ZFT the solution to your problem of introducing ‘a glass mountain’ is within the EGPWS box. As you state the system has an internal terrain database, and assuming that your simulator uses the real EGPWS hardware (the most sensible solution), then the terrain profiles can be accessed by the simulator - a real world terrain database for free. If you have any problems, and there could be many with the poor standards of simulating aircraft geographic position, then contact Honeywell as they have helped many operators.
EGPWS Simulators.
The use of the internal EGPWS terrain database in simulation can adds some interest to check rides; just how close do you fly to terrain during an engine out procedure. One operator had a nasty (positive) surprise during a simulated emergency turn procedure when the aircraft failed to clear the terrain due to incorrect performance planning.
Centaurus I totally agree with you on the need for practicing GPWS pull ups – how to handle the aircraft and to gain a feel for its capabilities during emergency procedures, to experience non normal attitudes, noting the speed loss and rate of change of parameters. In these respects the same applies to ACAS manoeuvres, how many pilots really know what a 0.75g push for a descent feels like?
With the advent of EGPWS practicing the pull up procedure is just as important, but this need suggests that earlier alerts or awareness information has been missed or ignored – which has been the case in some incidents. With a terrain amber alert the general procedure is to manoeuvre the aircraft to correct the situation, but the occurrence of the event probably indicates that the crew have misunderstood the situation, thus why not climb to a safe height and reassess. Those who do not climb / manoeuvre will increase the risk of having a red Terrain warning, which will require a well practiced pull up. With EGPWS it is important to make full use of all of the features, e.g. at least one pilot should have terrain displayed during take off and landing, and peaks mode can be used during cruise to identify mountainous terrain which may increase turbulence and the possibility of an upset. In aircraft that have the bank angle alert activated, this mode may provide that additional warning that prevents a full upset.
Good knowledge and correct use of safety equipment will aid all operations; ACAS, like EGPWS has shown many side benefits i.e. why your descent/climb clearance is denied due to preceding / crossing traffic – and it could give early awareness of possible wake turbulence.