General Operating Procedures — Page 57, Lesson 46

I want to walk you through the standard phraseology that every pilot must know for radio communications. These are the exact words and phrases defined by ICAO for use in air-ground and ground-ground voice communications. They are not optional or casual — they are the professional language of aviation. Let's start with Contact. When you hear or say "Contact," it means establish radio contact with the station or facility that follows. For example, "Contact Approach" means you are being told to call Approach on the frequency they will give you. Correction is used when an error has been made in a transmission or in a specific message you just sent. You say "Correction" and then state the correct version. So if you read back an altitude wrong, you say "Correction, descending to flight level two five zero." Disregard simply means ignore — treat the previous transmission as if it was never sent. Go ahead means proceed with your message. If a controller says "Go ahead," they are inviting you to transmit. How do you read is a question asking for the readability of your transmission. The pilot or controller is asking you to rate how well you can hear them, using the standard readability scale from 1 to 5. I say again means I repeat for clarity or emphasis. You use this when you want to restate something to make sure it is understood. Maintain means continue in accordance with the condition or conditions specified. For example, "Maintain flight level three five zero" means stay at that altitude. Monitor means listen out on a specific frequency. You are not expected to transmit — just listen. For example, "Monitor tower frequency" means tune to that frequency and listen for instructions. Negative means no, or permission is not granted, or that is not correct. It is the standard way to say no on the radio. Out means this exchange of transmissions is ended and no response is expected. You say "Out" when you are finished and do not need a reply. It is the last word in a complete exchange. Over means my transmission is ended and I expect a response from you. However, there is an important note: the word "OVER" is not normally used in VHF communications. In practice, on VHF, you simply finish your transmission and the other party knows you expect a reply because of the context and the pause. Read back means repeat all, or the specified part, of this message back to me exactly as received. This is critical for safety — when a controller gives you a clearance or instruction, you must read it back word for word to confirm you have it correctly. Recleared means a change has been made to your last clearance and this new clearance supersedes your previous clearance or part thereof. So if you were cleared to flight level two zero zero and then the controller says "Recleared flight level two five zero," the new clearance replaces the old one. Report means pass me the following information. For example, "Report passing flight level one zero zero" means tell me when you reach that altitude. Request means I should like to know something or I wish to obtain something. For example, "Request descent" means you are asking for permission to descend. Roger means I have received all of your last transmission. It does not mean yes or no — it only means the transmission was received. There is a very important note: under no circumstances is "Roger" to be used in reply to a question requiring a read back or a direct answer in the affirmative or negative. For those, you must use "Affirm" or "Negative" or actually read back the instruction. Say again means repeat all, or the following part, of your last transmission. If you missed part of a message, you say "Say again" or "Say again all after [word]" to ask for a repeat. Speak slower means reduce your rate of speech. You use this when the other party is talking too fast for you to copy. Standby means wait and I will call you. It is not a clearance to do anything — you just wait on that frequency until the controller comes back to you. Unable means I cannot comply with your request, instruction, or clearance. If a controller tells you to descend but you cannot due to traffic or an aircraft limitation, you say "Unable." Wilco is an abbreviation for "will comply." It means I understand your message and will comply with it. It combines the acknowledgment of "Roger" with the promise to follow the instruction. Finally, Words twice has two uses. As a request, it means communication is difficult, so please send every word or group of words twice. As information, it means since communication is difficult, every word or group of words in this message will be sent twice. So if you are in heavy static, you might say "Words twice" and then the controller will repeat each phrase twice. These are the building blocks of every radio exchange you will have as a pilot. Learn them exactly as written — there is no room for improvisation in standard phraseology.