Oh this old chestnut....I recall having an hour long discussion with a checkie in a sim debrief on this very topic. He was adamant I was incorrect in saying "leaving". It is in the aip as an example phrase including the word "leaving". Even showing said checkie the page he still did not accept it and even proceeded to email me a month later asking if I had found any further evidence of correct terminology. Suffice to say I had better things to do with my time. Its leaving!!!