When considering landing on a runway with marginal length or a difficult or obstructed departure path, the first stage of aeronautical decision-making is deciding whether to land in the first place. The next one is if you land, can you make it out safely? Quite often there are good reasons to do neither, with perhaps the biggest single factor being density altitude, usually when trying to take off at the planned time.
In case you’re thinking density altitude (DA) is strictly something that concerns mountain-flying enthusiasts like me, you should know it is not a concept unique to the high country. High-altitude pilots just have a head start when it comes to familiarity with DA. Anyone who’s flown in the summertime, including from sea-level airports, has experienced some form of DA.
