If you're on the 757 and want to switch to the 747, you must 1. not be subject to a transition freeze (18mo for newhires, 24mo after a lateral transition), 2. have a bid published that has original or recurred vacancies on the 747, and 3. be able to hold those original or recurred vacancies via seniority.

Newhire positions at UPS are the result of a system bid. A bid is published creating positions, all pilots on property who aren't subject to a transition freeze/seat lock can bid those original or recurred positions, and all unfilled positions after the bid is awarded are available for assignment to newhires.

Positions created by a bid are valid for 18 months. It is possible that positions remain from a previous bid when a new bid is published; those remaining positions from the first bid are only available for newhires and ARE NOT available for pilots on property to bid into on the new bid.