General Aviation Accident Prevention Program
U.S. Department of Transportation
Federal Aviation Administration
Radio Communications Phraseology And Techniques
- Radio communications are a critical link in the ATC system. The link
can be a strong bond between pilot and controller or it can be broken with
surprising speed and disastrous results. Discussion herein provide basic
procedures for new pilots and also highlights safe operating concepts for
- The single, most important thought in pilot-controller communications
is understanding. It is essential, therefore, that pilots acknowledge each
radio communication with ATC by using the appropriate aircraft call sign.
Brevity is important, and contacts should be kept as brief as possible,
but the controller must know what you want to do before he can properly
carry out his control duties. And you, the pilot, must know exactly what
he wants you to do. Since concise phraseology may not always be adequate,
use whatever words are necessary to get your message across.
- All pilots will find the Pilot/Controller Glossary very helpful in
learning what certain words or phrases mean. Good phraseology enhances
safety and is the mark of a professional pilot. Jargon, chatter and "CB"
slang have no place in ATC communications. The Pilot/Controller Glossary
is the same glossary used in the ATC controller's handbook. We recommend
that it be studied and reviewed from time to time to sharpen your communication
- Calls to air traffic control (ATC) facilities (ARTCCs, Towers, FSSs,
Central Flow, and Communications Control Centers) over radio and ATC operational
telephone lines (lines used for operational purposes such as controller
instructions, briefings, opening and closing flight plans, issuance of
IFR clearances and amendments, counter hijacking activities, etc.) may
be monitored and recorded for operational uses such as accident investigations,
accident prevention, search and rescue purposes, specialist training and
evaluation, and technical evaluation and repair of control and communications
- Listen before you transmit. Many time you can get the information
you want through ATIS Or by monitoring the frequency. Except for a few
situations where some frequency overlap occurs, If you hear someone else
talking, the keying of your transmitter will be futile and you will probably
jam their receivers causing them to repeat their call. If you have just
changed frequencies, pause, listen and make sure the frequency is clear.
- Think before keying your transmitter Know what you want to say
and if it is lengthy. e.g., a flight plan or IFR position report, jot it
- The microphone should be very close to your lips and after pressing
the mike button, a slight pause may be necessary to be sure the first word
is transmitted. Speak in a normal conversational tone.
- When you release the button, wait a few seconds before calling again.
The controller or FSS specialist may be jotting down your number, looking
for your flight plan, transmitting on a different frequency, Or selecting
his transmitter to your frequency.
- Be alert to the sounds or lack of sounds in your receiver. Check
your volume, recheck your frequency and make sure that your microphone
is not stuck in the transmit position. Frequency blockage can, and
has, occurred for extended periods of time due to unintentional transmitter
operation. This type of interference is commonly referred to as a "stuck
mike," and controllers may refer to it in this manner when attempting
to assign an alternate frequency. If the assigned frequency is completely
blocked by this type of interference, use the procedures described for
en route IFR radio frequency outage, to establish or reestablish communications
- Be sure that you are within the performance range of your radio equipment
and the ground station equipment. Remote radio sites do not always transmit
and receive on all of a facilities available frequencies, particularly
with regard to VOR sites where you can hear but not reach a ground station's
receiver. Remember that higher altitude increases the range of VHF "line
of sight" communications.
- The term initial contact or initial callup means the first radio call
you make to a given facility, Or the first call to a different controller
or FSS specialist within a facility. Use the following format:
- name of facility being called.
- your full aircraft identification as filed in the flight plan or as
discussed under Aircraft Call Signs below,
- type of message to follow or your request if it is short and
- the word "Over."
