Can i bring a bic lighter on a plane in my pocket?

The logic is that the cabin is pressurised and therefore the fuel in the lighter is safe. In the hold, which is usually not pressurised, the lighter could rupture and cause a fire. Whilst it is permitted legally, many individual airlines have their own policy forbidding them, and lets face it, you cannot smoke in the airport or on the plane, so for the sake of $1 it is not worth the effort. Buy one when you get to your destination.