The graphics engine was similar to their SVGA Harrier Assault (1992), one of the first SVGA sims. You could even insert your own navaids!
There remains to this day a dedicated band of enthusiasts who have created their own aircraft and scenarios for the Flight Sim Toolkit series of sims. The release of the source code by www.kuju.com has facilited the constant evolution of this sim for over 10 years now.
"The FST Engine has been upgraded based upon the original source code, currently at version 3.17 with a lot of enhancements more enhancements still to come including improved version of the tools." - Adrian Brown, June 2005
www.groundzero-simulations.co.uk >> 2005 update - web page is gone <<
Adrian Brown's site - www.flightsimtoolkit.co.uk - FST Flight Research Centre - for the latest information and screenshots - 2017 update: link is dead.
http://n.webring.com/hub?ring=flightsimtoolkit - Flight Simulation Toolkit Web Ring - 2017 update: link is dead