"NEW YORK RADIO, MOONEY THREE ONE ONE ECHO, OVER"
"COLUMBIA GROUND CESSNA THREE ONE SIX ZERO FOXTROT IFR MEMPHIS,
If radio reception is reasonably assured, inclusion of your request,
your position or altitude, the phrase "Have numbers" or "Information
Charlie received" (for ATIS) in the initial contact helps decrease
radio frequency congestion. Use discretion and do not overload the controller
with information he/she does not need. If you do not get a response from
the ground station, recheck your radios or use another transmitter but
keep the next contact short
"MIAMI CENTER BARON FIVE SIX THREE HOTEL, REQUEST VFR TRAFFIC ADVISORIES,
Initial Contact When your Transmitting and Receiving Frequencies
"ATLANTA CENTER, DUKE FOUR ONE ROMEO, REQUEST VFR TRAFFIC ADVISORIES,
TWENTY NORTHWEST ROME, SEVEN THOUSAND FIVE HUNDRED, OVER."
Subsequent Contacts and Responses to Callup from a Ground Facility.
- If you are attempting to establish contact with a ground station and
you are receiving on a different frequency than that transmitted, indicate
the VOR name or the frequency on which you expect a reply. Most FSSs and
control facilities can transmit on several VOR stations in the area. Use
the appropriate FSS call sign as indicated on charts.
New York FSS transmits on the Kennedy, Hampton and Calverton VORTACs If
you are in the Calverton area, your callup should be "NEW YORK RADIO,
CESSNA THREE ONE SIX ZERO FOXTROT, RECEIVING CALVERTON VOR, OVER."
- If the chart indicates FSS frequencies above the VORTAC or in FSS communications
boxes, transmit or receive on those frequencies nearest your location.
- when unable to establish contact and you wish to call any ground
station, use the phrase "ANY RADIO (tower) (station), GIVE CESSNA
THREE ONE SIX ZERO FOXTROT A CALL ON (frequency) OR (VOR)." If an
emergency exists or you need assistance, so state.
Use the same format as used for initial contact except you should state
your message or request with the callup in one transmission The ground
station name and the word "Over" may be omitted if the message
requires an obvious reply and there is no possibility for misunderstandings.
You should acknowledge all callups or clearances unless the controller
or FSS specialist advises otherwise. There are some occasions when the
controller must issue time-critical instructions to other aircraft and
he may be in a position to observe your response, either visually or on
radar. If the situation demands your response, take appropriate action
or immediately advise the facility of any problem. Acknowledgment is made
with one of the words "Wilco, Roger, Affirmative, Negative" or
other appropriate remarks (e.g., "PIPER TWO ONE FOUR LIMA, ROGER").
If you have been receiving services (e.g., VFR traffic advisories and you
are leaving the area or changing frequencies), advise the ATC facility
and terminate contact.
Acknowledgment of Frequency Changes
When advised by ATC to change frequencies, acknowledge the instruction.
If you select the new frequency without an acknowledgment, the controller's
workload is increased because he has no way of knowing whether you received
the instruction or have had radio communications failure.
Compliance with Frequency Changes.
When instructed by ATC to change frequencies, select the new frequency
as soon as possible unless instructed to make the change at a specific
time, fix, or altitude. A delay in making the change could result in an
untimely receipt of important information. If you are instructed to make
the frequency change at a specific time, fix, or altitude, monitor the
frequency you are on until reaching the specified time, fix, or altitudes
unless instructed otherwise by ATC.
DIRECT COMMUNICATIONS - CONTROLLERS AND PILOTS
- ARTCCs are capable of direct communications with IFR air traffic on
certain frequencies. Maximum communications coverage is possible through
the use of Remote Center Air/Ground (RCAG) sites comprised of both VHF
and UHF transmitters and receivers. These sites are located throughout
the U.S.. Although they may be several hundred miles away from the ARTCC,
they are remoted to the various ARTCCs by land lines or microwave links.
