Gday folk’s,
Thanks for all your replies - ending up passing with a healthy 92%, so pretty stoked.
Ended up using the CR3 for quick calculations (Above or below glide slope) and used the following formula for more precise true altitude calcs:
Find pressure height - - Elevation + (1013 + QNH) x 30 - - at temperature source (QNH @ Aerodrome OR OAT at aircraft)
Use pressure height to determine ISA DEV - - OAT - (15 x Pressure height x 2 / 1000)
Find true altitude with following formula - - 0.004 x ISA DEV x height above ground (parcel of air) - -
All the best,
WT