SITL: simple implementation of a fast jet

just increase the weight and the rest can be done with params

libraries/SITL/SIM_Plane.cpp

@@ -40,6 +40,11 @@ Plane::Plane(const char *home_str, const char *frame_str) :
     if (strstr(frame_str, "-heavy")) {
         mass = 8;
     }
+    if (strstr(frame_str, "-jet")) {
+        // a 22kg "jet", level top speed is 102m/s
+        mass = 22;
+        thrust_scale = (mass * GRAVITY_MSS) / hover_throttle;
+    }
     if (strstr(frame_str, "-revthrust")) {
         reverse_thrust = true;
     }