Since IFR operations are expedited through the use of direct communications,
pilots are requested to use these frequencies strictly for communications
pertinent to the control of IFR aircraft. Flight plan filing, en route
weather, weather forecasts and similar data should be requested through
FSSs, company radio, or appropriate military facilities capable of performing
- An ARTCC is divided into sectors. Each sector is handled by one or
a team of controllers and has its own sector discrete frequency. As a flight
progresses from one sector to another, the pilot is requested to change
to the appropriate sector discrete frequency.
- ATC Frequency Change Procedures:
- The following phraseology will be used by controllers to effect a frequency
(Aircraft Identification) CONTACT (facility name or location name and terminal
function) (frequency) AT (time, fix or altitude) OVER.
NOTE.- Pilots are expected to maintain a listening watch on the
transferring controller's frequency until the time, fix or altitude specified.
ATC will omit frequency change restrictions whenever pilot compliance is
expected upon receipt.
- The following phraseology should be utilized by pilots for establishing
contact with the designated facility;
At times controllers will ask pilots to verify that they are at a particular
altitude. The phraseology used will he: "VERIFY AT (altitude)."
In climbing or descending situations, controllers may ask pilots to "VERIFY
ASSIGNED ALTITUDE AS (altitude)." Pilots should confirm that they
are at the altitude stated by the controller or that the assigned altitude
is correct as stated. If this is not the case, they should inform the controller
of the actual altitude being maintained or the different assigned altitude.
- When a position report will be made:
(Name) CENTER, (aircraft identification), (position), OVER.
- When no position report will be made;
(Name) CENTER, (aircraft identification), ESTIMATING (reporting point and
time) AT (altitude or flight level) CLIMBING (or descending) TO MAINTAIN
(altitude or flight level) OVER.
- When operating in a radar environment and no position report is required:
(Name) CENTER, (aircraft identification) AT (exact altitude or flight level);
or, if appropriate,
LEAVING (exact altitude or flight level) CLIMBING (or descending) TO MAINTAIN
(altitude or flight level) OVER.
NOTE.- Exact altitude or flight level means to the nearest 100
foot increment. Exact altitude or flight level reports on initial contact
provide ATC with information required prior to using MODE C altitude information
for separation purposes.
ARTCC Radio Frequency Outage:
- CAUTION: Pilots should not take action to change their actual
altitude or different assigned altitude to the altitude stated in the controllers
verification request unless the controller specifically authorizes a change.
- ARTCCs normally have at least one back up radio receiver and transmitter
system for each frequency which can usually he placed into service quickly
with little or no disruption of ATC service. Occasionally, technical problems
may cause a delay but switchover seldom takes more than 60 seconds. When
it appears that the outage will not he quickly remedied, the ARTCC will
usually request a nearby aircraft, if there is one, to switch to the affected
frequency to broadcast communications instructions. It is important, therefore,
that the pilot wait at least 1 minute before deciding that the ARTCC has
actually experienced a radio frequency failure. When such an outage does
occur, the pilot should, if workload and equipment capability permit, maintain
a listening watch on the affected frequency while attempting to comply
with the following recommended communications procedures:
- If two-way communications cannot he established with the ARTCC after
changing frequencies, a pilot should attempt to recontact the transferring
controller for the assignment of an alternative frequency or other instructions.
- When an ARTCC radio frequency failure occurs after two-way communications
have been established, the pilot should attempt to reestablish contact
with the center on any other known ARTCC frequency, preferably that of
the next responsible sector when practicable, and ask for instructions.
However, when the next normal frequency change along the route is known
to involve another ATC facility, the pilot should contact that facility,
if feasible, for instructions. If communications cannot be reestablished
by either method, the pilot is expected to re quest communications instructions
from the FSS appropriate to the route of flight.
NOTE.- The exchange of information between an aircraft and an
ARTCC through an FSS is quicker than relay via company radio because the
FSS has direct interphone lines to the responsible ARTCC sector. Accordingly,
when circumstances dictate a choice between the two, during an ARTCC frequency
outage, relay via FSS radio is recommended.
