Chimbu,
A very informative post for our friend Shimuken.
However I see a slight flaw in the TA calculation example at YMML.
Assuming you were exactly on the correct glideslope at the OM check, wouldn't the Altimeter show 1380ft? (IA; 1500-120ft=1380, & TA=1500).
If Station Temp is ISA+ altimeter underreads compared to true altitude.
In your example, if the indicated Altitude was indeed 1500 and True Altitude 1620 you would now be way above glideslope on the ILS.
Cheers!
Z.
