The RMZ Donaueschingen, upper limit 1000 ft AGL, is located in airspace G (uncontrolled airspace) according to aviation law. The RMZ is valid 24 hours a day, 365 days a year, regardless of weather conditions.
Above 1000 ft AGL, it is joined by controlled airspace E.
The purpose of this flight operations regulation is to avoid midair collisions and thereby increase safety.
entry into and exit from the RMZ must be reported on frequency 126.690, and constant monitoring must be maintained within the RMZ.
In general, you should stay tuned to the frequency in the vicinity of the airfield or even during overflights at higher altitudes in order to learn of any IFR or VFR traffic in time.