The one calculation which I constantly find myself doing during the last 6 miles when establish on the ILS is "What should my rate of descent (RoD) be?"

Now I know that the glideslope gives that to me as a visual "..too high, too low, just right...." but somehow I always like to have secondary confirmation of these things especially when all I can see is wall to wall clouds outside the cockpit and I know that the ground is coming up to meet me in the not too distant future!

To have an indication of what the necessary RoD should be in order to land on the numbers and to correlate that to the aircraft's VSI would be a very comforting addition to SD's armory.

At the moment, I'm doing it in my head on the decent at a time when the workload is at its heaviest. Some how I really think that, since SD is doing this calculation constantly in the background; advises me at the start of the virtual ILS approach of the required RoD; a simple display inside the virtual ILS instrument followed by a quick flick of the eyes to the cockpit VSI would do the job in a matter of seconds.

So what do you think for all of us (V)FR fliers?




Biggles -- EGKB

Biggles-EGKB, iPlease permit me to iAgree with you once more.

Multiple airspeed by 5 and that gives me my RoD for a 3.5 deg glide slope - yes I remember that from my PPL training days. That's great if the aircraft is properly established on final and the aircraft remains in this ideal world but if SD's GS indicates that I am too high at 2nm with a ground speed of 80kts multiplying by 5 has a tendency to land me on the upwind numbers on a medium length runway (leaving me heavy on the brakes and no rubber on the tyres) and in the hedge on a short runway (leaving the airfield with no hedge and me a very expensive lawn mower)

Now with a constant display graphically (which SD already gives via the GS) and the possibility of displaying digitally the actual RoD required to achieve the landing point (just an idea at the moment), serves to improve my chances of landing on the downwind numbers which the nice people in the tower suggested might be a good idea next time I give it a go!

Also, thinking back to my PPL training days I never could quite understand the "rule of thumb" of multiplying the airspeed by 5 (it doesn't work) as you quite rightly state it is your ground speed that's important in working out the RoD not your airspeed and what is the one thing that the standard 6 pack instrument cockpit display doesn't give you that a GPS device like SD does -- yes, you've got it GROUNDSPEED.

Now where did I put my Pooleys?



Biggles -- EGKB