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Spoilers Up While Takeoff Power Set?  
User currently offlineCan258 From , joined Dec 1969, posts, RR:
Posted (7 years 3 months 1 week 23 hours ago) and read 3571 times:

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]

17 replies: All unread, jump to last
 
User currently offlineMandala499 From Indonesia, joined Aug 2001, 6968 posts, RR: 76
Reply 1, posted (7 years 3 months 1 week 22 hours ago) and read 3523 times:

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 !
User currently offlineFlyf15 From , joined Dec 1969, posts, RR:
Reply 2, posted (7 years 3 months 1 week 22 hours ago) and read 3523 times:

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.


User currently offlineAirfoilsguy From , joined Dec 1969, posts, RR:
Reply 3, posted (7 years 3 months 1 week 22 hours ago) and read 3519 times:

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?


User currently offlineCan258 From , joined Dec 1969, posts, RR:
Reply 4, posted (7 years 3 months 1 week 22 hours ago) and read 3517 times:

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


User currently offlineCan258 From , joined Dec 1969, posts, RR:
Reply 5, posted (7 years 3 months 1 week 22 hours ago) and read 3512 times:

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.


User currently offlineSushka From United States of America, joined Nov 1999, 4784 posts, RR: 14
Reply 6, posted (7 years 3 months 1 week 22 hours ago) and read 3501 times:

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!
User currently offlineKELPkid From United States of America, joined Nov 2005, 6428 posts, RR: 3
Reply 7, posted (7 years 3 months 1 week 22 hours ago) and read 3501 times:

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 :-)
User currently offlineSushka From United States of America, joined Nov 1999, 4784 posts, RR: 14
Reply 8, posted (7 years 3 months 1 week 22 hours ago) and read 3492 times:

Yeah thats kinda what happens on the CRJ and probably other jets only full deflection will put the spoiler up.


Pershoyu Spravoyu Litaki!
User currently offlineFlyf15 From , joined Dec 1969, posts, RR:
Reply 9, posted (7 years 3 months 1 week 21 hours ago) and read 3472 times:

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.


User currently offlineFr8Mech From United States of America, joined Sep 2005, 5658 posts, RR: 15
Reply 10, posted (7 years 3 months 1 week 21 hours ago) and read 3468 times:

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.
User currently offlineCan258 From , joined Dec 1969, posts, RR:
Reply 11, posted (7 years 3 months 1 week 21 hours ago) and read 3460 times:

Quoting Flyf15 (Reply 9):

Thanks Flyf15. Now I understood the reason.

Can258


User currently offlineCan258 From , joined Dec 1969, posts, RR:
Reply 12, posted (7 years 3 months 1 week 21 hours ago) and read 3457 times:

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.


User currently offlineAirfoilsguy From , joined Dec 1969, posts, RR:
Reply 13, posted (7 years 3 months 1 week 18 hours ago) and read 3375 times:

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.


User currently offlineDoug_Or From United States of America, joined Mar 2000, 3442 posts, RR: 3
Reply 14, posted (7 years 3 months 1 week 17 hours ago) and read 3371 times:

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
User currently offlinePhxpilot From United States of America, joined Jul 2005, 80 posts, RR: 2
Reply 15, posted (7 years 3 months 1 week 17 hours ago) and read 3365 times:

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.


User currently offlineTinPusher007 From United States of America, joined Feb 2005, 983 posts, RR: 1
Reply 16, posted (7 years 2 months 4 weeks 1 day 18 hours ago) and read 2908 times:

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."
User currently offlineSterling79 From United States of America, joined Sep 2007, 4 posts, RR: 0
Reply 17, posted (7 years 2 months 4 weeks 11 hours ago) and read 2786 times:
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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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