The Northrop Grumman E-10 MC2A was planned as a multi-role military aircraft to replace the Boeing 707-based E-3 Sentry and E-8 Joint STARS, the Boeing 747-based E-4B, and the RC-135 Rivet Joint aircraft in US military service. The E-10 was based on the Boeing 767-400ER commercial airplane. Development In 2003, the Northrop Grumman, Boeing, and Raytheon MC2A team was awarded a $215 million contract for pre-SDD (System Development and Demonstration) development of the aircraft. MC2A is an acronym for Multi-Sensor Command and Control Aircraft. The MC2A was intended to be the ultimate theater-wide combat control center. While the Northrop Grumman E-8 Joint STARS aircraft was a recent development, it is the last such type based on the 707. Installing the high technology systems envisaged for the MC2A on an increasingly obsolete airframe would not provide the capability required. The availability of powerful and reliable turbofans allowed a twinjet to be considered. In August 2003, Air International reported that the goal of integrating air- and ground-search radars on a single airframe was abandoned. Electronic interference between the active electronically scanned array (AESA) and ground-surveillance radars as well as the power requirements for both systems were cited as the reason. Instead the USAF decided to plan two separate E-10 fleets to be integrated with the proposed space-based radar system, air- and space-based ELINT/SIGINT assets, and space-based IMINT satellites. It would have been the central command authority for all air, land, and sea forces in a combat theater. The E-10 was also considered for use as a command center for unmanned combat air vehicles. The capability of the MC2A was to be raised incrementally, with each phase known as a "spiral". Spiral 1 Multi-Platform Radar Technology Insertion Program (MP-RTIP): This version would have provided substantial Joint Cruise Missile Defense (CMD) capability with focused AMTI modes and augment the E-8 Joint STARS in the ground surveillance role. Spiral 2 AWACS Capability: This version would have replaced the E-3. It was expected that the Spiral 2 version would use a variant of the Boeing Wedgetail's Multi-role Electronically Scanned Array. Spiral 3 SIGINT Platform: This version was intended to replace a wide range of SIGINT/ELINT aircraft. Beyond conceptual studies and preliminary research, this version was not being actively designed. Scale-back and cancellation In January 2006, the Air Force FY07 budget request revealed a reshaping of the E-10 program with the cancellation of the SDD program. Funding