Ah! Swiped from Wiki, but I couldn't find who wrote it.
"The Wandering Albatross has the largest wingspan of any living bird, typically ranging from 2.51 to 3.5 m (8 ft 3 in to 11 ft 6 in), with a mean span of 3.1 m (10 ft 2 in) in the Bird Island, South Georgia colony and an average of exactly 3 m (9 ft 10 in) in 123 birds measured off the coast of Malabar, New South Wales. The longest-winged examples verified have been about 3.7 m (12 ft 2 in). Even larger examples have been claimed, with two giants reportedly measuring 4.22 m (13 ft 10 in) and 5.3 m (17 ft 5 in) but these reports remain unverified. As a result of its wingspan, it is capable of remaining in the air without beating its wings for several hours at a time (travelling 22 m for every metre of drop)."
Note the last sentence in parenthesis.
There is a second article that gives the same figure.