W2F-1 Original designation of the Hawkeye, changed to E-2A in 1962. E-2A Initial production version, was W2F-1 before 1962. 59 built. TE-2A Two E-2As converted as crew trainers. YC-2A Two E-2As, BUNOs 148147 and 148148, converted as prototypes of the C-2 Greyhound E-2B As E-2A but fitted with improved computing, enlarged outer fins. 52 converted from E-2A. YE-2C Two E-2As, BUNOs 148712 and 148713, converted as E-2C prototypes. Designated as YE-2C and NE-2C respectively. These airframes then finished out their useful life being used as TE-2C pilot trainers. E-2C As the E-2B but with all new electronics, surveillance radar and search radar, 63 built. In "plus-models" the E-2C also has upgraded turboprop engines. E-2C Group 0 Initial production version of E-2C, fitted with AN/APS-120 or AN/APS-125 radar. Lengthened nose compared to earlier versionsGodfrey 1977, pp. 9–10.Jackson 2003, p. 687. E-2C Group I New radar (AN/APS-139), plus upgraded mission computer and upgraded engines. 18 new build aircraft.Winchester Air International December 2005, p. 47. E-2C Group 2 AN/APS-145 radar, further improved electronics. E-2C Group 2 Plus (Nav Upgrade) Avionics upgrade, inclusion of GPS into weapon system. E-2C Hawkeye 2000 New mission computer, Cooperative Engagement Capability (CEC) and additional satellite communications aerial. Originally designated Group 2+. E-2D A variant with new avionics suite, improved engines, a new "glass cockpit" and the potential for air-to-air refueling. E-2T/K E-2C variant for Republic of China (Taiwan), with parts taken from retired E-2Bs (USN BuNos 151709, 151710, 151724, 152479). However, these aircraft have the same level of electronics as the E-2C Group II Hawkeyes with their APS-145 radars and are referred to as E-2T, with "T" standing for Taiwan. On July 31, 1999, Taiwan was approved to acquire two additional E-2s built to Hawkeye 2000 standard. Later, the four original E-2Ts were also upgraded to the same standard. The upgraded aircraft were referred to as E-2Ks.
W2F-1 Original designation of the Hawkeye, changed to E-2A in 1962. E-2A Initial production version, was W2F-1 before 1962. 59 built. TE-2A Two E-2As converted as crew trainers. YC-2A Two E-2As BUNOs 148147 and 148148, converted as prototypes of the C-2 Greyhound E-2B As E-2A but fitted with improved computing, enlarged outer fins. 52 converted from E-2A. YE-2C Two E-2As, BUNOs 148712 and 148713, converted as E-2C prototypes. Designated as YE-2C and NE-2C respectively. These airframes then finished out their useful life being used as TE-2C pilot trainers. E-2C As the E-2B but with all new electronics, surveillance radar and search radar, 63 built. In "plus-models" the E-2C also has upgraded turboprop engines. E-2C Group 0 Initial production version of E-2C, fitted with AN/APS-120 or AN/APS-125 radar. Lengthened nose compared to earlier versionsGodfrey 1977, pp. 9–10.Jackson 2003, p. 687. E-2C Group I New radar (AN/APS-139), plus upgraded mission computer and upgraded engines. 18 new build aircraft.Winchester Air International December 2005, p. 47. E-2C Group 2 AN/APS-145 radar, further improved electronics. E-2C Group 2 Plus (Nav Upgrade) Avionics upgrade, inclusion of GPS into weapon system. E-2C Hawkeye 2000 New mission computer, Cooperative Engagement Capability (CEC) and additional satellite communications aerial. Originally designated Group 2+. E-2D A variant with new avionics suite, improved engines, a new "glass cockpit" and the potential for air-to-air refueling. E-2T/K E-2C variant for Republic of China (Taiwan), with parts taken from retired E-2Bs (USN BuNos 151709, 151710, 151724, 152479). However, these aircraft have the same level of electronics as the E-2C Group II Hawkeyes with their APS-145 radars and are referred to as E-2T, with "T" standing for Taiwan. On July 31, 1999, Taiwan was approved to acquire two additional E-2s built to Hawkeye 2000 standard. Later, the four original E-2Ts were also upgraded to the same standard. The upgraded aircraft were referred to as E-2Ks.