Here is a simple set of contact points from the aircraft.cfg file of an aircraft:
point.0 = 1, -18.8913, 0, -5.0749, 2165.354, 0, 0.551, 180, 0.25, 2.5, 0.69, 6, 6, 0, 173, 178
point.1 = 1, 1.4084, -6.3, -9.3048, 2165.354, 1, 1.4, 0, 0.5, 2.5, 0.891, 6, 6, 2, 173, 178
point.2 = 1, 1.4658, 6.2, -9.3182, 2165.354, 2, 1.4, 0, 0.5, 2.5, 0.891, 6, 6, 3, 173, 178
point.3 = 2, 8.1, 0, -2.2, 2100, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0
point.4 = 2, -1.6367, -20.333, 0.5573, 800.102, 0, 0, 0, 0, 0, 0, 0, 0, 5, 0, 0
point.5 = 2, -1.5, 20.333, 0.5, 800.102, 0, 0, 0, 0, 0, 0, 0, 0, 6, 0, 0
point.6 = 2, -24.5483, 0, -1.1743, 700.102, 0, 0, 0, 0, 0, 0, 0, 0, 9, 0, 0
If you go along to the seventh data entry for point 0, this is the wheel diameter (0.551). It's the seventh entry because the first one is 0, and the knowledgebase sticky says that the 6th entry is for the wheels, but you have to remember entry zero!
As you can see, points 0, 1 and 2 above are for the wheels of the aircraft as they have a wheel diameter entry. Those points also have a reading for static compression. When you experiment to raise the wheels up to ground level, you can try increasing the wheel diameter in the first three contact points. This will Not affect the visual model!
I have done this sort of thing in the past, but what with all the other stuff I tinker with, I can't remember what exactly I did
For example, I am trying to get more air traffic on all airbases. Trouble is, the air takeoff spawns also appear in the UI screen, at the point where the UI pilot's aircraft is - the big bangs get wearisome after a while