Is there a conflict in this NASA video

tgrayson said:
Does your airplane have a nose down pitching moment with increase thrust? (What airplane?)
Click to expand...

Well yes it does. The engines are in the back. (CRJ-200 or CRJ-900). When thrust is applied, the airplane may tend to have a pitching down moment. Then again, I'm going off of what I saw in the sim. Haven't actually stalled this plane on the line!

In my context, when I say "respecting the stick shaker" - you pull back to maintain the altitude while the speed builds and if you get the pusher - you've pulled back too much.

edit: also, in a swept wing aircraft, you use ailerons during the stall to maintain level flight as a primary means, rather than rudder as in a GA aircraft.
 
tgrayson said:
Preserving altitude in this scenario is perfectly reasonable.
Click to expand...

Trading altitude for airspeed would have saved a lot of lives. I've been in deep stalls with my nose very high and a billboard attached by a rope to my tail at 300 feet above the ground. I survived by sacrificing 100 feet of altitude.
 
mkusch said:
Trading altitude for airspeed would have saved a lot of lives. I've been in deep stalls with my nose very high and a billboard attached by a rope to my tail at 300 feet above the ground. I survived by sacrificing 100 feet of altitude.
Click to expand...

Understood, but there have been other scenarios in which trading altitude for airspeed has killed hundreds of people. That's why I said their training was "reasonable", and statistically, it may still be the best training scenario.
 
tgrayson said:
Understood, but there have been other scenarios in which trading altitude for airspeed has killed hundreds of people. That's why I said their training was "reasonable", and statistically, it may still be the best training scenario.
Click to expand...

But we changed the training. We don't do it that way anymore...
 
cencal83406 said:
Well yes it does. The engines are in the back. (CRJ-200 or CRJ-900). When thrust is applied, the airplane may tend to have a pitching down moment. Then again, I'm going off of what I saw in the sim. Haven't actually stalled this plane on the line! In my context, when I say "respecting the stick shaker" - you pull back to maintain the altitude while the speed builds and if you get the pusher - you've pulled back too much.
Click to expand...

In that setup, adding thrust will reduce the AoA, so pulling back on the yoke may not have much of a net AoA change. I expect that your yoke back pressure decreases as the recovery progresses, which would correspond to a decreasing AoA/increasing airspeed.

As long as you're not stalled, you probably have enough excess thrust to maintain altitude, which allows this technique to work.
 
tgrayson said:
Of course you don't, that would be politically unacceptable.;) Note that I'm not offering an opinion about whether it was best or not, just saying that statistically, it could be.
Click to expand...

New training is actually quite eye-opening (read, not fun to get close to red screening)....

"simulated base turn to final w/AP on - spoilers out, flaps 45, gear down, power at 60% N1 (I think lol, been about 6 months since I did it); look away from the instruments, when aircraft stalls the AP will kick off and prior to recovery, we are to yank back on the stick to induce a full stall, then start recovery procedures"

I've seen it take 3000 feet to recover from it... and I was PM at that point.
 
cencal83406 said:
Swept wing stalls tip to root. So, we're trying to keep the wings level in that regard.
Click to expand...

An unmodified swept wing does, which is why you have stall fences and wing twist. But even without that, the prospect of a wingtip stall is usually the reason you don't want to use ailerons, rather than why you do, so I don't understand that reasoning.
 
tgrayson said:
An unmodified swept wing does, which is why you have stall fences and wing twist. But even without that, the prospect of a wingtip stall is usually the reason you don't want to use ailerons, rather than why you do, so I don't understand that reasoning.
Click to expand...
:yeahthat:
 
tgrayson said:
An unmodified swept wing does, which is why you have stall fences and wing twist. But even without that, the prospect of a wingtip stall is usually the reason you don't want to use ailerons, rather than why you do, so I don't understand that reasoning.
Click to expand...
And this is what I understood and led to my question of why it was stated that a swept wing aircraft uses ailerons and not rudder?
 
subpilot said:
And this is what I understood and led to my question of why it was stated that a swept wing aircraft uses ailerons and not rudder?
Click to expand...

Don't know; there may be some other characteristics of a transport category aircraft that make rudder usage in this scenario less useful, or this could just be a standardization thing for this particular operator.

Personally, I teach maintaining heading by coordinated aileron and rudder. If an actual stall occurs, lower AoA, increase power, and roll level with coordinated aileron and rudder.

Since I don't teach "maintain heading with rudder", I don't find the described procedure unusual.
 
I know at ExpressJet, we were taught to power out of the stall (albeit, not a tail stall). If you had the pusher go off, you failed.
 
This was the most confusing post I have read thus far on JC, thanks folks. Half of you were talking tail stalls the other half wing stall. There were at least 4 different methods of recovery, but nobody claimed what kind of stall they were attempting to recover from. :insane:

IMO if you haven't, you should move the vid to about 20 minutes in and watch the last 3 minutes. Any future recovery methods discussed...it would be helpful to know what kind of stall the recovery procedure you mention is for. Thanks!
 
cencal83406 said:
max power spoilers in
pull up aggressively respecting the stick shaker
don't lose altitude (100 ft is a bust)

I can't emphasize this enough - we were taught to power out of the stall.
Click to expand...

They bust people on stalls? :banghead:

cencal83406 said:
Regular stall.... what do you do? Pull back? That's what we were taught...
Click to expand...

In both the ATR and 145 we are taught add power and lower the nose to 5 degrees.
 
You must log in or register to reply here.
Back
Top