FMS VNAV and altimeter setting.
What altimeter datum is used for FMS VNAV profile approaches in large commercial aircraft?
If the crew fails to set the QNH so that the aircraft is 1000ft low, i.e. 29.92 retained for a QNH of 28.92, would all of the waypoints be offset low, and thus the VNAV profile aims approx 3nm short of the runway?
Are there any differences between FMS database generated approach profiles and manual waypoints?
Are Boeing/Airbus FMS installations similar in these respects?