VSD
Thanks again, I have also tried changing the altimeter in the simulator and it does initially displace the aircraft symbol from the magenta approach path, however after a short time the approach path, leading to the runway, adjusts back to give the correct looking VSD picture with the incorrect subscale setting??
In the simulator, the VSD still showed aircraft on the magenta approach slope and all lined up for correct landing point on the runway, with the altimeter's set with a 10hpa difference to the simulator's S/L pressure. The terrain appeared to also stay in correct relationship to the runway elevation.
If the subscale was changed during the approach the display would look incorrect initially but would slowly realign to the changed altimeter setting.
However if the QNH was incorrectly set at transition and left that way, the VSD display appeared to show the runway and terrain in the correct position.
Some uncontrolled training papers I have, indicate that the VSD should show an incorrect altimeter setting but I have not been able to see it in the sim yet or quite fathom out technically how this would be achieved... might have to leave it to Bill's Astronauts and Engineers. cheers and thanks for reply's