I have been flying multiple times on different airlines and I have never had an issue. I have never been asked if I have enough oxygen for the flight. I have an approved portable machine and that was literally all I checked about when I took my first flight. Hope your flying experiences are as uneventful as mine.

Using 02 on a plane is easy, but it takes a lot of preparation. First you can only take a Portable 02 Concentrator, and you can only use one that's been approved by the FAA. There's a list on the FAA site of approved units. Then you need to find out what the airline you're flying expects you to do. Some require that your doc fill out a form that you carry with you and that you call the health desk for the airline to let them know that you're going to use 02 on the flight. It's important to do that, because some airlines can be very rigid and I know that people haven't been able to board if the rules haven't been followed. I think airlines are getting used to people using 02 and generally the staff are very helpful and kind, but every once in a while you'll run into someone who's just not going to let you do anything without following all the rules to the letter. You'll need to have at least 1.5 times the battery power required for all the time from wheels up on the first flight to wheels down on the last.

You'll be asked about the POC at every step of the trip: checking in,in the boarding lounge, the flight attendant: they all want to know that you know what you're doing and won't have any problems with the machine, you have enough battery power, etc. They may all ask to see the paperwork signed by your doc. I've even had an attendant take my POC to the pilot (who could have cared less!).

The most important thing is to call the health desk and ask them if you've done everything you need to do to fly that airline using a POC.