Plane: Don't lower nose when hand launching

ArduPlane/takeoff.cpp

@@ -168,8 +168,14 @@ void Plane::takeoff_calc_pitch(void)
             nav_pitch_cd = takeoff_pitch_min_cd;
         }
     } else {
-        nav_pitch_cd = ((gps.ground_speed()*100) / (float)aparm.airspeed_cruise_cm) * auto_state.takeoff_pitch_cd;
-        nav_pitch_cd = constrain_int32(nav_pitch_cd, 500, auto_state.takeoff_pitch_cd);
+        if (is_positive(g.takeoff_throttle_min_speed) || is_positive(g.takeoff_throttle_min_accel)) {
+            // Doing hand launch so don't lower pitch when low ground speed
+            nav_pitch_cd = MIN(auto_state.takeoff_pitch_cd, 500);
+        } else {
+            // Rise off ground takeoff so delay rotation until ground speed indicates adequate airspeed
+            nav_pitch_cd = ((gps.ground_speed()*100) / (float)aparm.airspeed_cruise_cm) * auto_state.takeoff_pitch_cd;
+            nav_pitch_cd = constrain_int32(nav_pitch_cd, 500, auto_state.takeoff_pitch_cd);
+        }
     }
 
     if (aparm.stall_prevention != 0) {