there is certainly little if any data published applicable to the big jets that passengers fly on. Thus neither the press nor the terrorists has anything other than speculation to think about.
The large transport aircraft designed and certified under the FAR/JAR part 25 have lots of margin for single site damage and taken together with the crew will likely get the plane back on the ground for the threats that are currently on the market.
The biggest problem that we currently face is the terror that uninformed speculation causes to our industry. I'm not saying the word "never" but there is a probability that means it is far more likely that it won't suceed with pilots that follow their training to fly with deteriorated systems..