Originally Posted by Lookin4Points

The last time I flew as a D3 it was three years ago so things may have changed. I used to do it often with friends. Make sure the passenger is wearing clothes that will allow them into first class. They have a list of what is allowed and what isn't. I can't remember too many things but shorts are not allowed and there are some rules on footware also. Domestically as a D3 there is no difference in cost between coach and first. If the only seat left is in first and the passenger isn't wearing the correct things then they are not flying. The D3 fares are based on mileage. As the mileage goes up the cost per mile goes down. Pricing is based on each flight segment. So it would be cheaper to take a 100 mile flight connecting to a 1300 mile flight than a 700 mile flight connecting to a 700 mile flight. I don't know what the fees are but I paid about $150 to fly nonstop DFW-HNL-DFW. I paid about $250 to fly DFW-SCL-DFW and just under $200 to fly DFW-LIM-DFW.

The previous post about D1s, D2s, and D3s is correct. D3s are the last on the plane. Connecting passengers get better priority than originating passengers on the connecting flight, but only within that particular D pass group. I think the earliest you could check in was four hours prior.