Words/phrases

Front 1

Acknowledge

Back 1

Let me know that you have received and understood my message.

Front 2

Advise Intentions

Back 2

Tell me what you plan to do.

Front 3

Affirmative

Back 3

Yes.

Front 4

ATC Advises

Back 4

Used to prefix a message of noncontrol information when it is relayed to an aircraft by other than an air traffic controller.

Front 5

ATC Clears

Back 5

Used to prefix an ATC clearance when it is relayed to an aircraft by other than an air traffic controller.

Front 6

ATC Requests

Back 6

Used to prefix an ATC request when it is relayed to an aircraft by other than an air traffic controller.

Front 7

Cleared For Takeoff

Back 7

ATC authorization for an aircraft to depart. It is predicated on known traffic and known physical airport conditions.

Front 8

Cleared To Land

Back 8

ATC authorization for an aircraft to land. It is predicated on known traffic and physical airport conditions.

Front 9

Correction

Back 9

An error had been made in the transmission and the correct version follows.

Front 10

Expedite

Back 10

Used by ATC when prompt compliance is required to avoid the development of an imminent situation, usually in conjunction with a request for best rate of climb/descent, without requiring an exceptional change in aircraft handling characteristics.

Front 11

Go Ahead

Back 11

Proceed with your message. NOT to be used for any other purpose.

Front 12

How Do You Hear Me?

Back 12

A question relating to the quality of the transmission or to determine how well the transmission is being received.

Front 13

Immediately

Back 13

Used by ATC when compliance with an action is required to avoid an imminent situation.

Front 14

I Say Again

Back 14

The message will be repeated.

Front 15

Negative

Back 15

"No" or "Permission NOT granted" or 'That is NOT correct."

Front 16

Out

Back 16

The conversation is ended and NO response is expected.

Front 17

Over

Back 17

My transmission is ended; I expect a response.

Front 18

Radar Contact

Back 18

Used by ATC to inform an aircraft that it is identified on the radar display and radar flight following will be provided until radar identification is terminated. Radar service may also be provided within the limits of necessity and capability. When a pilot is informed of "radar contact," he automatically discontinues reporting over compulsory reporting points.

Front 19

Radar Contact Lost

Back 19

Used by ATC to inform a pilot that radar data used to determine the aircraft's position is NO longer being received, or is NO longer reliable and radar service is NO longer being provided.

Front 20

Read Back

Back 20

Repeat my message back to me.

Front 21

Roger

Back 21

I have received all of your last transmission. It should NOT be used to answer a question requiring a "yes" or "no" answer.

Front 22

Say Again

Back 22

Used to request a repeat of the last transmission. Usually specifies transmission or portion thereof NOT understood it received, e.g., "Say again all after ABRAM VOR."

Front 23

Say Altitude

Back 23

Used by ATC to ascertain an aircraft's specific altitude/ flight level. When the aircraft is climbing or descending, the pilot should state the indicated altitude rounded to the nearest 100 feet.

Front 24

Speak Slower

Back 24

Used in verbal communications as a request to reduce speech rate.

Front 25

Squawk

Back 25

Activate specific codes in the aircraft transponder; e.g., "Squawk one zero two zero."

Front 26

Unable

Back 26

Indicated inability to comply with a specific instructions, request, or clearance.

Front 27

Stand By

Back 27

Means the controller or pilot must pause for a few seconds, usually to attend to other duties of higher authority. Also means to "wait" as in "stand by for clearance." If a delay is lengthy, the caller should re-establish contact.

Front 28

That Is Correct

Back 28

The understanding you have is right.

Front 29

Verify

Back 29

Request confirmation of information; e.g., "Verify assigned altitude."

Front 30

Wilco

Back 30

I have received your message, understand it, and will comply with it.

Front 31

Words Twice

Back 31

1. As a request: "Communication is difficult. Please say every phrase twice."

2. As information: "Since communications are difficult every phrase in this message will be spoken twice."