Jaybird180
Final Approach
Ummmmmmmmm.....Podiatric lethargy. Pediatrics involves children, not feet.
I used to call it somnopedosis. Sleepy feet.
Dan
Blame autocorrect
Ummmmmmmmm.....Podiatric lethargy. Pediatrics involves children, not feet.
I used to call it somnopedosis. Sleepy feet.
Dan
I'd rather that pilots learn to - Unload the wing
Question: is the act of relaxing the elevator position sufficient in itself to break the stall or does it require the act of unloading the wing (even an infinitessimally small amount)?
I edited my comment before I saw your reply. So, shouldn't it be called "reloading the wing" when you recover from a stall?No, this is not a semantics question and I'd imagine that an acro pilot would know the difference. I read about some stalls that require the elevator to be held forward to break the stall. Unloading the wing means n value minus 1.0G.
Even in a stall would the wing not be loaded? Its just loaded on the underside during a negative G and on the topside during a positive G. Is this not correct? During a stall the wing loading on the bottom of the wing might be slight but would there still not be forces acting upon the bottom of the wing?
Tony
You guys are really starting to screw with my mind.
No kidding. All I was trying to do is explain why "releasing back pressure" isn't always sufficient to "break" a stall. If anyone want's proof of this, take a 172 loaded with the CG near the aft limit, slow to about 60 KIAS with flaps up, run the trim all the way up, select full flaps while applying full power, and take your hands off the wheel. Yes this is an extreme case but there are plenty of more "normal" situations where simply "releasing the back pressure" won't "unload the wing" sufficiently to "break" a stall.Isn't it always amazing when folks take a simple concept and make it as confusing as possible?
Relaxing back pressure is to reduce the angle of attack below the stall angle. "Unloading the wing" is a bit misleading. The AoA will increase as the airplane stalls and starts heading downward with its nose still high, and a small reduction in pitch angle might not be enough to unstall the wing.
There's more to getting flying again than just letting off back pressure. One should be in the habit of going to a high power setting, too. If you were to stall on final, say, just reducing the pitch angle will kill you. You need a bunch of speed as well.
Dan
No such thing as less stalled, despite what is taught about spins (one wing more stalled than the other). It's like being a little pregnant.if you release back pressure you'll be in less of a stall, or back to normal flight if you've released a sufficient amount.
A true stall is the disturbance of airflow over the wing where the wing is no longer producing lift.Even in a stall would the wing not be loaded?
Speed and power have nothing to do with a stall. Hint for you, what is the stall speed at 0G?One should be in the habit of going to a high power setting, too. If you were to stall on final, say, just reducing the pitch angle will kill you. You need a bunch of speed as well.
Dan
No such thing as less stalled, despite what is taught about spins (one wing more stalled than the other). It's like being a little pregnant.
A true stall is the disturbance of airflow over the wing where the wing is no longer producing lift.
Speed and power have nothing to do with a stall. Hint for you, what is the stall speed at 0G?
Untrue. Stalled wings still produce quite a bit of lift - it's just less than unstalled wings, and typically not enough to maintain level flight. If stalled wings produced NO lift, the airplane would literally fall out of the sky like a rock once stalled. The airplane is still "flying" in a stall, it is just descending, and not producing lift as efficiently with turbulent airflow over the wings vs. streamline airflow.
Never heard of a "deep stall"? I think there are degrees, so yes, a plane can be "less stalled".No such thing as less stalled, despite what is taught about spins (one wing more stalled than the other). It's like being a little pregnant.
Roscoe and Dan seem to belive that power and stalls are tied together. They are not. In fact, there are cases where power can aggravate a stall.
They do fall out of the sky.
Not following the reason for your tangent. If you stall at 50' on final. I surely suggest you apply full power during stall recovery if you would like to avoid a very unfortunate arrival. I don't know what your simple non-statement of "power and stalls are not tied together" is supposed to mean.
You are severely lacking in aerodynamic knowledge. Stalled wings do in fact create quite a bit of lift. So if you go up in your 172, pull power off, and hold the yoke fully aft, you think this is the same thing as a rock falling to the ground? The same thing as the airplane suddenly not having wings at all? The airplane is still flying - just not very efficiently.
Critical AOA in most airplanes is typically between 15-20 degrees. The bottom surface of the wing will still push quite a bit of air downward when flying at this AOA. The top surface may be turbulent, which reduces the total downwash of air, or "lift", but quite a bit of lift is still generated when the wing is stalled. Just like sticking your hand out of the car window at a 20 degree angle. You are in need of some aerodynamic education. Nothing wrong with being ignorant, but it's the arrogant ignorance that makes internet forums such unpleasant places at times.
Unfortunately, that article misses proving a definition, as there may be many depending upon context. Many people think of them as successive recovery and secondary stall conditions. I do not think that is a matter of degree of stalls rather stall > recovery > stall ....Never heard of a "deep stall"? I think there are degrees, so yes, a plane can be "less stalled".
dtuuri
Then why not just say "reduce the angle of attack"? I don't know how many times I've heard pilots say they "unload the wing" to prevent a stall during a steep bank from base to final. Of course, it might not stall, but it won't turn either. Somehow the concept of "unloading" seems to lead to a thinking that it's sort of a free lunch on the part of many pilots, IMHO.In simplest terms unloading means reducing the AoA and hence the g force felt by the pilot.
