Air Traffic Organization Policy

JO 7340.2E
Effective Date:
July 24, 2014

Subject:  Contractions
Includes:  Change 2 dated 3/5/15 and Change 1 dated 11/13/14

Section 4. ICAO Aircraft Company Three-Letter Identifier and/or Telephony Designator Assignments and U.S. Special Telephony/Call Signs

1-4-1. GENERAL

a. This section contains information, direction, and guidance to be used when obtaining International Civil Aviation Organization (ICAO) company designators and telephony designators (call signs) for those operators and servicing organizations that request or are required to obtain designators. Commercial, domestic, and international operators use designators for air traffic control (ATC) operations. ICAO Three­Letter Identifiers and Telephonies and U.S. Special Telephonies/Call Signs are contained in Chapter 3 except for “For Official Use Only” Special Telephonies/Call Signs which are contained in FAA Order 7110.67, Special Aircraft Operations by Federal, State Law Enforcement, Military Organizations and Special Activities.

b. The Air Traffic Organization (ATO) headquarters' (HQ) Aeronautical Information Management (AIM) Office (AJV­2) (callsigns@faa.gov) assigns the designators when the Federal Aviation Administration (FAA) determines that designators are advantageous and operationally appropriate to the U.S. ATC system. In the interests of safety, AJV­2 reserves the right to revise or cancel a designator assignment in the event of confusion or misuse. The FAA will not assign a three­letter company identifier nor its associated telephony designator without their approval by ICAO for world­wide use.

c.  The four types of designators are entitled and described as follows:

1. Company designator (ICAO three­letter designator);

2. Telephony designator (used instead of phonetically pronouncing the three­letter company designator associated with the aircraft call sign);

3. Special telephony designator (special handling); and

4. Local telephony designator (local visual flight rules (VFR) operations only).


a. The company designator, together with a flight number, serves as the aircraft identification in the ATC system. Company designators are valid only for company business in accordance with the provisions of its operating certificate or servicing organization. Pilots will use standard identification procedures for personal flying. The company designator serves as the aircraft identification for the ATC system in several situations. The company designator and flight/trip number are used instead of the aircraft registration number for ATC security and operational purposes and may be used for the international telecommunications service when its use is advantageous.

b. ATO AJV­2 may assign a three­letter company designator to:

1. Scheduled aircraft operators that operate seven or more non­seasonal international air operations each week or at least 15 non­seasonal, domestic round­trip air operations each week;

2. Chartered aircraft operators that may require use of the AFTN;

3. Aircraft operators that require an ICAO three­letter designator for security purposes; or

4. Flight service companies and organizations that meet none of these requirements but are deemed worthy of an ICAO three­letter designator (i.e., Veterans Airlift Command).


a. The telephony designator (used instead of phonetically pronouncing the three­letter company designator associated with the aircraft call sign) is usually assigned by ATO AJV­2 at the same time as the ICAO three­letter designator. The call sign, together with a flight number, is the aircraft identification for radio voice communications with air traffic personnel.

b. The telephony designator should be phonetically pronounceable in English. The designator should not consist of more than two words and three syllables. Numbers and phonetic letters may not be assigned as part of a telephony designator; however, existing telephony designators which violate this rule will remain in effect.

c. Use of telephony designators:

1. Increases operational security and accountability;

2. Reduces online noise distractions that create similar sounding telephony designator confusion;

3. Expedites air and ground communication, enhances auditory recognition, and reduces potential for mistakes in verbal communication; and

4. Satisfies specific requirements for international flight operations.

The operator must include a new or changed telephony designator in the “Remarks” section of the operator's flight plans for at least 60 days following the new designator's effective date.


a. ATO may authorize a special telephony designator to enable special handling by ATC. Examples of situations in which ATO may authorize a special designator include:

1. Federal, state, local, or tribal governmental organizations operating within the continental United States (CONUS);

2. Commemorative flight;

3. Large number of aircraft participating in an organized race;

4. Aircraft operating during emergencies or disasters; or

5. Aircraft that need special handling for security or test purposes.

Special telephony designators may be issued as valid for a limited duration, corresponding to the event requiring special handling.

