diff --git a/templates/adsb_dashboard.html b/templates/adsb_dashboard.html
index 920d1e9..2cd93bb 100644
--- a/templates/adsb_dashboard.html
+++ b/templates/adsb_dashboard.html
@@ -316,6 +316,13 @@
     </main>
 
     <script>
+        // ============================================
+        // BIAS-T HELPER (reads from main dashboard localStorage)
+        // ============================================
+        function getBiasTEnabled() {
+            return localStorage.getItem('biasTEnabled') === 'true';
+        }
+
         // ============================================
         // STATE
         // ============================================
@@ -2424,7 +2431,8 @@ sudo make install</code>
                 const adsbDevice = parseInt(document.getElementById('adsbDeviceSelect').value) || 0;
 
                 const requestBody = {
-                    device: adsbDevice
+                    device: adsbDevice,
+                    bias_t: getBiasTEnabled()
                 };
                 if (remoteConfig) {
                     requestBody.remote_sbs_host = remoteConfig.host;
@@ -2605,7 +2613,7 @@ sudo make install</code>
                 const startResponse = await fetch('/adsb/start', {
                     method: 'POST',
                     headers: { 'Content-Type': 'application/json' },
-                    body: JSON.stringify({ device: device })
+                    body: JSON.stringify({ device: device, bias_t: getBiasTEnabled() })
                 });
 
                 const result = await startResponse.json();
diff --git a/templates/adsb_history.html b/templates/adsb_history.html
index 2efdf1f..fa512f1 100644
--- a/templates/adsb_history.html
+++ b/templates/adsb_history.html
@@ -240,6 +240,11 @@
     </div>
 
     <script>
+        // Bias-T helper (reads from main dashboard localStorage)
+        function getBiasTEnabled() {
+            return localStorage.getItem('biasTEnabled') === 'true';
+        }
+
         const historyEnabled = {{ 'true' if history_enabled else 'false' }};
 
         const summaryMessages = document.getElementById('summaryMessages');
@@ -632,7 +637,7 @@
                     method: 'POST',
                     headers: { 'Content-Type': 'application/json' },
                     credentials: 'same-origin',
-                    body: JSON.stringify({ device, source: 'adsb_history' })
+                    body: JSON.stringify({ device, source: 'adsb_history', bias_t: getBiasTEnabled() })
                 });
                 if (!resp.ok) {
                     sessionNotice.textContent = 'Start failed';
diff --git a/templates/ais_dashboard.html b/templates/ais_dashboard.html
index 2c9e54b..e964f46 100644
--- a/templates/ais_dashboard.html
+++ b/templates/ais_dashboard.html
@@ -190,6 +190,11 @@
     </main>
 
     <script>
+        // Bias-T helper (reads from main dashboard localStorage)
+        function getBiasTEnabled() {
+            return localStorage.getItem('biasTEnabled') === 'true';
+        }
+
         // State
         let vesselMap = null;
         let vessels = {};
@@ -542,7 +547,7 @@
                 fetch(`/controller/agents/${aisCurrentAgent}/ais/start`, {
                     method: 'POST',
                     headers: { 'Content-Type': 'application/json' },
-                    body: JSON.stringify({ device, gain })
+                    body: JSON.stringify({ device, gain, bias_t: getBiasTEnabled() })
                 })
                 .then(r => r.json())
                 .then(result => {
@@ -567,7 +572,7 @@
             fetch('/ais/start', {
                 method: 'POST',
                 headers: { 'Content-Type': 'application/json' },
-                body: JSON.stringify({ device, gain })
+                body: JSON.stringify({ device, gain, bias_t: getBiasTEnabled() })
             })
             .then(r => r.json())
             .then(data => {
@@ -1619,7 +1624,7 @@
                 fetch(`/controller/agents/${aisCurrentAgent}/ais/start`, {
                     method: 'POST',
                     headers: { 'Content-Type': 'application/json' },
-                    body: JSON.stringify({ device, gain })
+                    body: JSON.stringify({ device, gain, bias_t: getBiasTEnabled() })
                 })
                 .then(r => r.json())
                 .then(data => {
diff --git a/templates/partials/modes/ais.html b/templates/partials/modes/ais.html
index 57dac59..0896aec 100644
--- a/templates/partials/modes/ais.html
+++ b/templates/partials/modes/ais.html
@@ -45,7 +45,7 @@
         fetch('/ais/start', {
             method: 'POST',
             headers: { 'Content-Type': 'application/json' },
-            body: JSON.stringify({ device, gain })
+            body: JSON.stringify({ device, gain, bias_t: typeof getBiasTEnabled === 'function' ? getBiasTEnabled() : false })
         })
         .then(r => r.json())
         .then(data => {