In this paper the requirements of the upgrade of a cockpit avionics display for a military rotary-wing platform will be presented. The use of open standards-based architectures including ARINC 653 and ARINC 661 with COTS hardware platforms to meet these requirements will be considered. Experience gained by the use of these technologies on a European military helicopter programme will be presented, including the benefits of modular and incremental safety certification and positive impact in reducing operational and through-life costs.