Roscoe and Dan seem to belive that power and stalls are tied together. They are not. In fact, there are cases where power can aggravate a stall.
Discussion: P-A-R-E
Power (idle)
Aileron (neutralize)
Rudder (not applicable to this discussion - but the mnemonic is opposite spin)
Elevator (briskly forward and held until stall breaks)
This is the universal spin recovery technique which is required academics for stall recovery (cannot spin if you're not stalled - spiral is different)
1 - I didn't bring speed and power into the discussion. Someone else did, I just responded.
2- C-172 is a poor example of stalls during an academic discussion of the subject matter. And from a purely academic perspective, stalled wings produce no lift.
HOWEVER.. a deep stall doesn't happen at the break (necessarily, although perhaps it might). It happens as the angle of attack increases enough that the down wash envelopes the T-tail making recovery impossible. Recognize it soon enough, and you won't go there. Delay at your peril.the article does provide a definition, but it's unrelated to the discussion:
A deep stall (or super-stall) is a dangerous type of stall that affects certain aircraft designs,[27] notably those with a T-tail configuration. In these designs, the turbulent wake of a stalled main wing "blankets" the horizontal stabilizer, rendering the elevators ineffective and preventing the aircraft from recovering from the stall.
Never heard of a "deep stall"? I think there are degrees, so yes, a plane can be "less stalled".
dtuuri
Ianovic said:This whole "all or nothing" view of a stalled wing is bogus. Go fly something with aft CG and a lots of elevator authority, go up real high and ride a stall down and play with it. Fighter jets can fly WAY beyond the critical angle of attack. Google "NASA high alpha research".
HOWEVER.. a deep stall doesn't happen at the break (necessarily, although perhaps it might). It happens as the angle of attack increases enough that the down wash envelopes the T-tail making recovery impossible. Recognize it soon enough, and you won't go there. Delay at your peril.
dtuuri
I was taught that buffeting was onset or partial stall, the break was a full stall.
Sent from my iPad using Tapatalk
How do you envision a scenario in which you could possibly have an AoA "beyond critical" (or not, for that matter) and at the same time have 0G?Personally, I am comforted by knowing that I can unload the wing to break any stall, provided I can reduce load factor to the necessary value approaching 0G, because I KNOW a wing can never stall there (even beyond critical AoA), and hence my reason for mentioning it.
Deep stall is irrelevant to the discussion
Because most GA airplanes have no AoA display and without that how do you know when you've reduced the AoA? As already pointed out with a wing stall, the AoA increases even if the pitch attitude remains unchanged. That said, I have no problem if we substitute Reduce the AoA" for "unload the wing" as they are virtually synonymous.Then why not just say "reduce the angle of attack"?
I don't know how many times I've heard pilots say they "unload the wing" to prevent a stall during a steep bank from base to final. Of course, it might not stall, but it won't turn either. Somehow the concept of "unloading" seems to lead to a thinking that it's sort of a free lunch on the part of many pilots, IMHO.
You can lower the AoA in a steep bank but (assuming you maintain coordination) as you say the resulting loss of lift means the plane will be accelerating towards the ground and at some point you'll have to pay back the g loading. The turn won't stop however unless you reduce the g force to zero. Reducing the g load to that required for a level turn at a smaller bank angle does result in a shorter turn radius than you'd get using that smaller bank angle in level flight. For example a 45° bank in a level turn requires ≈1.4g and a 35° bank in level flight takes ≈1.22 g. The turn rate in a 45° bank while pulling 1.22 g generates a turn rate more than 23% greater than a level turn with a 35° bank.
It's relevant to the notion you've now retreated from that there is no such thing as a "less stalled" wing. If there wasn't, you would recover from a stall, in your language, by "unloading the wing" even by the slightest amount. You know in your heart the deeper the stall, the more "unloading" you need to do. (Gee, I really hate using that language. )
dtuuri
How do you envision a scenario in which you could possibly have an AoA "beyond critical" (or not, for that matter) and at the same time have 0G?
dtuuri
A true stall is the disturbance of airflow over the wing where the wing is no longer producing lift.
That isn't what I was looking for. You wrote, re: 0G, "...I KNOW a wing can never stall there (even beyond critical AoA)..." So, I asked:Simple: if I pull my AoA beyond critical, the wing stalls. If I want to live and recover right now, I PUSH (not just relax) the yoke and the wing immediately begins flying again.
because "even beyond critical AoA" there is still some lift and you won't be at 0G. If you think you can have one without the other, I suspect you're mistaken--at least as far as normal flight regimes go. Then the next thing is, you'll be "unloading your wing" from base to final, so as to tighten your turn without any penalty. That's a big no-no, IMO.How do you envision a scenario in which you could possibly have an AoA "beyond critical" (or not, for that matter) and at the same time have 0G?