New regulations for several regional airports
The notice applies to air traffic control at airports managed by DFS Aviation Services: Dortmund, Friedrichshafen, Karlsruhe/Baden-Baden, Niederrhein (Weeze), Mönchengladbach, Memmingen, Lahr, Paderborn, and Braunschweig. It replaces the previous regulation from 2024 and consolidates all procedures for low-visibility operations and the protection of instrument landing systems in an updated version.
While many pilots primarily associate the term „Low Visibility Procedures“ with CAT-II or CAT-III approaches, LVPs actually govern much more. They affect the entire ground and approach operations of an airport, dictating how aircraft, vehicles, and people may be moved once visibility deteriorates.
LVP are already starting earlier than many pilots suspect
One of the most important statements in the new announcement concerns the time at which the procedures are prepared or activated.
Even with a Runway Visual Range (RVR) of 1,000 metres or less or a main cloud base or vertical visibility of 300 feet or less Initial preparations are being initiated. These include, among other things, ensuring the readiness of the emergency power supply for approach lighting, as well as keeping the so-called sensitive and critical areas of the instrument landing system completely clear.
The actual operation in low visibility at affected airports generally begins at an RVR of 600 metres or less or a cloud base below 200 feet. This means the practical threshold is deliberately set above the actual definition of Low Visibility Operations according to ICAO, in order to enable a stable and safe transition to LVP operations.
What will change at the airport during LVP
Once the procedures are activated, the entire operation at the airfield changes.
Depending on the equipment, additional lighting systems are activated. These include, among others, runway centreline lighting, taxiway centreline lights, red stop bars and other special ground lighting. At the same time, other systems, such as certain glide path lights or EFAS systems, are switched off. The aim is to provide pilots with the clearest possible visual guidance in poor visibility conditions.
The movements of vehicles and ground personnel will also be considerably restricted. Only absolutely essential vehicles will be permitted to move on the apron and must maintain constant radio contact.
Protection of ILS signals receives high priority
A key focus of the new announcement is the protection of instrument landing systems.
While many pilots know that vehicles or aircraft must not be present in certain areas adjacent to the runway during a precision approach, it is less widely understood why this is necessary.
Metallic objects in close proximity to ILS aerials can affect the broadcast radio fields. Even small signal changes can lead to deviations in lateral or vertical guidance, particularly during CAT II and CAT III approaches.
For this reason, the DFS continues to differentiate between Sensitive areas and Critical Areas.
Under specific visibility conditions, special separation is applied as early as two nautical miles before the runway threshold so that aircraft taxiing or taking off do not affect the ILS signals. During LVP, Critical Areas must be clear no later than when the next approaching aircraft is four nautical miles from the touchdown point. If this is not possible, a go-around may be necessary.
Guard rails must never be overridden without authorisation.
Another important topic concerns the red stop bars.
Illuminated stop bars have the same meaning as a stop signal in road traffic. They must never be driven over without express permission.
If a pilot, despite receiving taxiing clearance, notices that a stop bar is still illuminated, they must stop before the bar and inform the Tower. Further clearance may only be issued after the situation has been appropriately checked. If a stop bar cannot be switched off due to a technical fault, it may only be crossed under the guidance of a Follow-Me vehicle.
New clarity for CAT-II and CAT-III approaches
The announcement also describes in detail the conditions under which precision approaches must be downgraded.
These include, among others:
- Failures of ILS components,
- Interference with GBAS systems,
- Sensitive or Critical Areas,
- Failures of individual RVR measuring points,
- Limitations of ground lighting,
- Failures of wind measurement systems,
- as well as various technical surveillance devices.
Depending on the type of failure, a CAT III approach may be downgraded to CAT II or CAT I, or it may be necessary to switch to another published instrument approach procedure. The notice contains extensive tables with the respective downgrading criteria.
Automatic landings only under defined conditions
A particularly interesting section concerns automatic landings (Autoland).
The DFS clarifies that the required signal quality for Autoland is only guaranteed if the procedures for CAT II or CAT III have been officially notified as being in operation and there are no technical restrictions.
Should the ILS signal be sufficient for a normal CAT II or CAT III approach, but not possess the necessary quality for automatic landings, pilots will be explicitly informed via ATIS, NOTAM, or radio communication with the message „ILS SIGNAL NOT USABLE FOR AUTOLAND“ Informed.
Impacts on Private Pilots
For most private pilots, there will be no immediate changes in daily flight operations.
Nevertheless, the new procedures are worth a look.
Anyone who flies IFR regularly or travels to one of the affected airports will increasingly hear corresponding ATIS messages in future and notice that ground traffic, taxi clearances, and separations will be significantly more conservative during LVPs.
Even pilots of modern aircraft with autopilot or autoland functions will gain more transparency from the new notice regarding when the required signal quality is actually ensured.
Conclusion
The new notice from DFS Aviation Services modernises procedures for low-visibility flight operations and clearly consolidises numerous regulations that were previously distributed. In terms of content, the focus is primarily on the early protection of ILS systems, clear criteria for activating low-visibility procedures, and detailed specifications for CAT-II, CAT-III, and autoland operations.
For IFR pilots, this primarily means more transparency and standardised procedures at the affected airports. VFR pilots, in turn, will gain a better understanding of why airport operations often change significantly long before the actual weather minima are reached in poor visibility.
Source references:
NFL
