From 67ba624624819b141202fe5ab9b44374f1922955 Mon Sep 17 00:00:00 2001
From: breadoven <56191411+breadoven@users.noreply.github.com>
Date: Mon, 5 May 2025 00:08:40 +0100
Subject: [PATCH 1/6] toilet bowling detection

---
 docs/Settings.md                             | 10 ++++++
 src/main/fc/settings.yaml                    |  6 ++++
 src/main/io/osd.c                            |  3 ++
 src/main/io/osd.h                            |  1 +
 src/main/navigation/navigation.c             |  2 ++
 src/main/navigation/navigation.h             |  3 +-
 src/main/navigation/navigation_multicopter.c | 33 ++++++++++++++++++++
 src/main/navigation/navigation_private.h     |  1 +
 8 files changed, 58 insertions(+), 1 deletion(-)

diff --git a/docs/Settings.md b/docs/Settings.md
index 39e3de90d52..0d676b47ea6 100644
--- a/docs/Settings.md
+++ b/docs/Settings.md
@@ -4052,6 +4052,16 @@ P gain of altitude PID controller (Multirotor)
 
 ---
 
+### nav_mc_toiletbowl_detection
+
+Sets sensitivity of toilet bowling detection for multirotors. On detection a heading correction is applied which should stop the toilet bowling. A setting of 2 works well for 5 inch multirotors. Increasing the setting will reduce sensitivity and delay detection. Set to 0 to disable. (Toilet bowling occurs most obviously during position hold when an inaccurate compass heading causes a rapidly increasing fast sweeping bowl shaped flight path).
+
+| Default | Min | Max |
+| --- | --- | --- |
+| 0 | 0 | 20 |
+
+---
+
 ### nav_mc_vel_xy_d
 
 D gain of Position-Rate (Velocity to Acceleration) PID controller. It can damp P and I. Increasing D might help when drone overshoots target.
diff --git a/src/main/fc/settings.yaml b/src/main/fc/settings.yaml
index 6ef471e3bb0..362f89527b6 100644
--- a/src/main/fc/settings.yaml
+++ b/src/main/fc/settings.yaml
@@ -2571,6 +2571,12 @@ groups:
         field: mc.inverted_crash_detection
         min: 0
         max: 15
+      - name: nav_mc_toiletbowl_detection
+        description: "Sets sensitivity of toilet bowling detection for multirotors. On detection a heading correction is applied which should stop the toilet bowling. A setting of 2 works well for 5 inch multirotors. Increasing the setting will reduce sensitivity and delay detection. Set to 0 to disable. (Toilet bowling occurs most obviously during position hold when an inaccurate compass heading causes a rapidly increasing fast sweeping bowl shaped flight path)."
+        default_value: 0
+        field: mc.toiletbowl_detection
+        min: 0
+        max: 20
       - name: nav_mc_althold_throttle
         description: "If set to STICK the FC remembers the throttle stick position when enabling ALTHOLD and treats it as the neutral midpoint for holding altitude. If set to MID_STICK or HOVER the neutral midpoint is set to the mid stick position or the hover throttle position respectively."
         default_value: "STICK"
diff --git a/src/main/io/osd.c b/src/main/io/osd.c
index 0bdb9e3375f..f34a38f6401 100644
--- a/src/main/io/osd.c
+++ b/src/main/io/osd.c
@@ -6359,6 +6359,9 @@ textAttributes_t osdGetSystemMessage(char *buff, size_t buff_size, bool isCenter
                     }
                 }
             }
+            if (STATE(MULTIROTOR) && isNavHoldPositionActive() && toiletBowlingHeadingCorrection) {
+                messages[messageCount++] = OSD_MESSAGE_STR(OSD_MSG_TOILET_BOWL);
+            }
         } else if (ARMING_FLAG(ARMING_DISABLED_ALL_FLAGS)) {    /* ADDS MAXIMUM OF 2 MESSAGES TO TOTAL */
             unsigned invalidIndex;
 
diff --git a/src/main/io/osd.h b/src/main/io/osd.h
index e55aeb22461..f0cc299a519 100644
--- a/src/main/io/osd.h
+++ b/src/main/io/osd.h
@@ -124,6 +124,7 @@
 #define OSD_MSG_ANGLEHOLD_PITCH     "(ANGLEHOLD PITCH)"
 #define OSD_MSG_ANGLEHOLD_LEVEL     "(ANGLEHOLD LEVEL)"
 #define OSD_MSG_MOVE_STICKS         "MOVE STICKS TO ABORT"
+#define OSD_MSG_TOILET_BOWL         "TOILET BOWLING !"
 
 #ifdef USE_DEV_TOOLS
 #define OSD_MSG_GRD_TEST_MODE       "GRD TEST > MOTORS DISABLED"
diff --git a/src/main/navigation/navigation.c b/src/main/navigation/navigation.c
index 03d4a3da36b..e655d1dce4f 100644
--- a/src/main/navigation/navigation.c
+++ b/src/main/navigation/navigation.c
@@ -201,6 +201,7 @@ PG_RESET_TEMPLATE(navConfig_t, navConfig,
         .slowDownForTurning = SETTING_NAV_MC_WP_SLOWDOWN_DEFAULT,
         .althold_throttle_type = SETTING_NAV_MC_ALTHOLD_THROTTLE_DEFAULT,                        // STICK
         .inverted_crash_detection = SETTING_NAV_MC_INVERTED_CRASH_DETECTION_DEFAULT,             // 0 - disarm time delay for inverted crash detection
+        .toiletbowl_detection = SETTING_NAV_MC_TOILETBOWL_DETECTION_DEFAULT,                     // 0 - sensitivity factor for toilet bowling detection
     },
 
