Totally unrelated but possibly interesting to someone: I had an issue many years ago when my daughter was four years old. We were on an Olympic 727 and she had to move because children weren't allowed in aisle seats. It seemed weird but I was told it was because of the position of drop-down masks on the 727, they might not be long enough to reach a small-person in C or D. The flight was half empty and we hadn't taken our allocated seats so my fault, but...what a great flight it was - only my second (and last) flight on a 727. I believe the allocated 737-200 had gone tech. and they had just this one 727 left in the fleet used mainly for this sort of thing. This was December 1999.