Spitfire Mk IIa performance tests - Patch 1.07.18301

[klem]

Originally Posted by =AN=Felipe

Sure Klem, ill use the real tests too in comparasion. So the altimeter was setted to 985mb 0ft at manston airfield, then i start to run the tests, so its about -400ft if we do by your technics, no winds and other things, if you are talking about that i do this way

thx klem

Hi Felipe,

Manston elevation is around 144 ft and Tangmere ~40 feet. I checked the Altimeter error two ways. I deliberately ditched in the sea and checked the output file for ditched altitude reading I_Altitude (when it hit the water) and also the 'True Height' or PosHeight from this:
Point3d pos = me.Place().Pos();
PosLongitudinal = pos.x;
PosLateral = pos.y;
PosHeight_m = pos.z
PosHeight_ft = PosHeight_m * 3.2808399
That indicated that the altimeter should be set to 992Mb.

Of course for low flying its the Sea level you want which in theory can change with the tides but I don't think that's modelled.

I also use HudLog to display some parameters on screen all the time including Altimeter Altitude and True Height so I can easily set the Altimeter. The frustrating thing is that I just loaded the mission again and found that it has changed to 995mb and I don't know why! Anyway its only something like 100 ft difference so no big deal with the FMs being as far off as they are. Funny thing is that if I ignore that and set it to 992 I seem to be about right over the sea low level.