Read original post at Wei-Meng Lee's Blog
Due to security reasons, your Windows Phone application is not allowed to modify some of the device’s settings directly. For example, you might want to programmatically turn on the airplane mode on the device. However, this is not allowed without the user’s explicit permission. The only way to turn on airplane mode is for the user to navigate to the Settings’s Airplane Mode page and turn it on manually.
In your application, instead of asking the user to navigate to the Settings page, you can directly bring them to the page, programmatically.