stilton - the GR1 had a Mach Hold setting. With this, you were free to move the throttle and the AP would vary the attitude to maintain the Mach number - usually used in the decent, though rarely.
The Basic Mode of the Tornado AP also allowed you to simply engage AP with no other modes selected and it would hold the attitude selected. If it was very close to straight & level, it would automatically select straight & level for you (can't remember the range I'm afraid).
There's no "database" on the GR (or F3
afaik). You get a moving map with selectable scales on the GR so you can at least point towards it, you also have access to TACAN display, though not VOR. So whilst not strictly speaking legal to flying in Class A, in the past it was done fairly regularly. Main problems occurred when you were asked by ATC to steer towards some arbitrary beacon and you couldn't find it on the map to head towards. On my GR1 IRET, I flew an airways leg and a full IF approach into Stansted.....all from the back seat too!
