A NATO E-3A AWACS plane will fly over Romanian airspace as part of a planned exercise on Tuesday, Romania's defence ministry said, according to Reuters. NATO had said AWACS (airborne early warning and control) planes will fly from their home airbases in Geilenkirchen, Germany, and Waddington in Britain. The Romanian ministry said AWACS planes fly at an altitude of 9,000 metres (5.6 miles), their radar can survey an area of up to 312,000 square kilometres and can detect low-flying targets. The NATO alliance said on Monday it will start reconnaissance flights over Poland and Romania to monitor the situation in neighbouring Ukraine where Russian forces have taken control of Crimea.