the pope does the tango. The big story for everyone who flies, the growing controversy over the tsa's decision to allow pocketknives on airplanes. Tough questions o capitol hill and david kerley has... See More
the pope does the tango. The big story for everyone who flies, the growing controversy over the tsa's decision to allow pocketknives on airplanes. Tough questions o capitol hill and david kerley has the story. Reporter: Even the union that represents 44,000 tsa officers this morning is joining air marshals, some pilots and flight attendants in opposing this move.Act, flight attendants went straight to the head of the tsa saying letting blades back on planes is a bad idea. A very controversial decision. Are you going to rescind your plan? No, I have to make sure that tsa's focus is on those things that are most destructive to the aircraft. Reporter: The tsa adminis administer's plan to let small knives on board to concentrate on the real risk to planes. In the briefs you get is there something that scares you every day? Yes. And it's not pocketknives? No, it is those nonmetallic improvised explosive deviceses, the bombs that are small, concealable and they are well designed, constructed. There is still a significant attempt and intent to get on -- particularly a u.S. Carrier to blow itup. Reporter: Johnleisto will play this, showing how a small amount of chemicals can put a hole in metal like a fuselage in a plane but pistole says the cockpit doors have made it difficult to hijack a plane with a knife. Even security experts question his move. It's really a hazard and it's a dangerous situation so to bring this back in foray is beyond my comprehension. Reporter: Here's what the officers say, this is the kind of knife that will be allowed. It's a folding knife, small. You can tell this one will be allowed under the new rules. Here's the problem, a knife like this, it has a locking blade, therefore, it would not be allowed. So when you bring your bag, how do you tell which one is allowed and which one isn't? The officers say it'll take them more time, george, the tsa administrator says that's not the case and will explain himself on the hill. David, thanks very much.
This transcript has been automatically generated and may not be 100% accurate.