Boeing E-3B / E-3C Sentry

The USAF ordered 34 Sentries, but only the first 24 were completed as E-3As; the final batch was delivered as E-3Cs. These ten new aircraft, delivered between 1981 and 1984, introduced the AN/APY-2 radar with an added maritime surveillance capability, more mission consoles and further system improvements. The 24 original 'core' E-3As were then modified to E-3B standard with improved computing and communications, giving the USAF a fleet of two closely related versions.

Both models were later updated together under the Block 30/35 programme, which added electronic support measures to identify emitters, GPS navigation and the JTIDS/Link 16 data link. From Tinker AFB, Oklahoma, the 552nd Air Control Wing deployed the aircraft worldwide, alongside units at Elmendorf in Alaska and Kadena in Japan.

Externally the E-3B and E-3C are almost indistinguishable from the E-3A — the differences are inside the cabin. From 2014 surviving aircraft of both versions began conversion to the E-3G Block 40/45 standard, while older airframes were retired.