     // Fixed wing
@@ -252,6 +253,7 @@ static navWapointHeading_t wpHeadingControl;
 navigationPosControl_t posControl;
 navSystemStatus_t NAV_Status;
 static bool landingDetectorIsActive;
+int16_t toiletBowlingHeadingCorrection;    // Indicates toilet bowling detected multirotor
 
 EXTENDED_FASTRAM multicopterPosXyCoefficients_t multicopterPosXyCoefficients;
 
diff --git a/src/main/navigation/navigation.h b/src/main/navigation/navigation.h
index eb1621e9f8d..4e69f02a649 100644
--- a/src/main/navigation/navigation.h
+++ b/src/main/navigation/navigation.h
@@ -197,7 +197,7 @@ typedef struct geozone_s {
     int32_t distanceHorToNearestZone;
     int32_t distanceVertToNearestZone;
     int32_t zoneInfo;
-    int32_t currentzoneMaxAltitude; 
+    int32_t currentzoneMaxAltitude;
     int32_t currentzoneMinAltitude;
     bool nearestHorZoneHasAction;
     bool sticksLocked;
@@ -464,6 +464,7 @@ typedef struct navConfig_s {
         bool slowDownForTurning;                // Slow down during WP missions when changing heading on next waypoint
         uint8_t althold_throttle_type;          // throttle zero datum type for alt hold
         uint8_t inverted_crash_detection;       // Enables inverted crash detection, setting defines disarm time delay (0 = disabled)
+        uint8_t toiletbowl_detection;           // Enables toilet bowling detection and heading correction (0 = disabled)
     } mc;
 
     struct {
diff --git a/src/main/navigation/navigation_multicopter.c b/src/main/navigation/navigation_multicopter.c
index 5d4b7a5b425..e12a6ca25a4 100644
--- a/src/main/navigation/navigation_multicopter.c
+++ b/src/main/navigation/navigation_multicopter.c
@@ -492,6 +492,33 @@ static float getVelocityExpoAttenuationFactor(float velTotal, float velMax)
     return 1.0f - posControl.posResponseExpo * (1.0f - (velScale * velScale));  // x^3 expo factor
 }
 
+static void isToiletBowlingDetected(void)
+{
+    static timeMs_t startTime = 0;
+
+    uint16_t courseToHoldPoint = calculateBearingToDestination(&posControl.desiredState.pos);
+    int16_t courseError = wrap_18000(courseToHoldPoint - 10 * gpsSol.groundCourse);
+    bool courseErrorCheck = ABS(courseError) > 3000 && ABS(courseError) < 15500;
+
+    uint16_t distanceToHoldPoint = calculateDistanceToDestination(&posControl.desiredState.pos);
+    bool distanceSpeedCheck = posControl.actualState.velXY * distanceToHoldPoint > (navConfig()->mc.toiletbowl_detection * 10000);
+
+    if (toiletBowlingHeadingCorrection) {
+        uint16_t correctedHeading = wrap_36000(posControl.actualState.yaw - 0.67 * toiletBowlingHeadingCorrection);
+        posControl.actualState.sinYaw = sin_approx(CENTIDEGREES_TO_RADIANS(correctedHeading));
+        posControl.actualState.cosYaw = cos_approx(CENTIDEGREES_TO_RADIANS(correctedHeading));
+    } else if (posControl.actualState.velXY > 100 && distanceToHoldPoint > 100 && courseErrorCheck  && distanceSpeedCheck) {
+        if (startTime == 0) {
+            startTime = millis();
+        } else if (millis() - startTime > 1000) {
+            // Try to correct heading error
+            toiletBowlingHeadingCorrection = courseError;
+        }
+    } else {
+        startTime = 0;
+    }
+}
+
 static void updatePositionVelocityController_MC(const float maxSpeed)
 {
     if (FLIGHT_MODE(NAV_COURSE_HOLD_MODE)) {
@@ -507,6 +534,12 @@ static void updatePositionVelocityController_MC(const float maxSpeed)
         }
     }
 
+    if (navConfig()->mc.toiletbowl_detection && isNavHoldPositionActive()) {
+        isToiletBowlingDetected();
+    } else {
+        toiletBowlingHeadingCorrection = 0;
+    }
+
     const float posErrorX = posControl.desiredState.pos.x - navGetCurrentActualPositionAndVelocity()->pos.x;
     const float posErrorY = posControl.desiredState.pos.y - navGetCurrentActualPositionAndVelocity()->pos.y;
 
diff --git a/src/main/navigation/navigation_private.h b/src/main/navigation/navigation_private.h
index a1f07e470c0..d656c33c15b 100644
--- a/src/main/navigation/navigation_private.h
+++ b/src/main/navigation/navigation_private.h
@@ -526,6 +526,7 @@ PG_DECLARE_ARRAY(navWaypoint_t, NAV_MAX_WAYPOINTS, nonVolatileWaypointList);
 
 extern navigationPosControl_t posControl;
 extern multicopterPosXyCoefficients_t multicopterPosXyCoefficients;
+extern int16_t toiletBowlingHeadingCorrection;
 
 /* Internally used functions */
 const navEstimatedPosVel_t * navGetCurrentActualPositionAndVelocity(void);

From ff7bbfb4b764e8db560106427d036d85e4667e53 Mon Sep 17 00:00:00 2001
From: breadoven <56191411+breadoven@users.noreply.github.com>
Date: Thu, 8 May 2025 11:07:24 +0100
Subject: [PATCH 2/6] improvements

