Toggle airplane mode in Android

This answer contains code necessary to do this. Also make sure you have the WRITE_SETTINGS permission.

Adapted from Controlling Airplane Mode:

// read the airplane mode setting
boolean isEnabled = Settings.System.getInt(
      getContentResolver(), 
      Settings.System.AIRPLANE_MODE_ON, 0) == 1;

// toggle airplane mode
Settings.System.putInt(
      getContentResolver(),
      Settings.System.AIRPLANE_MODE_ON, isEnabled ? 0 : 1);

// Post an intent to reload
Intent intent = new Intent(Intent.ACTION_AIRPLANE_MODE_CHANGED);
intent.putExtra("state", !isEnabled);
sendBroadcast(intent);