Copter: Initialise desired acceleration before loiter init

ArduCopter/mode_land.cpp

@@ -57,6 +57,7 @@ void Copter::ModeLand::gps_run()
     // if not auto armed or landed or motor interlock not enabled set throttle to zero and exit immediately
     if (!motors->armed() || !ap.auto_armed || ap.land_complete || !motors->get_interlock()) {
         zero_throttle_and_relax_ac();
+        loiter_nav->clear_pilot_desired_acceleration();
         loiter_nav->init_target();
 
         // disarm when the landing detector says we've landed

ArduCopter/mode_poshold.cpp

@@ -100,6 +100,7 @@ bool Copter::ModePosHold::init(bool ignore_checks)
         poshold.pitch_mode = POSHOLD_LOITER;
         // set target to current position
         // only init here as we can switch to PosHold in flight with a velocity <> 0 that will be used as _last_vel in PosControl and never updated again as we inhibit Reset_I
+        loiter_nav->clear_pilot_desired_acceleration();
         loiter_nav->init_target();
     }else{
         // if not landed start in pilot override to avoid hard twitch
@@ -133,6 +134,7 @@ void Copter::ModePosHold::run()
     // initialize vertical speeds and acceleration
     pos_control->set_speed_z(-get_pilot_speed_dn(), g.pilot_speed_up);
     pos_control->set_accel_z(g.pilot_accel_z);
+    loiter_nav->clear_pilot_desired_acceleration();
 
     // if not auto armed or motor interlock not enabled set throttle to zero and exit immediately
     if (!motors->armed() || !ap.auto_armed || !motors->get_interlock()) {

ArduCopter/mode_rtl.cpp

@@ -265,6 +265,7 @@ void Copter::ModeRTL::descent_run()
     if (!motors->armed() || !ap.auto_armed || !motors->get_interlock()) {
         zero_throttle_and_relax_ac();
         // set target to current position
+        loiter_nav->clear_pilot_desired_acceleration();
         loiter_nav->init_target();
         return;
     }
@@ -356,6 +357,7 @@ void Copter::ModeRTL::land_run(bool disarm_on_land)
     if (!motors->armed() || !ap.auto_armed || ap.land_complete || !motors->get_interlock()) {
         zero_throttle_and_relax_ac();
         // set target to current position
+        loiter_nav->clear_pilot_desired_acceleration();
         loiter_nav->init_target();
 
         // disarm when the landing detector says we've landed

ArduCopter/mode_throw.cpp

@@ -79,6 +79,7 @@ void Copter::ModeThrow::run()
         stage = Throw_PosHold;
 
         // initialise the loiter target to the curent position and velocity
+        loiter_nav->clear_pilot_desired_acceleration();
         loiter_nav->init_target();
 
         // Set the auto_arm status to true to avoid a possible automatic disarm caused by selection of an auto mode with throttle at minimum