The speed of flight is divided into four groups based on speed.
ð ə WORD_BOUNDARY s p iː d WORD_BOUNDARY ʌ v WORD_BOUNDARY f l aɪ t WORD_BOUNDARY ɪ z WORD_BOUNDARY d ɪ v aɪ d ɪ d WORD_BOUNDARY ɪ n t ʊ WORD_BOUNDARY f ɔ ɹ WORD_BOUNDARY ɡ ɹ uː p s WORD_BOUNDARY b eɪ s t WORD_BOUNDARY ɔ n WORD_BOUNDARY s p iː d WORD_BOUNDARY