The Boeing E-3 Sentry is an American-built Airborne Early Warning and Control Systems (AWACS) aircraft used by NATO, the RAF, USAF, French Air Force and the Royal Saudi Air Force. Built on a Boeing 707 airliner airframe, it is easily recognised by the large rotating radar dome fitted above the fuselage just aft of the wings.
The first production E-3 began in October 1975, the first aircraft being delivered to the USAF in 1977, which eventually received 34 aircraft. NATO received 18 E-3s which were based in Germany. The RAF received 7 aircraft, four aircaft were delivered to France and Saudi Arabia received 5 E-3s as well as 8 tanker aircraft based on the E-3.
In RAF service the aircraft were designated Sentry AEW1 and are based at RAF Waddington in Lincolnshire, the RAFs ISTAR hub. The fleet of 7 aircraft were operated jointly by nos 8 and 23 Sqns with an OU (Operational Conversion Unit) designated No 54 and 56 Sqns. As there were seven aircraft, they were individually named after the dwarves from Snow White and the Seven Dwarves, following a tradition of no 8 Sqn which had previously named their 11 Avro Shackleton AEW aircraft after characters from the TV cartoon series 'The Magic Roundabout'.
ZH101 - DOC
ZH102 - DOPEY
ZH103 - HAPPY
ZH104 - SLEEPY
ZH105 - SNEEZY
ZH106 - GRUMPY
ZH107 - BASHFUL
The E-3 is scheduled to be replaced by another Boeing-based aircraft, the E-7 'Wedgetail', based on the Boeing 737-700, in the early 2020s.
The image shows ZH101 'Doc' departing RAF Coningsby in 2016.