In civil aviation nowadays the trend is toward increasingly sustainable aircraft navigation. Initiatives such as the ¨Single European Sky¨ have endorsed this goal, shared by both the majority of the states of our continent and by its airlines. But there are contingencies that sometimes prevent the most logical route from being flown. Among them are a select few areas where civilian aircraft are excluded: the so-called ¨no-fly zones¨ (abbreviated NFZ).
Reasons for prohibiting commercial civil aviation in a given area are varied. And while usually it´s a particular country which enforces these zones (as stipulated in Article 9 of the International Civil Aviation Convention, occasionally there may be third parties involved. Article 9 stipulates:
¨Each Contracting State may, for reasons of military necessity or public security, uniformly restrict or prohibit the flights of the aircraft of other States over certain areas of its territory, provided that no distinction is made in this respect between the aircraft of the State of whose territory concerned, that are used in scheduled international air services, and the aircraft of the other contracting States that are used in similar services. Said prohibited areas must be of reasonable size and location, so as not to unnecessarily hinder air navigation. The description of such prohibited areas situated in the territory of a Contracting State and all subsequent modifications shall be communicated as soon as possible to the other Contracting States and to the International Civil Aviation Organization.¨
Therefore, there are certain rules when setting a no-fly zone:
- That said restriction equally affects the aircraft of the country itself and foreign ones.
- That they are not excessive in size or location.
- That this new situation be communicated as soon as possible to the relevant organisations..
Of course, the airspace, as an area belonging to the country in question, is governed by the principle of national sovereignty, so apart from exceptions we´ll get into below, each national government to decide how to apply it.
Reasons for Establishing a No-Fly Zone
First and foremost, the main reason is some form of national security, for example in cases of war or risk of terrorist attack. It is about protecting both the citizens who live under that space and those who fly over it. But there may also be other reasons of a military nature (pilot training, for example) and even ecological reasons (protecting a certain area from carbon emissions) or protection of an area that´s important for the national heritage.
Several examples in the case of Spain:
- Aircraft cannot fly over the Madrid´s Oriente Royal Palace or the adjacent Campo del Moro gardens below 1,220 meters (just over 4,000 feet), for reasons of heritage preservation.
- For security reasons, there are NFZs of 1,000 to 1,800m (3,280-5,905 ft.) over Spain´s five nuclear power plants.
- For environmental reasons – to protect local flora and fauna – over some national parks and natural areas such as Catalonia´s Ebro Delta, the marshes of Huelva in Andalusia, Toledo´s Cabañeros National Park, and Taburiente Caldera National Park on La Palma in the Canary Islands.
In addition, a no-fly zone imposed by an outside party (such as NATO) against countries even against their will may be due, times of conflict, to the fact that they´ve tried to use air assets to attack the civilian population, or are impeding humanitarian aid being flown in. These cases are often (but not always) sanctioned by the United Nations Security Council which holds that guaranteeing peace or the well-being of civilians takes precedence over national sovereignty.
No-fly zones first came into play after the end of the Cold War, with prominent examples including that of the United States against Saddam Hussein´s Iraq in 1990-91, over Bosnia and Herzegovina in 1993-94, and Libya in 2011 and 2018-19. Last year, a NATO-enforced NFZ was considered for Ukraine but discarded as being too risky.
The 3 Types of No-Fly Zones
As classified by Spain´s civil aviation authority Enaire:
- P – Areas prohibited to commercial flights but permitted to the armed forces.
- R – Restricted areas, which cannot be overflown over except in emergency situations or by special permit.
- D – Dangerous areas. In these cases, if it´s a temporarily restricted area, pilots will receive instructions in their flight plans as to when the events will take place which make it impossible for the aircraft to cross that airspace (for example, a volcanic eruption).
In addition, certain local areas and facilities may impose no-fly zones specifically for drones.