She's as tough as a pine knot.

... Sometimes you must seem to hurt something in order to do good for it.

Had a thought about a knot...then thought naught...

It's just a knot. They rub it out, it comes back.

It shows how tough it is to be a small player and really be able to get a foothold in the industry. I think it bodes well for larger airlines and it may prove difficult for other start-ups .

Getting married is also called tying the knot but wondering why it looks like a noose around the neck of the man only.