The last time I flew, the stewardess told everyone to put their phones in airplane mode. I didn’t, because my flip phone didn’t have an airplane mode. I didn’t know I was supposed to turn it off. Later she came by and said the pilot was complaining that he was still getting interference from someone’s phone. That’s when I figured it out and turned it off. I also didn’t realize that the phone boosts its signal when up there, trying to connect with a cell tower. My phone almost ran out of juice while I was out of state and I didn’t have a phone charger with me. I do have a smart phone now, so if I ever fly again, I’ll be prepared.