Ten of them flying wing-tip to wing-tip would cover the length of one Olympic pool, or just over two standard tennis courts:

The five-million-year-old bone from a sandstone boulder on the beach at Beaumaris, about 20km southeast of Melbourne, is the first pelagornis fossil found in Australia.
Senior curator of vertebrate palaeontology, Dr Erich Fitzgerald, said the bone belonged to the same species of pelagornis previously found in France, Morocco and Chile.
“Our pelagornis bone is similar in size to that of the pelagornis from Chile, which had a wingspan of at least five metres,” he said.
“That is twice the size of the largest albatross alive today. So, we now know that there were once birds with teeth soaring over coastal Victoria with a wingspan greater than the length of a Toyota LandCruiser.”