It was decided to pursue a full certification program, resulting in the production of two pre-production prototypes; at the same time, it was chosen to give the Bo 108 a new designation of EC135 to correspond with the newly created Eurocopter company.
Decidíuse buscar un programa completo de certificación construíndose dous prototipos de preprodución; ao mesmo tempo decidíuse darlle ao Bo 108 a nova designación de EC135 para corresponderse coa recentemente creada Eurocopter.