Efficiency on the Frequency

The controller is responsible for the frequency, as only they know who needs to receive which instruction next. For this reason, the controller must be calm, friendly, but also assertive / self-confident on the frequency.

Use Standard Phraseology

For all radio communications, the rule is: as short as necessary and as precise as possible. This is exactly what this phraseology is designed for. Avoid filling words and your own creations that the pilot does not understand.

Speak clearly, distinctly, and slowly

Every controller and pilot has their own pronunciation and dialect. Therefore, it is even more important to speak clearly, distinctly, and slowly so that the other side can understand. Otherwise, it may lead to radio communications having to be repeated multiple times until the other side understands. This significantly increases the frequency load, leaving less time for other important instructions.

Standby

The use of "standby" should be done with caution, as this often has further implications. The more pilots that are waiting, the more pilots will eventually need to be called back, while more and more pilots will be contacting you during high traffic situations. Thus, while "standby" initially helps, it only postpones the problem depending on the traffic situation. Eventually, you will be working reactively rather than proactively, just to clear the queue.

If it is foreseeable that the pilot will have to wait longer than 2 minutes for a response, they should always be informed of the reason (e.g., pushing traffic behind) or an approximate waiting time (e.g., standby, call you in 5 minutes or standby, number 5 for clearance). This avoids additional frequency load due to potential inquiries by impatient pilots. Additionally, it is advisable to note which pilots have received a standby (e.g., using ground states or additional plugins) to prevent forgetting them.

Keep Frequency Clear for Time-Critical Instructions

This often requires pre-planning, sometimes beyond one's own area of responsibility, and involves setting of priorities. If you see that a pilot will soon contact you and must immediately receive an instruction (e.g., after crossing a runway or for a turn onto the ILS), long instructions should not be given at that moment (e.g., IFR Pickup).

Blocked Frequency

On busy frequencies, it often happens that two transmissions are sent simultaneously and block each other. If neither sender can be identified, pilots should be informed with a "blocked." If one pilot can be identified, they can be addressed directly. The same applies to the second pilot.

Tip: Keep the Audio for Vatsim window always on top and look at it to determine both pilots that blocked out each other.

Use of "BREAK BREAK"

Instead of separating two radio transmissions with a "break break" (which is often unnecessary), it is usually easier for the pilot if there is a short pause between transmissions, or if the transmit button is briefly released. In a continuous speech flow, as with the use of this phraseology, one's own callsign can be easily missed because the pilot does not initially feel addressed.

Under no circumstances should a "break break" be used routinely between two transmissions that both require a readback. The risk is too high that the pilots will block each other.