Geilenkirchen (German pronunciation) is a town in the district Heinsberg, in North Rhine-Westphalia, Germany. It is situated near the border with the Netherlands, on the river Wurm, approx. 15 km north-east of Heerlen and 20 km north of Aachen. It was the site of Operation Clipper in November 1944. The town gives its name to nearby NATO Air Base Geilenkirchen. The base is home to 17 E-3A airborne early warning and control aircraft manned by crews from 14 nations.