Section 4. Radio and Interphone Communications

2-4-1. RADIO COMMUNICATIONS

Use radio frequencies for the special purposes for which they are intended. A single frequency may be used for more than one function except as follows:

TERMINAL.When combining positions in the tower, do not use ground control frequency for airborne communications.

2-4-2. MONITORING

Monitor interphones and assigned radio frequencies continuously.

2-4-3. PILOT ACKNOWLEDGMENT/READ BACK

Ensure pilots acknowledge all Air Traffic Clearances and ATC Instructions. When a pilot reads back an Air Traffic Clearance or ATC Instruction:

1. Ensure that items read back are correct.
2. Ensure the read back of hold short instructions, whether a part of taxi instructions or a LAHSO clearance.
3. Ensure pilots use call signs and/or registration numbers in any read back acknowledging an Air Traffic Clearance or ATC Instruction.

2-4-4. AUTHORIZED INTERRUPTIONS

As necessary, authorize a pilot to interrupt his/her communications guard.

2-4-5. AUTHORIZED TRANSMISSIONS

Transmit only those messages necessary for air traffic control or otherwise contributing to air safety.

2-4-6. FALSE OR DECEPTIVE COMMUNICATIONS

Take action to detect, prevent, and report false, deceptive, or phantom controller communications to an aircraft or controller. The following must be accomplished when false or deceptive communications occur:

1. Correct false information.
2. Broadcast an alert to aircraft operating on all frequencies within the area where deceptive or phantom transmissions have been received.
3. Collect pertinent information regarding the incident.
4. Notify the operations supervisor of the false, deceptive, or phantom transmission and report all relevant information pertaining to the incident.

2-4-7. AUTHORIZED RELAYS

1. Relay operational information to aircraft or aircraft operators as necessary. Do not agree to handle such messages on a regular basis. Give the source of any such message you relay.
2. Relay official FAA messages as required.
3. Relay operational information to military aircraft operating on, or planning to operate on IRs.

2-4-8. RADIO MESSAGE FORMAT

Use the following format for radio communications with an aircraft:

1. Sector/position on initial radio contact:
   1. Identification of aircraft.
   2. Identification of ATC unit.
   3. Message (if any).
   4. The word “over” if required.
2. Subsequent radio transmissions from the same sector/position must use the same format, except the identification of the ATC unit may be omitted.

   TERMINAL. You may omit aircraft identification after initial contact when conducting the final portion of a radar approach.

2-4-9. ABBREVIATED TRANSMISSIONS

Transmissions may be abbreviated as follows:

1. Use the identification prefix and the last 3 digits or letters of the aircraft identification after communications have been established with a U.S. civil aircraft using the aircraft registration as identification.
2. Do not abbreviate:
   1. Similar sounding aircraft identifications.
   2. Aircraft call signs, including:
      1. Aircraft having an International Civil Aviation Organization three letter designator (ICAO 3LD) and other aircraft with an FAA authorized call sign (U.S. special or local).
      2. Aircraft with a military call sign.
   3. Foreign aircraft using the foreign civil registration number as identification.
3. Omit the facility identification after communication has been established.
4. Transmit the message immediately after the callup (without waiting for the aircraft's reply) when the message is short and receipt is generally assured.
5. Omit the word “over” if the message obviously requires a reply.

2-4-10. INTERPHONE TRANSMISSION PRIORITIES

Give priority to interphone transmissions as follows:

1. First priority. Emergency messages including essential information on aircraft accidents or suspected accidents. After an actual emergency has passed, give a lower priority to messages relating to that accident.
2. Second priority. Clearances and control instructions.
3. Third priority. Movement and control messages using the following order of preference when possible:
   1. Progress reports.
   2. Departure or arrival reports.
   3. Flight plans.
4. Fourth priority. Movement messages on VFR aircraft.

2-4-11. PRIORITY INTERRUPTION

Use the words “emergency” or “control” for interrupting lower priority messages when you have an emergency or control message to transmit.

2-4-12. INTERPHONE MESSAGE FORMAT

Use the following format for interphone intra/interfacility communications:

1. Both the caller and receiver identify their facility and/or position in a manner that ensures they will not be confused with another position.
2. Between two facilities which utilize numeric position identification, the caller must identify both facility and position.
3. Caller states the type of coordination to be accomplished when advantageous. For example, handoff or APREQ.
4. The caller states the message.
5. The receiver states the response to the caller's message followed by the receiver's operating initials.
6. The caller states his or her operating initials.
7. Identify the interphone voice line on which the call is being made when two or more such lines are collocated at the receiving operating position.
8. TERMINAL.The provisions of subparagraphs a, b, c, e, f, g, and paragraph 2-4-13, Interphone Message Termination, may be omitted provided:
   1. Abbreviated standard coordination procedures are contained in a facility directive describing the specific conditions and positions that may utilize an abbreviated interphone message format; and
   2. There will be no possibility of misunderstanding which positions are using the abbreviated procedures.

