Q400 Spoiler use during taxi

[spanishflea]

I fly on the Dash 8 Q400s of FlyBe fairly regularly, and on our aircraft and the other Q400s I observe taxiing, the spoilers always seem to be up during taxi. I can never locate the exact moment they go up, but they dont go down again until the power is put on for departure.

Can anyone explain why this happens please, as I havent observed it on any other type before.

[Caudillo]

Not being a Q400 pilot myself, this is just a guess based on the workings of my own type - Perhaps on the Q400, as on my type, the spoilers automatically deploy when on the ground and travelling faster than a certain speed, as would be useful when having touched down. So in your case, I'd imagine it's due to taxying a little briskly. I imagine they retract both when the speed drops below this threshold, and when the thrust (or should that be power..?) levers are advanced beyond a certain TLA, to prevent you inadvertently flying about with thrust applied against them.

[QQ44QQ]

As part of the 'Line up' checks, prior to departure the spoilers are selected to 'Flight Mode'. This causes them to deploy. When the power levers are advanced the spoilers then retract. On landing the combination of the 'weight on wheels' and the position of the power levers will signal them to deploy to increase the drag on the landing roll and in the event of a rejected take-off. - Hope this helps QQ44QQ

[spanishflea]

Thanks very much guys!