I don't normally take the two together (Advil/Tylenol + Gravol) as I don't find I need them both at once. The Gravol seems to do the trick, all on its own (FWIW, I use the extra strength Gravol, though......the regular strength never seems to be quite enough).
I take one dose of Gravel 1/2 hour before boarding and never have a problem in the air

. My first flight, I was so sick to my stomach and headachy that I thought I'd expire by the time we landed at MCO. Gravol makes a world of difference (and as an added bonus, it makes you kinda sleepy......so you might even find you doze a bit on the plane).
I credit my survival to my awesome neurosurgeon at Toronto Western Hospital. I will never be able to thank him enough. My son was only two at the time....thanks to the talents of an incredible doctor, I have lived to see him grow up.
Just a reminder to everyone.....live your life to the fullest. This is no dress rehearsal.