From cf5bfc5dd9d34d2f9825be991aac07db5a116076 Mon Sep 17 00:00:00 2001
From: Erik Hofman <erik@ehofman.com>
Date: Thu, 23 Jan 2020 11:54:33 +0100
Subject: [PATCH] On-ground trimming needs fdmex active while in-air trimming
 does not for reliable operation. This might be a problem within the trimming
 routines but for now this works.

---
 src/FDM/JSBSim/JSBSim.cxx | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/src/FDM/JSBSim/JSBSim.cxx b/src/FDM/JSBSim/JSBSim.cxx
index aba6bcb61..dd6869d34 100644
--- a/src/FDM/JSBSim/JSBSim.cxx
+++ b/src/FDM/JSBSim/JSBSim.cxx
@@ -462,11 +462,17 @@ void FGJSBsim::init()
         fgic->SetVNorthFpsIC(gndVelNED(1));
         fgic->SetVEastFpsIC(gndVelNED(2));
         fgic->SetVDownFpsIC(gndVelNED(3));
+
+        fdmex->Resume();
+        do_trim();
+      }
+      else
+      {
+        do_trim();
+        fdmex->Resume();
       }
-      do_trim();
-      needTrim = false;
       fdmex->Setdt( delta_t );
-      fdmex->Resume();
+      needTrim = false;
     }
 
     copy_from_JSBsim(); //update the bus