2-4-13. INTERPHONE MESSAGE TERMINATION

Terminate interphone messages with your operating initials.

2-4-14. WORDS AND PHRASES

1. Use the words or phrases in radiotelephone and interphone communication as contained in the P/CG or, within areas where Controller Pilot Data Link Communications (CPDLC) is in use, the phraseology contained in the applicable CPDLC message set.
2. The word super must be used as part of the identification in all communications with or about super aircraft.
3. The word heavy must be used as part of the identification in all communications with or about heavy aircraft.
4. EN ROUTE.The use of the words super or heavy may be omitted except as follows:
   1. In communications with a terminal facility about super or heavy aircraft operations.
   2. In communications with or about super orheavy aircraft with regard to an airport where the en route center is providing approach control service.
   3. In communications with or about super or heavy aircraft when the separation from a following aircraft may become less than 5 miles by approved procedure.
   4. When issuing traffic advisories.
5. When in radio communications with “Air Force One” or “Air Force Two,” do not add the heavy designator to the call sign. State only the call sign “Air Force One/Two” regardless of the type aircraft.

2-4-15. EMPHASIS FOR CLARITY

1. Treat aircraft with similar sounding aircraft identifications by emphasizing appropriate digits, letters, or similar sounding words to aid in distinguishing between similar sounding aircraft identifications. Do not abbreviate similar sounding aircraft identifications.
2. Treat aircraft with similar sounding call signs by restating the call sign after the flight number.
3. Notify each pilot concerned when communicating with aircraft having similar sounding identifications.
4. Notify the operations supervisor-in-charge of any duplicate call signs or phonetically similar-sounding call signs when the aircraft are operating simultaneously within the same sector.

2-4-16. ICAO PHONETICS

Use the ICAO pronunciation of numbers and individual letters. (See the ICAO radiotelephony alphabet and pronunciation in TBL 2-4-1.)

TBL 2-4-1
ICAO Phonetics

2-4-17. NUMBERS USAGE

State numbers as follows:

1. Serial numbers. The separate digits.

   Number	Statement
   11,495	“One one four niner five.”
   20,069	“Two zero zero six niner.”

2. Altitudes or flight levels:
   1. Altitudes. Pronounce each digit in the number of hundreds or thousands followed by the word “hundred” or “thousand” as appropriate.

      Number	Statement
      10,000	“One zero thousand.”
      11,000	“One one thousand.”
      17,900	“One seven thousand niner hundred.”

      Number	Statement
      10,000	“Ten thousand.”
      11,000	“Eleven thousand.”
      17,900	“Seventeen thousand niner hundred.”

   2. Flight levels. The words “flight level” followed by the separate digits of the flight level.

      Flight Level	Statement
      180	“Flight level one eight zero.”
      275	“Flight level two seven five.”

   3. MDA/DH Altitudes. The separate digits of the MDA/DH altitude.

      MDA/DH Altitude	Statement
      1,320	“Minimum descent altitude, one three two zero.”
      486	“Decision height, four eight six.”

3. Time:
   1. General time information. The four separate digits of the hour and minute/s in terms of UTC.

      UTC	Time (12 hour)	Statement
      0715	1:15 a.m. CST	“Zero seven one five.”
      1915	1:15 p.m. CST	“One niner one five.”

   2. Upon request. The four separate digits of the hours and minute/s in terms of UTC followed by the local standard time equivalent; or the local time equivalent only. Local time may be based on the 24-hour clock system, and the word “local” or the time zone equivalent must be stated when other than UTC is referenced. The term “ZULU” may be used to denote UTC.

      UTC	Time (24 hour)	Time (12 hour)	Statement
      2230	1430 PST	2:30 p.m.	“Two two three zero, one four three zero Pacific or Local.” or “Two-thirty P-M.”

   3. Time check. The word “time” followed by the four separate digits of the hour and minutes, and nearest quarter minute. Fractions of a quarter minute less than eight seconds are stated as the preceding quarter minute; fractions of a quarter minute of eight seconds or more are stated as succeeding quarter minute.

      Time	Statement
      1415:06	“Time, one four one five.”
      1415:10	“Time, one four one five and one-quarter.”

   4. Abbreviated time. The separate digits of the minutes only.

      Time	Statement
      1415	“One five.”
      1420	“Two zero.”

4. Field elevation. The words “field elevation” followed by the separate digits of the elevation.

   Elevation	Statement
   17 feet	“Field elevation, one seven.”
   817 feet	“Field elevation, eight one seven.”
   2,817 feet	“Field elevation, two eight one seven.”

5. The number “0” as “zero” except where it is used in approved “group form” for authorized aircraft call signs, and in stating altitudes.

