 The Block 40/45 upgrade is the most extensive the E-3 has undergone, replacing its 1970s computer technology with an early 2000s standard and including a deployable ground system that receives, processes, and disseminates data.The Air Force plans to convert 24 AWACS to E-3G standard, while retiring seven from the fleet to avoid upgrade costs and harvest out-of-production components.E-3s have been involved in three hull-loss accidents, and one radar antenna was destroyed during RSIP development (see photo under Avionics).