FRTOL01What an ATZ and a MATZ Are
Both are zones around an aerodrome, shown on the CAA 1:500,000 VFR chart. But they're very different in law, and the radio calls follow from that.
Aerodrome Traffic Zone (ATZ)
An ATZ protects the traffic flying in and out of an aerodrome. It's a circle centred on the middle of the longest runway, rising from the surface to 2,000 ft above aerodrome level. The radius is 2 NM, or 2.5 NM where the longest runway is longer than 1,850 m (or where a 2 NM circle wouldn't reach at least 1.5 NM beyond a runway end, as notified in the AIP). It's active during the hours notified in the UK AIP.
Military Aerodrome Traffic Zone (MATZ)
A MATZ sits around many military aerodromes, with the aerodrome's own ATZ inside it. The usual shape is a cylinder of 5 NM radius from the surface to 3,000 ft above aerodrome level, plus one or two "stubs" lined up with the main instrument runway. Each stub is typically 5 NM long and 4 NM wide, from 1,000 ft to 3,000 ft above aerodrome level. Some MATZs differ, and where two aerodromes are close together their zones may be joined into a combined MATZ (CMATZ). Check the current AIP for the exact shape.
02Do You Have to Call?
For the ATZ, yes. For the MATZ, the law doesn't make you, but you'd be unwise not to.
- ATZ. Under Rule 11 of the UK Rules of the Air, before flying in an active ATZ you must get permission from ATC, or information from the FISO or air/ground operator. While inside, keep a listening watch and report your position and height when you enter and just before you leave. The ATZ at the centre of a MATZ is included.
- MATZ. For civil pilots a MATZ has no legal status, so you don't need permission to enter. The UK AIP strongly recommends a MATZ penetration service anyway. Military aircraft fly fast approaches through the zone, and the controller can only keep you apart from traffic they know about.
Many MATZ units also provide a Lower Airspace Radar Service (LARS), so you may already be talking to the right controller. If you're under a Traffic Service, you can ask for the penetration on the same frequency. See Basic Service versus Traffic Service for the difference. Military flying can run outside published hours, so it's worth calling anyway if you're unsure.
03The MATZ Penetration Call
CAP 413 says to be in two-way contact with the controlling aerodrome 15 NM or 5 minutes' flying time from the MATZ boundary, whichever is sooner. At 100 knots, 5 minutes is only about 8 NM, so for most light aircraft the 15 NM point comes first.
Make a short first call, then give the details when asked to "pass your message", in this order:
- Callsign and aircraft type
- Departure point and destination
- Present position
- LevelAltitude with the pressure setting you're using.
- Additional details and intentionsFlight rules, your next route point, and the request.
An example with the callsign G-JJER. Fenmoor is a fictional military aerodrome, and all codes and pressures are made up.
Fenmoor Approach, Golf Juliett Juliett Echo Romeo, request MATZ and ATZ penetration.
Golf Juliett Juliett Echo Romeo, Fenmoor Approach, pass your message.
Golf Juliett Juliett Echo Romeo, PA-28, from Newbridge to Ashcombe, one fower miles south of Fenmoor, altitude two thousand fower hundred feet, QNH one zero one niner, VFR, tracking north to Ashcombe.
Golf Echo Romeo, squawk six one fower tree, Traffic Service.
Squawk six one fower tree, Traffic Service, Golf Echo Romeo.
Golf Echo Romeo, MATZ and ATZ penetration approved, cross at height one thousand eight hundred feet, Fenmoor QFE one zero zero six.
MATZ and ATZ penetration approved, cross at height one thousand eight hundred feet, QFE one zero zero six, Golf Echo Romeo.
Golf Echo Romeo, report entering and leaving the MATZ.
Wilco, Golf Echo Romeo.
Golf Echo Romeo, entering MATZ.
Golf Echo Romeo, leaving MATZ.
If the controller can't let you through the ATZ, you'll hear something like "MATZ penetration approved, remain outside the ATZ". Read that restriction back and route around the inner zone.
04QFE, Heights and Level Changes
Military aerodromes fly their circuits and instrument patterns on QFE, so the controller will often give you a height on the aerodrome's QFE for the crossing.
Read back the height and the pressure setting, set the QFE, and fly the height given. Your altimeter now shows height above the military aerodrome, not altitude, so watch for high ground and airspace bases given as altitudes. Once clear, go back to the appropriate QNH.
While working a MATZ unit, follow its instructions, stay on frequency, tell the controller before changing heading or level, and report leaving the MATZ.
Pressure settings below 1,000 hPa are read back with "hectopascals", as in "QFE niner niner seven hectopascals". Our CAP 413 phraseology guide lists everything you must read back.