---
 src/main/io/osd.c                            |  2 +-
 src/main/io/osd.h                            |  2 +-
 src/main/navigation/navigation.c             |  3 +-
 src/main/navigation/navigation_multicopter.c | 73 +++++++++++---------
 src/main/navigation/navigation_private.h     |  2 +-
 5 files changed, 45 insertions(+), 37 deletions(-)

diff --git a/src/main/io/osd.c b/src/main/io/osd.c
index f34a38f6401..f27ad480dfb 100644
--- a/src/main/io/osd.c
+++ b/src/main/io/osd.c
@@ -6359,7 +6359,7 @@ textAttributes_t osdGetSystemMessage(char *buff, size_t buff_size, bool isCenter
                     }
                 }
             }
-            if (STATE(MULTIROTOR) && isNavHoldPositionActive() && toiletBowlingHeadingCorrection) {
+            if (STATE(MULTIROTOR) && mcToiletBowlingHeadingCorrection) {
                 messages[messageCount++] = OSD_MESSAGE_STR(OSD_MSG_TOILET_BOWL);
             }
         } else if (ARMING_FLAG(ARMING_DISABLED_ALL_FLAGS)) {    /* ADDS MAXIMUM OF 2 MESSAGES TO TOTAL */
diff --git a/src/main/io/osd.h b/src/main/io/osd.h
index f0cc299a519..10b6f0fadbd 100644
--- a/src/main/io/osd.h
+++ b/src/main/io/osd.h
@@ -124,7 +124,7 @@
 #define OSD_MSG_ANGLEHOLD_PITCH     "(ANGLEHOLD PITCH)"
 #define OSD_MSG_ANGLEHOLD_LEVEL     "(ANGLEHOLD LEVEL)"
 #define OSD_MSG_MOVE_STICKS         "MOVE STICKS TO ABORT"
-#define OSD_MSG_TOILET_BOWL         "TOILET BOWLING !"
+#define OSD_MSG_TOILET_BOWL         "!TOILET BOWLING!"
 
 #ifdef USE_DEV_TOOLS
 #define OSD_MSG_GRD_TEST_MODE       "GRD TEST > MOTORS DISABLED"
diff --git a/src/main/navigation/navigation.c b/src/main/navigation/navigation.c
index e655d1dce4f..78a1fb93d04 100644
--- a/src/main/navigation/navigation.c
+++ b/src/main/navigation/navigation.c
@@ -253,7 +253,7 @@ static navWapointHeading_t wpHeadingControl;
 navigationPosControl_t posControl;
 navSystemStatus_t NAV_Status;
 static bool landingDetectorIsActive;
-int16_t toiletBowlingHeadingCorrection;    // Indicates toilet bowling detected multirotor
+int16_t mcToiletBowlingHeadingCorrection;    // Indicates toilet bowling detected multirotor
 
 EXTENDED_FASTRAM multicopterPosXyCoefficients_t multicopterPosXyCoefficients;
 
@@ -1287,6 +1287,7 @@ static navigationFSMEvent_t navOnEnteringState_NAV_STATE_IDLE(navigationFSMState
     resetAltitudeController(false);
     resetHeadingController();
     resetPositionController();
+    mcToiletBowlingHeadingCorrection = 0;
 #ifdef USE_FW_AUTOLAND
     resetFwAutoland();
 #endif
diff --git a/src/main/navigation/navigation_multicopter.c b/src/main/navigation/navigation_multicopter.c
index e12a6ca25a4..7da751cc009 100644
--- a/src/main/navigation/navigation_multicopter.c
+++ b/src/main/navigation/navigation_multicopter.c
@@ -492,33 +492,6 @@ static float getVelocityExpoAttenuationFactor(float velTotal, float velMax)
     return 1.0f - posControl.posResponseExpo * (1.0f - (velScale * velScale));  // x^3 expo factor
 }
 
-static void isToiletBowlingDetected(void)
-{
-    static timeMs_t startTime = 0;
-
-    uint16_t courseToHoldPoint = calculateBearingToDestination(&posControl.desiredState.pos);
-    int16_t courseError = wrap_18000(courseToHoldPoint - 10 * gpsSol.groundCourse);
-    bool courseErrorCheck = ABS(courseError) > 3000 && ABS(courseError) < 15500;
-
-    uint16_t distanceToHoldPoint = calculateDistanceToDestination(&posControl.desiredState.pos);
-    bool distanceSpeedCheck = posControl.actualState.velXY * distanceToHoldPoint > (navConfig()->mc.toiletbowl_detection * 10000);
-
-    if (toiletBowlingHeadingCorrection) {
-        uint16_t correctedHeading = wrap_36000(posControl.actualState.yaw - 0.67 * toiletBowlingHeadingCorrection);
-        posControl.actualState.sinYaw = sin_approx(CENTIDEGREES_TO_RADIANS(correctedHeading));
-        posControl.actualState.cosYaw = cos_approx(CENTIDEGREES_TO_RADIANS(correctedHeading));
-    } else if (posControl.actualState.velXY > 100 && distanceToHoldPoint > 100 && courseErrorCheck  && distanceSpeedCheck) {
-        if (startTime == 0) {
-            startTime = millis();
-        } else if (millis() - startTime > 1000) {
-            // Try to correct heading error
-            toiletBowlingHeadingCorrection = courseError;
-        }
-    } else {
-        startTime = 0;
-    }
-}
-
 static void updatePositionVelocityController_MC(const float maxSpeed)
 {
     if (FLIGHT_MODE(NAV_COURSE_HOLD_MODE)) {
@@ -534,12 +507,6 @@ static void updatePositionVelocityController_MC(const float maxSpeed)
         }
     }
 
-    if (navConfig()->mc.toiletbowl_detection && isNavHoldPositionActive()) {
-        isToiletBowlingDetected();
-    } else {
-        toiletBowlingHeadingCorrection = 0;
-    }
-
     const float posErrorX = posControl.desiredState.pos.x - navGetCurrentActualPositionAndVelocity()->pos.x;
     const float posErrorY = posControl.desiredState.pos.y - navGetCurrentActualPositionAndVelocity()->pos.y;
 
