Swiss Airspace Classification

Chapter 20.2

Airspace Classes and Conditions of Use

The classification of an airspace serves to define the conditions under which the corresponding airspace may be used. The International Civil Aviation Organization (ICAO) has defined seven airspace classes with the associated conditions. In Switzerland, only the four airspace classes C, D, E and G are used.

General Airspace Classification Switzerland

Where no dedicated airspaces have been established, a general airspace classification applies. A distinction is made between the Central Plateau-Jura and the Alps. Over the Alps, the general classification depends on the operating hours of the Air Force.

Representation of Airspaces

The lateral extent of airspace is relatively easy to display and read on a chart. In the Swiss ICAO aeronautical chart, this is shown with blue lines, on which it is also written which class of airspace is applied.

It is more difficult to show the vertical dimension, i.e. the valid altitude of an airspace, on a chart.

There is a separate information field for each segment. This provides information on the classification, the upper and lower limits of the airspace and, where applicable, the air traffic control centre and its frequency for obtaining clearance for entry or transit.

Example: 3D representation of the CTR / TMA Bern

Overview of civil CTRs and TMAs

Source: VFR Manual, Skyguide

Overview of military CTRs and TMAs

Source: VFR Manual, Skyguide

Visibility and Distances from Clouds

In principle, a cloud separation of 1000 ft vertically and 1.5 km horizontally applies. The minimum visibility outside of airspace class G is 5 km below FL 100 and 8 km above FL 100. In airspace class G, flight visibilities reduced to not less than 1500 m may be permitted for flights operating at speeds of 140 kts IAS or less to give adequate opportunity to observe other traffic or any obstacles in time to avoid collision and the flight must take place outside of clouds.

Transponder obligation

A Mode S transponder must be carried and operated in the following cases:

• In airspaces C and D
• In Class E airspaces and above 7000ft AMSL
• For NVFR flights in all airspaces
• for VFR flights with powered or non-powered aircraft flying in airspace class G at an altitude above 300 m (1000 ft) above ground level according to the minimum values specified in SERA.5001;
• For helicopter departures in ground and high fog in all airspace classes.

In general:
If a transponder is carried and unless otherwise instructed by ATC, the transponder must always be operated and the code 7000 with altitude must be set.

Special VFR (SVFR) within Control Zones (CTR)

If visual meteorological conditions cannot be maintained within a control zone (CTR), air traffic control may authorise a Special VFR (SVFR) clearance within the control zone (CTR) during the day under the following conditions:

• outside clouds with visibility to the ground
• Minimum visibility of 1.5 km
• Maximum speed of 140 kts IAS
• Cloudbase minimum 600 ft / 180m / AGL or higher
  

Night VFR

For visual flights at night, the following minimum values must be maintained:

• Flight visibility: 8 km;
• Distance to clouds: horizontal: 1,5 km; vertical: 300 m (1000 ft)
• Ground visibility: uninterrupted up to and including 900 m (3000 ft) AMSL or 300 m (1000 ft) AGL; whichever is higher.

In Switzerland, VFR operations may also be conducted at night within a control zone in accordance with Special VFR. This does not apply abroad. If a transponder is carried and unless otherwise instructed by ATC, the transponder must always be operated and the code 7000 with altitude mode must be selected.

Flights under Instrument Flight Rules (IFR) in Airspace Classes E and G

Flights according to instrument flight rules also take place in airspace classes E and G. It is therefore all the more important that the airspace is constantly monitored by the pilot (see & avoid) and that cloud clearances are maintained. Especially in the vicinity of regional civil airfields (e.g. Bern, Grenchen, etc.) and military airfields, an increased volume of IFR traffic is to be expected. In addition, there is a Low Flight Network (LFN) in Switzerland for helicopter flights of the Swiss Air Force and Rega according to instrument flight rules.