Traveling and long flight are known to increase the chance of gout attacks. If I were making the trip in a few days I would get an OK from the doctor and do below:
*** Before the trip.
1) Start taking prophylactic dosage of gout attack medicine, such as Indomethacin 25 mg, or Colchicine 0.6 mg a day. This can prevent a gout attack and catch it early if the attack occurs.
2) Avoid dehydration. Drink 2~3 litres or more of water a day until the color of urine is clear.
3) Avoid heat, stress, and exhaustion.
4) Avoid fasting and gorging. Have more smaller meals instead of fewer large ones.
5) Keep the urine pH above 6. Test it with a pH paper. If it's below 6, drink some baking soda in water. (Read the product directions.)
5) Avoid alcohol beverage. If it can't be avoided, taking some baking soda in water before and after the drinks to keep the urine pH above 6.
6) Ask the doctor for the gout attack med to take to the trip. If Indomethacin is given, ask for some Nexum, Prilosec, etc in case Indomethacin hurts the stomach. If Colchicine is given, ask for some Lomotil to stop the side effect diarrhea.
7) Also ask the doctor for some strong pain killer (Opiate anesthesia) for the emergency use.
*** During the flight -- drink plenty of water, avoid fasting for too long, and walk around often.
*** During the trip: Do 1)~5) and

Take the gout attack med at the first twinge. If not sure if it is a gout attack or not, take the gout med anyways. It's better to be safe than sorry.
9) In case can't get to the hospital quickly and have no gout med around when gout attacks, go to the local store to buy some Ibuprofen and baking soda. Amer. Academy of Family Physicians recommends taking Ibuprofen 800 mg 4 times a day to treat gout attacks.
More gout info can be found at Icuredmygout.org . Bon voyage.