Can258
Topic Author
Posts: 49
Joined: Thu Sep 20, 2007 12:19 am

Spoilers Up While Takeoff Power Set?

Thu Sep 20, 2007 2:32 am

Hi everyone,

I was in one of AtlasJet (KK) ' s CRJ900 's going from IST to ADB . We taxied on 36L at Istanbul, lined up while spoilers were up. Spoilers were still up when the takeoff power was set . We started rolling and few seconds later , spoilers were down again and then we took off . I saw this for the first time and I wonder what's the reason for it .

Does anyone have any ideas?

Thanks,

Can258

[Edited 2007-09-19 19:34:00]

[Edited 2007-09-19 19:35:18]
 
mandala499
Posts: 6460
Joined: Wed Aug 29, 2001 8:47 pm

RE: Spoilers Up While Takeoff Power Set?

Thu Sep 20, 2007 3:46 am

It could have been the spoilers playing in roll augmentation mode... was it a crosswind take off?

Mandala499
When losing situational awareness, pray Cumulus Granitus isn't nearby !
 
flyf15
Posts: 6633
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RE: Spoilers Up While Takeoff Power Set?

Thu Sep 20, 2007 3:49 am

The only time you should see spoilers up on a CRJ during normal takeoff (ie: not during an abort or anything like that) is when there is an extremely strong crosswind requiring a very large amount of aileron deflection during the takeoff roll. It is feasible that the upwind spoileron (most outer and smallest spoiler) will extend partially.

If power is increased to takeoff power (beyond 79% N1) with any spoilers extended other than the above mentioned example (ie: ground or flight spoilers actuated or an uncommanded spoiler extension), the pilots will receive a takeoff configuration warning "CONFIG SPOILERS", which would result in them initiating a low speed abort.
 
airfoilsguy
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Joined: Sun Oct 09, 2005 7:28 am

RE: Spoilers Up While Takeoff Power Set?

Thu Sep 20, 2007 3:52 am

Quoting Flyf15 (Reply 2):
the pilots will receive a takeoff configuration warning "CONFIG SPOILERS", which would result in them initiating a low speed abort.

Doesn't it also slam the throttles back to idle?
It's not a near miss it's a near hit!!
 
Can258
Topic Author
Posts: 49
Joined: Thu Sep 20, 2007 12:19 am

RE: Spoilers Up While Takeoff Power Set?

Thu Sep 20, 2007 3:55 am

Quoting Mandala499 (Reply 1):
It could have been the spoilers playing in roll augmentation mode

Mandala499 thanks for your reply .It was probably because of crosswind. However can you please explain what roll augmentation mode does in CRJ's ?

Thanks
Can258
 
Can258
Topic Author
Posts: 49
Joined: Thu Sep 20, 2007 12:19 am

RE: Spoilers Up While Takeoff Power Set?

Thu Sep 20, 2007 3:57 am

Quoting Flyf15 (Reply 2):
The only time you should see spoilers up on a CRJ during normal takeoff (ie: not during an abort or anything like that) is when there is an extremely strong crosswind requiring a very large amount of aileron deflection during the takeoff roll.

There was probably crosswind but I don't think it was extremely strong.
 
sushka
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RE: Spoilers Up While Takeoff Power Set?

Thu Sep 20, 2007 4:10 am

My guess is the same, It must have been a crosswind takeoff. How many spoilers did you see up?
In light crosswind takeoffs, I try not to add too much aileron to try and avoid spoileron deployment
Pershoyu Spravoyu Litaki!
 
KELPkid
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RE: Spoilers Up While Takeoff Power Set?

Thu Sep 20, 2007 4:11 am

Quoting Can258 (Reply 5):
Quoting Flyf15 (Reply 2):
The only time you should see spoilers up on a CRJ during normal takeoff (ie: not during an abort or anything like that) is when there is an extremely strong crosswind requiring a very large amount of aileron deflection during the takeoff roll.

There was probably crosswind but I don't think it was extremely strong.

I don't know how Turkish regional jet pilots are trained, but in my private pilot training, my first flight instructor taught me that with a crosswind takeoff, you start the takeoff roll with the ailierons fully deflected, and as the aircraft gains speed and the control surfaces gain aerodynamic effectiveness, then you return the ailieron controls towards neutral, keeping just what you need to maintain runway heading  Smile I'm sure that various airlines around the world re-endoctrinate brand new regional jet pilots on crosswind technique to fit their op specs and training manuals, though  Wink
Celebrating the birth of KELPkidJR on August 5, 2009 :-)
 
sushka
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RE: Spoilers Up While Takeoff Power Set?

Thu Sep 20, 2007 4:20 am

Yeah thats kinda what happens on the CRJ and probably other jets only full deflection will put the spoiler up.
Pershoyu Spravoyu Litaki!
 
flyf15
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Joined: Tue May 18, 1999 11:10 am

RE: Spoilers Up While Takeoff Power Set?

Thu Sep 20, 2007 4:58 am

Quoting Airfoilsguy (Reply 3):
Doesn't it also slam the throttles back to idle?

In the CRJ, the only time you'll see that happen is with an inadvertent thrust reverser deployment.

