Hello all, I am booked on a retrun JAL flight from LHR via Helsinki to Osaka in November. I am currently in Premium Economy. I have over 100k of Avios in BA to fritter away. Is there any way I can use these to upgrade one or more segments of this trip to Business with Avios? And is it worth it? I have booked via JAL, and phoned and asked them, but they seem to be unable to give me an answer. My understanding is that JAL and BA are on Oneworld, so it should be easy to do. Or am in being hopeful and green ?