Radio and Interphone Communications
Readback of clearances
Pilots must acknowledge clearances. They are not required to read back any specific details, only acknowledge that they have received and understood it. If a pilot does readback certain details, ensure that the readback is correct. Certain types of clearances do require a readback; those situations will be covered in later lessons.
{Reference FAAO 7110.65 2-4-3}
Phonetics and Numbers
To eliminate some ambiguity, each letter of the alphabet is associated with a word. These words are used whenever you pronounce letters on the radio. The 7110.65 has a complete list of the phonetic pronunciations in chapter 2, section 4. You will use these phonetic pronunciations regularly.
Altitudes
Altitudes are grouped into thousands and hundreds of feet. The word “feet” is omitted when referencing altitudes on the radio. For example:
5000' would be spoken as “five thousand.”
15000' would be spoken as “one five thousand.”
Altitudes may be restated in group form for emphasis. For example, you could say “maintain one one
thousand, eleven thousand.”
Flight levels
Altitude assignments at or above 18,000' MSL are called “flight levels.” They are called “flight levels” because the pilot uses a constant altimeter setting and does not reference local altimeter settings until he descends back below 18,000'. When referencing flight levels, first state the term “flight level” followed by each digit of a flight level spoken individually. For example:
“Flight level two zero zero.”
“Flight level three four zero.”
Time
Time always references zulu time (sometimes known as UTC Coordinated Universal Time or GMT Greenwich Mean Time), which is a standard time used around the world. VRC or ASRC will calculate this time for you (presuming that your computer system time and time zone is set correctly), and display it at the top of the screen.
When referencing time on the radio, always speak it as four digits. For example:
“Time one seven four five.”
“Time two three five nine.”
You may choose to add quarter minutes to the above if desirable. For example:
“Time zero four one two and one-quarter.”
“Time one one zero two and one-half.”
“Time two two five two and three-quarters.”
Altimeter setting
Altimeter settings are always issued in inches of mercury. When advising a pilot of the altimeter setting, use four digits and omit the decimal point. For example, an altimeter setting of 30.01” of mercury would be spoken, “Altimeter three zero zero one.”
Surface wind
Wind direction is always issued in degrees from magnetic north, and velocity in knots. The direction is always given in three digits and the velocity in the number of digits required. Pronounce each number individually, and omit the reference to “degrees” and “knots.” For example:
A wind of 50° at 20 knots would be spoken, “Wind zero five zero at two zero.”
A wind of 330° at 5 knots would be spoken, “Wind three three zero at five.”
Headings
Aircraft headings are issued in reference to magnetic north. When assigning an aircraft a heading, it is issued using three digits spoken individually. For example:
A heading of 360 degrees would be spoken, “heading three six zero.”
A heading of 040 degrees would be spoken, “heading zero four zero.”
A heading of 5 degrees would be spoken, “heading zero zero five.”
Transponder codes
When issuing a transponder code always speak each digit individually. For example:
“Squawk Zero One Six Five”
“ Squawk Three Seven Zero Four”
Frequencies
When issuing a frequency, each digit is spoken individually. Zeroes beyond the first decimal place and all digits beyond two decimal places are not spoken. The word “point” is used for the decimal point. For example:
125.000 MHz would be spoken, “One Two Five point Zero.”
123.500 MHz would be spoken, “One Two Three point Five.”
119.950 MHz would be spoken, “One One niner point Nine Five.”
133.375 MHz would be spoken, “One Three Three point Three Seven.”
Speeds
Each digit of an airspeed is spoken individually. Each digit of a mach number is spoken individually, and the word “point” is used for the decimal point. For example:
250 Knots would be spoken “Two Five Zero knots.”
Mach .8 would be spoken “Mach point eight.”
Mach 1.2 would be spoken “Mach one point two.”
Mach .75 would be spoken “Mach point seven five.”
Distances
Distances are always given in nautical miles, except visibility whish is ALWAYS in Satuate Miles (SM). State each digit of a distance followed by the word “mile.”
{Reference: FAAO 7110.65 2-4-16 through 2-4-18}
Facility identification
On initial contact with each aircraft, always state your facility identification. On subsequent communications, the facility identification may be omitted.
