Domhnal Slattery, the chief executive of Avolon, is stepping down from his role as leader of the aviation leasing giant. Slattery turned Avolon from a startup in Dublin into one of the world’s largest aircraft lessors in 12 years. Avolon’s chief financial officer Andy Cronin has been appointed chief executive designate and he will take on the role of chief executive by the end of this year. Slattery co-founded Avolon at the height of the last financial crisis and successfully turned it into the world’s third-largest aircraft lessor. Slattery’s departure, which is amicable, has been rumoured for some months. The…