Even more exciting was the harbour turn -permitted into the early 1970s,- involving a letdown onto 31 followed by a break off to the left once through the Lai Mun gap and then a right hand 180 circling approach around the harbour over Central on the island, rejoining the normal 13 approach over Kowloon before the chequer board after Stonecutters. It was this which was responsible for building height restrictions on the north side of HK island and southern Kowloon until at least the mid 70s. Air New Zealand DC8s used this out of choice, maybe to retain recency, and Qantas operated a 707 training flight of about 2 hours duration during a scheduled turnaround about once a month doing repeated circuits and touch and gos on a pattern of 13 departures and arrivals via a 31 letdown, interrupted at intervals by normal scheduled movements which were much less numerous then.