I'll share my native traveling experiences here. I flew to Montana and back last year with a part serrated native, no problem. I flew out to college this year with it as well, once again no problem. I flew home at Christmas break with a plain micarta calypso jr, and tried to fly back to college after break with a plain edge BF native. Sorry if I offend anyone here, it's not my intent. The "rent-a-cop" at the security post could barely speak english so I may not be representing him exactly as it was. I unclipped it and put it in the basket. He opened it up and said I couldn't take it through. I informed him that under 4" was the law and that it was clearly under that limit. He agreed, so I asked why it couldn't go. From what I could understand, he said, "It's because of the sharpness" while pointing to the grind lines. He knew almost nothing about knives as he couldn't close it and he never felt the edge for real sharpness. If he had, it would have scared the crap out of him. I had to leave shortly, so I didn't argue anymore and just checked it with my other baggage. No one ever noticed or said a work about the baby wayne goddard on my keychain though. For most times, where the security personel are halfway qualified, you should be fine. But you might get unlucky and find an idiot as I did. Just my 2 cents.