REP manages the flight envelope in order to add features that X-Plane does not provide by default.
The airfoils installed by REP give the right stall speed at the right attitude. The same happens for the climb V-speeds (Vy and Vx) and the climb vertical speed, that will match the ones reported in the real world airplane manual.
There’s an example of how precise REP is in this post.
One of the most interesting things is the stall behavior. REP will, in fact, change the way the airplane stalls basing on the wing type.
The plan may warn you before a stall with a real stall buffet. No other airplane in X-Plane does that! If you’re using HeadShake, you’ll feel the vibrations during the stall as well.
Many X-Plane addons focus on the flight dynamics and actually don’t care about how the airplane acts and feels on the ground.
We think that’s a huge error.
Different aicrafts acts differently when on the ground because they have different landing gear systems, different weight distributions and many other little discrepancies that make an airplane alive.
For example, the Cessna 210 is equipped with a spring-loaded nose gear, that is, the nose gear is pivoting by itself and it’s not directly connected to the rudders. The pilot steers only using the aerodinamic effect of the rudder and the differential braking. That’s what you have to do with X-Plane too.
You won’t need to have any special hardware for that, by the way. If you fly with just the joystick, REP will recognize your hardware configuration and provide you different ways of applying the differential braking.
X-Plane has exaggerated cross wind effects when on the ground. If you’re lucky enough to be able to turn in crosswind conditions, the tires will scratch continuosly.
REP fixes this problem and make taxiing in crosswind as real as it gets!