Sir, I recall that the new London airport study of several years ago considered at least two Thames estuary sites (letter, Apr 4). These were dismissed as potentially dangerous to approaching and departing aircraft owing to the risk of bird strikes in that vicinity. Except for the exemplary airmanship of the captain, the airliner ditching in the Hudson River in 2009 could have been just such a disaster brought about by bird strike. Has the bird population of the Thames estuary altered in recent years?
Peter Fraser
Baughurst, Hants