Melbourne Tullamarine variable transition level
 

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.

I can't find it on the DAP charts so perhaps it is not CASA being anal but Jeppesen... Pull ya head in Nev! :ok:

Maybe Leddie could advise if the standard of yank driver is now so low that they need to be reminded that some FLs are not available when your ears are popping due to low pressure.

I wonder if ATC would even allocate a FL if it were not available due low QNH?

Geez mate it worries me greatly that you believe the standard here is better then the US. No doubt your evidence is based on extensive flying there and overseas.

Bloggsie,
What are you smoking now?? More of that No.! Good A__T??
The US transition altitude/level is 18,000/FL180 with no transition layer.
No low QNH problem there!!
Needless to say, Australia has to be unique, resulting in building in a few gotcha problems that can be "Examined", having a "No Problems" system just wouldn't do.
Tootle pip!!

PS: If US standards are so low, how come they regularly produce the best air safety outcome statistics?? In weather and geographical situations just a tad more demanding than anything in AU.

So QNH 1000, 18,000 would be above FL180, would it not?

Yank ATC: "Traffic is Leddie 456 at 18,000ft!"

Bloggs 123, cruising at FL180: "Is he above me or below me?? I'm using See and Avoid but I don't know which way to look, up or down!!"

(I hope I've got that right... :confused:)

Plenty of jets pranged there, none here...

If the QNH is less than 29.92, you would not be assigned FL180.

Bloggsie,
Such in-depth, concise and relevant analysis, NOT.

Quite simply, with between 5 and 10,000 IFR aircraft airborne over the "Lower 48" at any one time, and 50,000+ active flight plans in the system in any 24 hour period, 18,000/FL180 simply has been demonstrated to not be a risk factor ---- that there are alternatives to the Australian anal retentive approach to aviation is a point lost on far too many Australian participants in aviation ---- a group in which, clearly, I believe you belong.
Have you ever actually operated in US airspace?

Needless to say, I am equally impressed by your in-depth knowledge of aviation safety statistics. Could I suggest you expand your knowledge of the subject ---- firstly acquaint yourself with ICAO definitions of accidents and incidents (not Australian home -grown definitions) then get into the various databases, starting with NTSB, Boeing, EASA, Nial (AOPA US) and so on. There is no shortage of international comparisons.

If you really try, you can learn something new (and real) every day, and it might help to dispel a certain complacency ---- one of the major threats to air safety.

One thing you might learn is Australian aviation is so small, it is little more than a rounding error, another is how mediocre our real record actually is.

Tootle pip!!

Thank you Fathom. So in effect, the yanks have the same setup as us: unusable FLs with low QNHs. Back to you, Leaddie.

Use whatever definitions you like, leddie, bent metal is bent metal.

Who's side are you on?! :eek::}

nope. thread over.

Balloon's link shows me that the yanks have exactly the same Galapagos "levels not available when QNH is yada yada yada" system that we have.

Bloggsie,
Please read it again, they are NOT the same, the US has no transition layer.
As for the "other details" from the US AIP, (or the AIM) take a closer look at the altimeter settings.
Tootle pip!!