On an instrument flight you talk to a chain of controllers, each responsible for one phase. Knowing who comes next makes every frequency change predictable.
The chain, in order
| Position | Also called | What they do for you |
|---|---|---|
| ATIS | Information | A recorded broadcast: weather, runway in use, QNH and notices, with a letter that changes each update |
| Clearance delivery | Delivery, DEL | Gives your IFR clearance: route, initial altitude, squawk |
| Apron or ramp | At some airports: pushback and taxi on the apron | |
| Ground | GND | Taxi from the stand to the runway holding point, and back after landing |
| Tower | TWR | Line-up, take-off and landing clearances, and the airspace close to the airport |
| Departure | DEP | Climb-out, radar vectors and the first part of the route |
| Area control | Centre, Control, CTR | En route at cruise levels; hands you on sector by sector |
| Approach | APP, Arrival | Descent from the STAR, vectors and sequencing onto the approach |
| Tower | Landing clearance | |
| Ground | Taxi in |
Not every airport has every position. At quiet airports one controller may do several jobs. When you fly with live controllers online, a controller higher in the chain often covers positions that are not staffed below them, so check who is actually providing service before you call.
Frequency changes
A controller hands you on with an instruction such as:
SVA123, contact Jeddah Approach one one niner decimal one, good day.
Read the frequency back, change, wait for a gap, then check in with your callsign, your level and any assigned heading or speed:
Jeddah Approach, SVA123, descending flight level one two zero, heading two seven zero.
Who is responsible for what
Controllers keep aircraft separated from each other and, in controlled airspace, give you instructions that keep you clear of terrain on radar vectors. You remain responsible for flying the aircraft accurately, following the clearance, and saying "unable" if you cannot comply. If an instruction is unclear, ask: "say again".
For flight simulation and training only. Real-world procedures vary by country and operator; always follow the published charts and your local rules.
Keep reading
- Radio phraseology basics: How to structure a call, what you must read back, and how to say numbers and letters on the radio.
- Squawk codes and emergencies: The transponder codes everyone should know, how to declare an emergency, and what to do if the radio fails.