Landing physics in P3D vs XPL

[G550flyer 1,013]

There are two fundamental problems with landing physics in both platforms. In P3D-FSX, the ground effect too strong. If you flare properly, you will float for ever. In X-plane, its too weak. If you flare properly, it will pound down. Some of the talented aircraft developers have engineered the issue out. How does real ground effect work?

 

1. In aircraft, mostly heavy metal that I fly and have flown, the flare is a 2 to 3 degree pitch change. This will diminish, not stop the sink rate.

 

2. You enter ground effect at an altitude about half of the aircraft's wing span. You notice this as a gradual 200 to 300 feet per minute loss of sink rate. You will also notice that the nose will tend to drop as you enter ground effect.

 

3. On approach in a normal jet on a 3 degree glide path, you are looking at 700 to 800 feet per minute sink rate. The aircraft is properly trimmed for your approach speed, REF+5/additives. As you cross the threshold, you start to bleed your additives and your +5. As you slow, now your yoke is a little nose heavy. As you enter ground effect, you start to lose sink as it gradually impacts the aircraft and inertia. Ground effect makes your nose a little heavier. As you apply the flare at 20 to 30 feet, you make a 2 to 3 degree pitch change and pull power. You will find that it takes some back pressure to keep the pitch constant. You never trim, you just keep that back pressure and adjust to keep your flare pitch. As you are doing this, the pitch change is also decreasing your sink. In this text book fashion, you will end up in a text book lightly firm touch down. As you gain experience, you will learn to adjust pitch change rate and power pull timing to get a nice touch right in the target zone. If you find this happening in the sims, the developer did an excellent job with the model.

 

Rich