I am flying in a few weeks and my doctor had to fill out a form for United Airlines. I will be using it for taxiing, takeoff and landing at 2L. I'm a little nervous about it, but I have batteries that will last a total of 18 hours (My flight is 3 hours long). I was told I can bring a medical bag with my CPAP machine and all supplies only relating to my COPD. I don't use oxygen at all but I do attach it at night at 1L for my CPAP (my doctor said I didn't have to but I feel more secure with it). Has anyone flown with POC and is 2L enough? Any advice/experience will be greatly appreciated. Thank you