Airspace infringements – aircraft entering areas they are not authorised to be in – are a key safety issue for LVNL. Such incidents pose a substantial risk to both recreational and commercial traffic.
What is an airspace infringement?
Internationally, an airspace infringement is defined as follows.
“A flight into notified airspace without previously requesting and obtaining approval from the controlling authority of that airspace in accordance with international and national regulations.”
Both the civilian and the military air traffic control services report all airspace infringements to the Aviation Incidents Analysis Bureau (Analysebureau Luchtvaartvoorvallen) at the Human Environment and Transport Inspectorate (Inspectie voor Leefomgeving en Transport, ILT).
A total of 1,565 infringements were recorded in civilian airspace between 1 January 2010 and 31 December 2016. In 59 of these cases, there was a substantive risk to operational flight safety. A clear peak is observed in the summer season, when a relatively high volume of recreational air traffic uses Dutch skies.
Infringements are reported from all areas of notified airspace, but the majority occur in the vicinity of Amsterdam Schiphol Airport and Maastricht Aachen Airport.
Amsterdam Schiphol Airport
A substantial amount of recreational traffic uses airspace close to Schiphol in the summer, particularly along the North Sea coast. There are also training and local flights over the provinces of Flevoland and Noord-Holland, originating at Lelystad Airport. And the northbound air corridor from Rotterdam via the IJsselmeer lake passes close to Schiphol’s restricted airspace, too.
Most of the incidents in this region involve recreational flights unintentionally entering the airport’s approach zone, particularly due to carelessness with altitude. The lower boundary of the approach zone is 1500 feet, whilst the majority of recreational traffic flies at between 1200 and 1500 feet – that is, within just 300 feet of that boundary. It therefore only takes a minor deviation from the planned flight level to penetrate the zone from below. Common causes include updraughts – a frequent occurrence in the summer months – steering errors and incorrectly calibrated altimeters.
A safety risk arises when there is also low-flying commercial traffic in the vicinity. And because Schiphol is one of Europe’s busiest airports, with between 106 and 110 movements per hour, there is a real danger that an infringement of its airspace could compromise safety.
Maastricht Aachen Airport
Most infringements in the vicinity of Maastricht Aachen Airport are caused by the relative complexity of the airspace in the area. East-west and west-east flights between Germany and Belgium frequently forget to contact air traffic control in Maastricht when crossing the narrow strip of Dutch territory separating them. In other cases, careless navigation results in an aircraft briefly entering the Maastricht control zone.
A total of 518 infringements were recorded around Maastricht Aachen Airport between 1 January 2010 and 31 December 2016. Again, these are more common in the summer season than in the winter.
Research shows that there are various underlying causes of airspace infringements.
Inadequate flight preparation.
Use of outdated navigation charts.
Use of an outdated navigation database.
Navigational errors or loss of situational awareness.
Excessive pressure of work in the cockpit.
Inadequate access to information.
Inexpert use of radiotelephony.
Prevention is better than cure
In the National Airspace infringements Working Group the problem of airspace infringements is periodically discussed and are measures developed. As well as members from the ministry and LVNL, this includes representatives of the Aircraft Owners and Pilots Association Netherlands (AOPA), the Royal Netherlands Aeronautical Association (Koninklijke Nederlandse Vereniging voor Luchtvaart, KNVvL), the Human Environment and Transport Inspectorate (Inspectie Leefomgeving en Transport, ILT), Royal Netherlands Air Force High Command (Commando Luchtstrijdkrachten, CLSK), the Aviation Section of National Police Services Agency (Korps Landelijke Politiediensten, KLPD), the Dutch Civil Airports Association (Nederlandse Vereniging van Luchthavens, NVL), the Netherlands Association of Commercial Aviation (NACA), the Royal Netherlands Meteorological Institute (Koninklijk Nederlands Meteorologisch Instituut, KNMI) and the National Aerospace Laboratory (Nationaal Lucht- en Ruimtevaartcentrum, NLR).
In recent years, the following measures have been taken
Regular reports and trend analyses from the Aviation Incidents Analysis Bureau (Analysebureau Luchtvaartvoorvallen).
Harmonisation of reporting protocols for civilian and military air traffic control organisations.
Assessment of European recommendations.
Active communications targeting recreational pilots.
Compilation of an enforcement covenant, with both preventive and reactive components.
Combining aeronautical information from LVNL and the KNMI on the LVNL website.
Advice to monitor the flight information frequency when flying below Schiphol airspace.
Rezoning of the airspace around Maastricht Aachen Airport.
Compilation of a code of conduct for recreational avaiation.
Reassessment of training requirements.
Development of technological support facilities.
After the downward trend that was seen from 2010, in 2016, the number of reported airspace infringements rose once more for the first time. All of the parties must have a proactive attitude, linked to structural improvements, to manage this safety risk.