AIRCRAFT CALL SIGNS
- Precautions In the Use of Call Signs.
Air ambulance Flights.
- Improper use of call signs can result in pilots executing a clearance
intended for another aircraft. Call signs should never be abbreviated on
an initial contact or at any time when other aircraft call signs have similar
numbers/sounds or identical letters/number (e.g., Cessna 6132F, Cessna
1622F, Baron 123F, Cherokee 7732F, etc.).
Assume that a controller issues an approach clearance to an aircraft at
the bottom of a holding stack and an aircraft with a similar call sign
(at the top of the stack) acknowledges the clearance with the last two
or three numbers of his call sign. If the aircraft at the bottom of the
stack did not hear the Clearance and intervene, flight safety would be
affected, and there would be no reason for either the controller or pilot
to suspect that anything is wrong. This kind of "human factors"
error can strike swiftly and is extremely difficult to rectify.
- Pilots; therefore, must be certain that aircraft identification is
complete and clearly identified before taking action on an ATC clearance.
ATC specialists will not abbreviate call signs of air carrier or other
civil aircraft having authorized call signs. ATC specialists may initiate
abbreviated call signs of other aircraft by using the prefix and the Last
three digits/letters of the aircraft identification after communications
are established. The pilot may use the abbreviated call sign in subsequent
contacts with the ATC specialist. When aware of similar/identical call
signs, ATC specialists will take action to minimize errors by emphasizing
certain numbers/letters, by repeating the entire call sign, repeating the
prefix, or by asking pilots to use a different call sign temporarily. Pilots
should use the phrase "VERIFY CLEARANCE FOR (your complete call sign)"
if doubt exists concerning proper identity.
- Civil aircraft pilots should state the aircraft type, model or manufacturer's
name followed by the digits/ letters of the registration number. When the
aircraft manufacturer's name or model is stated, the prefix "N"
is dropped (e.g. Aztec Two Four Six Four Alpha).
BONANZA SIX FIVE FIVE GOLF.
BREEZY SIX ONE THREE ROMEO EXPERIMENTAL (omit "Experimental"
after initial contact).
- Air Taxi or other commercial operators not having FAA authorized call
signs should prefix their normal identification with the phonetic word
TANGO AZTEC TWO FOUR SIX FOUR ALPHA.
- Air carriers and commuter air carriers having FAA authorized call signs
should identify themselves by stating the complete call sign, using group
form for the numbers and the word "heavy" if appropriate.
UNITED TWENTY-FIVE HEAVY.
MIDWEST COMMUTER SEVEN ELEVEN.
- Military aircraft use a variety of systems including serial numbers,
word call signs and combinations of letters/numbers. Examples include Army
Copter 48931, Air Force 61782, Reach 31792, Pat 157, Air Evac 17652, Navy
Golf Alfa Kilo 21, Marine 4 Charlie 36, etc.
Student Pilots Radio Identification.
- Civilian air ambulance flights responding to medical emergencies (carrying
patients, organ donors, organs, or other urgently needed lifesaving medical
material) will be expedited by ATC when necessary. When expeditious handling
is required, add the word "LIFEGUARD" in the remarks of the flight
plan. In radio communication, use the call sign "LIFEGUARD" followed
by the aircraft type and registration letters/numbers. When requested by
the pilot, necessary notification to expedite ground handling of patients,
etc., is provided by ATC; however, when possible, this information should
be passed in advance through non-ATC communications systems. Extreme discretion
is necessary in using the term "LIFEGUARD." It is intended only
for those missions of an urgent medical nature and for use only for that
portion of the flight requiring expedited handling.
- Similar provisions have been made for the use of "AIR EVAC"
and "MED EVAC" by military air ambulance flights, except that
these military flights will receive priority handling only when specifically
LIFEGUARD CESSNA TWO SIX FOUR SIX.
- The FAA desires to help the student pilot in acquiring sufficient practical
experience in the environment in which he will be required to operate.
