It means they need 13 more than they currently have.... it does not mean the people already there are safe.... it is not simply a vacancy bid, in which case the 13 most senior people asking for LGA would get it.... it is a displacement/vacancy bid.... if they have 65 now (which they do) and they want to end up with 78.... and 100 people from other bases senior to him list LGA as there displacement preference, then he could be pushed out. Does that explain it any better? The problem here is that on a displacement, you bid and get whatever you have listed in your preferences.... base, equipment and seat. Whatever your personal seniority can hold is what you will get.