-2-7 Phonetic Alphabet, the regulations specifically state that the use of the phonetic alphabet should be used to spell out groups of letters, single letters, or difficult words during adverse communication conditions.  

The chart of the letters and numbers is included in the Aeronautical Informational Manual. Included in the chart are the characters with the Morse code and telephony. The international alphabet pronunciation is also included.  You can find the information here.

We are happy to email you a printable aviation alphabet.

When to use the phonetic aviation alphabet and numbers?

The aviation alphabet and numbers are used by pilots, including general aviation, commercial aviation, and military aviation.  Other aviation providers use the alphabet such as fixed-base operators (FBO), surface vehicles operating on an airport, Automatic Terminal Information Service (ATIS), and air traffic controllers (ATC). 

Airports have airport identifiers that use letters and numbers. Taxiways are labeled by letter. The approach fixes, which tell you where to be in the sky for landing at an airport, are also short groups of letters. 

Every highway in the sky, also known as airways or jet routes, have numbers and/or letters. If you are below 18,000 feet, the highway is a Victor airway or ‘V’ followed by numbers. If you are above 18,000 feet, the highway is a Jet route or ‘J’ followed by numbers.

We recently began using GPS routes, which are known as ‘T’ routes and ‘Q’ routes, which also have numbers after the ‘T’ or ‘Q’. 

Every highway in the sky has specific places called fixes dotted along its path, which are in essence on ramps and off-ramps to that highway. Guess what, those too are are labeled by a group of letters.  

Every airplane must have a tail number, which is an identification number like a license plate, and it must be displayed on the airplane. Every airplane’s tail number starts with a letter that identifies which country the airplane is registered in.  In the United States, airplane tail numbers begin with the letter ‘N’. In Canada, airplane tail numbers begin with the letter ‘C’.  In Mexico, they have several variations depending on the type of operation, but all start with the letter ‘X’.

Letters and numbers are used in radio communications. Clear communication of altitudes, approach fixes, in route fixes, runways, radio frequencies, weather, time, and transponder codes all require the use of the phonetic alphabet and numbers.

What is the language of aviation?

In the United States, the Code of Federal Regulations (CFR) issued by the Department of Transportation and Federal Aviation Administrations contains the rules of aeronautics.  

14  CFR Section 61, Subpart E, Section 61.103 lists the requirements for the age, language, and pilot certificate requirements.  The section specifically states that the ability to read, write and understand the English language is a basic requirement for a Federal Aviation Airman Certificate. The examiner issuing the certificate includes a notation of “English proficient”.  A copy of the CFR can be found here.

The United States Department of Transportation, Federal Aviation Administration also issued an Advisory Circular that specifies the Aviation English Language Standard (AELS).  A copy of that Advisory Circular can be found here.

English is the required language but the aviation alphabet and numbers are actually international, as they were created by North Atlantic Treaty Association (NATO) and adopted by the International Civil Aviation Organization (ICAO).

History of the Phonetic Aviation Alphabet and Numbers

The International Civil Aviation Organization and the North Atlantic Treaty Association (NATO) alphabet is not the first phonetic alphabet to be used. 

In 1932 and a few years prior, the International Telecommunications Union (ITU) first used a phonetic alphabet.  This was a non-military alphabet. The alphabet consisted of the following:

• A – Amsterdam
• B – Baltimore
• C – Casablanca
• D – Denmark
• E – Edison
• F – Florida
• G – Gallipoli
• H – Havana
• I – Italia
• J – Jerusalem
• K – Kilogramme
• L – Liverpool
• M – Madagascar
• N – New York
• O – Oslo
• P – Paris
• Q – Quebec
• R – Roma
• S – Santiago
• T – Tripoli
• U – Upsala
• V – Valencia
• W – Washington
• X – Xanthippe
• Y – Yokohama
• Z – Zurich

I must say, I think I would have a hard time memorizing that phonetic alphabet.  The number of syllables in some of the words could really draw out a tail number.  Can you imagine hearing and then repeating New York, Two, Tree, Casablanca, Xanthippe cross Amsterdam, Kilogramme, Edison, Kilogramme, Yokohama at 10,000? 

I can see why they moved to a simpler system.  That call number is some kind of tongue twister and could take up substantial time on a busy frequency.  

World War II sparked the adoption of the phonetic alphabet in 1941 in a Joint Army/Navy alphabet called the “Able Baker”. In 1943 the British Royal Airforce also adopted the alphabet.  The words were shortened and changed as follows:

• A – Able
• B – Baker
• C – Charlie
• D – Dog
• E – Easy
• F- Fox
• G – George
• H – How
• I – Item
• J – Jig
• K – King
• L – Love
• M – Mike
• N – Nan
• O- Oboe
• P – Peter
• Q – Queen
• R – Roger
• S – Sugar
• T – Tare
• U – Uncle
• V – Victor
• W – William
• X – X-ray
• Y – Yoke
• Z – Zebra

However, the Able Baker alphabet received much criticism as the words were very English and did not incorporate the sounds or terms of other languages.  North Atlantic Treaty Organization (NATO) began a project to establish a universal phonetic alphabet, which included hiring linguistic experts.  

The alphabet chosen had to be an active word in English, French, and Spanish, as well as have similar spellings.  

Each word had to be easy to pronounce, easy to read, and clearly used over the radio.  

Additionally, the word could not have a negative meaning or be associated with something negative.  

The creation of the universal phonetic alphabet provides the standard in which all aviators use.

Current Phonetic Aviation Alphabet and Numbers

In March of 1956, The International Civil Aviation Organization adopted the current version of the phonetic alphabet and numbers, which is the North Atlantic Treaty Organization alphabet. The organization also included international alphabet flags and international phonetic alphabet signals for each letter and number.  

Use of Phonetic Aviation Alphabet Outside of Aviation

You can now find examples of the phonetic alphabet in common conversation and even movie titles. Ever heard the phrase Whiskey Tango Foxtrot?

If you have any stories of how the aviation alphabet and numbers saved you or did not, email us. We would love to hear about it.