diff --git a/Tools/autotest/arduplane.py b/Tools/autotest/arduplane.py
index 0ce2fde3cd..4961dbcf2f 100644
--- a/Tools/autotest/arduplane.py
+++ b/Tools/autotest/arduplane.py
@@ -1028,6 +1028,27 @@ class AutoTestPlane(AutoTest):
         if ex is not None:
             raise ex
 
+        self.start_subtest("Not use RC throttle input when THR_FAILSAFE==2")
+        self.takeoff(100)
+        self.set_rc(3, 1800)
+        self.set_rc(1, 2000)
+        self.wait_attitude(desroll=45, timeout=1)
+        self.context_push()
+        self.set_parameters({
+            "THR_FAILSAFE": 2,
+            "SIM_RC_FAIL": 1,  # no pulses
+        })
+        self.delay_sim_time(1)
+        self.wait_attitude(desroll=0, timeout=5)
+        self.assert_servo_channel_value(3, self.get_parameter("RC3_MIN"))
+        self.set_parameters({
+            "SIM_RC_FAIL": 0,  # fix receiver
+        })
+        self.zero_throttle()
+        self.disarm_vehicle(force=True)
+        self.context_pop()
+        self.reboot_sitl()
+
     def test_throttle_failsafe_fence(self):
         fence_bit = mavutil.mavlink.MAV_SYS_STATUS_GEOFENCE
 
@@ -2260,7 +2281,7 @@ function'''
         self.wait_waypoint(4, 4, timeout=1200, max_dist=120)
 
         # Disarm
-        self.disarm_vehicle()
+        self.disarm_vehicle_expect_fail()
 
         self.progress("Mission OK")
 
@@ -2357,7 +2378,7 @@ function'''
             raise NotAchievedException("Airspeed did not reduce with lower SOAR_VSPEED")
 
         # Disarm
-        self.disarm_vehicle()
+        self.disarm_vehicle_expect_fail()
 
         self.progress("Mission OK")
 
@@ -2864,7 +2885,7 @@ function'''
             self.context_clear_collection("STATUSTEXT")
             ###################################################################
 
-            self.disarm_vehicle()
+            self.disarm_vehicle(force=True)
 
         except Exception as e:
             self.print_exception_caught(e)
diff --git a/Tools/autotest/common.py b/Tools/autotest/common.py
index 358d6b09e9..4ada08a10a 100644
--- a/Tools/autotest/common.py
+++ b/Tools/autotest/common.py
@@ -4243,6 +4243,22 @@ class AutoTest(ABC):
                      timeout=timeout)
         return self.wait_disarmed()
 
+    def disarm_vehicle_expect_fail(self):
+        '''disarm, checking first that non-forced disarm fails, then doing a forced disarm'''
+        self.progress("Disarm - expect to fail")
+        self.run_cmd(mavutil.mavlink.MAV_CMD_COMPONENT_ARM_DISARM,
+                     0,  # DISARM
+                     0,
+                     0,
+                     0,
+                     0,
+                     0,
+                     0,
+                     timeout=10,
+                     want_result=mavutil.mavlink.MAV_RESULT_FAILED)
+        self.progress("Disarm - forced")
+        self.disarm_vehicle(force=True)
+
     def wait_disarmed_default_wait_time(self):
         return 30
 
@@ -11012,7 +11028,7 @@ switch value'''
         # ok done, stop the engine
         if self.is_plane():
             self.zero_throttle()
-            if not self.disarm_vehicle():
+            if not self.disarm_vehicle(force=True):
                 raise NotAchievedException("Failed to DISARM")
 
     def test_frsky_d(self):
diff --git a/Tools/autotest/quadplane.py b/Tools/autotest/quadplane.py
index 4ede8602c3..923e9b4ed9 100644
--- a/Tools/autotest/quadplane.py
+++ b/Tools/autotest/quadplane.py
@@ -248,20 +248,7 @@ class AutoTestQuadPlane(AutoTest):
             self.progress("Waiting for Motor1 to speed up")
             self.wait_servo_channel_value(5, spin_min_pwm, comparator=operator.ge)
 
-            self.progress("Disarm/rearm with GCS - expect to fail")
-            self.run_cmd(mavutil.mavlink.MAV_CMD_COMPONENT_ARM_DISARM,
-                         0,  # DISARM
-                         0,
-                         0,
-                         0,
-                         0,
-                         0,
-                         0,
-                         timeout=10,
-                         want_result=mavutil.mavlink.MAV_RESULT_FAILED)
-
-            self.progress("Disarm/rearm with GCS - forced")
-            self.disarm_vehicle(force=True)
+            self.disarm_vehicle_expect_fail()
             self.arm_vehicle()
 
             self.progress("Verify that airmode is still on")