I downloaded the SR22 here to check it out -->
http://simviation.com/1/search?submit=1&keywords=CirrusSR22.zip&categoryId=The landing light works for me but I had to enable the "Aircraft landing-lights illuminate ground" option from FS Settings > Advanced > Aircraft for it to display properly. (I don't usually fly at night.)
I noticed the cabin lighting was too far forward. This can be corrected in the [LIGHTS] section of Aicraft.cfg. I changed the bold entry in the red line.
[LIGHTS]
//SR20
//Types: 1=beacon, 2=strobe, 3=navigation, 4=cockpit
light.0=3, -4.496, -17.75, -0.163, fx_navred
light.1=3, -4.496, 17.75, -0.163, fx_navgre
light.2=2, -3.740, -17.50, -0.163, fx_strobe
light.3=2, -3.740, 17.50, -0.163, fx_strobe
// light.4=4, -0.31, 0.00, 1.26, fx_vclightgk
light.5=4, -4.84, 0.00, 2.15, fx_vclightNOTE: The fx_vclightgk fx file is missing from the download so I remarked light.4 out. // All seems to work fine without it.