@@ -596,8 +563,48 @@ static float computeVelocityScale(
     return constrainf(scale, 0, attenuationFactor);
 }
 
+static void checkForToiletBowling(void)
+{
+    bool isHoldingPosition = ((FLIGHT_MODE(NAV_COURSE_HOLD_MODE) && posControl.cruise.multicopterSpeed < 50) || navGetCurrentStateFlags() & NAV_CTL_HOLD);
+    uint16_t distanceToHoldPoint = calculateDistanceToDestination(&posControl.desiredState.pos);
+
+    if (posControl.actualState.velXY < 100 || distanceToHoldPoint < 100 || !isHoldingPosition || posControl.flags.isAdjustingPosition) {
+        return;
+    }
+
+    /* Compare required course back to hold point against actual GPS CoG
+     * Toilet bowling likely if heading error > 30 dges. Also ignore errors > 155 degs -> could be caused by gusting wind */
+    int16_t courseError = wrap_18000(calculateBearingToDestination(&posControl.desiredState.pos) - 10 * gpsSol.groundCourse);
+    bool courseErrorCheck = ABS(courseError) > 3000 && ABS(courseError) < 15500;
+
+    /* vel x distanceToHoldPoint provides good indication of toilet bowling with value rising rapidly when hold control is lost */
+    bool distanceSpeedCheck = posControl.actualState.velXY * distanceToHoldPoint > (navConfig()->mc.toiletbowl_detection * 10000);
+
+    static timeMs_t startTime = 0;
+    if (courseErrorCheck && distanceSpeedCheck) {
+        if (startTime == 0) {
+            startTime = millis();
+        } else if (millis() - startTime > 1000) {
+            /* Set heading correction if check conditions exist > 1s. 2/3 of actual course error seems to work best */
+            mcToiletBowlingHeadingCorrection = 0.67 * courseError;
+        }
+    } else {
+        startTime = 0;
+    }
+}
+
 static void updatePositionAccelController_MC(timeDelta_t deltaMicros, float maxAccelLimit, const float maxSpeed)
 {
+    if (navConfig()->mc.toiletbowl_detection) {
+        if (mcToiletBowlingHeadingCorrection) {
+            uint16_t correctedHeading = wrap_36000(posControl.actualState.yaw - mcToiletBowlingHeadingCorrection);
+            posControl.actualState.sinYaw = sin_approx(CENTIDEGREES_TO_RADIANS(correctedHeading));
+            posControl.actualState.cosYaw = cos_approx(CENTIDEGREES_TO_RADIANS(correctedHeading));
+        } else {
+            checkForToiletBowling();
+        }
+    }
+
     const float measurementX = navGetCurrentActualPositionAndVelocity()->vel.x;
     const float measurementY = navGetCurrentActualPositionAndVelocity()->vel.y;
 
diff --git a/src/main/navigation/navigation_private.h b/src/main/navigation/navigation_private.h
index d656c33c15b..7b2bfac7537 100644
--- a/src/main/navigation/navigation_private.h
+++ b/src/main/navigation/navigation_private.h
@@ -526,7 +526,7 @@ PG_DECLARE_ARRAY(navWaypoint_t, NAV_MAX_WAYPOINTS, nonVolatileWaypointList);
 
 extern navigationPosControl_t posControl;
 extern multicopterPosXyCoefficients_t multicopterPosXyCoefficients;
-extern int16_t toiletBowlingHeadingCorrection;
+extern int16_t mcToiletBowlingHeadingCorrection;
 
 /* Internally used functions */
 const navEstimatedPosVel_t * navGetCurrentActualPositionAndVelocity(void);

From f95b489987a39a3f3238fc0d04fdf4879f3dcc9c Mon Sep 17 00:00:00 2001
From: breadoven <56191411+breadoven@users.noreply.github.com>
Date: Tue, 1 Jul 2025 22:59:21 +0100
Subject: [PATCH 3/6] fixes

---
 src/main/io/osd.h                            | 2 +-
 src/main/navigation/navigation.c             | 1 -
 src/main/navigation/navigation_multicopter.c | 6 ++++--
 3 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/main/io/osd.h b/src/main/io/osd.h
index 10b6f0fadbd..55ac371077c 100644
--- a/src/main/io/osd.h
+++ b/src/main/io/osd.h
@@ -124,7 +124,7 @@
 #define OSD_MSG_ANGLEHOLD_PITCH     "(ANGLEHOLD PITCH)"
 #define OSD_MSG_ANGLEHOLD_LEVEL     "(ANGLEHOLD LEVEL)"
 #define OSD_MSG_MOVE_STICKS         "MOVE STICKS TO ABORT"
-#define OSD_MSG_TOILET_BOWL         "!TOILET BOWLING!"
+#define OSD_MSG_TOILET_BOWL         "!MAG BAD>FIX ATTEMPTED!"
 
 #ifdef USE_DEV_TOOLS
 #define OSD_MSG_GRD_TEST_MODE       "GRD TEST > MOTORS DISABLED"
diff --git a/src/main/navigation/navigation.c b/src/main/navigation/navigation.c
index 78a1fb93d04..ad116ebd9fa 100644
--- a/src/main/navigation/navigation.c
+++ b/src/main/navigation/navigation.c
@@ -1287,7 +1287,6 @@ static navigationFSMEvent_t navOnEnteringState_NAV_STATE_IDLE(navigationFSMState
     resetAltitudeController(false);
     resetHeadingController();
     resetPositionController();
-    mcToiletBowlingHeadingCorrection = 0;
 #ifdef USE_FW_AUTOLAND
     resetFwAutoland();
 #endif
diff --git a/src/main/navigation/navigation_multicopter.c b/src/main/navigation/navigation_multicopter.c
index 7da751cc009..758c46786af 100644
--- a/src/main/navigation/navigation_multicopter.c
+++ b/src/main/navigation/navigation_multicopter.c
@@ -568,7 +568,8 @@ static void checkForToiletBowling(void)
     bool isHoldingPosition = ((FLIGHT_MODE(NAV_COURSE_HOLD_MODE) && posControl.cruise.multicopterSpeed < 50) || navGetCurrentStateFlags() & NAV_CTL_HOLD);
     uint16_t distanceToHoldPoint = calculateDistanceToDestination(&posControl.desiredState.pos);
 
