b. To convert from Standard Time to Coordinated
Universal Time:
TBL 4-2-3

Standard Time to Coordinated Universal Time
Eastern Standard Time .
Central Standard Time .
Mountain Standard Time .
Pacific Standard Time .
Alaska Standard Time .
Hawaii Standard Time .

Add 5 hours
Add 6 hours
Add 7 hours
Add 8 hours
Add 9 hours
Add 10 hours

NOTE-
For daylight time, subtract 1 hour.

c. 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

d. Time may be stated in minutes only
(two figures) in radiotelephone communications
when no misunderstanding is likely to occur.
e. 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
a. 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.

Radio Communications Phraseology

REFERENCE-
AIM, Paragraph 4-3-13 , Traffic Control Light Signals

(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.
b. 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

4-2-7