We all know that pressure altimeters are calibrated to ISA. Therefore any deviation from ISA will result in an error which is proportional to the ISA deviation and the height of the a/c above the airfield pressure datum. As previously stated this error is approx 4ft/1000ft per degree C of difference.
Look in the AERAD Flight Information Supplement page AER28 for the correction table ( sorry not familiar with Jeppersen).
Work out the ISA deviation for the airfield temperature/elevation.
Enter table at this ISA deviation, move horizontally to appropriate 'height above airfield' column and extract correction to be added to minima.
This works for all minima DH, DA, MDH, MDA and also for MSA etc.
Thus for ILS app to DH of 200ft at airfield with 5000ft elevation and temp of -20 C correction is......20ft. For NBD with MDH of 600ft to same airfield the correction is .....60ft. For MSA of 8000ft to same airfield the correction is .... 300ft.
Mental gymnastics not required