-    if (posControl.actualState.velXY < 100 || distanceToHoldPoint < 100 || !isHoldingPosition || posControl.flags.isAdjustingPosition) {
+    if (posControl.actualState.velXY < 100 || distanceToHoldPoint < 100 || !isHoldingPosition || (posControl.flags.isAdjustingPosition && navConfig()->general.flags.user_control_mode == NAV_GPS_ATTI)) {
+
         return;
     }
 
@@ -585,7 +586,7 @@ static void checkForToiletBowling(void)
         if (startTime == 0) {
             startTime = millis();
         } else if (millis() - startTime > 1000) {
-            /* Set heading correction if check conditions exist > 1s. 2/3 of actual course error seems to work best */
+            /* Set heading correction if check conditions exist > 1 sec. 2/3 of actual course error seems to work best */
             mcToiletBowlingHeadingCorrection = 0.67 * courseError;
         }
     } else {
@@ -1050,6 +1051,7 @@ void calculateMulticopterInitialHoldPosition(fpVector3_t * pos)
 void resetMulticopterHeadingController(void)
 {
     updateHeadingHoldTarget(CENTIDEGREES_TO_DEGREES(posControl.actualState.yaw));
+    mcToiletBowlingHeadingCorrection = 0;
 }
 
 static void applyMulticopterHeadingController(void)

From 1c05da0c750584230b2be94e79b7d2a50b216e04 Mon Sep 17 00:00:00 2001
From: breadoven <56191411+breadoven@users.noreply.github.com>
Date: Wed, 22 Apr 2026 20:58:34 +0100
Subject: [PATCH 4/6] change setting functionality + osd message

---
 docs/Settings.md                             |  4 ++--
 src/main/fc/settings.yaml                    |  4 ++--
 src/main/io/osd.h                            |  2 +-
 src/main/navigation/navigation_multicopter.c | 15 +++++++++++----
 4 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/docs/Settings.md b/docs/Settings.md
index 0d676b47ea6..317987b4bee 100644
--- a/docs/Settings.md
+++ b/docs/Settings.md
@@ -4054,11 +4054,11 @@ P gain of altitude PID controller (Multirotor)
 
 ### nav_mc_toiletbowl_detection
 
-Sets sensitivity of toilet bowling detection for multirotors. On detection a heading correction is applied which should stop the toilet bowling. A setting of 2 works well for 5 inch multirotors. Increasing the setting will reduce sensitivity and delay detection. Set to 0 to disable. (Toilet bowling occurs most obviously during position hold when an inaccurate compass heading causes a rapidly increasing fast sweeping bowl shaped flight path).
+Sets the sensitivity of toilet bowling detection for multirotors and whether a heading correction is applied on detection which should stop the toilet bowling occuring. Sensitivity can be set from 1 to 9. A setting of 2 works well for 5 inch multirotors. Increasing the setting will reduce sensitivity and delay detection. If a heading correction is required on detection the sensitivity setting should be multiplied by 10, e.g. set to 20 for a sensitivity of 2 with heading correction on detection. If no heading correction is required, e.g. setting of 2, then toilet bowling detection will be indicated only by an OSD system message. Set to 0 to disable detection entirely.
 
 | Default | Min | Max |
 | --- | --- | --- |
-| 0 | 0 | 20 |
+| 0 | 0 | 90 |
 
 ---
 
diff --git a/src/main/fc/settings.yaml b/src/main/fc/settings.yaml
index 362f89527b6..432287d9eb4 100644
--- a/src/main/fc/settings.yaml
+++ b/src/main/fc/settings.yaml
@@ -2572,11 +2572,11 @@ groups:
         min: 0
         max: 15
       - name: nav_mc_toiletbowl_detection
-        description: "Sets sensitivity of toilet bowling detection for multirotors. On detection a heading correction is applied which should stop the toilet bowling. A setting of 2 works well for 5 inch multirotors. Increasing the setting will reduce sensitivity and delay detection. Set to 0 to disable. (Toilet bowling occurs most obviously during position hold when an inaccurate compass heading causes a rapidly increasing fast sweeping bowl shaped flight path)."
+        description: "Sets the sensitivity of toilet bowling detection for multirotors and whether a heading correction is applied on detection which should stop the toilet bowling occuring. Sensitivity can be set from 1 to 9. A setting of 2 works well for 5 inch multirotors. Increasing the setting will reduce sensitivity and delay detection. If a heading correction is required on detection the sensitivity setting should be multiplied by 10, e.g. set to 20 for a sensitivity of 2 with heading correction on detection. If no heading correction is required, e.g. setting of 2, then toilet bowling detection will be indicated only by an OSD system message. Set to 0 to disable detection entirely."
         default_value: 0
         field: mc.toiletbowl_detection
         min: 0
-        max: 20
+        max: 90
       - name: nav_mc_althold_throttle
         description: "If set to STICK the FC remembers the throttle stick position when enabling ALTHOLD and treats it as the neutral midpoint for holding altitude. If set to MID_STICK or HOVER the neutral midpoint is set to the mid stick position or the hover throttle position respectively."
         default_value: "STICK"
diff --git a/src/main/io/osd.h b/src/main/io/osd.h
index 55ac371077c..0f77de99fdc 100644
--- a/src/main/io/osd.h
+++ b/src/main/io/osd.h
@@ -124,7 +124,7 @@
 #define OSD_MSG_ANGLEHOLD_PITCH     "(ANGLEHOLD PITCH)"
 #define OSD_MSG_ANGLEHOLD_LEVEL     "(ANGLEHOLD LEVEL)"
 #define OSD_MSG_MOVE_STICKS         "MOVE STICKS TO ABORT"
-#define OSD_MSG_TOILET_BOWL         "!MAG BAD>FIX ATTEMPTED!"
+#define OSD_MSG_TOILET_BOWL         "!TOILET BOWLING DETECTED!"
 
