The German Aerospace Center (DLR) operates a fleet of specialized research aircraft through its Flight Operations Facilities in Braunschweig and Oberpfaffenhofen. The Dornier DO-228 is used for applications including Earth observation, atmospheric research, and flight testing. The purpose of this tender is to select a qualified and reliable service provider for spare parts supply and minor maintenance tasks on the DO-228 fleet in compliance with European and national aviation regulations as well as DLR’s internal operational standards. The DO-228 fleet includes:  D-CEFD / Oberpfaffenhofen, Germany  D-CFFU / Oberpfaffenhofen, Germany  D-CODE / Braunschweig, Germany