Each position has a radio callsign. Most callsigns begin with the city name of the airport (Atlanta for example) followed by a position. For example:
“Atlanta Tower”
“Atlanta Ground”
“Atlanta Clearance Delivery”
“Atlanta Approach”
“Atlanta Center”
{Reference: FAAO 7110.65 2-4-8 & 2-4-19}
Pilots must acknowledge clearances. They are not required to read back any specific details, only acknowledge that they have received and understood it. If a pilot does readback certain details, ensure that the readback is correct. Certain types of clearances do require a readback; those situations will be covered in later lessons.
{Reference FAAO 7110.65 2-4-3}
Phonetics and Numbers
To eliminate some ambiguity, each letter of the alphabet is associated with a word. These words are used whenever you pronounce letters on the radio. The 7110.65 has a complete list of the phonetic pronunciations in chapter 2, section 4. You will use these phonetic pronunciations regularly.
Altitudes
Altitudes are grouped into thousands and hundreds of feet. The word “feet” is omitted when referencing altitudes on the radio. For example:
5000' would be spoken as “five thousand.”
15000' would be spoken as “one five thousand.”
Altitudes may be restated in group form for emphasis. For example, you could say “maintain one one
thousand, eleven thousand.”
Flight levels
Altitude assignments at or above 18,000' MSL are called “flight levels.” They are called “flight levels” because the pilot uses a constant altimeter setting and does not reference local altimeter settings until he descends back below 18,000'. When referencing flight levels, first state the term “flight level” followed by each digit of a flight level spoken individually. For example:
“Flight level two zero zero.”
“Flight level three four zero.”
Time
Time always references zulu time (sometimes known as UTC Coordinated Universal Time or GMT Greenwich Mean Time), which is a standard time used around the world. VRC or ASRC will calculate this time for you (presuming that your computer system time and time zone is set correctly), and display it at the top of the screen.
When referencing time on the radio, always speak it as four digits. For example:
“Time one seven four five.”
“Time two three five nine.”
You may choose to add quarter minutes to the above if desirable. For example:
“Time zero four one two and one-quarter.”
“Time one one zero two and one-half.”
“Time two two five two and three-quarters.”
Altimeter setting
Altimeter settings are always issued in inches of mercury. When advising a pilot of the altimeter setting, use four digits and omit the decimal point. For example, an altimeter setting of 30.01” of mercury would be spoken, “Altimeter three zero zero one.”
Surface wind
Wind direction is always issued in degrees from magnetic north, and velocity in knots. The direction is always given in three digits and the velocity in the number of digits required. Pronounce each number individually, and omit the reference to “degrees” and “knots.” For example:
A wind of 50° at 20 knots would be spoken, “Wind zero five zero at two zero.”
A wind of 330° at 5 knots would be spoken, “Wind three three zero at five.”
Headings
Aircraft headings are issued in reference to magnetic north. When assigning an aircraft a heading, it is issued using three digits spoken individually. For example:
A heading of 360 degrees would be spoken, “heading three six zero.”
A heading of 040 degrees would be spoken, “heading zero four zero.”
A heading of 5 degrees would be spoken, “heading zero zero five.”
Transponder codes
When issuing a transponder code always speak each digit individually. For example:
“Squawk Zero One Six Five”
“ Squawk Three Seven Zero Four”
Frequencies
When issuing a frequency, each digit is spoken individually. Zeroes beyond the first decimal place and all digits beyond two decimal places are not spoken. The word “point” is used for the decimal point. For example:
125.000 MHz would be spoken, “One Two Five point Zero.”
123.500 MHz would be spoken, “One Two Three point Five.”
119.950 MHz would be spoken, “One One niner point Nine Five.”
133.375 MHz would be spoken, “One Three Three point Three Seven.”
Speeds
Each digit of an airspeed is spoken individually. Each digit of a mach number is spoken individually, and the word “point” is used for the decimal point. For example:
250 Knots would be spoken “Two Five Zero knots.”
Mach .8 would be spoken “Mach point eight.”
Mach 1.2 would be spoken “Mach one point two.”
Mach .75 would be spoken “Mach point seven five.”
Distances
Distances are always given in nautical miles, except visibility whish is ALWAYS in Satuate Miles (SM). State each digit of a distance followed by the word “mile.”
{Reference: FAAO 7110.65 2-4-16 through 2-4-18}
Facility identification
On initial contact with each aircraft, always state your facility identification. On subsequent communications, the facility identification may be omitted.