 #ifdef USE_DEV_TOOLS
 #define OSD_MSG_GRD_TEST_MODE       "GRD TEST > MOTORS DISABLED"
diff --git a/src/main/navigation/navigation_multicopter.c b/src/main/navigation/navigation_multicopter.c
index 758c46786af..8d4716ef8b0 100644
--- a/src/main/navigation/navigation_multicopter.c
+++ b/src/main/navigation/navigation_multicopter.c
@@ -578,8 +578,13 @@ static void checkForToiletBowling(void)
     int16_t courseError = wrap_18000(calculateBearingToDestination(&posControl.desiredState.pos) - 10 * gpsSol.groundCourse);
     bool courseErrorCheck = ABS(courseError) > 3000 && ABS(courseError) < 15500;
 
+    uint8_t sensitivity = navConfig()->mc.toiletbowl_detection;
+    if (sensitivity > 9) {
+        sensitivity /= 10;
+    }
+
     /* vel x distanceToHoldPoint provides good indication of toilet bowling with value rising rapidly when hold control is lost */
-    bool distanceSpeedCheck = posControl.actualState.velXY * distanceToHoldPoint > (navConfig()->mc.toiletbowl_detection * 10000);
+    bool distanceSpeedCheck = posControl.actualState.velXY * distanceToHoldPoint > (sensitivity * 10000);
 
     static timeMs_t startTime = 0;
     if (courseErrorCheck && distanceSpeedCheck) {
@@ -598,9 +603,11 @@ static void updatePositionAccelController_MC(timeDelta_t deltaMicros, float maxA
 {
     if (navConfig()->mc.toiletbowl_detection) {
         if (mcToiletBowlingHeadingCorrection) {
-            uint16_t correctedHeading = wrap_36000(posControl.actualState.yaw - mcToiletBowlingHeadingCorrection);
-            posControl.actualState.sinYaw = sin_approx(CENTIDEGREES_TO_RADIANS(correctedHeading));
-            posControl.actualState.cosYaw = cos_approx(CENTIDEGREES_TO_RADIANS(correctedHeading));
+            if (navConfig()->mc.toiletbowl_detection > 9) {
+                uint16_t correctedHeading = wrap_36000(posControl.actualState.yaw - mcToiletBowlingHeadingCorrection);
+                posControl.actualState.sinYaw = sin_approx(CENTIDEGREES_TO_RADIANS(correctedHeading));
+                posControl.actualState.cosYaw = cos_approx(CENTIDEGREES_TO_RADIANS(correctedHeading));
+            }
         } else {
             checkForToiletBowling();
         }

From 7351a646072867d292fb84ee9788afc58488f5d6 Mon Sep 17 00:00:00 2001
From: breadoven <56191411+breadoven@users.noreply.github.com>
Date: Thu, 28 May 2026 12:11:54 +0100
Subject: [PATCH 5/6] change to warning only, setting removed

---
 docs/Settings.md                             | 10 ------
 src/main/fc/settings.yaml                    |  6 ----
 src/main/io/osd.c                            |  2 +-
 src/main/navigation/navigation.c             | 10 +++---
 src/main/navigation/navigation.h             |  1 -
 src/main/navigation/navigation_multicopter.c | 34 ++++++--------------
 src/main/navigation/navigation_private.h     |  2 +-
 7 files changed, 16 insertions(+), 49 deletions(-)

diff --git a/docs/Settings.md b/docs/Settings.md
index 317987b4bee..39e3de90d52 100644
--- a/docs/Settings.md
+++ b/docs/Settings.md
@@ -4052,16 +4052,6 @@ P gain of altitude PID controller (Multirotor)
 
 ---
 
-### nav_mc_toiletbowl_detection
-
-Sets the sensitivity of toilet bowling detection for multirotors and whether a heading correction is applied on detection which should stop the toilet bowling occuring. Sensitivity can be set from 1 to 9. A setting of 2 works well for 5 inch multirotors. Increasing the setting will reduce sensitivity and delay detection. If a heading correction is required on detection the sensitivity setting should be multiplied by 10, e.g. set to 20 for a sensitivity of 2 with heading correction on detection. If no heading correction is required, e.g. setting of 2, then toilet bowling detection will be indicated only by an OSD system message. Set to 0 to disable detection entirely.
-
-| Default | Min | Max |
-| --- | --- | --- |
-| 0 | 0 | 90 |
-
----
-
 ### nav_mc_vel_xy_d
 
