If the person trying to smuggle the manpad was an 80 year white lady with a walker, I have full confidence that the airport security would catch her at least 3 times out of 7.
If it was a young Middle Eastern male with a fake passport, the odds drop to 1 out of 1000.
As far as I know, a manpacked portable missile system has no sharp edges or points, so it should be able to be brought through security and loaded on to the aircraft.
I'm not sure if it will fit under the seat or in the overhead compartment.
p.s. I don't work for Airport Security.