Aviation Theory

(Continued from part 2: Aircraft Callsigns) (part 1: Contact Procedures)

4-2-6. GROUND STATION CALL SIGNS

   Pilots, when calling a ground station, should begin with the name of the facility being called followed by the type of the facility being called as indicated in Table 4-2-1.

Table 4-2-1

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  Facility                         Call Sign
------------------------------------------------------------
 Airport UNICOM                   "Shannon UNICOM"
 FAA Flight Service Station       "Chicago Radio"
 FAA Flight Service Station       "Seattle Flight Watch"
 (Enroute Flight Advisory Service (Weather))
 Airport Traffic Control Tower    "Augusta Tower"
 Clearance Delivery Position (IFR)"Dallas Clearance Delivery"
 Ground Control Position in Tower "Miami Ground"
 Radar or Nonradar Approach       "Oklahoma City Approach"
  Control Position
 Radar Departure Control Position "St. Louis Departure"
 FAA Air Route Traffic CTRL CTR   "Washington Center"
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4-2-7. PHONETIC ALPHABET

   The International Civil Aviation Organization (ICAO) phonetic alphabet is used by FAA personnel when communications conditions are such that the information cannot be readily received without their use. ATC facilities may also request pilots to use phonetic letter equivalents when aircraft with similar sounding identifications are receiving communications on the same frequency. Pilots should use the phonetic alphabet when identifying their aircraft during initial contact with air traffic control facilities. Additionally, use the phonetic equivalents for single letters and to spell out groups of letters or difficult words during adverse communications conditions. (See Table 4-2-2)

Table 4-2-2 - Phonetic Alphabet / Morse Code

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 Character  Morse Code Telephony  Phonetic (Pronunciation)
------------------------------------------------------------
    A           .-                 Alfa      (AL-FAH)
    B           -...               Bravo     (BRAH-VOH)
    C           -.-.               Charlie   (CHAR-LEE)
    D           -..                Delta     (DELL-TA)
    E           .                  Echo      (ECK-OH)
    F           ..-.               Foxtrot   (FOKS-TROT)
    G           --.                Golf      (GOLF)
    H           ....               Hotel     (HOH-TEL)
    I           ..                 India     (IN-DEE-AH)
    J           .---               Juliett   (JEW-LEE-ETT)
    K           -.-                Kilo      (KEY-LOH)
    L           .-..               Lima      (LEE-MAH)
    M           --                 Mike      (MIKE)
    N           -.                 November  (NO-VEM-BER)
    O           ---                Oscar     (OSS-CAH)
    P           .--.               Papa      (PAH-PAH)
    Q           --.-               Quebec    (KEH-BECK)
    R           .-.                Romeo     (ROW-ME-OH)
    S           ...                Sierra    (SEE-AIR-RAH)
    T           -                  Tango     (TANG-GO)
    U           ..-                Uniform   (YOU-NEE-FORM)
    V           ...-               Victor    (VIK-TAH)
    W           .--.-              Whiskey   (WIS-KEY)
    X           -..-               X-ray     (ECKS-RAY)
    Y           -.--               Yankee    (YANG-KEY)
    Z           --..               Zulu      (ZOO-LOO)
 
    1           .----              One       (WUN)
    2           ..---              Two       (TOO)
    3           ...--              Three     (TREE)
    4           ....-              Four      (FOW-ER)
    5           .....              Five      (FIFE)
    6           -....              Six       (SIX)
    7           --...              Seven     (SEV-EN)
    8           ---..              Eight     (AIT)
    9           ----.              Nine      (NIN-ER)
    0           -----              Zero      (ZEE-RO)
------------------------------------------------------------

4-2-8. FIGURES

1. Figures indicating hundreds and thousands in round number, as for ceiling heights, and upper wind levels up to 9,900 shall be spoken in accordance with the following:
   
