diff --git a/src/FDM/YASim/FGFDM.cpp b/src/FDM/YASim/FGFDM.cpp index 3bf8c8079..9fdbecd61 100644 --- a/src/FDM/YASim/FGFDM.cpp +++ b/src/FDM/YASim/FGFDM.cpp @@ -583,8 +583,12 @@ Wing* FGFDM::parseWing(XMLAttributes* a, const char* type) w->setTaper(attrf(a, "taper", 1)); w->setDihedral(attrf(a, "dihedral", defDihed) * DEG2RAD); w->setCamber(attrf(a, "camber", 0)); - w->setIncidence(attrf(a, "incidence", 0) * DEG2RAD); - w->setTwist(attrf(a, "twist", 0) * DEG2RAD); + + // These come in with positive indicating positive AoA, but the + // internals expect a rotation about the left-pointing Y axis, so + // invert the sign. + w->setIncidence(attrf(a, "incidence", 0) * DEG2RAD * -1); + w->setTwist(attrf(a, "twist", 0) * DEG2RAD * -1); // The 70% is a magic number that sorta kinda seems to match known // throttle settings to approach speed.