Not normally for Q400. in my euoprean company the SOP is to set fast on the boots when the ICE DETECT annunciation comes up on the ED. You would have selected Prop De-ICE and the Ref switch as or slightly before you encountered the cloud, unless it was dark and you didn't know you were IMC.
However, the Dash is good at letting you know it's IMC as it bounces about a bit and whistles through the wipers in cloud (I wish I knew why!).
I've had the pleasure of the ATP and it hoovered up Ice like nothing else, and being so over powered
, just stopped climbing. The Q400 really does have an excess of power, so climbing through it is a valid and good option.
In decent, it's usual in heavier icing, like I encountered least week, that the ice clings on for a while, and when the SAT shows about +1 degree, it will start shedding. The wipers and spigot clear quite quickly, if you are at 235kts too, as you have a couple of knots of heating there too.
Usually, if you are not sure, you'll brief and bug the speeds for Icing, flap 35 and +15kts on VREF. The second bug is set at VClimb, in our SOPS, so you need to decide early in the appraoch whether it's icing or not. Re scheduling speeds (not something PNF can do for you) in a late stage of approach is not a sensible idea.
Lots of us Q400 drivers are really wondering what caused this. We do not get a lot of SIM time on icing, you just put the stuff on and it works. Individual boot failures are covered, you can isolate left and right sides, or work the system manually, (not that difficult) you just rotate a switch above the skipper's head, to ensure the contamination is symetrical.
I expect the NTSB may focus on when he put the icing on, how long for, etc. When you start it in Automatic, the sequence starts at the outer wings and works inwards before going to the tail. If you switch it off, it completes a full cycle before finishing though.
It's also rare to see a Turboprop without a few patches on boots as well.
I believe Bombardier are looking into an alternative heating system using seramic conducting coatings, but don't know any more. Using bleed air would be fine at lower altitudes, where the flat rating is in place, as the engine has plenty of margin, but not really suitable at cruise levels.
I certainly await the NTSB's report, and will refrain from speculation until then.