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Old 07-13-2007, 06:03 PM   #1  
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Default Crj-200 Stall Characteristics

This is for all you CRJ-200 experts:

A friend of mine told me that when he was in SIM practicing departure stalls, there was one characteristic he encountered during the recovery portion of the maneuver. He was taught that once the SIM hits the shaker, he was to apply power and call for "Set Max. Thrust". However, shorty after power application, he noticed the thing wanting to pitch down regardless of what he did to hold the pitch attitude constant. And at some point he hit the pusher!

My question is this: is this a normal departure stall characteristic for a CRJ or what? How do you suppose to control the pitch down tendecy after the application of power? What do you recommend or what do you do about such characteristic?

Let's hear from the experts!
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Old 07-13-2007, 06:09 PM   #2  
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Default my understanding

I'm by no means an expert, but here's my understanding.....

Supposedly the pitching down moment is caused by the engines' location in the back of the airplane as opposed to wing mounted ones and where the thrust line is in relation to the body of mass being pushed.

As for getting the pusher, I believe that has to do with the smoothness of getting that nose up and maintaining that pull. If you pull it too hard you put some more loads on those wings or at least make the computer think that and get a pusher as means of protection.

Guys....? chime in.
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Old 07-13-2007, 06:29 PM   #3  
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I'm going to wager a guess and say nobody on this board knows what the stall characteristics of a CRJ (or ERJ, for that matter) are. All we know is what the approach to a stall is like.
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Old 07-13-2007, 06:37 PM   #4  
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I'm going to wager a guess and say nobody on this board knows what the stall characteristics of a CRJ (or ERJ, for that matter) are. All we know is what the approach to a stall is like.
We did a "Full Stall" in the sim in DFW, and no joke it took more than 5,000ft to recover.............
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Old 07-13-2007, 06:45 PM   #5  
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Quote:
Originally Posted by schone View Post
I'm by no means an expert, but here's my understanding.....

Supposedly the pitching down moment is caused by the engines' location in the back of the airplane as opposed to wing mounted ones and where the thrust line is in relation to the body of mass being pushed.

As for getting the pusher, I believe that has to do with the smoothness of getting that nose up and maintaining that pull. If you pull it too hard you put some more loads on those wings or at least make the computer think that and get a pusher as means of protection.

Guys....? chime in.
I'm no expert either, but I think you're right. The nose will pitch down with an increase of thrust (especially with max power). The RJ recovers from an incipient stall using only thrust to increase speed as opposed to increased thrust and a low pitch attitude as is the recovery techniques with smaller recips.

When max power is set, the nose will tend to drop and if the controls are not smooth to correct this, the aircraft will end up in a secondary stall as indicated by the stick pusher activation.

Your sim partner should smoothly (and maybe a tad slower)set the thrust to max power. Then smoothly maintain your target attitude.

Also, the perfomance of each simulator differs, some are more sensitive than others. Others need tweaking to bring them closer to reality.
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Old 07-13-2007, 06:48 PM   #6  
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I loved training in the T-37... could stall and spin the crap out of that bird... my favorite was an inverted spin... now that was sporty hanging in the straps...
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Old 07-13-2007, 07:06 PM   #7  
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In the sim world- max thrust and spoilers in while respecting the shaker does the trick in the checkride.. You will hold within 50 ft. (As I recall) The nose up attitude is only a few degrees but within a few seconds you are out of the shaker with a healthy positive trend vector. Then its all about getting the flaps up and getting the thing trimmed again. If you do "yank" and get the pusher you are looking at the bucking bronco which could turn into a 5000' adventure. Hope it helps..
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Old 07-13-2007, 07:16 PM   #8  
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I've done a stall to stick push in the CRJ several times (in the actual aircraft on delivery acceptance test flights). It's really no big deal, and the aircraft recovers quite nicely provided that you have enough room to lower the nose a few degrees and SMOOTHLY apply power. Of course altitude wasn't an issue since we did them at 15,000'.

As mentioned before, the nose down tendancy when initially applying power is due to the engines being mounted above the longitudinal axis of the aircraft. Since the thrust axis is above this line (and above the "center of balance" from nose to tail), the addition of power creates "asymmetrical thrust" above the center of balance (if that makes any sense).

My recommendation on any maneuver is to go through it at a reasonable pace and not rush the recovery. Another good thing to do anytime that you add power from slow speed is thumb the trim for about half a second as you apply power. This is good for both the stall recovery and a go around.

1, because (in the case of a go around), it will disconnect the A/P. (Although pushing TOGA will as well).

And 2 because it gets the aircraft moving in the right direction as you apply power and counteracts that initial nose down tendancy. Once you get moving in the correct direction, then simply thumb it out (odds are you'll need to take out even more than you just put in, or the plane will do a tailstand and fly off like a homesick angel).

The sim is a bit squirrely, but in real life the actual approach to stall, shake and subsequent stick push is a nice smooth and stable approach. The nose drops before you even hit the buffet, and at altitudes where the air is thicker, the push isn't even that abrupt (maybe -.25g? If that?).
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Old 07-13-2007, 07:20 PM   #9  
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Josh your clue to go through at a reasonable pace is right on.....when stalling and spinning the T-37... we use to take a couple of deep breaths.... enjoy the ride and then perform the boldface.
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Old 07-13-2007, 07:26 PM   #10  
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Josh your clue to go through at a reasonable pace is right on.....when stalling and spinning the T-37... we use to take a couple of deep breaths.... enjoy the ride and then perform the boldface.
It's a great rule when you're doing anything in an aircraft. With the exception of cabin/pressure hull fires and rapid decompressions at altitudes above FL250, there are very few things that can kill you in an aircraft rapidly... except simultaneous brain farting of both pilots.
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