Each position has a radio callsign. Most callsigns begin with the city name of the airport (Atlanta for example) followed by a position. For example:
“Atlanta Tower”
“Atlanta Ground”
“Atlanta Clearance Delivery”
“Atlanta Approach”
“Atlanta Center”
{Reference: FAAO 7110.65 2-4-8 & 2-4-19}
Civilian
When filing a flight plan, civil aircraft may use either their registration number or a three letter contraction followed by a flight number. In the RW, the total callsign cannot exceed seven characters; this limit is not enforced on vatsim, so you will often see callsigns of more than seven characters.
Callsign using registration number
U.S. registered civilian aircraft are all issued a registration number beginning with the letter "N."
Prefixes of “L” or “T” may be used prior to the "N" in the callsign. “L” indicates a Lifeguard flight; “T” indicates that it is an air taxi flight. As stated above, do not give priority to lifeguard flights on vatsim.
When the controller initiates communication with an aircraft, he should state the callsign, speaking each digit individually and using phonetic pronunciation for the letters (except when “L” is used as a prefix, see below for an example) . For example:
N303ZS - “November three zero three zulu sierra”
TN8734S - “Tango November eight seven three four sierra”
LN1TS - “Lifeguard November One Tango Sierra”
If a pilot calls and uses his aircraft type in his callsign, you may do the same. For example:
N303ZS - “Learjet three zero three zulu sierra”
N312PD - “Cessna three one two papa delta” or “Skylane three one two papa delta”
N1336N - “Bonanza one three three six november” or “Beech one three three six november”
Authorized Callsigns
The FAA will authorize callsigns for certain companies. On vatsim, there is no oversight of these callsigns and pilots may use them at their discretion. When communicating with these aircraft, state the callsign followed by the flight number in group form. For example:
UAL43 - “United forty three”
FDX102 - “FedEx one zero two”
SWA2358 - “Southwest twenty three fifty eight”
Zeros can be tricky in callsigns. If present they must be used in either group form or individual form, if needed. For example:
UAL001 - “United zero zero one”
SKW6040 - “Skywest sixty forty”
DAL1001 - “Delta ten zero one”
FDX500 - “FedEx five hundred”
Military
The following abbreviations are used for military flights:
A – Air Force C – Coast Guard
G – National Guard
R – Army
VM – Marine
VV – Navy
On vatsim, pilots don't always follow official guidance on callsign construction. The most basic military callsign, is the service identifier (see above) followed by a serial number. State the service name followed by the number. For example:
A4003 - “Air Force four zero zero three”
VVHK562 - “Navy Hotel Kilo five six two"
VM800 - “Marine eight zero zero”
Military pilots may also choose a pronounceable word as a callsign followed by a number (in the RW, this combination cannot exceed seven characters, this limit is not enforced on vatsim). For example:
HAWK25 - “Hawk two five”
STRYK50 - “Strike five zero”
Foreign Callsigns
Foreign registered aircraft often have registration numbers composed of only letters. In these cases phonetic pronunciation is optional. For example:
CGFFC - “Charlie golf foxtrot foxtrot charlie” or “C-G-F-F-C”
For foreign air carriers, you may use separte digits in the callsign in place of group form, if that is used by the pilot. For example:
BAW23 - “Speedbird two three” or “Speedbird twenty three”
{Reference: FAAO 7110.65 2-3-5 & 2-4-20}
Abbreviated callsigns
After communications have been established, you may abbreviate the callsign of aircraft that do not use an authorized callsign. For example:
N8734S - “November three four sierra” or “Cessna three four sierra”
UAL1452 – must always be “United fourteen fifty two”
Heavy aircraft
Except for center controllers, heavy aircraft must always be identified by appending the term “heavy” to the end of the callsign. A pilot of a heavy aircraft should file “H/” prior to his aircraft type when filing a flight plan. The 7110.65 appendix A also identifies heavy aircraft. For example:
UAL43 (a Boeing 767) - “United forty three heavy”
AFR026 (an Airbus 340) - “Air France zero two six heavy”
N129P (a Boeing 747) - “November one two niner papa heavy” or “Boeing one two niner papa heavy” or
"November two niner papa heavy" or "Boeing two niner papa heavy"
CGFFC (a DC10) - “Charlie golf foxtrot foxtrot charlie heavy” or “C-G-F-F-C heavy”
Radio Message Format
When communicating with an aircraft, each transmission should begin with the aircraft's callsign, followed by your callsign, followed by the message. For example:
“American one forty four, Atlanta Ground, runway two six left taxi via foxtrot.”
