Civil Airspace Overlays

Summary: A guide to the civil airspace layers on the map, how they are grouped, the height control, and what each abbreviation means.

The Civil Overlays section shows UK civil airspace, built from the current UK AIP each AIRAC cycle, with the en-route sectors drawn at their real levels. Each overlay is colour-coded, and clicking any polygon opens a plain-language popup (see Airspace Frequencies & the Height Control). The layers are grouped by what they are rather than by height:

Boundaries

• FIR (Flight Information Region) / UIR (Upper Information Region) / Oceanic — the top-level regions UK airspace is divided into for air traffic services.

Controller Sectors

• London Sectors and Scottish Sectors — the en-route air traffic control sectors, each volume at its published levels, named as the controllers name them (Daventry South, Borders, Solway, Grampian, Pennine…).
• London Terminal (TC) — the Terminal Control sectors around London.
• Western Radar — the radar service over the south-west, FL195 and above.

Controlled Airspace

• CTR (Control Zone) — controlled airspace around a busier airport, usually surface to a set altitude.
• CTA (Control Area) — controlled airspace that doesn’t extend to the surface.
• TMA (Terminal Manoeuvring Area) — controlled airspace around a busy airport or group of airports, above the surface CTRs.
• Free Route (FRA) — airspace where aircraft can plan direct routes rather than following fixed airways.

Around Airfields

• ATZ (Aerodrome Traffic Zone) — protected airspace around an airfield.
• MATZ (Military Aerodrome Traffic Zone) — the military equivalent.
• LARS (Lower Airspace Radar Service) — a radar advisory service available to aircraft flying outside controlled airspace, drawn as each unit’s published circle.
• Recreational and UAS Zone — areas with specific rules for recreational flying or drones.

Each overlay can be switched on or off independently, so you can build up exactly the picture of controlled airspace you want to see.

Showing Airspace at a Height

Airspace stacks: a CTA may sit over a CTR under a TMA under a sector. One control at the top of the section picks the height you care about — All heights, a band (Surface – 5,000 ft, 5,000 ft – FL195, Above FL195), or an exact level — and every layer then draws just the volumes an aircraft at that height would be inside. A layer with nothing at the chosen height moves to a Not at this height line rather than sitting there switched on and drawing nothing; picking it there switches it on and goes back to all heights. The section remembers your choice. Military Overlays has the same control, with its own choice.