As more and more pilots get their training at large, controlled airports with long, flat, paved runways, fewer new pilots have much, if any, real-world experience dealing with sloping runways. Even some seasoned pilots experience problems at a new airport with a runway of a different size or slope than what they’re used to.
One major potential issue on approach to a sloping runway has to do with visual illusions that can make it seem like you’re too high or too low. A downsloping runway can give you the impression you are lower than you really are. As a result, when flying an approach to a downsloping runway it can seem like you’re undershooting, even if you are on the proper glidepath.
The opposite can occur when you’re flying an approach to an upsloping runway. In this case, you will see too much of the runway, which can give you the impression that you are high and overshooting. If you attempt to correct, you might fly a lower than normal approach, which could result in a hard landing, or possibly even a touchdown shy of the runway.
For these reasons, there’s a tendency to land long on a downsloping runway – exactly what you want to avoid. The reverse is true on an upsloping runway: Pilots often get fooled and have to pour on the power at the last moment to keep from slamming into the runway.
The trick is to pick a touchdown spot and focus on that initially rather than taking in the view of the entire runway. With the effects of the visual illusion minimized, you’re chances of flying the proper glidepath all the way to touchdown go way up.