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An armed F-16 should have no problem at all shooting down an airliner as long as they get there early enough. A single missile might not do it but several are pretty much a sure thing and any pilot worth his salt can hit it with 20mm fire. Airliners just aren't that maneuverable and they aren't designed to take damage. Even a controlled destruction of the engines with gunfire isn't out of the question. Those engines are huge and just one round would do it.

Airforce-one has much more chance of surviving damage, mostly through system redundancy, safeing and countermeasures to make it more difficult for a missile to lock on, but it can't fly without engines.

But any such action has to be undertaken long before the airliner is over a city. Once over a major city the benefits of shooting an airliner down largely disappear. The exception being if there is some singular high-value target.

Even in that case your not going to ram the airliner. Two airplanes falling randomly into a city is not any better than just one.