American Airlines was the last US flagged air carrier to offer continuous flow therapeutic medical oxygen for special needs passengers in the 48 states. As of July 23, 2012, American will no longer offer inflight medical oxygen. Alaska Airlines is the only carrier left that will provide oxygen on a limited amount of flights with in Alaska and Alaska to Seattle or Portland. Continental Micronesia also provides the in flight Therapeutic oxygen service out of Guam. You can of course use a FAA Approved Portable Oxygen Concentrator on American Airlines as well as any airline flying in and out of the US as per the Air Carrier Access Act. There are currently 12 different Portable Oxygen Concentrators that can be used on commercial airlines approved by the FAA. These machines are designed for most people using oxygen. There are some people that can not use a Portable Oxygen Concentrator. Of the 12 that are approved, 4 of the products will deliver a continuous flow. All of the machines offer a Pulse Delivery which delivers oxygen upon inspiration only up to a setting of 6 . The continuous flow machines reach a max setting of 3 LPM (Liters per Minute). Many International carriers offer on-board medical oxygen. However, those numbers are decreasing as well. Extra batteries are needed for long flights, plus any delays. There are new machines awaiting FAA approval like the SimplyGo made by Phillips Respironics. This machine is half the weight of other continuous flow portable oxygen concentrators, the batteries last longer too. It is important to understand that the advent of portable oxygen concentrators, even with their limitations, have allowed many more people to travel with oxygen than ever before. All of the low-cost carriers have had access to passengers needing medical oxygen since 2005, the first federal approval mandating the use of these machines during flight. These airlines never provided oxygen on the ground, a separate service was needed to provide airport oxygen. Portable oxygen concentrators have made traveling with oxygen so much easier. As the machines get smaller, last longer, and offer higher flows of oxygen, more people who are oxygen dependent will be able to travel. Advanced Aeromedical at aeromedic.com is an information resource for people traveling with oxygen, ready to assist at 800-346-3556 in the USA or +1-757-481-1590 internationally.