Christchurch Departures
Appreciate your reply. My feeling on the matter tends towards your second reason, that ATC might specify for traffic separation purposes. I have heard pilots question the need to go in the opposite direction, which in this case is towards Woodend near the eastern seaboard, then track northwest, before heading on a more westerly course. This example relates to International flights to Australia and Singapore. It has been interesting to observe that QF flights using 767's and 747's, do not appear to have to reach Woodend, whereas, invariably SQ flight 298, (which has used 747's and A340's and latterly the 777), does. Could it be that ATC over-utilises the air space, considering it is far from congested. While this emphasises larger safety margins which is to be applauded, might it also mean that it makes life easier for ATC but annoying for long haul pilots. The extra distance would seem to involve an extra 15 to 20 minutes of flight time which does not sound a lot yet seems avoidable and unnecessary.