If you can maintain your composure, I'd do it.... If you think you'll be acting stupid and making mistakes, then don't do it, because security can make your trip hell. It's one thing to see a grown man a little tipsy on a plane, it's another thing to see a teenager on a plane who can barely see straight..

I think a practice run is in order. Take the amount of weed you'd like to take before the flight.. then have a friend come over and give you a series of commands and such "take your shoes off and put them on the belt, empty out your pockets, step through this doorway," then try sitting for 5 hours straight.

I have a feeling you're gonna get way more fucked up than you think.

If you can maintain your composure while your friend is giving you these commands, and you feel good to sit for 5 hours.. then do it.