E-3 sentry

[Barambilla]

Yesterday, 2009-01-28 I saw a E-3 Sentry Awacs circling to the east of my location (Vosselaar/ Turnhout). I could identify the plane in binoculars. sorry, no pics... The plane made frequent tours in a relatively large (but completely visible) circle, over a long span of time. Does anybody have an idea about which plane and what would have been its task. Nato-excercise? thx

[AirBozz]

thats what an AWACS does 8 hours long
it was at FL290...