On some aircraft when I land the aircraft will go right through the Runway. Or when i bring the nose down after landing the main gear, the nose gear will go right through the runway as if it collapsed. I know I am not bringing it in HOT, does the problem lie in the aircraft  or somthing else i installed some scereny a while back but though i took it out seeing i saw what looked like Blocks of land if anybody knows what I am talking about. Is the promblem in the Aircraft i download, is the aircrafft Bad is their anyway I could fix this thanks.

I'm sure JohnP is right. Unless it happens with the defaults it's most likely the aircraft, especially if they were originally intended for FS2000. It can usually be fixed but you would need to know the basics of Aircraft.cfg editing. This can be time consuming & involve a lot of messing around. It might be best to try a later version of the aircraft designed specifically for FS2002. IMHO