I can't actually think of a reason why anyone would require a knife of any kind on a plane.
Really tough steak?
Nah, just tenderise it with the end of Horatius' pool cue.
box cutters are knives and although technically lockable, in my experience, the lock is generally not very good, and they are certainly small
Pppfft. The last time I ate meat on a plane it was so tough I could have thrown it through a window. No need for knives or cues, just threaten to suck people out the windows by launching your lunch through one.
Somehow I think swinging a hockey stick on a plane would present its own problems.

I would think cross check before swinging.
I played lacrosse. Without the fear of penalties and against someone not wearing pads and a helmet, I could do some serious damage in several different ways. Let's not forget, most people don't wear cups everyday either!![]()
I would think cross check before swinging.
In NHL crosschecking is quickest way to get suspension
Ask Pat Kaleta of Buffalo - get 5 games (costing him 72,000) for cross checking Rangers Brad Richards into boards .....
If I see a referee with a knife on a plane...
...you'll get two minutes for cross-checking!