Quoting KELPkid (Reply 7):
I don't know how Turkish regional jet pilots are trained, but in my private pilot training, my first flight instructor taught me that with a crosswind takeoff, you start the takeoff roll with the ailierons fully deflected, and as the aircraft gains speed and the control surfaces gain aerodynamic effectiveness, then you return the ailieron controls towards neutral, keeping just what you need to maintain runway heading Smile I'm sure that various airlines around the world re-endoctrinate brand new regional jet pilots on crosswind technique to fit their op specs and training manuals, though

We just fly the airplane down the runway... whatever aileron deflection is needed to keep the wings level is what we put in. Although, you are correct, when it is particularly strong, I will start out with a fairly large amount of deflection at the start of the roll until I'm able to get a feel of whats actually needed.

Quoting Can258 (Reply 4):
However can you please explain what roll augmentation mode does in CRJ's ?

When the ailerons are at or near their full deflection, the spoilerons will extend as required to augment the roll. The CRJ has a completely astonishing roll-rate though... I doubt I've ever needed a spoileron to assist in roll during flight. About the only time I can think it would be necessary would be encountering wake turbulence or doing some other drastic emergency type maneuver.
 
fr8mech
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RE: Spoilers Up While Takeoff Power Set?

Thu Sep 20, 2007 5:03 am

Quoting Airfoilsguy (Reply 3):
Doesn't it also slam the throttles back to idle?

I'm guessing the only thing that slams the throttles back on any aircraft is the pilot. Don't know about the CRJ, but on any of the big birds I've worked, a take-off config warning will have no affect on throttle position.

On a CRJ, is the spoiler switch, for TO warning, on the handle or does it look at actual spoiler position?
When seconds count...the police are minutes away.
 
Can258
Topic Author
Posts: 49
Joined: Thu Sep 20, 2007 12:19 am

RE: Spoilers Up While Takeoff Power Set?

Thu Sep 20, 2007 5:12 am

Quoting Flyf15 (Reply 9):

Thanks Flyf15. Now I understood the reason.

Can258
 
Can258
Topic Author
Posts: 49
Joined: Thu Sep 20, 2007 12:19 am

RE: Spoilers Up While Takeoff Power Set?

Thu Sep 20, 2007 5:16 am

Quoting Airfoilsguy (Reply 3):
Doesn't it also slam the throttles back to idle?

I am not a pilot however I have some experience in simulators ( I know it is not like the real thing) and I don't think in any aircraft it does slam them to idle. It just warns pilots to be aware of the situation. The rest depends on the pilot in command I guess.
 
airfoilsguy
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RE: Spoilers Up While Takeoff Power Set?

Thu Sep 20, 2007 8:19 am

Quoting Can258 (Reply 12):
Quoting Airfoilsguy (Reply 3):
Doesn't it also slam the throttles back to idle?

I am not a pilot however I have some experience in simulators ( I know it is not like the real thing) and I don't think in any aircraft it does slam them to idle. It just warns pilots to be aware of the situation. The rest depends on the pilot in command I guess.

I remember hearing somewhere that happens if you try and take off with and incorrect configuration. It could be BS.
It's not a near miss it's a near hit!!
 
doug_or
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Joined: Sat Mar 18, 2000 9:55 am

RE: Spoilers Up While Takeoff Power Set?

Thu Sep 20, 2007 8:28 am

Quoting Airfoilsguy (Reply 13):
I remember hearing somewhere that happens if you try and take off with and incorrect configuration. It could be BS.

Might have been confused with the below (which is true)

Quoting Flyf15 (Reply 9):
In the CRJ, the only time you'll see that happen is with an inadvertent thrust reverser deployment.
When in doubt, one B pump off
 
phxpilot
Posts: 60
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RE: Spoilers Up While Takeoff Power Set?

Thu Sep 20, 2007 8:35 am

In the CRJ-900 two spoiler panels will deploy, depending on the control wheel deflection. They are the two outermost panels and are considered multifunction spoilers because they are also used as flight spoilers and ground spoilers as well as roll spoilers. On the CRJ-200 there is only one.

On the CRJ-200 the thrust lever is slammed to idle (watch your fingers) during an inadvertant thrust reverser deployment. In that aircraft the thrust levers are directly connected to the engine. In the -900 the thrust lever does not move because there is no mechanical linkage to the engine. The levers are simply potentiometers and send an electrical signal to the FADEC.
 
tinpusher007
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RE: Spoilers Up While Takeoff Power Set?

Fri Sep 28, 2007 7:49 am

Quoting Phxpilot (Reply 15):
On the CRJ-200 the thrust lever is slammed to idle (watch your fingers) during an inadvertant thrust reverser deployment. In that aircraft the thrust levers are directly connected to the engine. In the -900 the thrust lever does not move because there is no mechanical linkage to the engine. The levers are simply potentiometers and send an electrical signal to the FADEC.

Exactly! As well on the -900, if a thrust revereser is inadvertantly deployed uncommanded, the FADEC will automatically schedule idle thrust to that engine, but the throttle will not move on its own.
"Flying isn't inherently dangerous...but very unforgiving of carelessness, incapacity or neglect."
 
sterling79
Posts: 4
Joined: Thu Sep 27, 2007 12:58 pm

RE: Spoilers Up While Takeoff Power Set?

Sat Sep 29, 2007 2:40 pm

Not too familiar with the crj-900 but I have worked on gulfstreams and globals for quite some time and it is common for gulfstreams to start the take off roll with spoilers up. I supose it depends on the operator but the explanation i was given was that above a certain power setting spoilers should always retract so by starting the take off with spoilers up it serves as yet another check to make sure that they do retract when expected otherwise the take off is aborted.

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