To receive additional assistance while operating in areas of concentrated
air traffic, a student pilot need only identify himself as a student pilot
during his initial call to an FAA radio facility
DAYTON TOWER THIS IS FLEETWING 1284, STUDENT PILOT, OVER.
- This special identification will alert FAA ATC personnel and enable
them to provide the student pilot with such extra assistance and consideration
as be may need. This procedure is not mandatory.
DESCRIPTION OF INTERCHANGE OR LEASED AIRCRAFT
- Controllers issue. traffic information based on familiarity with airline
equipment and color/markings. When an air carrier dispatches a night using
another company's equipment and the pilot does not advise the terminal
ATC facility, the possible confusion in aircraft identification can compromise
- Pilots flying an "interchange" or "leased" aircraft
not bearing the colors/markings of the company operating the should inform
the terminal ATC facility on first contact the name of the operating company
and trip number, followed by the company name as displayed on the aircraft
and aircraft type.
AIR CAL 311, UNITED (INTERCHANGE/LEASE), BOEING 727.
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 the following examples.
Airport Unicom "Shannon Unicom"
FAA Flight Service Station "Chicago Radio"
FAA FSS (En Route flight Advisory Service (Weather) "Seattle Flight Watch"
Airport Traffic Control Tower "Augusta Tower"
Clearance Delivery Position (IFR) "Dallas Clearance Delivery"
Ground Control Position in Tower "Miami Ground"
Radar or NonRadar Approach Control Position "Oklahoma City Approach"
Radar Departure Control Position "Denver Departure"
FAA Air Route Traffic Control Center "Washington Center"
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
CHARACTER MORSE CODE TELEPHONY PHONIC (PRONUNCIATION)
A Alfa (AL-FAH)
B Bravo (BRAH-VOH)
C Charlie (CHAR-LEE) or (SHAR-LEE)
D Delta (DELL-TAH)
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) or (OO-NEE-FORM)
V Victor (VIK-TAH)
W Whiskey (WISS-KEY)
X Xray (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)
- Figures indicating hundred and thousands in round number, as for ceiling
heights, and upper wind levels up to 9900 shall be spoken in accordance
with the following:
4500.............................................FOUR THOUSAND FIVE HUNDRED
- Numbers above 9900 shall be spoken by separating the digits preceding
the word "thousand"
10,000.............................................ONE ZERO THOUSAND
13,500.............................................ONE THREE THOUSAND FIVE
- Transmit airway or jet route numbers as follows:
J533.............................................J FIVE THIRTY-THREE
- All other numbers shall be transmitted by pronouncing each digit
- When a radio frequency contains a decimal point, the decimal point
is spoken as "POINT."
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 and all other
aircraft required to use ICAO Procedures
ALTITUDES AND FLIGHT LEVELS
- Up to but not including 18,000 feet MSL - state the separate digits
of the thousands, plus the hundreds, if appropriate.
12,000.............................................ONE TWO THOUSAND
12,500.............................................ONE TWO THOUSAND FIVE
- At and above, 18,000 feet MSL (FL 180) state the words "flight
level" followed by the separate digits of the flight level.
190.............................................FLIGHT LEVEL ONE NINER
The three digits of bearing, course, heading or wind direction should
always be magnetic. The word "true" must be added when it applies
(magnetic course) 005.............................................ZERO
(true course) 050.............................................ZERO FIVE
(magnetic bearing) 360.............................................THREE
(magnetic heading) 100.............................................ONE
(wind direction) 220.............................................TWO TWO
The separate digits of the speed followed by the word "KNOTS."
Except, controllers may omit the word "KNOTS" when using speed
adjustment procedures, e.g., "REDUCE/INCREASE SPEED TO TWO FIVE ZERO."
(speed) 25O.............................................TWO FIVE ZERO KNOTS
(speed) 190.............................................ONE NINER ZERO
The separate digits of the mach number preceded by "MACH."