After the first contact with an aircraft you may omit your facility identification. For example:
“American one forty four, runway two six left taxi via foxtrot.”
{Reference: FAAO 7110.65 2-4-8}
Interphone Message Format
When communicating with another controller via interphone, begin the call by stating who you are calling and who you are. After the receiving controller acknowledges, then go ahead with your request. At the end of the communication, each controller should state his/her initials. For example:
Caller: “Atlanta Center, Hickory Tower”
Receiver: “Atlanta Center”
Caller: “Request release of november one two three tango, runway two four ”
Receiver: “November one two three tango, released, QW.”
Caller: “LM”
{Reference: FAAO 7110.65 2-4-12}
Use of text interphone versus voice interphone on vatsim
Text interphone (via chat box between the two controllers) is often used on vatsim. This is mainly due to the difficulty in gauging how busy another controller is. In the RW, busy positions are staffed by two controllers, so one may communicate with aircraft on the radio the other may communicate with other controllers via interphone. We don't have the luxury of staffing a position with multiple controllers, so normally text is used for interphone communication.
Aircraft Types
When you are required to issue traffic information, describe aircraft as follows.
Military
Use the type aircraft. For example:
F18 - “F-eighteen”
A10 - “A ten”
Air carrier
Issue the type aircraft, or company name plus aircraft type. For example:
B737 - “Boeing seven thirty seven” or “Southwest Boeing seven thirty seven”
General aviation
Issue model or designator. To decode the model or designator see 7110.65 appendix A. For example:
BE36 - “Beechcraft Bonanza” or “Bonanza”
PA27 - “Aztec” or “Piper Aztec”
Heavy
For heavy aircraft, always precede the type with “heavy.” For example:
L1011 - “Heavy L-ten-eleven” or “Heavy Lockheed L-ten-eleven”
B1 - “Heavy B one”
IL62 - “Heavy I-L sixty-two”
Airspace Classes
When referencing classes of airspace, the term “class” need not be used. For example:
“November six tango charlie, cleared to enter Atlanta bravo airspace, maintain VFR at six thousand five hundred.”
“Caravan six two hotel, remain clear of Greer Charlie airspace.”
{Reference: FAAO 7110.65 2-4-22}
When filing a flight plan, civil aircraft may use either their registration number or a three letter contraction followed by a flight number. In the RW, the total callsign cannot exceed seven characters; this limit is not enforced on vatsim, so you will often see callsigns of more than seven characters.
Callsign using registration number
U.S. registered civilian aircraft are all issued a registration number beginning with the letter "N."
Prefixes of “L” or “T” may be used prior to the "N" in the callsign. “L” indicates a Lifeguard flight; “T” indicates that it is an air taxi flight. As stated above, do not give priority to lifeguard flights on vatsim.
When the controller initiates communication with an aircraft, he should state the callsign, speaking each digit individually and using phonetic pronunciation for the letters (except when “L” is used as a prefix, see below for an example) . For example:
N303ZS - “November three zero three zulu sierra”
TN8734S - “Tango November eight seven three four sierra”
LN1TS - “Lifeguard November One Tango Sierra”
If a pilot calls and uses his aircraft type in his callsign, you may do the same. For example:
N303ZS - “Learjet three zero three zulu sierra”
N312PD - “Cessna three one two papa delta” or “Skylane three one two papa delta”
N1336N - “Bonanza one three three six november” or “Beech one three three six november”
Authorized Callsigns
The FAA will authorize callsigns for certain companies. On vatsim, there is no oversight of these callsigns and pilots may use them at their discretion. When communicating with these aircraft, state the callsign followed by the flight number in group form. For example:
UAL43 - “United forty three”
FDX102 - “FedEx one zero two”
SWA2358 - “Southwest twenty three fifty eight”
Zeros can be tricky in callsigns. If present they must be used in either group form or individual form, if needed. For example:
UAL001 - “United zero zero one”
SKW6040 - “Skywest sixty forty”
DAL1001 - “Delta ten zero one”
FDX500 - “FedEx five hundred”
Military
The following abbreviations are used for military flights:
A – Air Force C – Coast Guard
G – National Guard
R – Army
VM – Marine
VV – Navy
