Two large RAF Chinook helicopters were involved in low flying exercises over Falmouth and Truro last night.
The aircraft, from RAF Odiham in Hampshire, had come to the county for crew to train in instrument flying.
Because of low cloud and fog, they then landed at RNAS Culdrose overnight before returning to their base this morning.
A spokesman for Culdrose said there was nothing unusual in the exercise although residents in the Falmouth, Truro, Mawnan Smith area would have heard the familiar throbbing noise of the twin rotor aircraft at low level during the early evening.
Weather conditions in Cornwall were ideal for instrument training, said a spokesman.
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