diff --git a/src/java/com/android/internal/telephony/LocaleTracker.java b/src/java/com/android/internal/telephony/LocaleTracker.java
index dc8ad32..13d7dfb 100755
--- a/src/java/com/android/internal/telephony/LocaleTracker.java
+++ b/src/java/com/android/internal/telephony/LocaleTracker.java
@@ -73,6 +73,9 @@
     /** Event for incoming cell info */
     private static final int EVENT_RESPONSE_CELL_INFO = 5;
 
+    /** Event to fire if the operator from ServiceState is considered truly lost */
+    private static final int EVENT_OPERATOR_LOST = 6;
+
     // Todo: Read this from Settings.
     /** The minimum delay to get cell info from the modem */
     private static final long CELL_INFO_MIN_DELAY_MS = 2 * SECOND_IN_MILLIS;
@@ -85,6 +88,13 @@
     /** The delay for periodically getting cell info from the modem */
     private static final long CELL_INFO_PERIODIC_POLLING_DELAY_MS = 10 * MINUTE_IN_MILLIS;
 
+    /**
+     * The delay after the last time the device camped on a cell before declaring that the
+     * ServiceState's MCC information can no longer be used (and thus kicking in the CellInfo
+     * based tracking.
+     */
+    private static final long SERVICE_OPERATOR_LOST_DELAY_MS = 10 * MINUTE_IN_MILLIS;
+
     /** The maximum fail count to prevent delay time overflow */
     private static final int MAX_FAIL_COUNT = 30;
 
@@ -166,6 +176,11 @@
                 onSimCardStateChanged(msg.arg1);
                 break;
 
+            case EVENT_OPERATOR_LOST:
+                updateOperatorNumericImmediate("");
+                updateTrackingStatus();
+                break;
+
             default:
                 throw new IllegalStateException("Unexpected message arrives. msg = " + msg.what);
         }
@@ -247,7 +262,7 @@
      *
      * @param state SIM card state. Must be one of TelephonyManager.SIM_STATE_XXX.
      */
-    private synchronized void onSimCardStateChanged(int state) {
+    private void onSimCardStateChanged(int state) {
         mSimState = state;
         updateLocale();
         updateTrackingStatus();
@@ -270,8 +285,17 @@
      * @param operatorNumeric MCC/MNC of the operator
      */
     public void updateOperatorNumeric(String operatorNumeric) {
+        if (TextUtils.isEmpty(operatorNumeric)) {
+            sendMessageDelayed(obtainMessage(EVENT_OPERATOR_LOST), SERVICE_OPERATOR_LOST_DELAY_MS);
+        } else {
+            removeMessages(EVENT_OPERATOR_LOST);
+            updateOperatorNumericImmediate(operatorNumeric);
+        }
+    }
+
+    private void updateOperatorNumericImmediate(String operatorNumeric) {
         // Check if the operator numeric changes.
-        if (!Objects.equals(mOperatorNumeric, operatorNumeric)) {
+        if (!operatorNumeric.equals(mOperatorNumeric)) {
             String msg = "Operator numeric changes to \"" + operatorNumeric + "\"";
             if (DBG) log(msg);
             mLocalLog.log(msg);
diff --git a/tests/telephonytests/src/com/android/internal/telephony/LocaleTrackerTest.java b/tests/telephonytests/src/com/android/internal/telephony/LocaleTrackerTest.java
index a14129d..d161246 100644
--- a/tests/telephonytests/src/com/android/internal/telephony/LocaleTrackerTest.java
+++ b/tests/telephonytests/src/com/android/internal/telephony/LocaleTrackerTest.java
@@ -44,14 +44,19 @@
 import org.mockito.ArgumentCaptor;
 
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.List;
 
 public class LocaleTrackerTest extends TelephonyTest {
 
     private static final String US_MCC = "310";
+    private static final String LIECHTENSTEIN_MCC = "295";
+
     private static final String FAKE_MNC = "123";
-    private static final String US_COUNTRY_CODE = "us";
+
     private static final String COUNTRY_CODE_UNAVAILABLE = "";
+    private static final String US_COUNTRY_CODE = "us";
+    private static final String LIECHTENSTEIN_COUNTRY_CODE = "li";
 
     private LocaleTracker mLocaleTracker;
 
@@ -156,11 +161,12 @@
     @Test
     @SmallTest
     public void testNoSim() throws Exception {
+        // updateOperatorNumeric("") will not trigger an instantaneous country change
         mLocaleTracker.updateOperatorNumeric("");
         sendGsmCellInfo();
         sendServiceState(ServiceState.STATE_EMERGENCY_ONLY);
         assertEquals(US_COUNTRY_CODE, mLocaleTracker.getCurrentCountry());
-        verifyCountryCodeNotified(new String[]{COUNTRY_CODE_UNAVAILABLE, US_COUNTRY_CODE});
+        verifyCountryCodeNotified(new String[]{US_COUNTRY_CODE});
         assertTrue(mLocaleTracker.isTracking());
     }
 
@@ -183,11 +189,11 @@
         verifyCountryCodeNotified(new String[]{COUNTRY_CODE_UNAVAILABLE, US_COUNTRY_CODE});
         assertFalse(mLocaleTracker.isTracking());
 
