You must make arrangements ahead of time when flying. When you make your reservation, ask the airline about its policies on portable oxygen.
Before your trip, you need to get the airline’s permission to use oxygen. Most U.S. airlines require at least a 48-hour notice, but others need longer. Always check with your airline well before your travel date. Foreign airlines may have different requirements.
Find out which POCs are approved by the Federal Aviation Administration (FAA). You can’t bring your POC on the plane unless your airline approves it.
If you don’t have an FAA-approved POC, ask if you can rent one.
Try to get a nonstop or direct flight to prevent worries about layovers or missing a connecting flight.
Some airlines may provide oxygen for a fee.
Ask your insurance company whether you need supplementary coverage for traveling with oxygen.
Get a prescription for supplemental oxygen from your physician, and keep this with you -- always. This prescription should state your medical condition and your need for in-flight oxygen and also give specifics on how long oxygen should be used and on the oxygen flow rate.
The airlines may have their own forms for your doctor to fill out, so be sure to get these back from your doctor in plenty of time.
You might need an increase in the oxygen flow rate during air travel; your doctor will know. Be sure to talk to the doctor about this so you have no discomfort breathing during the flight.
The airlines may require you to bring ample batteries to power your POC. Most airlines require that your batteries last 50% longer (or 3 hours longer, in the case of some airlines) than the total time of your trip -- from the time you leave your home until you get to your final destination.
Some airlines may allow empty tanks to be stowed, but filled ones are not allowed aboard.