AP_TECS: created accessor for TECS_LAND_ARSPD param

libraries/AP_SpdHgtControl/AP_SpdHgtControl.h

@@ -68,8 +68,11 @@ public:
 	// return maximum climb rate
 	virtual float get_max_climbrate(void) const = 0;
 
-	// return landing sink rate
-	virtual float get_land_sinkrate(void) const = 0;
+    // return landing sink rate
+    virtual float get_land_sinkrate(void) const = 0;
+
+    // return landing airspeed
+    virtual float get_land_airspeed(void) const = 0;
 
 	// set path_proportion accessor
     virtual void set_path_proportion(float path_proportion) = 0;

libraries/AP_TECS/AP_TECS.h

@@ -87,6 +87,11 @@ public:
         return _land_sink;
     }
 
+    // return landing airspeed
+    float get_land_airspeed(void) const {
+        return _landAirspeed;
+    }
+
     // return height rate demand, in m/s
     float get_height_rate_demand(void) const {
         return _hgt_rate_dem;