Donaustahl

Donaustahl is a small Bavarian manufacturer at Hutthurm, near Passau, that builds loitering munitions, the avionics that fly them and the warheads they carry. It describes itself as an “offense-tech” company and defines itself against the pace of the established defence industry. Stefan Thumann, its founder, chief executive and chief designer, puts the ambition in one line: he does not want projects in a drawer, he wants products in a warehouse.

The system it is known for is the ALMP Maus, an adaptive loitering munition platform. Its distinguishing feature is unglamorous and deliberate: the airframe is made from specially treated wood rather than carbon fibre, which the company says cuts frame production cost by roughly 75%. The rest is conventional in the best sense — an effective combat radius of five to seven kilometres, a climb rate of 18 to 22 metres per second, a maximum payload of 2.7 kilograms, and infrared imaging so it can be flown at night. Modularity is the point of the “adaptive” label: the same platform takes a shaped-charge warhead for armour, a fragmentation load against infantry, or an anti-materiel fit.

Two further product lines sit behind it. The Combat Stack is UAV avionics designed to be assembled without soldering, which matters when airframes are built close to the front by people who are not electronics technicians. The Sonyashnyk family covers the warheads themselves: HEFRAG-2000 and HEFRAG-1100 fragmentation types, the HEAT-2000 for armour and the HEDEV-5000 class against structures. The company also lists the ALMP Ratte and ALMP Stryga alongside the Maus, and sells training drawn from operational use.

Germany’s economics ministry granted an export licence for the Maus in July 2024, under conditions, and the first deliveries went to Kraken, a special unit under Ukraine’s Main Directorate of Intelligence. Donaustahl has said it shipped a double-digit number of the platforms along with quick-release and ignition systems for PG-7 warheads. For a company of its size that licence is the notable part: it is a German firm cleared to export a weapon system directly to a Ukrainian intelligence formation.

That visibility appears to have carried a cost. In December 2025 Thumann was warned that Russia was planning to kill him, and he has lived in hiding since, moving every few weeks under constant protection. Two people described as low-level agents have been arrested. Bavaria’s interior ministry has confirmed it is aware of the case and declined to say more while federal prosecutors investigate. Nothing has been proven in court, and no Russian official has been charged.