TSA Security for oversized items?

Recently I attempted to check in 50 minutes prior to a US domestic flight. But I was denied checking my suitcase and was told by the airline employee that I could only check baggage up to 1 hour before a flight¹. I was given the choice of taking my (full sized) suitcase on my original flight as hand luggage or rebooking on another, later flight. For various reasons I opted for the re-booking (which in hindsight made for a horrendous travel experience due to unrelated issues).

But I am curious to know how the TSA should have handled me attempting to take my suitcase through the TSA checkpoint. Being a full sized suitcase it would not have fitted through the X-Ray machine, and I am not even sure that they would have even allowed me to proceed through security with it². I assume that there are probably hand search policies that they can apply, but this is so far out of my experience that I have no clue.

Can anyone explain what the TSA should³ have done in the case of me attempting to get a full-sized suitcase through a TSA security checkpoint when said suitcase would not fit through an x-ray machine?

Note that there was also nothing in my suitcase that I could not have taken onto the plane in hand luggage.

I am also guessing that taking my suitcase through security is actually less secure than checking it. My belief is that after a bag is checked that there should be some sort of automated scanning applied to it, but at the TSA checkpoint they could not do a similar level of scanning and would have to rely solely on visual inspections.

Can anyone tell me if I am right or wrong in this respect?

^{1. In subsequent emails with the airlines customer service, it was pointed out that this was a TSA rule and not an airline rule.}

^{2. I have previously seen airlines/security aggressively enforce size and weight restrictions on standard carry on sized luggage before even getting to the TSA checkpoint. So I can't imagine what they would have thought seeing me dragging my "hand luggage" along}

^{3. Note that I say should rather than would because I know how capricious the TSA can be.}

Best Answer

From time to time, passengers have to take unusually large items as carry on. For example because they have some fragile item or because they were delayed and had to carry on luggage they'd intended to check. You can be fairly sure that the airline wouldn't allow you to try to take something through security if security would refuse to screen it. (Though staff are not infallible and they may have suggested that you do something impossible.)

I have once had to carry on a large bag that I'd intended to check. However, it was small enough to fit through the X-ray machine so there was no issue with that. If a bag wouldn't fit, I see no organizational reason why security couldn't just open it and search it by hand. Obviously, if everybody had bags like that, screening them would take forever but, in reality, it's probably only a few bags a day. I've flown a couple-few times a year for the last fifteen years or so and I don't recall ever seeing somebody have a bag or other carry-on that wouldn't fit through the machine.