   EXAMPLE:
   500 - FIVE HUNDRED
   4,500 - FOUR THOUSAND FIVE HUNDRED
    
2. Numbers above 9,900 shall be spoken by separating the digits preceding the word "thousand."
   
   EXAMPLE:
   10,000 - ONE ZERO THOUSAND
   13,500 - ONE THREE THOUSAND FIVE HUNDRED
    
3. Transmit airway or jet route numbers as follows:
   
   EXAMPLE:
   V12 - VICTOR TWELVE     
   J533 - J FIVE THIRTY-THREE
    
4. All other numbers shall be transmitted by pronouncing each digit.
   
   EXAMPLE:
   10 - ONE ZERO
    
5. When a radio frequency contains a decimal point, the decimal point is spoken as "POINT."
   
   EXAMPLE:
   122.1 - ONE TWO TWO POINT ONE

NOTE - ICAO Procedures require the decimal point be spoken as "DECIMAL," and FAA will honor such usage by military aircraft and all other aircraft required to use ICAO Procedures.

4-2-9. ALTITUDES AND FLIGHT LEVELS

1. Up to but not including 18,000 feet MSL, state the separate digits of the thousands plus the hundreds if appropriate.
   
   EXAMPLE:
   12,000 - ONE TWO THOUSAND
   12,500 - ONE TWO THOUSAND FIVE HUNDRED
    
2. At and above 18,000 feet MSL (FL 180), state the words "flight level" followed by the separate digits of the flight level.
   
   EXAMPLE:
   190 - FLIGHT LEVEL ONE NINER ZERO
   275 - FLIGHT LEVEL TWO SEVEN FIVE

4-2-10. DIRECTIONS

The three digits of bearing, course, heading, or wind direction should always be magnetic. The word "true" must be added when it applies.

EXAMPLE:
(Magnetic course) 005 - ZERO ZERO FIVE
(True course) 050 - ZERO FIVE ZERO TRUE
(Magnetic bearing) 360 - THREE SIX ZERO
(Magnetic heading) 100 - HEADING ONE ZERO ZERO
(Wind direction) 220 - WIND TWO TWO ZERO

4-2-11. SPEEDS

The separate digits of the speed followed by the word "KNOTS." Except, controllers may omit the word "KNOTS" when using speed adjustment procedures; for example, "REDUCE/INCREASE SPEED TO TWO FIVE ZERO."

EXAMPLES:
(Table 4-40[1])
(Speed) 250 - TWO FIVE ZERO KNOTS
(Speed) 190 - ONE NINER ZERO KNOTS

The separate digits of the Mach number preceded by "MACH."

EXAMPLES:
(Table 4-40[2])
(Mach number) 1.5 - MACH ONE POINT FIVE
(Mach number) 0.64 - MACH POINT SIX FOUR
(Mach number) 0.7 - MACH POINT SEVEN

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4-2-12. TIME

1. FAA uses Coordinated Universal Time (UTC) for all operations. The word "local" or the time zone equivalent shall be used to denote local when local time is given during radio and telephone communications. The term "Zulu" may be used to denote UTC.
   
   EXAMPLE:
   0920 UTC - ZERO NINER TWO ZERO ZULU
   ZERO ONE TWO ZERO PACIFIC OR LOCAL,
   OR ONE TWENTY AM
    
2. To Convert from Standard Time to Coordinated Universal Time:
   
   Table 4-2-3
   Standard Time to Coordinated Universal Time
   
   Eastern Standard Time    Add 5 hours
   Central Standard Time    Add 6 hours
   Mountain Standard Time   Add 7 hours
   Pacific Standard Time    Add 8 hours
   Alaska Standard Time     Add 9 hours
   Hawaii Standard Time     Add 10 hours
   
   NOTE - For Daylight Time, subtract 1 hour.
    
3. A reference may be made to local daylight or standard time utilizing the 24-hour clock system. The hour is indicated by the first two figures and the minutes by the last two figures.
   
