Aeroplane - airplane
aeroplane is the traditional British spelling - and pronunciation. (It has three syllables - 'AIR-oh-plane' IPA: /ˈeər əʊ pleɪn/.) The US version airplane has only two syllables: /ˈeər pleɪn/. (There was an attempt in 1928 to have the BBC adopt the form airplane instead of aeroplane (Broadcast English I. 21), but it failed to win acceptance - as did a pronunciation of four syllables, 'airy-oh-plane' /ˈeər ɪ əʊ pleɪn/.)
Aviation professionals dislike the abbreviation plane. They are taught (at least in Britain) to say aircraft, which may be the easiest solution to any problems you find with this word.
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