Lan Chile doesn't. I expect that Iberia doesn't since they use similar seats, but I dont know for sure. The Qantas 747 I was on didn't drop down, but it was also a very old jet and I think their seats have been updated since. I believe you will find Cathay's the most comfortable in part also because your feet are not next to the person in front of you like BA's are. They are fully behind the seat.