Counter-drone operations in Austria: the conditions under which the Bundesheer may intervene

As drones are increasingly seen as a threat, Austria too is asking ever more often when and how the Austrian Armed Forces (Bundesheer) can actually be called upon for counter-drone defence. The Ministry of Defence has now published information on this.

Legal basis for counter-drone defence

If aircraft or drones use Austrian airspace without authorisation, military airspace surveillance can act independently and with suitable means under Section 26 of the Military Powers Act (Militärbefugnisgesetz, MBG). This also applies when no “threat to the operational readiness of the Bundesheer” is involved.

Unlike crewed aircraft, a drone cannot be contacted directly. To establish its identity after unauthorised use of airspace, it must therefore usually be brought down deliberately. Under the Military Powers Act, this “bringing down” is permitted as part of the “direct exercise of coercive force against property”.

The principle of proportionality carries particular weight here, for instance to avoid collateral damage. Whether electronic or kinetic means are used to end the unauthorised use of airspace depends on the circumstances of each case.

Proportionality and limits

If unauthorised airspace use is ended immediately – for example by deliberately bringing down a drone to safeguard air sovereignty or the operational readiness of the Bundesheer – this must be indispensable and proportionate. Trivial cases are excluded, for instance when the drone is obviously harmless or the location and duration of the violation argue against it.

Use of weapons that endangers life – for instance against a “drone operator” – is only ever permitted in self-defence or defence of others to protect human life.

Cooperation with the Ministry of the Interior

As an “ultima ratio”, the Bundesheer could also provide a security-police assistance mission under Section 2 (1) (b) of the Defence Act 2001 (Wehrgesetz 2001, WG 2001). This requires that the competent security authority cannot handle a specific task with its own means or with other support mobilised at short notice. The drone flight must also be expected to constitute a criminal offence, for example a danger to life and limb.

In that case, the military forces deployed are subject solely to the rules governing the security executive, in particular the Security Police Act and the Use of Weapons Act 1969. If direct communication with the security police is no longer possible immediately before intervening, independent action may be taken under Art. 79 (5) of the Federal Constitutional Act (B-VG) – for example by the military pilot.