There are several issues here.
If there is any snow or ice on the airplane it must be de- iced. Typically with hot Type I fluid applied with a giant pressure sprayer to not only melt, but also blast off, any adhering ice or snow. Type 1 fluid runs off the plane like water, carrying the melted and dislodged contamination with it. Assuming it’s not actively precipping or blowing fallen snow while this process is being done, at the end of the process the airplane is 100% clean & ready to fly.
BUT … if any frozen precip, or even very cold liquid rain is falling, the airplane must immediately be anti- iced. This is generally done using Type IV fluid which is very different stuff from Type I. Type IV is hot, is thick and goopy, and is gently sprayed to form a solid layer over over the wings and tail. It sticks to the airplane. This protective layer absorbs what fell on the plane during the de-icing process and will absorb what falls on the plane during start, taxi, and takeoff.
Depending on the temp, the type of precip, the wind, and the intensity of precip, the protective coating may last anywhere from 5 minutes to a couple hours. Measured from when the coating starts being applied. If it takes 4 minutes to spray the whole plane, you have 1 minute (!) to get airborne after they finish. Good luck with that! If you time out, you need to once again use Type I to blast off all the accumulated gunk and sodden used-up Type 4, then reapply a fresh coat of Type IV to keep you safe through liftoff.
More realistically, once the so-called “hold-over time” of effective protection gets to be much less than 10 minutes for a bizjet or 20 for an airliner, the effort is futile. Even with de-ice facilities next to the takeoff end of the runway you can’t get the airplane clean fast enough to get it airborne before the weather overwhelms your protection and you have to start over. So instead you cancel or delay the flight.
The “laminar” bit is a bit of a red herring. All wings are designed to have as laminar a flow as is reasonable. Some take pursuit of laminarity a little farther than others. But yes, extra good laminarity implies extra sensitivity to contamination, be that insects or ice.
For any wing, extra-laminar or typically laminar, even very minor ice can utterly destroy the lift. A common cliché is “surface roughness equal to 80 grit sandpaper will cut lift by 80%”. There’s no speed at which you could compensate for that degree of loss of lift. Now consider that in an anti-iced plus precip takeoff, the degree of contamination along each wing is random and may not be the same. Percentagewise, it takes very little difference between the two wings’ lift to exceed your max roll control authority.
Bottom line: If you have crap on your jet’s wings, you crash. Pretty much for sure. So don’t do that. Lots of airliners crashed in the 1960-80s and a few into the 90s learning this lesson. But the regulators and the industry get it now. And have the tools to cope with heavy freezing precip. But not for insane blizzards, nor for freezing rain. And now they have the discipline to say “These conditions are untenable. We’re staying here until / unless it improves.” And the tools with which to pretty reliably determine “untenable.” There’s always some gray area, but that’s where the attitude difference between “Safety first” and “Let’s go; it’ll be fine” comes in.
I don’t know the exact weather at Bangor that day. Nor those guy’s decision processes. Nor their degree of training or icing mindset. But this crash didn’t have to happen.
