Be sure to check out HAAB before trying to land there if you only have FSX default scenery. The airport has been sunk into the ground with steep cliffs at the boundaries. If you try to land, high hills at the edge of the runway need to be passed high, only descending to land after you're clear of the hills. I found a decent airport on AVSIM but I'm not sure whether the surrounding land has been flattened. I used ADE to flatten a large area well beyond the boundaries and hadn't deleted the HAAB scenery while leaving the CVX.bgl active.
I flew a AN-225 and needed all the runway available ... my landing gear scraped the hills but I was able to stop before the end of the runway. HAAB has to be one of the highest capitol airports in the world at 7600'.