Guys,
On a similar note, since finding the different style of EM diagram sometimes seen in reports dated that far back, like the ones at this location:
http://www.fourthfightergroup.com/eagles/spit109turn.gifI decided to reproduce the same type of analysis they have used and piggy back it onto the work I've already done for the Aces High aircraft. Now when I produce an EM analysis for any aircraft, I automatically get both types of diagram. There are advantages and disadvantages to both methods. The diagrams I've been producing were not conceived until the 1960s and they have the advantage that they can be overlaid with one another for a far easier comparison. The disadvantage with the type of EM diagram that originated in the late 30s is that they can't be overlaid. So for example, here is an overlay of the AH Spitfire MkI and the Me109e
The main advantage to producing the type of EM diagrams seen in those early reports is that they can be compared with the ones that exist for the real aircraft. For example, the Spitfire in the diagram above has this diagram:
But let's compare that with the diagram for the real Spitfire MkI.
Here we can see that both the real Spitfire and the AH Spitfire have the same corner velocity at that altitude and configuration, so let's compare a turn. Just for example I've selected a 5g turn at the corner speed of 250mph. I've indicated on the diagram for the real Spitfire that it would need to descend at 16 degrees below the horizon to sustain that turn and it would turn a full circle in about 14.5 seconds with a radius of about 850ft. You can see from the diagram for the AH Spitfire that it would also make the same turn in about 14.5 seconds with a radius of 850ft, and that it would need to descend at an angle of 23 degrees below the horizon, a descending turn only 6 degrees steeper than the real aircraft. But the turn rates and radii for the turn, along with the corner speed are amazingly close. The difference in the angle of descent is probably due to differences in engine power available at that altitude between the real world tests and Aces High, and perhaps some differences in weight.
It is interesting that both diagrams are essentially the same shape, and that they agree quite closely in many respects, indicating that the flight model in Aces High has accounted for all of the aerodynamic factors that would influence the shape of the curves to any significant degree. A worthy achievement indeed. Kudos to HTC.
This is even more significant, because I've made a similar comparison with the Spitfire and 109e from other simulations, and so far Aces High has first place for accuracy. I'm just thinking of writing up the whole comparison for an article on SimHQ.
Merry Christmas guys...
Badboy
