Dash speed brakes

Actually the Outside Spoiler on the Q400's at QX have Red on the inside and Black on the outside (I remembered this in GS because they're UGA's colors)...as seen here:

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milleR said:
lol what? How much time do you have in the Dash?

The 8-100's had the same spoiler setup as the STOL designed Dash 7, since that's what the plane was based off of. Because the Dash 8 couldn't meet the stol performance of the -7, when they designed the 8-200 and -300 series they did away with the system. The Q-400 is a totally different beast, despite the same type. Spoilers are needed both for braking and roll control since it's substantially larger and heavier than the previous aircraft.

Edit: never seen a dash that wasn't painted white, blue, black, or gray.
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About 3300 hours in the Dash spilt between the 100, 200 and 300. And there is a difference between the roll spoilers and the ground spoilers insofar as their functionality , they are two different control systems that share the same physical flight control surfaces and it was NOT inherited from the Dash 7. It was a completely new system from the ground up. You cannot deploy the roll spoilers as "air brakes" in either the 100 or 400 in flight. They are lift dumping devices with WOW and another two conditions, flight/taxi switch to flight and power levers at or near flight idle if that was what you were implying.

And contrary to what you think, there are some 200's around with a Flight/Taxi switch and an activated ground spoiler system. In fact, a Bombardier flight test pilot that was shadowing our crews for a while told us that the old straight leg 300's had the option for the system available but no one ordered it which is why it was later discontinued ( contrary to the logical order the Dash 8 300 BTW was developed before the 200). The reason there are 200's with the system is because some operators self-modified their 200's to have it due to heavier than normal military payloads. The Q400 is certainly different in many respects to the prior models, but the need for ground spoilers is questionable at best. Just another example of Bombardier over-engineering.

And every one of our 100's has the spoilers painted red! Ass hat-tish? Go fly a kite man!
 
RightSeatGirl said:
About 3300 hours in the Dash spilt between the 100, 200 and 300. And there is a difference between the roll spoilers and the ground spoilers insofar as their functionality , they are two different control systems that share the same physical flight control surfaces and it was NOT inherited from the Dash 7. It was a completely new system from the ground up. You cannot deploy the roll spoilers as "air brakes" in either the 100 or 400 in flight. They are lift dumping devices with WOW and another two conditions, flight/taxi switch to flight and power levers at or near flight idle if that was what you were implying.

And contrary to what you think, there are some 200's around with a Flight/Taxi switch and an activated ground spoiler system. In fact, a Bombardier flight test pilot that was shadowing our crews for a while told us that the old straight leg 300's had the option for the system available but no one ordered it which is why it was later discontinued (the Dash 8 300 BTW was developed before the 200). The reason there are 200's with the system is because some operators self-modified their 200's to have it due to heavier than normal military payloads. The Q400 is certainly different in many respects to the prior models, but the need for ground spoilers is questionable at best. Just another example of Bombardier over-engineering.

And every one of our 100's has the spoilers painted red!
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I certainly wasn't implying the use of spoilers as "air brakes" since that's not how they're employed. However, on the -400 the inboard and outboard spoilers are used for lateral control in flight and are the only flight control surfaces available in the event of an aileron cable jam. They are also used as lift dumping devices on landing.

To my understanding, the 8-100 used a very similar wing and almost identical control surfaces to the Dash 7, hence the ground spoilers.

I apologize for the tenor of my first post; my wife is right, I can really come across as an ass sometimes.
 
milleR said:
I apologize for the tenor of my first post; my wife is right, I can really come across as an ass sometimes.
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Well, good thing is you're stand-up enough to admit to that. That's commendable in and of itself.

Just proof before post! :D
 
milleR said:
I certainly wasn't implying the use of spoilers as "air brakes" since that's not how they're employed. However, on the -400 the inboard and outboard spoilers are used for lateral control in flight and are the only flight control surfaces available in the event of an aileron cable jam. They are also used as lift dumping devices on landing.

To my understanding, the 8-100 used a very similar wing and almost identical control surfaces to the Dash 7, hence the ground spoilers.

I apologize for the tenor of my first post; my wife is right, I can really be an ass sometimes.
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The utilization of the spoilers for roll control is the same across the whole Dash family as is the "design roots" of the fuselage and wing. But there was nothing mechanical that was carried over from the Dash 7 to the 8. The 7 did have a flight/taxi switch that did the same thing. But the system itself despite its identical function on the 8 was all new to design out several maintenance heavy flaws in the 7's systems namely the costly flap WOW auto retract feature. I'm not certain about the following but I believe I recall our guys that flew the 7 telling me the roll spoilers were all mechanical on the thing vs. the hydraulically actuated system on the 8.

