5.2 Replying & Terminating Communications

5.2 Replying & Terminating Communications

Quick Answer: When called, reply as soon as possible with GO AHEAD (send the message) or STANDBY plus the minutes of delay. Unsure the call is for you? Do not reply until it is repeated and understood. Unsure who called? STATION CALLING + your ID + SAY AGAIN OVER. End the exchange with OUT (no reply expected). After solid contact, you may drop THIS IS/OVER and shorten call signs if interference is unlikely.

RIC-21 §5.7.2 Replying closes the loop after the calling formats in §5.7.1. The ROC-A exam loves the contrast between GO AHEAD and STANDBY, the two different “uncertainty” rules (is it for me? vs who are you?), and the precise meaning of OUT versus OVER.

Reply as soon as possible

Operators hearing a call directed to their station shall reply as soon as possible and advise the calling station either:

• to proceed with the message — GO AHEAD, or
• not to proceed — STAND BY, followed by the anticipated number of minutes of delay.

Official examples (RIC-21)

Proceed:

PIPER FOXTROT X-RAY QUEBEC QUEBEC
THIS IS
TORONTO TOWER
GO AHEAD

Delay:

PIPER FOXTROT X-RAY QUEBEC QUEBEC
THIS IS
TORONTO TOWER
STAND BY TWO MINUTES

Key points for exam answers:

“STAND BY” without a time is incomplete against the study-guide model—RIC-21 shows STAND BY TWO MINUTES (anticipated delay stated). Do not invent slang such as “hang on,” “wait one,” or “ten-four.”

Structure of a correct reply mirrors the call format: address the station that called you (their call sign first), THIS IS, your identification, then GO AHEAD or STAND BY ….

Uncertainty rule 1 — is this call for me?

When station operators hear a call but are uncertain that the call is intended for their station, they should not reply until the call has been repeated and understood.

Why: a premature answer on the wrong aircraft or ground unit steals the channel and can cause two stations to believe they are in contact when they are not. Silence until the call is clear is the safety choice.

Uncertainty rule 2 — who is calling me?

When station operators hear a call but are not sure of the identity of the calling station, they should reply immediately using:

1. The words STATION CALLING
2. The called station’s identification (your own ID—the station that was addressed)
3. The words SAY AGAIN
4. OVER

Example (RIC-21):

STATION CALLING CESSNA FOXTROT NOVEMBER JULIETT INDIA
SAY AGAIN
OVER

Read that carefully for traps:

• You do not invent a guessed call sign for the unknown caller.
• You identify yourself (the station that was called) after STATION CALLING.
• You request a full repeat of the caller’s identity with SAY AGAIN and leave the floor open with OVER.

Compare the two uncertainty cases side by side:

Mixing these two rules is a classic exam fail.

Terminating communications — OUT

To terminate communications, simply conclude the transmission with the word OUT, which means “conversation is ended and no response is expected.”

Example (RIC-21):

TORONTO TOWER
THIS IS
PIPER FOXTROT X-RAY QUEBEC QUEBEC
RECEIVED RUNWAY CLEARANCE
OUT

OUT versus OVER (must-know contrast)

Never use the slang mash-up “OVER AND OUT”—Appendix B / §5.5 bans that style of CB/police slang. If you want a reply, end with OVER. If the exchange is finished, end with OUT.

After contact is established — abbreviations

RIC-21 (message-handling context in §5.7.4, applied once contact is solid) allows efficiency on subsequent calls:

• The words THIS IS and OVER may be omitted, and
• If no likelihood of interference exists, the call sign for the station being called may be abbreviated.

Example of abbreviated subsequent contact:

SCHEFFERVILLE RADIO BRAVO CHARLIE CONFIRM RIGHT ON SIERRA

Here the aircraft has already been identified in the full exchange; the ground/air pair shortens to function name + distinctive registration letters when the risk of confusion is low.

Rules of thumb for the exam:

1. Initial contact: full format (called, THIS IS, calling, frequency as required, OVER).
2. After contact: may omit THIS IS/OVER; may abbreviate called sign if no interference risk.
3. If the channel is busy or identity could be confused, stay with full call signs.

Worked reply drills

Drill A — Ready for traffic
Aircraft: “Toronto Tower, this is Piper FXQQ, on frequency one one eight decimal seven, over.”
Tower: “Piper Foxtrot X-ray Quebec Quebec, this is Toronto Tower, go ahead.”

Drill B — Not ready
Same call-up.
Tower: “Piper Foxtrot X-ray Quebec Quebec, this is Toronto Tower, stand by two minutes.”

Drill C — Unknown caller
You hear your call sign but not theirs.
You: “Station calling Cessna Foxtrot November Juliett India, say again, over.”

Drill D — End of exchange
You have the clearance and need nothing more.
You: “… received runway clearance, out.”

Exam-oriented checklist

1. Called clearly → reply ASAP.
2. Ready → GO AHEAD; not ready → STAND BY + minutes.
3. Maybe not me → wait for repeat.
4. Don’t know caller → STATION CALLING [me] SAY AGAIN OVER.
5. Done → OUT (not OVER AND OUT).
6. Later calls → optional omit THIS IS/OVER; abbreviate only if safe.

Official source

RIC-21 Issue 3, §5.7.2 Replying (and related abbreviation note in §5.7.4), ISED study guide for the Restricted Operator Certificate with Aeronautical Qualification (ROC-A).