05ATZ Calls for ATC, AFIS and Air/Ground
The station's suffix tells you what kind of service you're getting, and therefore what you can expect to hear.
| Suffix | Service | What you get |
|---|---|---|
| Tower | Air traffic control | Clearances and instructions. You need permission to enter. |
| Information | Aerodrome flight information service (AFIS) | Information to help you fly safely. The FISO can't refuse entry. |
| Radio | Air/ground communication service | Basic information only, such as the runway and known traffic. |
These use the fictional aerodrome Newbridge with each kind of unit, to compare the wording.
ATC: Transit Through the ATZ
Newbridge Tower, Golf Juliett Juliett Echo Romeo, request ATZ transit.
Golf Juliett Juliett Echo Romeo, Newbridge Tower, pass your message.
Golf Juliett Juliett Echo Romeo, PA-28, from Ashcombe to Hillford, six miles north of Newbridge, altitude one thousand niner hundred feet, QNH one zero one niner, VFR, request transit overhead Newbridge southbound.
Golf Echo Romeo, cross the ATZ overhead the aerodrome southbound, height one thousand fife hundred feet, QFE one zero one two, report entering the ATZ.
Cross the ATZ overhead southbound, height one thousand fife hundred feet, QFE one zero one two, wilco, Golf Echo Romeo.
AFIS: Entering for Landing
Newbridge Information, Golf Juliett Juliett Echo Romeo, PA-28, seven miles west, altitude two thousand feet, QNH one zero one niner, inbound for landing.
Golf Echo Romeo, runway one niner, left-hand, QFE one zero one two, one aircraft in the circuit.
Runway one niner, left-hand, QFE one zero one two, Golf Echo Romeo.
There's no "cleared" and no "approved": the FISO passes information, and you decide how to join.
Air/Ground: Transiting the ATZ
Newbridge Radio, Golf Juliett Juliett Echo Romeo, PA-28, fife miles east, altitude one thousand eight hundred feet, QNH one zero one niner, routeing overhead Newbridge westbound, request traffic information.
Golf Echo Romeo, Newbridge Radio, runway one niner left-hand, QNH one zero one niner, no reported traffic.
Runway one niner left-hand, QNH one zero one niner, will report entering and leaving the ATZ, Golf Echo Romeo.
Whichever type of unit it is, report your position and height as you enter and just before you leave. Joining to land instead? See our overhead join radio calls.
06Common Mistakes
- Calling too late. Call by 15 NM, not at the boundary.
- Treating MATZ approval as ATZ approval when the controller said "remain outside the ATZ".
- Missing the QFE or the height from the read-back, or reading back a QFE and then not setting it.
- Forgetting to go back to QNH after leaving, then misreading heights near high ground or airspace.
- Expecting a clearance from "Information" or "Radio". They can't give one, and you'll be waiting for words that never come.
- Not reporting entering and leaving an ATZ, which the Rules of the Air require.
07MATZ and ATZ Calls in the Practical Test
Expect at least one call to cross someone else's airspace in the FRTOL practical test, and a MATZ is a favourite.
The examiner listens for an early call, the details in order, a full read-back of the approval, height and QFE, and the reports on entering and leaving. In your planning time, mark the 15 NM point on your chart.
Numbers in these calls follow the pronunciation in our aviation phonetic alphabet guide. If you're between units and need a service en route, see London Information radio calls. If the radio fails near a zone, follow the VFR radio failure procedure and stay outside. The Mayday and Pan call order applies wherever you are.
08MATZ and ATZ Questions
Do civilian pilots need permission to enter a MATZ?
No. A MATZ has no legal status for civil pilots, so permission isn't required. The UK AIP strongly recommends getting a MATZ penetration service anyway. The ATZ at the centre of a MATZ is different: you must have permission to enter it during its notified hours.
When should I call for a MATZ penetration?
CAP 413 says to be in two-way contact with the controlling aerodrome 15 NM or 5 minutes' flying time from the boundary, whichever is sooner. At typical light aircraft speeds, 15 NM comes first.
Why do military controllers give a QFE for MATZ penetration?
Military circuits and instrument patterns are flown on QFE, so a height above the aerodrome makes separation simple. Read back the level and pressure setting, set it, and go back to the appropriate QNH when you leave.
How big is an ATZ?
A circle of 2 NM radius, or 2.5 NM where the longest runway is longer than 1,850 m (or where a 2 NM circle wouldn't reach at least 1.5 NM beyond a runway end, as notified in the AIP), centred on the middle of the longest runway, from the surface to 2,000 ft above aerodrome level. Check the current AIP for each aerodrome's actual zone and hours.
Can an AFIS or air/ground operator refuse me entry to an ATZ?
No. Only an air traffic controller can approve or refuse entry. A FISO or air/ground operator gives you information, and you must get that information, keep a listening watch and report entering and leaving.
09Official Sources
This guide is a summary. Zone shapes and hours change, so always check the current documents.
This guide and the FRTOL app aren't approved by or affiliated with the UK CAA, and they don't replace your instructor or the official documents. Example calls are illustrative. Checked against CAP 413 (edition 24) in November 2026.