+        // updateOperatorNumeric("") will not trigger an instantaneous country change
         mLocaleTracker.updateOperatorNumeric("");
         waitForHandlerAction(mLocaleTracker, 100);
-        assertEquals(COUNTRY_CODE_UNAVAILABLE, mLocaleTracker.getCurrentCountry());
-        verifyCountryCodeNotified(new String[]{COUNTRY_CODE_UNAVAILABLE, US_COUNTRY_CODE,
-                COUNTRY_CODE_UNAVAILABLE});
+        assertEquals(US_COUNTRY_CODE, mLocaleTracker.getCurrentCountry());
+        verifyCountryCodeNotified(new String[]{COUNTRY_CODE_UNAVAILABLE, US_COUNTRY_CODE});
         sendServiceState(ServiceState.STATE_POWER_OFF);
         assertFalse(mLocaleTracker.isTracking());
     }
@@ -211,6 +217,70 @@
 
     @Test
     @SmallTest
+    public void testToggleAirplaneModeOosPlmn() throws Exception {
+        sendServiceState(ServiceState.STATE_POWER_OFF);
+        mLocaleTracker.updateOperatorNumeric("");
+        waitForHandlerAction(mLocaleTracker, 100);
+        assertEquals(COUNTRY_CODE_UNAVAILABLE, mLocaleTracker.getCurrentCountry());
+        verifyCountryCodeNotified(new String[]{COUNTRY_CODE_UNAVAILABLE});
+        assertFalse(mLocaleTracker.isTracking());
+
+        // Override the setUp() function and return an empty list for CellInfo
+        doAnswer(invocation -> {
+            Message m = invocation.getArgument(1);
+            AsyncResult.forMessage(m, Collections.emptyList(), null);
+            m.sendToTarget();
+            return null; }).when(mPhone).requestCellInfoUpdate(any(), any());
+
+        sendServiceState(ServiceState.STATE_OUT_OF_SERVICE);
+        waitForHandlerAction(mLocaleTracker, 100);
+        assertTrue(mLocaleTracker.isTracking());
+        waitForHandlerAction(mLocaleTracker, 100);
+        assertEquals(COUNTRY_CODE_UNAVAILABLE, mLocaleTracker.getCurrentCountry());
+
+        mLocaleTracker.updateOperatorNumeric(US_MCC + FAKE_MNC);
+        assertEquals(US_COUNTRY_CODE, mLocaleTracker.getCurrentCountry());
+        verifyCountryCodeNotified(new String[]{COUNTRY_CODE_UNAVAILABLE, US_COUNTRY_CODE});
+
+        mLocaleTracker.updateOperatorNumeric("");
+        waitForHandlerAction(mLocaleTracker, 100);
+        assertEquals(US_COUNTRY_CODE, mLocaleTracker.getCurrentCountry());
+        verifyCountryCodeNotified(new String[]{COUNTRY_CODE_UNAVAILABLE, US_COUNTRY_CODE});
+
+        mLocaleTracker.updateOperatorNumeric(LIECHTENSTEIN_MCC + FAKE_MNC);
+        waitForHandlerAction(mLocaleTracker, 100);
+        assertEquals(LIECHTENSTEIN_COUNTRY_CODE, mLocaleTracker.getCurrentCountry());
+        verifyCountryCodeNotified(new String[]{
+                COUNTRY_CODE_UNAVAILABLE, US_COUNTRY_CODE, LIECHTENSTEIN_COUNTRY_CODE});
+    }
+
+    @Test
+    @SmallTest
+    public void testToggleAirplaneModeNoCellInfo() throws Exception {
+        sendServiceState(ServiceState.STATE_POWER_OFF);
+        mLocaleTracker.updateOperatorNumeric("");
+        waitForHandlerAction(mLocaleTracker, 100);
+        assertEquals(COUNTRY_CODE_UNAVAILABLE, mLocaleTracker.getCurrentCountry());
+        verifyCountryCodeNotified(new String[]{COUNTRY_CODE_UNAVAILABLE});
+        assertFalse(mLocaleTracker.isTracking());
+
+        // Override the setUp() function and return an empty list for CellInfo
+        doAnswer(invocation -> {
+            Message m = invocation.getArgument(1);
+            AsyncResult.forMessage(m, Collections.emptyList(), null);
+            m.sendToTarget();
+            return null; }).when(mPhone).requestCellInfoUpdate(any(), any());
+
+        sendServiceState(ServiceState.STATE_OUT_OF_SERVICE);
+        waitForHandlerAction(mLocaleTracker, 100);
+        assertTrue(mLocaleTracker.isTracking());
+        waitForHandlerAction(mLocaleTracker, 100);
+        assertEquals(COUNTRY_CODE_UNAVAILABLE, mLocaleTracker.getCurrentCountry());
+    }
+
+
+    @Test
+    @SmallTest
     public void testGetCellInfoDelayTime() throws Exception {
         assertEquals(2000, LocaleTracker.getCellInfoDelayTime(0));
         assertEquals(2000, LocaleTracker.getCellInfoDelayTime(1));