It is not fanciful at all to suspect that air travel can lead to gout attacks. Aircraft cabins are supposed to be pressurized at a level equivalent to an altitude of 9000 feet. In addition, much of the air fed into the cabin is recycled, so it contains even less oxygen than air at 9000 feet on land. That means you're getting much less oxygen in your system than at altitudes near sea level. There is at least one medical journal paper describing the higher incidence of gout attacks among people who move to a much higher altitude. It's the same reason that sleep apnea causes gout attacks.

In most modern aircraft, cabin pressurization is automatically controlled, not under the control of the pilot. In my experience, the Airbus 319 is the worst aircraft for producing in me symptoms of prolonged oxygen deprivation. I have sworn off flying anywhere in that aircraft.

It's also worth pointing out that the potential for dehydration is also much higher on long flights. Drink a lot of water before and during the flight to reduce the chances of an attack. It works for me!