I am a preloaded. I also do some air driving. Mainly shuttling late air out to drivers during the week as needed; sometimes I make deliveries on Saturdays (about 2 days a month on average). I have a volunteering obligation this coming Saturday and I am afraid that I am going to be required to work (I now have the lowest seniority). Two guys on the air driver list went to FT ground. If they ask me to, am I requires to work on Saturday? What are the repercussions if I say no?