(mach number) 1.5.............................................MACH ONE
(mach number) .64.............................................MACH POINT
(mach number) .7..............................................MACH POINT
- FAA uses Greenwich Mean Time (GMT or Z) for all operations.
- To Convert from Standard Time to Greenwich Mean 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
NOTE.- For Daylight Time subtract 1 hour.
The 24-hour clock system is used in radiotelephone transmissions The
hour is indicated by the first two figures and the minutes by the last
Time may be stated in minutes only (two figures) in radio telephone
communications when no misunderstanding is likely to occur.
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 eight seconds are stated as the preceding
quarter minute; fractions of a quarter minute of eight seconds or more
are stated as the succeeding quarter minute.
0000.............................................ZERO ZERO ZERO ZERO
0920.............................................ZERO NINER TWO ZERO
0929:05.............................................TIME, ZERO NINER TWO
0929:10.............................................TIME, ZERO NINER TWO
NINER AND ONE QUARTER
COMMUNICATIONS WITH TOWER WHEN AIRCRAFT TRANSMITTER OR RECEIVER OR
BOTH ARE INOPERATIVE
- Receiver inoperative - If you have reason to believe your receiver
is inoperative, remain outside or above the airport traffic 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. 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.
- Transmitter inoperative - Remain outside or above the airport
traffic 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 ad dressed 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
- Transmitter and receiver inoperative - Remain outside or above
the airport traffic 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
- 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.
NOTE.-Refer to FAR-91.87 and FAR-91.77.
TRAFFIC CONTROL LIGHT SIGNALS
- The following procedures are used by ATCTs in the control of aircraft
not equipped with radio. These same procedures will be used to control
aircraft equipped with radio if radio contact cannot be established. ATC
personnel use a directive traffic control signal which emits an intense
narrow light beam of a selected color (either red, white, or green) when
controlling traffic by light signals.
- Although the traffic signal light offers the advantage that some control
may be exercised over non radio equipped aircraft, pilots should be cognizant
of the disadvantages which are:
Between sunset and sunrise, a pilot wishing to attract the attention
of the control tower should turn on a landing light and taxi the aircraft
into a position, clear of the active runway, so that light is visible to
the tower. The landing light should remain on until appropriate signals
are received from the tower.
Portable traffic control light signals:
- The pilot may not be looking at the control tower at the time a signal
is directed toward him.
- The directions transmitted by a light signal are very limited since
only approval or disapproval of a pilot's anticipated actions may be transmitted.
No supplement or explanatory information may be transmitted except by the
use of the "General Warning Signal" which advises the pilot to
be on the alert.
Type of Signal On the Ground In Flight
STEADY GREEN Cleared for take-off Cleared to land
FLASHING GREEN Cleared to taxi Return for landing
(to be followed by steady green at
STEADY RED Stop Give way to other aircraft
and continue circling
FLASHING RED Taxi clear of landing area Airport unsafe-do not land
(runway) in use
FLASHING WHITE Return to starting point on airport
ALTERNATING RED & GREEN General Warning Signal General Warning Signal
Exercise Extreme Caution Exercise Extreme Caution
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.
COMMUNICATIONS FOR VFR FLIGHTS
- FSSs are allocated frequencies for different functions, for Airport
Advisory Service the pilot should contact the FSS on 123.6 MHz, for example.
Other FSS frequencies are listed with the FSS in the Airport/Facility Directory.
If you are in doubt as to what frequency to use to contact an FSS, transmit
on 122.1 MHz and advise them of the frequency you are receiving on.
- On VFR flights, guard the voice channel of VORs for broadcasts and
calls from FAA FSSs. Where the VOR voice channel is being utilized for
ATIS broadcasts, pilots of VFR flights are urged to guard the voice channel
of an adjacent VOR. When in contact with a control facility, notify the
controller if you plan to leave the frequency. This could save the controller
time by not trying to call you on that frequency.
