Originally Posted by
Stretch06
Except when the airlines don't need it for weather and still opt to use it because of fuel efficiencies, or because it is more precise than an RNAV.
If it is only going to be used on the days when the weather really warrants its use, why not leave the airspace as is, and then have a NOTAM for the 30 days a year. Similar to a Temp Restricted Airspace setup.
There are no efficiency gains for the airlines from a 34 GLS. It is merely a more accurate approach allowing a lower minima. When 34 is in use, it is rare that a lower minima is useful, it’s usually CAVOK, excepting occasional heavy rain.
It is, however, a safer approach. From memory, in recent years, Singair have royally screwed up an RNAV onto 34, and VOZ screwed up a visual from over Essendon. There are threads about both these incidents on this forum - both 777’s I think, and both descended way below profile. I think the Singair was at 900 feet at 10NM so at least they were under the lane
I would imagine that most GLS profiles will follow exactly the same path as the RNAV. That is, a continuous descent via the STAR onto final. This would mean no change to current jet altitudes over the lane. However the GLS (unlike the RNAV) allows ATC discretion to vector onto the approach at a lower altitude. They may do this occasionally to optimise arrival rates, but I wouldn’t expect it to be the norm. So I wouldn’t be too worried about wake turbulence.
As to CASA’s poor form in communication, no argument there. They’ve known this was coming for a couple of years now.