Riding Icarus by Lily Hyde

When the abandoned trolley-bus in which Masha lives with her grandmother takes flight one night, like Dorothy's house in Kansas, it is only the start of her strange adventures in even stranger lands. Witches and giants, magic and riddles all combine to make this a wonderful fairy tale for older children, in which Masha must rescue her mother and find out the secret to living happily ever after.

Synopsis by Foyles.co.uk

This is a magical modern fairytale set in Kiev, featuring a girl called Masha who lives in a flying trolleybus called Icarus.When rich Uncle Igor sends her mother abroad to work, Masha stays in Kiev and moves into an old, disused trolleybus called Icarus. But one night there is a terrible storm and Icarus takes off! Masha is transported to an enchanted place where she discovers that, on midsummer eve, she will be able to wish for whatever her heart desires. But will Masha be able to find the enchanted place again and work out her heart's desire in time? And will she make the right wish to bring her mother back home so they can escape Igor's clutches for ever?