FYI, I had no problem using the Rino 120 on 4 US Airway's flights. I used it in full view of everyone - had to keep the unit close to the window to maintain signal. I kept the radio off and only used the GPS at 10,000 ft or higher. It was a lot of fun and helped pass the time. I also used it on St. Maarten to find my first cache and also to keep track of where I was.