MATZ, LARS and getting a service
Leaving the circuit means talking to people who do not know you are coming. The words you use to ask decide what you get, and the four services are not four ways of saying the same thing — each one commits the controller to something different.
The four services, and what each one obliges the controller to do
Ask for the service you actually want. A Basic Service is not a lesser Traffic Service; it is a different arrangement in which nobody is watching out for you.
- Basic Service
- General information for any phase of flight (e.g. weather, changes of serviceability). Traffic information only if the controller happens to have it. You remain entirely responsible for your own collision avoidance, terrain clearance and navigation.
- Traffic Service
- A surveillance (radar) service: the controller passes traffic information on relevant conflicting traffic. You decide on and take your own avoiding action — no avoiding advice is given.
- Deconfliction Service
- A surveillance service giving traffic information AND deconfliction advice (headings and/or levels) to keep you clear of other traffic — usually IFR/IMC. You may accept it or not, but if you don't comply you take responsibility for your own separation.
- Procedural Service
- A non-surveillance service: instructions are based on reported positions (no radar). Deconfliction advice is given against other procedural traffic; traffic information where possible.
How to ask
The request is a specific phrase, and the specific phrase is what gets you the specific thing.
- “Request radio check”
- Confirm your transmissions are readable (you'll get a readability 1–5).
- “Request taxi / taxi information”
- To taxi for departure — “taxi” at an ATC field, “taxi information” at an Air/Ground field.
- “Request Basic / Traffic / Deconfliction Service”
- To receive that air traffic service (see above).
- “Request MATZ penetration”
- To cross a Military Aerodrome Traffic Zone (see below).
- “Request zone transit”
- To cross a control zone / CTR.
- “Request Special VFR”
- A clearance to fly VFR in a control zone when conditions are below the normal VFR minima.
- “Request joining instructions”
- How to join the circuit at your destination.
- “Request change to <station> <freq>”
- To change to another frequency (a mandatory readback).
- “Request climb / descent to <level>”
- A level change (read back the level instruction).
Crossing a MATZ
A MATZ is a Military Aerodrome Traffic Zone. Crossing one isn't compulsory for civil flights, but you should request penetration so the military controller knows you're there and can pass traffic information.
- Call the controlling military unit (the “Zone” or “Radar”) and request MATZ penetration.
- On “pass your message”, give aircraft type, position, heading, altitude with the pressure setting, and your routing.
- Read back any squawk, the pressure setting (often the aerodrome QFE for the stub) and any instructions.
“Wattisham Zone, G-ABCD, Cessna 152, 5 miles east of Wattisham, heading 270, altitude 2000 feet QNH 1013, VFR routing to Cambridge, request MATZ penetration.”
Note what is being asked for by name. “MATZ penetration” is a request to enter a defined volume of airspace. Asking for a Basic Service instead is a different request, and it gets a different answer.
Transiting a control zone
Controlled airspace is different again: here you need a clearance, not a service, and the clearance has parts you must read back.
- You can't enter controlled airspace (a control zone or area) without a clearance. Call the controlling unit and request a zone transit, then pass your details when asked.
- The clearance may be a Special VFR (SVFR) clearance — permission to fly in the zone, usually with a route and a level restriction.
- Read back the clearance, the route and any level restriction — they are mandatory readbacks.
- If you're not cleared, remain clear of the zone.
Worked example
“… cleared to the zone boundary, route via Whiskey, Special VFR not above altitude 1500 feet” → readback: “Cleared to the zone boundary, route via Whiskey, Special VFR not above altitude 1500 feet, G-ABCD”
Where talking to them is not optional
A MATZ crossing is a courtesy you should extend. These two are not. Both are marked on the chart and both have a hard rule about what you must have done before you enter.
- RMZ — Radio Mandatory Zone
- You must ESTABLISH two-way radio contact with the notified unit BEFORE you enter. Two-way is achieved only once you've passed your callsign, aircraft type, position, level, flight rules and intentions AND received an acknowledgement. If you can't make contact, stay outside. Marked “RMZ” on the chart.
- TMZ — Transponder Mandatory Zone
- You must have a serviceable transponder operating with the correct mode (Mode S / Mode C — “squawk Charlie”). If you can't comply (no transponder or a failure), get permission from the controlling unit first, otherwise remain outside. Marked “TMZ” on the chart.
Practise this at your airfield
Reading it is the easy half. Pick your own airfield, with its real frequencies and today’s weather, and say these calls out loud until they stop being something you remember and start being something you do.
Find your airfield →Written from the same vetted study data the app uses, and checked against it on 11 September 2026. TowerTalk is a training aid: your instructor and your examiner are the authority on whether you are ready.