MC2A The Northrop Grumman E-10 MC2A was to be a 767-400ER-based replacement for the USAF's 707-based E-3 Sentry AWACS, E-8 Joint STARS , and RC-135 SIGINT aircraft. [ 154 ] The E-10 MC2A would have included an all-new AWACS system, with a powerful Active Electronically Scanned Array (AESA) that was also