EMERGENCY LOCATOR TRANSMITTERS
- GENERAL. Emergency Locator Transmitters (ELT's) are required
for most general aviation airplanes (FAR 91.52). ELT's of various types
have been developed as a means of locating downed aircraft. These electronic,
battery operated transmitters emit a distinctive downward swept audio tone
on 121.5 MHz and 243.0 MHz. If "armed" and when subject to crash
generated forces, they are designed to automatically activate and continuously
emit these signals. The transmitters will operate continuously for at least
48 hours over a wide temperature range. A properly installed and maintained
ELT can expedite search and rescue operations and save lives.
- TESTING. ELT's should be tested in accordance with the manufacturer's
instructions, preferably in a shielded or screened room to prevent the
broadcast of signals which could trigger a false alert. When this cannot
be done, aircraft operational testing is authorized on 121.5 MHz and 243.0
MHz as follows:
FALSE ALARMS. Caution should be exercised to prevent the inadvertent
activation of ELT's in the air or while they are being handled on the ground.
Accidental or unauthorized activation will generate an emergency signal
that cannot be distinguished from the real thing, leading to expensive
and frustrating searches. A false ELT signal could also interfere with
genuine emergency transmissions and hinder or prevent the timely location
of crash sites. Frequent false alarms could also result in complacency
and decrease the vigorous reaction that must be attached to all ELT signals.
Numerous cases of inadvertent activation have occurred as a result of aerobatics,
hard landings, movement by ground crews, and aircraft maintenance. These
false alarms can be minimized by monitoring 121.5 MHz and/or 243.0 MHz
- Tests should be conducted only during the first 5 minutes after any
hour. If operational tests must be made outside of this timeframe, they
should be coordinated with the nearest FAA Control Tower or FSS.
- Tests should be no longer than three audible sweeps.
- If the antenna is removable, a dummy load should be substituted during
- Airborne tests are not authorized.
IN-FLIGHT MONITORING AND REPORTING Pilots are encouraged to
monitor 121.5 MHz and/or 243.0 MHz while in flight to assist in identifying
possible emergency ELT transmissions. On receiving a signal, report the
following information to the nearest air traffic facility:
- Prior to engine shut down at the end of each flight.
- When the ELT is handled during installation or maintenance.
- When maintenance is being performed in the vicinity of the ELT.
- When the aircraft is moved by a ground crew.
- If an ELT signal is heard, turn off the ELT to determine if it is transmitting.
If it has been activated, maintenance might be required before the unit
is returned to the "ARMED" position.
- Your position at the time the signal was first heard.
- Your position at the time the signal was last heard.
- Your position at maximum signal strength.
- Your flight altitudes and frequency on which the emergency signal was
heard - 121.5 MHz or 243.0 MHz. If possible, positions should be given
relative to a navigation aid. If the aircraft has homing equipment, provide
the bearing to the emergency signal with each reported position.
SEARCH AND RESCUE SATELLITE (SARSAT)
Search and rescue is a lifesaving service provided through the combined
efforts of the federal agencies signatory to the national search and rescue
plan, and the agencies responsible for search and rescue in each state.
Operational resources are provided by the U.S. Coast Guard, Department
of Defense components, the Civil Air Patrol, the Coast Guard Auxiliary,
state, county, and local law enforcement and other public safety agencies.
The introduction of the SARSAT system enhances the effectiveness of search
and rescue. SARSAT also amplifies the importance of assuring that your
ELT remains silent, except for testing or in an actual emergency. Search
and rescue missions launched because of a FALSE ELT signal are costly and
unnecessary. Search and rescue services include search for missing aircraft,
survival aid, rescue, and emergency medical help for the occupants after
an accident site is located.
Check your radio on 121.5 MHz or 243.0 MHz before you leave your aircraft.
Your ELT may be transmitting.