Originally Posted by
neville_nobody
Probably someone in CASA trying to score points by getting them to publish the bleeding obvious on the charts. It is referencing the AIP and the change in transition level with the QNH. The issue is a moot point, as how many times a year will you see a QNH sub 980, which is what you would need for a FL120 Transition Level.
You say that, but then a few years ago ATRs (I think it was) got grounded because they didn't have performace charts for +40 degree temps. While it may be rare, putting this little bit of info on a chart saves some embarrassment when it does happen.