Diana
Final Approach
How do you all do the falling leaf stall? Do you use partial power, or do you use power at idle?
How do you all do the falling leaf stall? Do you use partial power, or do you use power at idle?
I do it at idle. But I suppose different airplanes might require different technique.How do you all do the falling leaf stall? Do you use partial power, or do you use power at idle?
Brian, you really need to come to the midwest. And then we could do a falling leaf stall.Well, I go out in the Fall and find a good Maple tree. Then I need a rake so I can get a really good pile of leaves going...
Brian, you really need to come to the midwest. And then we could do a falling leaf stall.
That's how I was taught to do it in the Citabria. Seems like Chip and I did it at idle in the Extra. But that was awhile back, so I'm not sure now.I do it at idle. But I suppose different airplanes might require different technique.
Yes to the above but you keep the wings level with rudder. As you are deep into a stall, the control response is mushy and it typically rolls both left and right as you try to keep it level. Just as a falling leaf might roll from side to side - and hence the name.Idle is fairly standard for the stall - the falling leaf is a power-off stall variation. All it really is (in the variation I use; there may be others although I haven't heard of them) is a power-off stall from which you delay the recovery (power remains off, stick remains back) while maintaining coordination (no spin).
I've actually had students recover from a power-off stall and immediately enter into a second stall but never described it as more than a secondary stall.
IMHO what has been described is not a stall recovery followed by a secondary, but a stick-all-the-way-back continuous stall...no relaxation of back pressure thus no recovery. It is the gold-plated way to teach a student the importance of the rudder at high angles of attack/low airspeed, because every time a wing drops it is picked up with rudder, and that it is not the throttle that breaks the stall.
Bob Gardner
A secondary stall is due to a poorly executed recovery. A "falling leaf" stall is an intentional maneuver in which you purposely delay recovery.I've actually had students recover from a power-off stall and immediately enter into a second stall but never described it as more than a secondary stall.
No spin is the result of coordinated flight.Yes to the above but you keep the wings level with rudder. As you are deep into a stall, the control response is mushy and it typically rolls both left and right as you try to keep it level. Just as a falling leaf might roll from side to side - and hence the name.
So your coordinated flight is not so great, but for sure, no spin!
-Skip
Usually, the first few practices should include only approaches to stalls, with recovery initiated as soon as the first buffeting or partial loss of control is noted. In this way, the pilot can become familiar with the indications of an approaching stall without actually stalling the airplane. Once the pilot becomes comfortable with this procedure, the airplane should be slowed in such a manner that it stalls in as near a level pitch attitude as is possible. The student pilot must not be allowed to form the impression that in all circumstances, a high pitch attitude is necessary to exceed the critical angle of attack, or that in all circumstances, a level or near level pitch attitude is indicative of a low angle of attack. Recovery should be practiced first without the addition of power, by merely relieving enough back-elevator pressure that the stall is broken and the airplane assumes a normal glide attitude. The instructor should also introduce the student to a secondary stall at this point. Stall recoveries should then be practiced with the addition of power to determine how effective power will be in executing a safe recovery and minimizing altitude loss. (p. 4-5)
Welcome to the board!Greetings Pilots of America!
I had to get a Statement of Demonstrated Ability for my original class 3 medical (I walk with a limp) which involved a flight test. We did a few basic PTS manuevers and the examiner asked "have you ever done an "oscillatory stall?"
She had me pin the yoke all the way back in the Cessna 150 (power off) and apply the necessary rudder inputs while the airplane stalled and dipped in succession. After three or so nods, she announced that my rudder work was fine and she was late for dinner.
Thats my falling leaf story!
Agreed as I've heard multiple secondary stalls referred to as falling leaf stalls.A secondary stall is due to a poorly executed recovery. A "falling leaf" stall is an intentional maneuver in which you purposely delay recovery.
IMHO what has been described is not a stall recovery followed by a secondary, but a stick-all-the-way-back continuous stall...no relaxation of back pressure thus no recovery. It is the gold-plated way to teach a student the importance of the rudder at high angles of attack/low airspeed, because every time a wing drops it is picked up with rudder, and that it is not the throttle that breaks the stall.
Bob Gardner
Bob, can you explain this a bit more, please? I'm sitting in my hotel in NYC and trying to envision this.
I'm very comfortable with power-off stalls and power-on stalls. I actually think they're kind of fun. And I want to try the kind of stall described in this thread with my CFI when I get back to Glens Falls later in the week.
But I'm not getting the "every time a wing drops it is picked up with rudder" thing. I can understand why the ailerons are not likely to be effective (although I don't see how they can have the opposite effect unless using an aileron in a stall will increase the angle of attack and deepen the stall but I'm not quite picturing that right now) and I do understand why the rudder is still effective. But I don't get the "picking up a wing with the rudder thing", to the point that I'm not even sure if you use same-side or opposite rudder.
If I were sitting in the cockpit while this was going on, I'd be real tempted to look at the turn coordinator and use whichever rudder was indicated by that, with the obvious goal of keeping the ball centered. Short of that, my gut says opposite rudder because we want to essentially initiate a turn opposite the direction in which the wing is rolling and because PARE calls for opposite rudder in spin recovery -- but I don't understand exactly why it works.
My best guess is that we're turning the aircraft and speeding up the outside wing, which will tend to reduce or eliminate the stall on that side. But that's a WAG and I could believe that the relative wind and the dihedral are also coming into play. So please, someone, help this poor student understand.
Thanks!
IMHO what has been described is not a stall recovery followed by a secondary, but a stick-all-the-way-back continuous stall...no relaxation of back pressure thus no recovery. It is the gold-plated way to teach a student the importance of the rudder at high angles of attack/low airspeed, because every time a wing drops it is picked up with rudder, and that it is not the throttle that breaks the stall.
