I was going to take your word on this, but I remembered the last time I had flown prior to 9-11-2001. It was sometime in 1993 and I distinctly remember being warned--I think by my boss--not to carry my knife on board. I left my Old Timer stockman at home. I did a little digging and found this:

Statement of James C. May ( president and CEO of the Air Transport Association of America) to the National Commission on Terrorist Attacks Upon the United States
May 22, 2003

“Let me be completely candid with regard to the reported role of box cutting devices in the attack. Under pre-9/11 FAA regulations only ‘knives with blades four inches long or longer and/or knives considered illegal under local law’ were prohibited. Under a non-regulatory Checkpoint Operations Guide, developed by the FAA, the Regional Airline Association and the ATA, with FAA approval interpreting the FAA regulations, box cutting devices were considered a restricted item posing a potential danger. This meant that if such a device was identified, it could be kept off the aircraft. The FAA mandated metal-detection walk-through systems, however, were designed and tested to detect metallic items about the size of a small handgun or larger. The pre-9/11 screening system was not designed to detect or prohibit these types of small items, and we have no information indicating they were identified in the actual 9/11 screening of the terrorists.”

He seems to be suggesting that there were restrictions on knives at the time even if they were not prohibited by FAA regulations.

Obviously a moot point though since blades of any sort were not being screened for.

Regards, Vince