There have been a couple decent threads on this in the past year. While people have discussed various reasons as to how the airlines might rationalize banning them on planes, I think the consensus is that there's no reasonable reason to ban them. I've been able to use it on planes just fine. I usually get a flight attendant who asks me what it is. When I show it to them, they're always fascinated with it. They think it's neat to see our current speed and where we're located. I've never had a flight attendant tell me to turn it off.