There are several threads about this in other forums, but the problem is knowing whether the information is up-to-date and reliable.
I can confirm that Newcastle has a covered outdoor smoking area in one of the bars in departures - you have to buy a drink to use it, but that's a small price to pay when you need your fix! There are signs up stating NCL are looking to improve their airside smoking facilities.
Schiphol has several smoking areas airside - some are within bars but you're not always forced to buy a drink (at least I wasn't).
Heathrow has no smoking facilities after security.
I'm only commenting on the airports I've personally visited in the last few months, for the reasons stated above.
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