 D gain of Position-Rate (Velocity to Acceleration) PID controller. It can damp P and I. Increasing D might help when drone overshoots target.
diff --git a/src/main/fc/settings.yaml b/src/main/fc/settings.yaml
index 432287d9eb4..6ef471e3bb0 100644
--- a/src/main/fc/settings.yaml
+++ b/src/main/fc/settings.yaml
@@ -2571,12 +2571,6 @@ groups:
         field: mc.inverted_crash_detection
         min: 0
         max: 15
-      - name: nav_mc_toiletbowl_detection
-        description: "Sets the sensitivity of toilet bowling detection for multirotors and whether a heading correction is applied on detection which should stop the toilet bowling occuring. Sensitivity can be set from 1 to 9. A setting of 2 works well for 5 inch multirotors. Increasing the setting will reduce sensitivity and delay detection. If a heading correction is required on detection the sensitivity setting should be multiplied by 10, e.g. set to 20 for a sensitivity of 2 with heading correction on detection. If no heading correction is required, e.g. setting of 2, then toilet bowling detection will be indicated only by an OSD system message. Set to 0 to disable detection entirely."
-        default_value: 0
-        field: mc.toiletbowl_detection
-        min: 0
-        max: 90
       - name: nav_mc_althold_throttle
         description: "If set to STICK the FC remembers the throttle stick position when enabling ALTHOLD and treats it as the neutral midpoint for holding altitude. If set to MID_STICK or HOVER the neutral midpoint is set to the mid stick position or the hover throttle position respectively."
         default_value: "STICK"
diff --git a/src/main/io/osd.c b/src/main/io/osd.c
index f27ad480dfb..d53c9ffc038 100644
--- a/src/main/io/osd.c
+++ b/src/main/io/osd.c
@@ -6359,7 +6359,7 @@ textAttributes_t osdGetSystemMessage(char *buff, size_t buff_size, bool isCenter
                     }
                 }
             }
-            if (STATE(MULTIROTOR) && mcToiletBowlingHeadingCorrection) {
+            if (STATE(MULTIROTOR) && mcToiletBowlingDetected) {
                 messages[messageCount++] = OSD_MESSAGE_STR(OSD_MSG_TOILET_BOWL);
             }
         } else if (ARMING_FLAG(ARMING_DISABLED_ALL_FLAGS)) {    /* ADDS MAXIMUM OF 2 MESSAGES TO TOTAL */
diff --git a/src/main/navigation/navigation.c b/src/main/navigation/navigation.c
index ad116ebd9fa..ed4fdf3bf38 100644
--- a/src/main/navigation/navigation.c
+++ b/src/main/navigation/navigation.c
@@ -201,7 +201,6 @@ PG_RESET_TEMPLATE(navConfig_t, navConfig,
         .slowDownForTurning = SETTING_NAV_MC_WP_SLOWDOWN_DEFAULT,
         .althold_throttle_type = SETTING_NAV_MC_ALTHOLD_THROTTLE_DEFAULT,                        // STICK
         .inverted_crash_detection = SETTING_NAV_MC_INVERTED_CRASH_DETECTION_DEFAULT,             // 0 - disarm time delay for inverted crash detection
-        .toiletbowl_detection = SETTING_NAV_MC_TOILETBOWL_DETECTION_DEFAULT,                     // 0 - sensitivity factor for toilet bowling detection
     },
 
     // Fixed wing
@@ -253,7 +252,6 @@ static navWapointHeading_t wpHeadingControl;
 navigationPosControl_t posControl;
 navSystemStatus_t NAV_Status;
 static bool landingDetectorIsActive;
-int16_t mcToiletBowlingHeadingCorrection;    // Indicates toilet bowling detected multirotor
 
 EXTENDED_FASTRAM multicopterPosXyCoefficients_t multicopterPosXyCoefficients;
 
@@ -3876,10 +3874,10 @@ void getWaypoint(uint8_t wpNumber, navWaypoint_t * wpData)
 
 int isGCSValid(void)
 {
-    return (ARMING_FLAG(ARMED) && 
-            (posControl.flags.estPosStatus >= EST_TRUSTED) && 
-            posControl.gpsOrigin.valid && 
-            posControl.flags.isGCSAssistedNavigationEnabled && 
+    return (ARMING_FLAG(ARMED) &&
+            (posControl.flags.estPosStatus >= EST_TRUSTED) &&
+            posControl.gpsOrigin.valid &&
+            posControl.flags.isGCSAssistedNavigationEnabled &&
             (posControl.navState == NAV_STATE_POSHOLD_3D_IN_PROGRESS));
 }
 
diff --git a/src/main/navigation/navigation.h b/src/main/navigation/navigation.h
index 4e69f02a649..44e59898201 100644
--- a/src/main/navigation/navigation.h
+++ b/src/main/navigation/navigation.h
@@ -464,7 +464,6 @@ typedef struct navConfig_s {
         bool slowDownForTurning;                // Slow down during WP missions when changing heading on next waypoint
         uint8_t althold_throttle_type;          // throttle zero datum type for alt hold
         uint8_t inverted_crash_detection;       // Enables inverted crash detection, setting defines disarm time delay (0 = disabled)
-        uint8_t toiletbowl_detection;           // Enables toilet bowling detection and heading correction (0 = disabled)
     } mc;
 
     struct {
diff --git a/src/main/navigation/navigation_multicopter.c b/src/main/navigation/navigation_multicopter.c
index 8d4716ef8b0..de3b0a41c64 100644
--- a/src/main/navigation/navigation_multicopter.c
+++ b/src/main/navigation/navigation_multicopter.c
@@ -63,6 +63,7 @@ static int16_t altHoldThrottleRCZero = 1500;
 static pt1Filter_t altholdThrottleFilterState;
 static bool prepareForTakeoffOnReset = false;
 static sqrt_controller_t alt_hold_sqrt_controller;
+bool mcToiletBowlingDetected;
 
 float getSqrtControllerVelocity(float targetAltitude, timeDelta_t deltaMicros)
 {
@@ -568,8 +569,7 @@ static void checkForToiletBowling(void)
     bool isHoldingPosition = ((FLIGHT_MODE(NAV_COURSE_HOLD_MODE) && posControl.cruise.multicopterSpeed < 50) || navGetCurrentStateFlags() & NAV_CTL_HOLD);
     uint16_t distanceToHoldPoint = calculateDistanceToDestination(&posControl.desiredState.pos);
 
