I flew home from Richmond, VA this past March with my Inogen oxygen concentrator. It’s a little larger than a lunchbox and was the first concentrator that was FAA approved for in-flight use with a battery life of 2 to 4 hours. When I arrived at the TSA checkpoint I was the only passenger in the area, but I got he full pr0noscan plus left sided patdown while they swabbed the concentrator body and tubing (as well as my hands)for ‘residue’. Even though it says clearly on the device it is approved by the FAA for use, I was admonished to ‘not turn it on and use it while on board the aircraft’, and for awhile they were discussing making me go back and check it through as baggage. Flights are generally pressurized to 8,000 feet and there’s a good reason why I live close to sea level.
Yeah, I used it anyway. It was a bitch waiting the 15 minutes for them to decide what to do with me while they dicked around with it turned off just after I’d humped my carryons a quarter mile from the hot, humid parking garage. Waterboarding is too good for the likes of them.