2.
12,500 . . . . . one two thousand five hundred

4.5.3.2 At and above 18,000’ MSL (FL 180) by stating the words “flight level” followed by the separated digits of the flight level.
EXAMPLE.
1.
190. . . . . . . . Flight Level One Niner Zero

2.
275. . . . . . . . Flight Level Two Seven Five

4.5.4 Directions
4.5.4.1 The three digits of a magnetic course, bearing, heading or wind direction, should always be magnetic. The word “true” must be added when it applies.
EXAMPLE.
1.
(Magnetic course) 005 . . . . . . zero zero five

2.
(True course) 050 . . . . . . . . . . zero five zero  true

3.
(Magnetic bearing) 360 . . . . . three six zero

4.
(Magnetic heading) 100 . . . . . heading one zero zero

5.
(Wind direction) 220 . . . . . . . . wind two two zero

4.5.5 Speeds
4.5.5.1 The separate digits of the speed are to be followed by the word “KNOTS” except that controllers may omit the word “KNOTS” when using speed adjustment procedures (e.g., “REDUCE/IN-CREASE SPEED TO TWO FIVE ZERO”).
EXAMPLE.
1.
(Speed) 250 . . . . . . . . . . . . . . . two five zero knots

2.
(Speed) 190 . . . . . . . . . . . . . . . one niner zero knots

4.5.5.2 The separate digits of the Mach number are to be preceded by the word “Mach.”
EXAMPLE.
1.
(Mach number) 1.5 . . . . . . . . . Mach one point five

2.
(Mach number) 0.64 . . . . . . . . Mach point six four

3.
(Mach number) 0.7 . . . . . . . . . Mach point seven

4.5.6 Time
4.5.6.1 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, zero one two zero pacific or local, or one twenty AM
4.5.6.2 To convert from Standard Time to UTC:
TBL GEN 3.4.5
Standard Time to Coordinated Universal Time
Eastern Standard Time Central  Add 5 hours 
Standard Time  Add 6 hours 
Mountain Standard Time  Add 7 hours 
Pacific Standard Time Alaska  Add 8 hours 
Standard Time  Add 9 hours 
Hawaii Standard Time  Add 10 hours 

NOTE.
For daylight time, subtract 1 hour.
4.5.6.3 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.
1.
0000. . . . . . . . . . . . . . . . . . . . . zero zero zero zero

2.
0920. . . . . . . . . . . . . . . . . . . . . zero niner two zero

4.5.6.4 Time may be stated in minutes only (two figures) in radio telephone communications when no misunderstanding is likely to occur.
4.5.6.5 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 or more, but less than eight seconds more, are stated as the preceding quarter minute; fractions of a quarter minute of eight seconds or more are stated as the succeeding quarter minute.
EXAMPLE.
1.
0929:05 . . . .  time, zero niner two niner

2.  
0929:10 . . . . time, zero niner two niner and one.quarter

4.5.7 Communications with Tower when Aircraft Transmitter/Receiver or Both are Inoperative
4.5.7.1 Arriving Aircraft
   a) Receiver Inoperative. If you have reason to believe your receiver is inoperative, remain outside or above Class D airspace 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. 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 when downwind and/or turning base leg.

   b) Transmitter Inoperative. Remain outside or above Class D airspace 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 navigational lights.
　
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