The Eiffel Tower grew by six metres (20 feet) on Tuesday when vertigo-defying engineers fitted a new radio antenna on top of the Paris monument with the aid of a helicopter. The tallest building in Paris, known affectionately as the Iron Lady, measures 330 metres in height after the new addition. A smattering of tourists watched as the antenna was lowered into position on Tuesday morning, with the two engineers tasked with securing it to the structure barely visible from the ground. The new antenna will be used to transmit digital radio for the capital region. “It’s a moment of great pride, hi…