Dash 8 spoilers

[sky7]

I tried a search so link me and forgive me if I am resurecting.

Horizon dash pilots always deploy spoiler/speed brakes when cleared for t/o or po-and-ho, then retract them with power up. My uneducated stab is something to do with arming them for a rejected t/o.

anyone? Thanks

[Dugie8]

Originally Posted by sky7

I tried a search so link me and forgive me if I am resurecting.

Horizon dash pilots always deploy spoiler/speed brakes when cleared for t/o or po-and-ho, then retract them with power up. My uneducated stab is something to do with arming them for a rejected t/o.

anyone? Thanks

Horizon may have a different version of the Dash 8 200 that Ive flown, but the -200's I flew only had the spoilers pop up if you moved the control wheel a certain amount, and then it was only on the down wing side. And then on landing or rejected takeoff, they were armed by the the power levers going beyond a certain point.

Now the -100 model had a spoiler "switch", that armed them for take off (rejected take off) and landing. What happens is when you arm them, they pop up and you see that on the powered flight control dispaly, that simply shows the spoilers "up". When the power levers are moved out of ground range the spoilers retract. So really what you are seeing is simply the system testing itself when it is armed (maybe QX dash 200s have a different system).

On the Dash 100,200, and 300 models you cannot deploy the spoilers in flight, no airbrake handle since you have two 13 foot diameter ones on each wing anyway!

There is a third set of spoilers/airbreaks on the Dash as well, they are in the center of the wings, but I think most operators have those disabled??

Just fyi, if I remember correctly it was a fairly long runway requirement (especially if it was wet) for a ground spoiler failure in flight, 5500 feet or so I think. The airplane was real heavy without the roll spoilers too, makes for a fun single engine approach in the sim

Just looking at some pictures of QX 400s I found this http://www.airliners.net/open.file/0233967/L/
if you look, you see a switch labeled spoilers, (flight/taxi) that is the switch that gets "flipped" as you taxi onto the runway, and the spoilers pop up. It is up (or in the flight mode) because it is a magnetically held switch in the taxi position, a power loss, ie engine shutdown, will cause it to spring to the flight position.

[drstrangelove]

The -100 ground spoiler test sounds correct but dude what -200 are you flying? The spoilers all deploy in flight, they are roll spoilers. Below 140 both will rise with control input, above 140 only the inboard lifts.

Iv'e never heard of center spoilers and I've been on top and never seen where they would be. I won't say it's not there but QX doesn't have any and we sure don't.

[Dugie8]

Originally Posted by drstrangelove

The -100 ground spoiler test sounds correct but dude what -200 are you flying? The spoilers all deploy in flight, they are roll spoilers. Below 140 both will rise with control input, above 140 only the inboard lifts.

Iv'e never heard of center spoilers and I've been on top and never seen where they would be. I won't say it's not there but QX doesn't have any and we sure don't.

The -100 at PDT had a center spoiler that was disabled, I don't think any other models even had them.

[drstrangelove]

Never knew. Thx for clearing it up.

[Dugie8]

Originally Posted by drstrangelove

Never knew. Thx for clearing it up.

No prob, I didn't make it very clear in my post I was speaking to the -100 model about the center spoiler.