It is a bit of an anomaly in Oz procedures.
O/S they have 'stop heights' on SID plates, such as 6000' at LHR and 3000' at DXB. Your clearance will be "Cleared to XYZ, BS1 departure, squawk 1234". In the notes section and/or in a Frequency box on the SID plate will be information on when to change after takeoff and what frequency...usually asap after passing 500' (agl).
Thus there is no need for 'amended' altitudes because they are unable, understandably, to clear you direct to cruise level.
Invariably you're cleared higher, traffic permitting, as soon as you change to departure frequency after takeoff.
It makes perfect sense and is a system that works very well...not to mention greatly simplifying clearance delivery/readback...unlike Oz clearances that generally go along the lines of "XYZ cleared to sydney via laravale 2, amended 6000', Flight plan route, departure frequency (or is it "First frequency airborne") 123.4"
What would you rather listen to, absorb and readback?
Last edited by Chimbu chuckles; 1st Feb 2008 at 05:42.