To answer the other question above the reason the F/T switch has the mag release is in case the crew forgets to flip it up before T/O (I've NEVER done that by the way...LOL). It's recommended by Bombardier for reason($) of wear and tear that the F/T switch should be manually actuated vs. letting it auto release.

But again, the whole system is re-"dumb"dant..Once a Dash 8 is on the ground..it's done with lift LOL, a washing machine with wings would be more aerodynamic.....the props going into flight idle even without the power levers going over the gates putting the big fans into disc-ing is plenty on any runway you're gonna fly a Dash onto in a 121 operation. Our company even wanted Bombardier to develop an STC to eliminate the ground spoilers even on the 100's to save weight and maint. I've flown the plane several times with the system MEL'd and noticed zero difference though just to satisfy the pencil-pushing nature of the FAA we do take a slight weight penalty. And I do not miss the system on the 300's at all either.
 
I'll look tomorrow and see what the differences on the Q400's landing distances with spoilers and without.

I like having them on the Q400, it a'int yo daddy's Dash 8
 
SurferLucas said:
I'll look tomorrow and see what the differences on the Q400's landing distances with spoilers and without.

I like having them on the Q400, it a'int yo daddy's Dash 8
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I'd be a little surprised if the difference is all that significant, but I'd like to know for my own info even if I'm wrong so please follow up with that.
 
Probably not on the Q400, since we have anti-skid and reverse...once you get it on the ground, you can slow it down fairly quickly.

Ok, so here's what I found in the performance manual: Airport elevation of less than 1000ft MSL
@ 57K landing weight and NP1020 (not reduced Np of 850), at a Vref of 115kts the landing distance is - 4017ft
@ the same weight, NP1020 and a Vref of 115kts with Ground Spoilers INOP - 4620ft
@ the same weight, NP1020 and a Vref of 115kts with Anti-Skid INOP - 5978ft

Going into somewhere like Santa Rosa (KSTS) with a runway of 5115ft, with the Ground Spoilers INOP and at MLW of 62,000lbs...you'd still be able to land with a little room to spare (4825ft appox).
 
when ive had them inop, ive noticed the airplane likes to lift off the runway in gusts, and youve got a much better chance of activating the anti skid ( tons of fun in the Q) with initial brake application.

it has a significant impact when the weather is less than ideal, and becomes a significant issues.
 
TUCKnTRUCK said:
when ive had them inop, ive noticed the airplane likes to lift off the runway in gusts, and youve got a much better chance of activating the anti skid ( tons of fun in the Q) with initial brake application.

it has a significant impact when the weather is less than ideal, and becomes a significant issues.
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I hate autocorrect, I hate it that much more when it doesn't work. Oh well
 
I have never actually paid enough attention to a Q400 or one of Piedmonts 100's to see if the spoilers come up on landing. I thought they just went up before take off as a test, much like we do a control test in ours and verify they work by use of the PFCS.
 
Rocketman99 said:
I'd wager against that. The Dash flies like an absolute piece of poorly designed crap. Which is what it happens to be.

The interesting thing is that the flight/taxi switch in the spoilers is magnetically held down in taxi and when you push up the power levers the switch automagically flips back into the flight position. Which begs the question, why the hell do we move the switch ourselves if it's going to flip itself anyway if(when) we forget. Sort of like the main bus tie...
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HAHAHA I love the DC logic system.
 
SurferLucas said:
Probably not on the Q400, since we have anti-skid and reverse...once you get it on the ground, you can slow it down fairly quickly.

Ok, so here's what I found in the performance manual: Airport elevation of less than 1000ft MSL
@ 57K landing weight and NP1020 (not reduced Np of 850), at a Vref of 115kts the landing distance is - 4017ft
@ the same weight, NP1020 and a Vref of 115kts with Ground Spoilers INOP - 4620ft
@ the same weight, NP1020 and a Vref of 115kts with Anti-Skid INOP - 5978ft

Going into somewhere like Santa Rosa (KSTS) with a runway of 5115ft, with the Ground Spoilers INOP and at MLW of 62,000lbs...you'd still be able to land with a little room to spare (4825ft appox).
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Stupid jet pilot here, but do you all use "reduced Np" for noise, and does that increase landing distance? (logic there: higher pitch = less drag)
 
Autothrust Blue said:
Stupid jet pilot here, but do you all use "reduced Np" for noise, and does that increase landing distance? (logic there: higher pitch = less drag)
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In the king air it would add some distance because you would have to go fine pitch before you could reverse.
 
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