Alex and some of the internet are noting that airline security might cost lives and does cost liberty. Yglesias asks one counterfactual: How many airplanes would be “blown up by terrorists” if there were no airline security?  

I might have asked instead how many airplanes would be flown into skyscrapers and nuclear power plants (big propaganda rewards available), but I have another counterfactual that is more econ-oriented: What security protocols would a purely private air travel system enforce?  
I suspect that if security were up to the private sector it would be quite stringent.  Airlines and airports would compete partly on safety, and as we all know, people overestimate the risks of air travel.  It’s possible that private sector inspections would be even more invasive, less respectful: Would an airline want the reputation as the company that lost passengers–or one of the best surf spots in California–because they were afraid of offending an elderly lady?   
I say no. If you value personal autonomy at airports (a big if) you should probably devote your efforts to weakening TSA, not introducing laissez faire air security.  
Coda: I often think about these words by Alex, on the related issue of competitive governments:
Competitive law appears to increase efficiency but it’s less clear that competition among governments gives rise to a libertarian world.  Homeowner associations, for example, often impose stricter zoning regulations than cities.  You could say that the system as a whole is more libertarian, but no one lives in the system as a whole.