Hey jvic, I travel out of DIA to, but with differing luck:
October '00: CRKT w/ 3.75" blade, serrated, initial guy calls his supervisor, the "css" and it is AOK, FAA rule is 4" or shorter.
November '00: Nope, says another CSS, DENVER's rule is less than 3.5 inches(!). So I quietly agreed, but went down to the south security checkpoint. They told me the same down there! I had to check it, and they asked which airline I was on. I didn't even think about it, and told them the ACTUAL one I was on(oops). When I had gone back to the same ticket counter that I checked in at, the lady recognized me, but the computer had a block on my name to check baggage! I had to go to a check in stand called "secondary screening". My check-in bag was THOUGHOULY x-rayed in a big machine, much larger than the checkpoint machines, and it took alot longer. After it went through, I ran off for my flight, lucky to make it after the delay. I was pissed. Now how was I supposed to kill a hijacker, let alone open my bag of peanuts?
January '01: Same CSS as 10/00, no problem.
So: FAA rule: less than 4" blade. And let them know that you know this. The clincher is local rules though, so check beforehand if possible.
Gunfighter- I looked the FAA website up and down before I went out in Oct, but found nothing. If they say the FAA rule is not 4" demand to see said rule in writing, because they are FOS. BUT- check the local laws, that's the variable here.
I actually had no idea a knife was allowed until I found out on the old AR-15 board. Now I always fly armed. I really think a good, folding fighting knife is a superb CQB weapon, especially on a plane.