Lesson 4 of 5 — Module 2: The language of aviation radio

Standard words — Roger, Wilco, Affirmative, Negative, Unable

What each word means in the Pilot/Controller Glossary, and when 'roger' is the wrong answer.

Lesson notes

What this lesson covers

What Roger, Wilco, Affirmative, Negative and Unable mean in the Pilot/Controller Glossary — with Say again, Stand by, Verify and Correction — and when 'roger' is the wrong answer.

The explanation

Roger means only 'I have received all of your last transmission'. It is not yes, and it must not be used to answer a question that needs a yes or a no — for that, say Affirmative (yes) or Negative (no, permission not granted, or that is not correct).

Wilco means 'I have received your message, understand it, and will comply with it'. Acknowledge every call-up and clearance with your identification, at the start or the end, and one of the standard words:

YouPiper Two One Four Lima, roger

Unable means you cannot comply with an instruction, request or clearance. Say it with your call sign and, briefly, why — then what you can do. Never read back an instruction you will not comply with:

YouUnable six thousand five hundred, able four thousand five hundred, Cessna One Seven Two Sierra Papa

Say again asks for a repeat — best when you name the part you missed, 'say again all after (fix)'. Stand by is a pause, not an approval or a denial; call again if the wait is long. Verify asks for confirmation; Correction means an error was made and the correct version follows.

Key points

Roger = received. Not yes, and never the answer to a yes/no question.
Wilco = received, understood, will comply.
Affirmative / Negative answer a question.
Unable — and say what you can do instead.
Stand by is neither an approval nor a denial.

Common mistakes

Answering a yes/no question with 'roger'.
Taking 'stand by' as an approval (or a denial).
Reading back an instruction you will not comply with, instead of saying 'unable'.
Acknowledging without your aircraft identification.

Sources

[P/CG Chg 3 §ROGER] · [P/CG Chg 3 §WILCO] · [P/CG Chg 3 §AFFIRMATIVE; NEGATIVE] · [P/CG Chg 3 §UNABLE] · [P/CG Chg 3 §SAY AGAIN] · [P/CG Chg 3 §STAND BY] · [P/CG Chg 3 §VERIFY; CORRECTION] · [AIM Chg 3 §4-2-3 c]

Acknowledging & reading back

Acknowledge every call-up and clearance with your identification — at the start or the end — and one of the standard words. [AIM 4-2-3 c]

Wilco: Received, understood, will comply. [P/CG]
Roger: Received all of your last transmission. Never an answer to a yes/no question. [P/CG]
Affirmative / Negative: Yes / No. [P/CG]
Unable: Cannot comply with the instruction. Say what you can do instead. [P/CG]
Say again: Repeat — “say again all after (fix)”. [P/CG]
Stand by: A pause, not an approval or a denial. Call again if the wait is long. [P/CG]

What must be read back

Runway assignments: The runway, including left/right/center, in the first readback of a taxi, departure or landing clearance. [AIM 4-4-7 b 4]
Hold-short instructions: Word for word. ATC is required to obtain this readback. [AIM 4-3-18 a 9, 10]
Any clearance to enter a runway: Line up and wait, cross runway (number), cleared for takeoff. [AIM 4-3-18 a 9]
Altitudes, vectors, altitude restrictions: In the sequence given, with your identification. [AIM 4-4-7 b 2]
Squawk codes and frequency changes: Read back the code; acknowledge the frequency. [AIM 4-2-3 d]
Not read back: Wind, traffic information, weather — acknowledged, never required.

November Five Charlie Tango, roger, cleared to land runway nine left.

Runway three six left, taxi via Alpha, hold short of taxiway Charlie, Cessna Six Zero Foxtrot.

Practice & test

Test: Standard words & phrasesmultiple-choice questions on this lesson's topic, with explanations

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Next lesson: What must be read back →

Study aid only — always defer to the FAA AIM and Pilot/Controller Glossary and current official publications, and to your instructor and examiner.

Lesson notes

What this lesson covers

What Roger, Wilco, Affirmative, Negative and Unable mean in the Pilot/Controller Glossary — with Say again, Stand by, Verify and Correction — and when 'roger' is the wrong answer.

The explanation

YouPiper Two One Four Lima, roger

YouUnable six thousand five hundred, able four thousand five hundred, Cessna One Seven Two Sierra Papa

Key points

Roger = received. Not yes, and never the answer to a yes/no question.

Wilco = received, understood, will comply.

Affirmative / Negative answer a question.

Unable — and say what you can do instead.

Stand by is neither an approval nor a denial.

Common mistakes

Answering a yes/no question with 'roger'.

Taking 'stand by' as an approval (or a denial).

Reading back an instruction you will not comply with, instead of saying 'unable'.

Acknowledging without your aircraft identification.