   EXAMPLE:
   0000 - ZERO ZERO ZERO ZERO
   0920 - ZERO NINER TWO ZERO
    
4. Time may be stated in minutes only (two figures) in radio telephone communications when no misunderstanding is likely to occur
    
5. Current time in use at a station is stated in the nearest quarter minute in order that pilots may use this information for time checks. Fractions of a quarter minute less than 8 seconds are stated as the preceding quarter minute; fractions of a quarter minute of 8 seconds or more are stated as the succeeding quarter minute
   
   EXAMPLE:
   0929:05 - TIME, ZERO NINER TWO NINER
   0929:10 - TIME, ZERO NINER TWO NINER AND ONE-QUARTER

4-2-13. COMMUNICATIONS WITH TOWER WHEN AIRCRAFT TRANSMITTER OR RECEIVER OR BOTH ARE INOPERATIVE

1. Arriving Aircraft -
   1. Receiver inoperative:
   
   (a) If you have reason to believe your receiver is inoperative, remain outside or above the Class D surface area until the direction and flow of traffic has been determined; then, advise the tower of your type aircraft, position, altitude, intention to land, and request that you be controlled with light signals.
   REFERENCE - Traffic Control Light Signals, paragraph 4-3-13.
   
   (b) When you are approximately 3 to 5 miles from the airport, advise the tower of your position and join the airport traffic pattern. From this point on, watch the tower for light signals. Thereafter, if a complete pattern is made, transmit your position downwind and/or turning base leg.
   
   2. Transmitter inoperative: Remain outside or above the Class D surface area until the direction and flow of traffic has been determined; then, join the airport traffic pattern. Monitor the primary local control frequency as depicted on Sectional Charts for landing or traffic information, and look for a light signal which may be addressed to your aircraft. During hours of daylight, acknowledge tower transmissions or light signals by rocking your wings. At night, acknowledge by blinking the landing or navigation lights. To acknowledge tower transmissions during daylight hours, hovering helicopters will turn in the direction of the controlling facility and flash the landing light. While in flight, helicopters should show their acknowledgement of receiving a transmission by making shallow banks in opposite directions. At night, helicopters will acknowledge receipt of transmissions by flashing either the landing or the search light.
   
   3. Transmitter and receiver inoperative: Remain outside or above the Class D surface area until the direction and flow of traffic has been determined; then, join the airport traffic pattern and maintain visual contact with the tower to receive light signals. Acknowledge light signals as noted above.
    
2. Departing Aircraft - If you experience radio failure prior to leaving the parking area, make every effort to have the equipment repaired. If you are unable to have the malfunction repaired, call the tower by telephone and request authorization to depart without two-way radio communications. If tower authorization is granted, you will be given departure information and requested to monitor the tower frequency or watch for light signals as appropriate. During daylight hours, acknowledge tower transmissions or light signals by moving the ailerons or rudder. At night, acknowledge by blinking the landing or navigation lights. If radio malfunction occurs after departing the parking area, watch the tower for light signals or monitor tower frequency.
   
   REFERENCE - FAR Part 91.129 and FAR Part 91.125.

4-2-14. COMMUNICATIONS FOR VFR FLIGHTS

1. FSSs and Supplemental Weather Service Locations (SWSLs) are allocated frequencies for different functions; for example, 122.0 MHz is assigned as the Enroute Flight Advisory Service frequency at selected FSSs. In addition, certain FSSs provide Local Airport Advisory on 123.6 MHz. Frequencies are listed in the A/FD. If you are in doubt as to what frequency to use, 122.2 MHz is assigned to the majority of FSSs as a common enroute simplex frequency.
   
   NOTE - In order to expedite communications, state the frequency being used and the aircraft location during initial callup.
   
   EXAMPLE:
   DAYTON RADIO, THIS IS NOVEMBER ONE TWO THREE FOUR FIVE ON ONE TWO TWO POINT TWO, OVER SPRINGFIELD VOR, OVER.
    
2. Certain VOR voice channels are being utilized for recorded broadcasts; that is, ATIS, HIWAS, etc. These services and appropriate frequencies are listed in the Airport/Facilities Directory. On VFR flights, pilots are urged to monitor these frequencies. When in contact with a control facility, notify the controller if you plan to leave the frequency to monitor these broadcasts.

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