A special identifier, from four to five characters, is assigned in conjunction with the special telephony. The special identifier, when pronounced, is the special telephony.


A local telephony designator must be used only for communication with local airport traffic control towers (ATCT) and/or air traffic facilities during VFR operations; they must not be used for filing flight plans.

Flight schools or other operators which operate predominantly in a limited airspace are encouraged to investigate a local telephony identifier if it will improve communications and enhance safety. (ICAO will not grant a three­letter identifier to this type of operator.)


Companies and service organizations make all requests for designators to the appropriate Air Traffic Service Center. ATO AJV­2 (callsigns@faa.gov) administers final designator assignment.

a. Company Designator/Telephony Designator. The operator or service organization must submit the following information for a three­letter designator and the telephony designator request:

1. The name and address of operator or servicing organization;

2. The type of aircraft operation or service provided (a list of the operators served is required for service operations);

3. If applicable, a copy of the operator published flight schedule, monthly flight history, or projected flight schedule, highlighting international flight activity;

4. If applicable, a copy of the FAA certificate which authorizes the company's operations and states the 14 CFR part under which operations are to be conducted; and

5. Choices for requested three­letter designators and telephony designators, listed in their desired order. At least five choices are recommended to eliminate potential back­and­forth communications in the event a choice is not available/granted.

b. Special Telephony Designator.
Government aircraft operators (U.S. State, local, tribal, and law enforcement aircraft) desiring special telephony designators must contact Air Traffic System Operations Security via email at 9­ATOR­HQ­IFOS@faa.gov. All others must contact ATO AJV­2 (callsigns@faa.gov). Operators must submit the following information for the special telephony designator request:

1. Type of flight;

2. Type of handling required;

3. Type and number of aircraft; and

4. Routes and duration of operation.

Special telephony designators do not receive a three­letter identifier.

c. Local Telephony Designator.
Local telephony designators are used only for communications with air traffic facilities for VFR operations as specified in a letter of agreement (LOA) between the local facility or service area and the requesting applicant. The LOA will contain provisions to ensure that the applicant uses local telephony designators only with facilities or service areas that are signatories to the agreement. The appropriate service center must review the LOA, coordinate with the military liaison to ensure the designator is not in use, add its recommendations to the letter, and forward the signed LOA to ATO AJV­2. The service center or facility will issue the signed LOA to the applicant.


a. When an assigned three­letter company designator and/or telephony designator is no longer required, the company must notify ATO AJV­2 (callsigns@faa.gov) in writing. ATO AJV­2 must not reassign any designator it has released for at least 60 calendar days. Notification of change or release should be made when:

1. Operations are permanently suspended or cancelled;

2. Company name or address changes; or

3. A single operating certificate is issued resulting in a company name holding more than one designator. (Typically one of the existing designators is retained, and the other is cancelled.)

b. Principal Operations Inspectors (POI) must notify ATO AJV­2 when a company operating certificate is revoked or surrendered.

c. If a company fails to use a three­letter company designator or telephony designator for two years on an Instrument Flight Rules (IFR) flight plan in U.S.­controlled airspace, AJV­2 will place them on a watch list. AJV­2 will revoke and release any three­letter company designator and telephony designator that is not used for three years on an IFR flight in U.S.­controlled airspace. Any requests for a waiver of this policy should be made in writing to AJV­2 (callsigns@faa.gov).


The AFTN system also uses ICAO three­letter designators for identification, communication, and billing purposes. The AFTN system is an integrated, international system of aeronautical fixed circuits. The AFTN system provides the exchange of messages and flight plans between aeronautical and fixed stations within the network.


The required administrative period for approval of a three­letter company and/or telephony designator is approximately 45 calendar days. ATO AJV­2 establishes an effective date for the designator. ATO AJV­2 advises the FAA facilities affected that the numbers will be published in FAA and ICAO documents (the current editions of ICAO Doc 8585, Designators for Aircraft Operating Agencies, Aeronautical Authorities, and Services, and FAA Order JO 7340.2, Contractions). Failure to submit the proper documentation may delay a designator assignment.


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