“Drones are not mosquitoes,” Estonia’s defense minister Hanno Pevkur noted recently, highlighting the sophistication of protecting modern airspace. That advice now cuts strongly in Denmark, where Aalborg Airport was compelled to shut for the second time in a week following large, unauthorized drones breaching its airspace. The incident interrupted civilian and military operations, with at least three incoming flights rerouted and several cancellations documented, FlightRadar24 reported.
National Police Commissioner Thorkild Fogde confirmed, “Once again, we have verified these objects violating the airspace over the airport as drones,” and said similar reports were made at three other Danish airports overnight, though only those at Aalborg were confirmed. The frequency and size of such intrusions indicate an able operator employing drones far beyond the capabilities and range of enthusiast models. Fogde added that destroying such drones is problematic: You need to have the means to take down the drones… without jeopardizing flight safety around the airport … and you have to take public security into consideration.
The challenge is in the technical realities of intercepting drones close to active runways. Slow-flying, low-altitude drones particularly those built from wood, fiberglass, or polystyrene may successfully elude standard radar calibrated for high-speed, metal-hulled aircraft. They become virtually indistinguishable from birds or small aircraft on radar displays. As exemplified by recent Russian drone intrusions into Poland, even NATO’s sophisticated detection networks failed to detect and track such intruders before they entered sensitive areas.
Airport counter-drone measures need a multi-layered approach: electro-optical sensors for seeing, radio frequency scanners to identify control signals, and electronic warfare systems that can jam communications without affecting airport functions. But jamming is not always effective some drones employ fiber-optic tethered control or autonomous flight, making them immune to signal disruption. Low-cost kinetic options, like mini-anti-drone missiles or interceptor drones, are being developed by European startups but still don’t have mass production on offer.
The Danish incidents follow increased European sensitivity. This month, Russian drones entered Polish and Romanian airspace, causing NATO allies to commit to beefed-up defenses. In Norway, the airspace of Oslo Airport was shut down for three hours following a distinct drone sighting. They identify what Lithuanian defense official Tomas Godliauskas describes as a “technology gap” in Europe’s capacity to counter unmanned aerial threats especially those from within national borders, evading customary perimeter defenses.
Aalborg’s status as an operational air base is yet another concern. Although officials would not report what military equipment was involved, the possible intelligence-collection or obstructionist intent of the drones cannot be ruled out. Two or three large drones brought all takeoffs and landings to a standstill in Copenhagen earlier this week, in what Prime Minister Mette Frederiksen called “the most severe attack on Danish infrastructure so far.”
The operational and economic effects of these closures are instant thousands of stranded passengers, delayed cargo schedules, and compromised military preparedness. The strategic effects, however, are more expansive: chronic, unretaliated incursions undermine public trust in airspace security and reveal chinks in critical infrastructure. As Pevkur cautioned, Europe requires technology that is good enough, it’s affordable and can be produced in mass to counter the scale of modern drone threats.
For security professionals in aviation, the Danish incidents highlight the need to combine high-tech detection equipment with quick-response interception systems. The new threat picture large drones operated by experienced pilots, able to stay on station over sensitive areas calls for answers that are technically solid and operationally secure in high-density civilian airspace. Absent such action, Europe’s airspaces above airports could remain open not only to passengers, but to chronic, high-tech penetrations.
