@@ -189,11 +189,18 @@ function fgfs () {

                 local candidate_airport=${fgfs_arg%:*}; [[ $candidate_airport == $fgfs_arg ]] && candidate_airport=${fgfs_arg%+*}

                 local candidate_parking=${fgfs_arg#*:}; [[ $candidate_parking == $fgfs_arg ]] && unset candidate_parking

                 local candidate_runway=${fgfs_arg#*+};  [[ $candidate_runway  == $fgfs_arg ]] && unset candidate_runway

-                local terrafs=${candidate_airport#-}

-                if [[ $terrafs != $candidate_airport && -x $HOME/.fgfs/terrafs && -d $HOME/.fgfs/terrafs.d ]]; then

-                    candidate_airport=$terrafs

-                    $HOME/.fgfs/terrafs $HOME/.fgfs/terrafs.d

+                if [[ -x $HOME/.fgfs/terrafs && -d $HOME/.fgfs/terrafs.d ]]; then

+                    if test $(grep -Ec "^terrafs\s+$HOME/.fgfs/terrafs.d" /proc/mounts) -eq 0 \

+                    && echo "$HOME/.fgfs/terrafs.d present but not mounted !"                 \

+                    && test -x $HOME/.fgfs/mount.terrafs                                      \

+                    && read -q "mount_terrafs?go to mount it ? (y/N) "                        \

+                    && [[ "${mount_terrafs:-n}" = "y" ]]; then

+                        $HOME/.fgfs/mount.terrafs || return 1

+                    else

+                        echo "mount it manually, or remove it to use TerraSync"

+                        return 1

+                    fi

                     fgfs_args+=(--fg-scenery=$HOME/.fgfs/terrafs.d)

                     fgfs_args+=(--disable-terrasync)

                     local scenes_dir=$HOME/.fgfs/terrafs.d

@@ -703,8 +710,8 @@ EOH

     export ${DISCRETE_GPU[@]}

     $FGDIR/install/flightgear/bin/fgfs ${fgfs_args[@]}

     unset fgfs_args ${DISCRETE_GPU[@]%=*}

-    

-    if grep -q $HOME/.fgfs/terrafs.d /proc/mounts; then

-        fusermount -u $HOME/.fgfs/terrafs.d

+

+    if test ${mount_terrafs:-n} = y; then

+        $HOME/.fgfs/mount.terrafs

     fi

 }