On vatsim, pilots don't always follow official guidance on callsign construction. The most basic military callsign, is the service identifier (see above) followed by a serial number. State the service name followed by the number. For example:
A4003 - “Air Force four zero zero three”
VVHK562 - “Navy Hotel Kilo five six two"
VM800 - “Marine eight zero zero”
Military pilots may also choose a pronounceable word as a callsign followed by a number (in the RW, this combination cannot exceed seven characters, this limit is not enforced on vatsim). For example:
HAWK25 - “Hawk two five”
STRYK50 - “Strike five zero”
Foreign Callsigns
Foreign registered aircraft often have registration numbers composed of only letters. In these cases phonetic pronunciation is optional. For example:
CGFFC - “Charlie golf foxtrot foxtrot charlie” or “C-G-F-F-C”
For foreign air carriers, you may use separte digits in the callsign in place of group form, if that is used by the pilot. For example:
BAW23 - “Speedbird two three” or “Speedbird twenty three”
{Reference: FAAO 7110.65 2-3-5 & 2-4-20}
Abbreviated callsigns
After communications have been established, you may abbreviate the callsign of aircraft that do not use an authorized callsign. For example:
N8734S - “November three four sierra” or “Cessna three four sierra”
UAL1452 – must always be “United fourteen fifty two”
Heavy aircraft
Except for center controllers, heavy aircraft must always be identified by appending the term “heavy” to the end of the callsign. A pilot of a heavy aircraft should file “H/” prior to his aircraft type when filing a flight plan. The 7110.65 appendix A also identifies heavy aircraft. For example:
UAL43 (a Boeing 767) - “United forty three heavy”
AFR026 (an Airbus 340) - “Air France zero two six heavy”
N129P (a Boeing 747) - “November one two niner papa heavy” or “Boeing one two niner papa heavy” or
"November two niner papa heavy" or "Boeing two niner papa heavy"
CGFFC (a DC10) - “Charlie golf foxtrot foxtrot charlie heavy” or “C-G-F-F-C heavy”
Radio Message Format
When communicating with an aircraft, each transmission should begin with the aircraft's callsign, followed by your callsign, followed by the message. For example:
“American one forty four, Atlanta Ground, runway two six left taxi via foxtrot.”
After the first contact with an aircraft you may omit your facility identification. For example:
“American one forty four, runway two six left taxi via foxtrot.”
{Reference: FAAO 7110.65 2-4-8}
Interphone Message Format
When communicating with another controller via interphone, begin the call by stating who you are calling and who you are. After the receiving controller acknowledges, then go ahead with your request. At the end of the communication, each controller should state his/her initials. For example:
Caller: “Atlanta Center, Hickory Tower”
Receiver: “Atlanta Center”
Caller: “Request release of november one two three tango, runway two four ”
Receiver: “November one two three tango, released, QW.”
Caller: “LM”
{Reference: FAAO 7110.65 2-4-12}
Use of text interphone versus voice interphone on vatsim
Text interphone (via chat box between the two controllers) is often used on vatsim. This is mainly due to the difficulty in gauging how busy another controller is. In the RW, busy positions are staffed by two controllers, so one may communicate with aircraft on the radio the other may communicate with other controllers via interphone. We don't have the luxury of staffing a position with multiple controllers, so normally text is used for interphone communication.
Aircraft Types
When you are required to issue traffic information, describe aircraft as follows.
Military
Use the type aircraft. For example:
F18 - “F-eighteen”
A10 - “A ten”
Air carrier
Issue the type aircraft, or company name plus aircraft type. For example:
B737 - “Boeing seven thirty seven” or “Southwest Boeing seven thirty seven”
General aviation
Issue model or designator. To decode the model or designator see 7110.65 appendix A. For example:
BE36 - “Beechcraft Bonanza” or “Bonanza”
PA27 - “Aztec” or “Piper Aztec”
Heavy
For heavy aircraft, always precede the type with “heavy.” For example:
L1011 - “Heavy L-ten-eleven” or “Heavy Lockheed L-ten-eleven”
B1 - “Heavy B one”
IL62 - “Heavy I-L sixty-two”
Airspace Classes
When referencing classes of airspace, the term “class” need not be used. For example:
“November six tango charlie, cleared to enter Atlanta bravo airspace, maintain VFR at six thousand five hundred.”
“Caravan six two hotel, remain clear of Greer Charlie airspace.”
{Reference: FAAO 7110.65 2-4-22}
