Initially, the E-3 Sentry airborne warning and control system aircraft was considered to be the prime candidate for the airborne early warning mission by the JASDF. However, the Japanese Defense Agency realized that the E-3 would not be readily available due to USAF needs and opted to procure E-2 Hawkeye aircraft. The Japan Air Self-Defense Force bought thirteen E-2C aircraft to improve its early warning capabilities. The E-2C was put into service with the Airborne Early Warning Group (AEWG) at Misawa Air Base in January 1987.