bananahead checked in at T2, so was already airside. I'll be flying BA LHR-ARN, landing at T2, and then have a bit over two hours before my QR flight leaves ARN-DOH out of T5. Is there any way to take the airside bus after landing at T2 from LHR? Or will I need to clear passport control/immigration, walk to T5, and re-clear security there?