Originally Posted by
George Glass
Sunny, see GreenGhost39’s post.
The rule that causes the grief at Sydney is the forecast maximum crosswind on 16/34. ATC goes to single runway ops. when the crosswind is nowhere near aircraft operating limits. In Melbourne a 21 knot southerly with a 6 knot tailwind on 27 will mean 45 minutes COBT delay plus airborne holding for a CBR-MEL flight. Given the magnitude of the mayhem these rules cause on a routine basis isn’t it possible that the rules are a horses ar#e? Maybe its just me.
We all know that the crosswind is nowhere near the aircraft operating limits (but may well be beyond the first officers operating limits, but that's another story for another day) however the rule-set is from CASA. Lobby CASA to get the rules changed.
One thing that has changed in the last 20-25 years is the increased use of wind analysers that accurately display the instantaneous, mean (2 minute average) and peak winds. Wind back 20 years, single anemometer and wind socks, there is a LOT more data available to the TWR ATCs. Perhaps there needs to be more education around the wording "including gusts" and how this relates to the instantaneous, mean and peak winds, which winds are used for which purpose.
For information, the RWY 34L anemometer is owned (and maintained) by the BoM and is the one recorded on the METAR and SPECI. There will often be major differences between this wind and the ATIS wind (for obvious reasons).
Also, COBT doesn't mean no holding, it should mean significantly less holding than a "free for all", the current rules around COBT do need changing and ACDM should result in better outcomes. Recent feedback provided by Industry to Airservices has resulted in an adjustment to have more aircraft airborne to "keep pressure on the system" to maximise throughput but always having aircraft in the pipeline.