diff --git a/src/initialization/FGSimplexTrim.cpp b/src/initialization/FGSimplexTrim.cpp
index b04f8cda4c9946384a29d513f62631f10a2240e9..58300316091f418f6c44ab1c8d83ac74ffcbca48 100644
--- a/src/initialization/FGSimplexTrim.cpp
+++ b/src/initialization/FGSimplexTrim.cpp
@@ -245,11 +245,11 @@ FGSimplexTrim::FGSimplexTrim(FGFDMExec * fdmPtr, TrimMode mode)
 	ss.x.add(new FGStateSpace::Beta);
 	ss.x.add(new FGStateSpace::Phi);
 	ss.x.add(new FGStateSpace::P);
-	ss.x.add(new FGStateSpace::R);
-	ss.x.add(new FGStateSpace::Alt);
 	ss.x.add(new FGStateSpace::Psi);
-	ss.x.add(new FGStateSpace::Longitude);
+	ss.x.add(new FGStateSpace::R);
 	ss.x.add(new FGStateSpace::Latitude);
+	ss.x.add(new FGStateSpace::Longitude);
+	ss.x.add(new FGStateSpace::Alt);
 
 	ss.u.add(new FGStateSpace::ThrottleCmd);
 	ss.u.add(new FGStateSpace::DaCmd);