-    if (posControl.actualState.velXY < 100 || distanceToHoldPoint < 100 || !isHoldingPosition || (posControl.flags.isAdjustingPosition && navConfig()->general.flags.user_control_mode == NAV_GPS_ATTI)) {
-
+    if (!isHoldingPosition || posControl.actualState.velXY < 100 || distanceToHoldPoint < 100 || (posControl.flags.isAdjustingPosition && navConfig()->general.flags.user_control_mode == NAV_GPS_ATTI)) {
         return;
     }
 
@@ -578,21 +578,17 @@ static void checkForToiletBowling(void)
     int16_t courseError = wrap_18000(calculateBearingToDestination(&posControl.desiredState.pos) - 10 * gpsSol.groundCourse);
     bool courseErrorCheck = ABS(courseError) > 3000 && ABS(courseError) < 15500;
 
-    uint8_t sensitivity = navConfig()->mc.toiletbowl_detection;
-    if (sensitivity > 9) {
-        sensitivity /= 10;
-    }
-
-    /* vel x distanceToHoldPoint provides good indication of toilet bowling with value rising rapidly when hold control is lost */
-    bool distanceSpeedCheck = posControl.actualState.velXY * distanceToHoldPoint > (sensitivity * 10000);
+    /* vel x distanceToHoldPoint provides good indication of toilet bowling with value rising rapidly when hold control is lost
+     * 30000 should provide a reliable detection threshold without excessive delay or false triggers */
+    bool distanceSpeedCheck = posControl.actualState.velXY * distanceToHoldPoint > (30000);
 
     static timeMs_t startTime = 0;
     if (courseErrorCheck && distanceSpeedCheck) {
         if (startTime == 0) {
             startTime = millis();
-        } else if (millis() - startTime > 1000) {
-            /* Set heading correction if check conditions exist > 1 sec. 2/3 of actual course error seems to work best */
-            mcToiletBowlingHeadingCorrection = 0.67 * courseError;
+        } else {
+            // Set detection flag if check conditions exist > 1 sec
+            mcToiletBowlingDetected = millis() - startTime > 1000;
         }
     } else {
         startTime = 0;
@@ -601,17 +597,7 @@ static void checkForToiletBowling(void)
 
 static void updatePositionAccelController_MC(timeDelta_t deltaMicros, float maxAccelLimit, const float maxSpeed)
 {
-    if (navConfig()->mc.toiletbowl_detection) {
-        if (mcToiletBowlingHeadingCorrection) {
-            if (navConfig()->mc.toiletbowl_detection > 9) {
-                uint16_t correctedHeading = wrap_36000(posControl.actualState.yaw - mcToiletBowlingHeadingCorrection);
-                posControl.actualState.sinYaw = sin_approx(CENTIDEGREES_TO_RADIANS(correctedHeading));
-                posControl.actualState.cosYaw = cos_approx(CENTIDEGREES_TO_RADIANS(correctedHeading));
-            }
-        } else {
-            checkForToiletBowling();
-        }
-    }
+    if (!mcToiletBowlingDetected) checkForToiletBowling();
 
     const float measurementX = navGetCurrentActualPositionAndVelocity()->vel.x;
     const float measurementY = navGetCurrentActualPositionAndVelocity()->vel.y;
@@ -1058,7 +1044,7 @@ void calculateMulticopterInitialHoldPosition(fpVector3_t * pos)
 void resetMulticopterHeadingController(void)
 {
     updateHeadingHoldTarget(CENTIDEGREES_TO_DEGREES(posControl.actualState.yaw));
-    mcToiletBowlingHeadingCorrection = 0;
+    mcToiletBowlingDetected = false;
 }
 
 static void applyMulticopterHeadingController(void)
diff --git a/src/main/navigation/navigation_private.h b/src/main/navigation/navigation_private.h
index 7b2bfac7537..cf444e263b3 100644
--- a/src/main/navigation/navigation_private.h
+++ b/src/main/navigation/navigation_private.h
@@ -526,7 +526,7 @@ PG_DECLARE_ARRAY(navWaypoint_t, NAV_MAX_WAYPOINTS, nonVolatileWaypointList);
 
 extern navigationPosControl_t posControl;
 extern multicopterPosXyCoefficients_t multicopterPosXyCoefficients;
-extern int16_t mcToiletBowlingHeadingCorrection;
+extern bool mcToiletBowlingDetected;
 
 /* Internally used functions */
 const navEstimatedPosVel_t * navGetCurrentActualPositionAndVelocity(void);

From 353c8d9474fc56f4bd4ee03fb4fdf0eed5d74fec Mon Sep 17 00:00:00 2001
From: breadoven <56191411+breadoven@users.noreply.github.com>
Date: Thu, 28 May 2026 12:43:28 +0100
Subject: [PATCH 6/6] Update navigation_multicopter.c

---
 src/main/navigation/navigation_multicopter.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/main/navigation/navigation_multicopter.c b/src/main/navigation/navigation_multicopter.c
index de3b0a41c64..602574dbea2 100644
--- a/src/main/navigation/navigation_multicopter.c
+++ b/src/main/navigation/navigation_multicopter.c
@@ -63,7 +63,6 @@ static int16_t altHoldThrottleRCZero = 1500;
 static pt1Filter_t altholdThrottleFilterState;
 static bool prepareForTakeoffOnReset = false;
 static sqrt_controller_t alt_hold_sqrt_controller;
-bool mcToiletBowlingDetected;
 
 float getSqrtControllerVelocity(float targetAltitude, timeDelta_t deltaMicros)
 {
@@ -299,6 +298,7 @@ bool adjustMulticopterHeadingFromRCInput(void)
  * XY-position controller for multicopter aircraft
  *-----------------------------------------------------------*/
 static float lastAccelTargetX = 0.0f, lastAccelTargetY = 0.0f;
+bool mcToiletBowlingDetected;
 
 void resetMulticopterBrakingMode(void)
 {