TMZ North-East - background and objectives
The TMZ North-East, which has been in place since 2022, was set up to increase traffic safety in the airspace between St. Gallen-Altenrhein (LSZR) and Friedrichshafen (EDNY). The area is characterised by intensive IFR traffic, sometimes at low altitudes, as well as numerous VFR activities: Powered flight, gliding, parachuting and hang gliding.
The aim of TMZ NE is to make all relevant aircraft detectable on the radar so that air traffic control can provide traffic information at an early stage. Nevertheless, technical detection does not replace the most important element: the personal situational awareness of every pilot.
Requirements in the TMZ NE
Minimum requirements for all aircraft
A Mode S transponder with elementary surveillance is required for entry into the TMZ NE. The transponder is normally operated at 7000. Exceptions only apply to non-motorised air sports equipment such as hang gliders, parachutes and model aircraft.
Voluntary but recommended willingness to listen
Pilots should switch to Alps radar (119.925 MHz) and set transponder code 2677 before approaching. This enables air traffic control to indicate IFR traffic or avoid immediate conflicts.
In the neighbouring airspace of the German TMZ EDNY, this listening readiness is not voluntary but mandatory - a difference that many Swiss VFR pilots do not always have on their radar.
Documentation in official publications
The relevant details on TMZ NE can be found in the VFR Manual (RAC) and in the AIP Switzerland under ENR 2.2. Both documents should be consulted regularly, as adjustments - e.g. due to new approach procedures - are possible at any time.
IFR traffic in the TMZ - Why vectors, STARs and RNAV procedures are important
IFR traffic in the region mainly uses satellite-based RNAV approaches. These are often executed in the characteristic ICAO T configuration. This „T“ can be recognised particularly well in Friedrichshafen; in St. Gallen-Altenrhein, the VFR reporting point Victor also plays a role.
Even if IFR approaches are published, in practice they are often supplemented by vectors. Lining up on the final approach segment often takes place in echo airspace - i.e. where VFR aircraft are also travelling. In addition, there are both STARs (Standard Arrival Routes) and SIDs (Standard Instrument Departures), which lie almost entirely in echo airspace below FL100.
An example: The STAR to the ILS from St. Gallen-Altenrhein begins shortly after the VOR Zurich East CDE below 6,500 ft MSL. This means that IFR approach routes cross routes that are also used intensively by VFR pilots.
Recommendations for VFR pilots
1. establish listening readiness
Even if there is no obligation to do so, the voluntary willingness to listen significantly improves the probability of timely traffic information. Mode S transponders immediately show the ATCOs the callsign, altitude and direction of flight.
2. keep an eye on IFR approach routes
A look at the IFR charts or corresponding apps helps to understand where IFR aircraft are guided. However, STARs, SIDs and routes are not always binding. Direct-to instructions or vectoring are common and should be taken into account in your own situational awareness.
3. particularly attentive on or near the extended centre line
Anyone crossing the extended centreline of EDNY or LSZR is potentially in the flight path of an IFR aircraft descending or climbing.
4. observe the semicircle rule for vertical equalisation
By adhering to the semi-circle rule, 500 ft of vertical separation is created, which often provides the decisive safety gain.
5. take the importance of cloud clearances seriously
IFR crews must use see-and-avoid outside of clouds. However, the visual scan of the airspace takes up to 20 seconds. At typical GA speeds, this means that more than 1.5 km are travelled over ground in this time.
Large vertical and horizontal distances to clouds increase the chance that IFR crews will recognise VFR traffic in good time.
Recommendations for IFR pilots
1. actively plan VFR traffic
The ICAO VFR chart shows that almost all gliding and powered flight activities are concentrated in the area of TMZ NE. In the vicinity of the two airports, particular attention must be paid to:
- intensive weekend motorised flight activity
- Gliding to well over 7,000 ft in thermals
- Skydiving operations (partly without transponder)
- Hang gliders on thermally active days
2. do not expect staggering by the ATC
In Airspace E there is no separation between IFR and VFR granted by ATC. Traffic instructions are helpful, but do not replace see-and-avoid.
3. SERA evasion rules are universal
IFR pilots also have no „right of way“. Avoidance behaviour follows the SERA rules - regardless of whether a flight is conducted under IFR or VFR.
4. react flexibly in the event of imminent convergence
The PIC is obliged to intervene if a conflict arises - even if you are in procedure or under radar control. Safety comes before procedure.
Additional information from the practice of other European TMZs
Experience from TMZs in Germany, Austria and the south of France has shown this:
- The most frequent AIRPROX messages occur when crossing the extended centreline.
- Many conflicts are caused by late frequency changes.
- Pilots often underestimate how far IFR traffic has to go sideways to avoid the weather.
- The most efficient safety gains are achieved by consistently using Mode S transponders and listening readiness, even if this is not mandatory.
These patterns are very similar to those observed in eastern Switzerland.
Conclusion
The TMZ North-East fulfils an important task, but can only achieve its full potential if pilots actively contribute to traffic safety. VFR and IFR traffic share the same airspace - often at low altitudes and in the immediate vicinity of busy approach routes. Good preparation, in-depth knowledge of IFR procedures, consistent use of the transponder and a high level of attentiveness in the cockpit remain the cornerstones of safe flight behaviour. Every measure to increase situational awareness, whether through radio contact, map study or collision warning systems, significantly increases safety in a dynamic and demanding airspace such as the TMZ NE.
Source references:
Staysafe.aero
