Originally Posted by ESpen36

I wouldn't read too much into the 3-class F cabin going from wide open to full within minutes at boarding time. It might not just be op-ups. Employees (non-revving for personal travel) are allowed to list for the highest available class of service, and receive those seats if inventory is available after all paid and upgrade revenue pax have been cleared. I have recently been on mulitple flights (transcon, Hawaii, etc) where the F cabin was mostly empty until just an hour before boarding, but then boarded totally full with a number of employees and their families. It's one of the perks of being an airline employee, and I'm fine with it.

Shenanigans would be if the GA working the flight cleared the non-revs before clearing all revenue upgrades and paid pax awaiting seat assignments. These days, it's less likely to happen with automated processing/auditing of flights behind the scenes, according to one agent with whom I spoke. The only way it can happen legitimately is if it's "positive-space" employee travel, sometimes called "must-ride"--typically a pilot who is being repositioned to work another flight, and his contract stipulates that he MUST travel in the F cabin when it is on-duty, work-related travel. When off-duty/commuting, pilots often have to take seats in Y, or even a jumpseat in order to squeeze aboard the last flight of the night home.