   As Zero	As Group
   “Field elevation one six zero.” “Heading three zero zero.” “One zero thousand five hundred.”	“Western five thirty.” “EMAIR One Ten.” “Ten thousand five hundred.”

6. Altimeter setting. The word “altimeter” followed by the separate digits of the altimeter setting.

   Setting	Statement
   30.01	“Altimeter, three zero zero one.”

7. Surface wind. The word “wind” followed by the separate digits of the indicated wind direction to the nearest 10-degree multiple, the word “at” and the separate digits of the indicated velocity in knots, to include any gusts.
8. Heading. The word “heading” followed by the three separate digits of the number of degrees, omitting the word “degrees.” Use heading 360 degrees to indicate a north heading.

   Heading	Statement
   5 degrees	“Heading zero zero five.”
   30 degrees	“Heading zero three zero.”
   360 degrees	“Heading three six zero.”

9. Radar beacon codes. The separate digits of the 4-digit code.

   Code	Statement
   1000	“One zero zero zero.”
   2100	“Two one zero zero.”

10. Runways. The word “runway,” followed by the separate digits of the runway designation. For a parallel runway, state the word “left,” “right,” or “center” if the letter “L,” “R,” or “C” is included in the designation.

    Designation	Statement
    3	“Runway Three.”
    8L	“Runway Eight Left.”
    27R	“Runway Two Seven Right.”

11. Frequencies.
    1. The separate digits of the frequency, inserting the word “point” where the decimal point occurs.
       1. Omit digits after the second digit to the right of the decimal point.
       2. When the frequency is in the L/MF band, include the word “kiloHertz.”

          Frequency	Statement
          126.55 MHz	“One two six point five five.”
          369.0 MHz	“Three six niner point zero.”
          121.5 MHz	“One two one point five.”
          135.275 MHz	“One three five point two seven.”
          302 kHz	“Three zero two kiloHertz.”

    2. USAF/USN. Local channelization numbers may be used in lieu of frequencies for locally based aircraft when local procedures are established to ensure that local aircraft and ATC facilities use the same channelization.

       Frequency	Statement
       275.8 MHz	“Local channel one six.”

    3. Issue TACAN frequencies by stating the assigned two or three-digit channel number.
12. Speeds.
    1. The separate digits of the speed followed by “knots” except as required by paragraph 5-7-2, Methods.

       Speed	Statement
       250	“Two five zero knots.”
       190	“One niner zero knots.”

    2. The separate digits of the Mach number preceded by “Mach.”

       Mach Number	Statement
       1.5	“Mach one point five.”
       0.64	“Mach point six four.”
       0.7	“Mach point seven.”

13. Miles. The separate digits of the mileage followed by the word “mile.”

2-4-18. NUMBER CLARIFICATION

1. If deemed necessary for clarity, and after stating numbers as specified in paragraph 2-4-17, Numbers Usage, controllers may restate numbers using either group or single‐digit form.

2-4-19. FACILITY IDENTIFICATION

Identify facilities as follows:

1. Airport traffic control towers. State the name of the facility followed by the word “tower.” Where military and civil airports are located in the same general area and have similar names, state the name of the military service followed by the name of the military facility and the word “tower.”
2. Air route traffic control centers. State the name of the facility followed by the word “center.”
3. Approach control facilities, including RAPCONs, RATCFs, and ARACs. State the name of the facility followed by the word “approach.” Where military and civil facilities are located in the same general area and have similar names, state the name of the military service followed by the name of the military facility and the word “approach.”
4. Functions within a terminal facility. State the name of the facility followed by the name of the function.
5. When calling or replying on an interphone line which connects only two non-VSCS equipped facilities, you may omit the facility name.
6. Flight service stations. State the name of the station followed by the word “radio.”
7. Radar facilities having ASR or PAR but not providing approach control service. State the name of the facility, followed by the letters “G-C-A.”

2-4-20. AIRCRAFT IDENTIFICATION

Use the full identification in reply to aircraft with similar sounding identifications. For other aircraft, the same identification may be used in reply that the pilot used in his/her initial callup except use the correct identification after communications have been established. Identify aircraft as follows:

1. U.S. registry aircraft. State one of the following:
   1. Civil. State the prefix “November” when establishing initial communications with U.S. registered aircraft followed by the ICAO phonetic pronunciation of the numbers/letters of the aircraft registration. The controller may state the aircraft type, the model, the manufacturer's name, followed by the ICAO phonetic pronunciation of the numbers/letters of the aircraft registration if used by the pilot on the initial or subsequent call.
   2. Aircraft having an ICAO 3LD and other FAA authorized call sign (U.S. special or local). State the call sign followed by the flight number in group form.
   3. Air taxi and commercial operators not having FAA authorized call signs. State the prefix “TANGO” on initial contact, if used by the pilot, followed by the registration number. The prefix may be dropped in subsequent communications.
   4. Air carrier/taxi ambulance. State the prefix “MEDEVAC” if used by the pilot, followed by the call sign and flight number in group form.
   5. Civilian air ambulance. State the word “MEDEVAC” followed by the numbers/letters of the registration number.
   6. U.S. military. State one of the following:
      1. The service name, followed by the word “copter,” when appropriate, and the last 5 digits of the serial number.
      2. Special military operations. State one of the following followed by the last 5 digits of the serial number:
      3. Air evacuation flights. “AIR EVAC,” “MARINE AIR EVAC,” or “NAVY AIR EVAC.”
      4. Rescue flights. (Service name) “RESCUE.”
      5. Air Mobility Command. “REACH.”
      6. Special Air Mission. “SAM.”
      7. USAF Contract Aircraft “LOGAIR.”
      8. Military tactical and training:
         1. U.S. Air Force, Air National Guard, Military District of Washington priority aircraft, and USAF civil disturbance aircraft. Pronounceable words of 3 to 6 letters followed by a 1 to 5 digit number.
         2. Navy or Marine fleet and training command aircraft. The service name and 2 letters, or a digit and a letter (use letter phonetic equivalents), followed by 2 or 3 digits.
   7. Presidential aircraft and Presidential family aircraft:
      1. When the President is aboard a military aircraft, state the name of the military service, followed by the word “One.”
      2. When the President is aboard a civil aircraft, state the words “Executive One.”
      3. When a member of the President's family is aboard any aircraft, if the U.S. Secret Service or the White House Staff determines it is necessary, state the words “Executive One Foxtrot.”
   8. Vice Presidential aircraft:
      1. When the Vice President is aboard a military aircraft, state the name of the military service, followed by the word “Two.”
      2. When the Vice President is aboard a civil aircraft, state the words “Executive Two.”
      3. When a member of the Vice President's family is aboard any aircraft, if the U.S. Secret Service or the White House Staff determines it is necessary, state the words “Executive Two Foxtrot.”
   9. DOT and FAA flights. The following alphanumeric identifiers and radio/interphone call signs are established for use in air/ground communications when the Secretary of Transportation, Deputy Secretary of Transportation, FAA Administrator or FAA Deputy Administrator have a requirement to identify themselves. (See TBL 2-4-2.)

      TBL 2-4-2
      DOT and FAA Alphanumeric Identifiers and Call Signs

      Official	Identifier	Call Sign
      Secretary of Transportation	DOT-1	Transport-1
      Deputy Secretary of Transportation	DOT-2	Transport-2
      Administrator, Federal Aviation Administration	FAA-1	Safeair-1
      Deputy Administrator, Federal Aviation Administration	FAA-2	Safeair-2

   10. Other Special Flights.
       1. Flight Inspection of navigational aids. State the call sign “FLIGHT CHECK” followed by the digits of the registration number.
       2. USAF or other government aircraft engaged in aerial sampling/surveying missions. State the call sign “SAMP” followed by a three-digit flight number.
   11. Use a pilot's name in identification of an aircraft only in special or emergency situations.
2. Foreign registry. State one of the following:
   1. Civil. State the aircraft type or the manufacturer's name followed by the letters/numbers of the full aircraft registration, or state the letters or digits of the full aircraft registration. Do not abbreviate.
   2. ICAO 3LD. State the associated telephony followed by the flight number in group form, or separate digits may be used if that is the format used by the pilot. Do not abbreviate.
   3. Foreign Military. Except for military services identified in FAA Order JO 7340.2, Contractions, state the name of the country and the military service followed by the separate digits or letters of the registration or call sign. For military services listed in FAA Order JO 7340.2, state the approved telephony followed by the separate digits of the flight number.

2-4-21. DESCRIPTION OF AIRCRAFT TYPES

Except for super andheavy aircraft, describe aircraft as follows when issuing traffic information.

1. Military:
   1. Military designator, with numbers spoken in group form, or
   2. Service and type, or
   3. Type only if no confusion or misidentification is likely.
2. Air Carrier:
   1. Manufacturer's model or type designator.
   2. Add the manufacturer's name, company name or other identifying features when confusion or misidentification is likely.
3. General Aviation and Air Taxi:
   1. Manufacturer's model or type designator.
   2. Manufacturer's name, or add color when considered advantageous.
4. When issuing traffic information to aircraft following a super aircraft, specify the word super before the manufacturer's name and model.
5. When issuing traffic information to aircraft following a heavy aircraft, specify the word heavy before the manufacturer's name and model.

2-4-22. AIRSPACE CLASSES

A, B, C, D, E, and G airspace are pronounced in the ICAO phonetics for clarification. The term “Class” may be dropped when referring to airspace in pilot/controller communications.