With just two helicopters, both located in the western part of the country, it was difficult to provide adequate national coverage. This led to efforts to expand the HEMS (helicopter emergency medical services) operation. In 1998, the Dutch Ministry of Health, Welfare and Sport (VWS) committed to supporting the continuation of the service. Meanwhile, ANWB MAA established agreements with the 11 designated trauma centers across the Netherlands, enabling the helicopters to land there. In 2004, the first five brand- new Eurocopter EC135 helicopters were delivered, replacing the older MBB Bö 105s. At the same time, two new permanent bases were opened: at Volkel Air Base (Lifeliner 3), where the medical crew was provided by Radboud University Medical Center in Nijmegen, and at Groningen Airport Eelde (Lifeliner 4), staffed by medical personnel from the University Medical Center Groningen (UMCG). With the arrival of the EC135s, night-flight testing also began. Following an extensive training and evaluation phase, the Ministry of Health approved 24-hour trauma helicopter operations by ANWB MAA in 2011.