Anonymous wrote:I looked this up recently; US Airways, at least, requires the kid be 5.

I *might* send my kid alone at five, if we could escort him to the gate, if the grandparents could meet him at the gate, and (critically) if my kid was okay with it. But I really would have to wait until he was five.

FWIW, we fly reasonably frequently, he's a good flyer, and he likes flying.

You are required by the airline to take your child to the gate and there must be someone waiting for the child at the receiving airport. You get a buddy pass to get through security.

My 6 yr old flew this past summer from DC to an airport in the Midwest and did fantastic. We were able to take him to the gate with a buddy pass and my mom was at the gate at the receiving airport. My 6 yr old is fairly confident and the flight was an self esteem booster. The airline charges a $100 each way for a child flying without a guardian.

My parents sent me and my brother alone on flights starting at age 12 and 10 respectively. Nonstop flights of 3 hours or less.
I'd likely be ok with it at age 12 or so (middle schooler) for a nonstop flight of 6 hours or less. Would make sure kid had both a cell, strict instructions to call if anything came up, with friends/relatives meeting at the gate.
I'd let a teen of 14 or so (high schooler) travel on longer flights unaccompanied, with connections. Would have to make a quick call or text to let me know the connection was made and that he/she met friends/relatives at baggage claim.