Bob Gardner
I think You're doing pretty good. Engineers who really understand aerodynamics will probbaly cringe but...But I'm not getting the "every time a wing drops it is picked up with rudder" thing. I can understand why the ailerons are not likely to be effective (although I don't see how they can have the opposite effect unless using an aileron in a stall will increase the angle of attack and deepen the stall but I'm not quite picturing that right now) and I do understand why the rudder is still effective. But I don't get the "picking up a wing with the rudder thing", to the point that I'm not even sure if you use same-side or opposite rudder.
If I were sitting in the cockpit while this was going on, I'd be real tempted to look at the turn coordinator and use whichever rudder was indicated by that, with the obvious goal of keeping the ball centered. Short of that, my gut says opposite rudder because we want to essentially initiate a turn opposite the direction in which the wing is rolling and because PARE calls for opposite rudder in spin recovery -- but I don't understand exactly why it works.
My best guess is that we're turning the aircraft and speeding up the outside wing, which will tend to reduce or eliminate the stall on that side. But that's a WAG and I could believe that the relative wind and the dihedral are also coming into play. So please, someone, help this poor student understand.
Thanks!
If the nose drops and the airplane recovers of it's own accord, I think that's okay. Someone mentioned the left-right-left banking as the picture of the "falling leaf." But maintaining wings level (using rudder to keep the wings from dropping left-right) with the nose bobbing up and down as the airplane stalls-unstalls-stalls, is the "falling leaf" goal I visualize when explaining the maneuver.Bob, some airplanes, depending on W&B, will recover from the stall even with the stick all the way back to the stops. In order to remain in the falling leaf you *MIGHT* need to enter the stall and relieve a little pressure a little while later to avoid the self-recovery caused by the stall deepening which may cause a loss of elevator authority. But for the most part, yes, you keep the yoke/stick back to the stops the entire time.
I think You're doing pretty good. Engineers who really understand aerodynamics will probbaly cringe but...
Yes, the ailerons can have the opposite effect because "using an aileron in a stall will increase the angle of attack and deepen the stall." Aileron increases AoA - that's how it increases lift to bank and turn the airplane. The stall happens when the critical AoA is exceeded and a cause of a wing drop is (in the vernacular) one wing being "more stalled" than the other. Increasing the AoA on the "more stalled" wing makes the situation worse.
As to the rudder, it's really the same as any other use of the rudder - to control yaw. In this case the yaw is in the direction of the dropped wing. To visualize, the dropped wing is not simply a bank with the nose straight ahead - it is a bank accompanied by yaw in the direction of the bank. Think of it as a pre-incipient spin. Lifting the wing with (opposite) rudder is essentially spin recovery technique - power idle (it is), ailerons neutral (aha!), rudder opposite to the direction of yaw (aha! aha!), and elevator to increae AoA and recover from the stall.
So when we talk about using rudder to lift the wing instead of aileron, we're really just talking about understanding the connection between stalls and spins. It's (or at least it should be) part of out training in spin awareness and recovery (whether or not we do real spins.
(btw, not everyone talks about rudder only in the dipped wing situation. Folks do talk about using coordinated aileron and rudder, but given the effect of the two controls in the dripped wing situation, the net result isn't much different)
You are welcome.Mark,
Thank you!
Sometimes you have to hear something said in a particular way. This helped a lot! Thanks!
If the nose drops and the airplane recovers of it's own accord, I think that's okay. Someone mentioned the left-right-left banking as the picture of the "falling leaf." But maintaining wings level (using rudder to keep the wings from dropping left-right) with the nose bobbing up and down as the airplane stalls-unstalls-stalls, is the "falling leaf" goal I visualize when explaining the maneuver.
Bob, can you explain this a bit more, please? I'm sitting in my hotel in NYC and trying to envision this.
I'm very comfortable with power-off stalls and power-on stalls. I actually think they're kind of fun. And I want to try the kind of stall described in this thread with my CFI when I get back to Glens Falls later in the week.
But I'm not getting the "every time a wing drops it is picked up with rudder" thing. I can understand why the ailerons are not likely to be effective (although I don't see how they can have the opposite effect unless using an aileron in a stall will increase the angle of attack and deepen the stall but I'm not quite picturing that right now) and I do understand why the rudder is still effective. But I don't get the "picking up a wing with the rudder thing", to the point that I'm not even sure if you use same-side or opposite rudder.
If I were sitting in the cockpit while this was going on, I'd be real tempted to look at the turn coordinator and use whichever rudder was indicated by that, with the obvious goal of keeping the ball centered. Short of that, my gut says opposite rudder because we want to essentially initiate a turn opposite the direction in which the wing is rolling and because PARE calls for opposite rudder in spin recovery -- but I don't understand exactly why it works.
My best guess is that we're turning the aircraft and speeding up the outside wing, which will tend to reduce or eliminate the stall on that side. But that's a WAG and I could believe that the relative wind and the dihedral are also coming into play. So please, someone, help this poor student understand.
Thanks!
The real revelation came when the DPE showed the same trick in cruise and made it clear that it was a smoooooother way to fly on a bumpy day. QUOTE]
My DPE called the rudder trick the poor man's wing leveler. When you need two hands to wrestle with a sectional just use the rudder to keep level.
-Skip
When letting a youngster take the controls of the plane, I "help" keep the wings level with the rudder.My DPE called the rudder trick the poor man's wing leveler. When you need two hands to wrestle with a sectional just use the rudder to keep level.The real revelation came when the DPE showed the same trick in cruise and made it clear that it was a smoooooother way to fly on a bumpy day.
-Skip
If I were sitting in the cockpit while this was going on, I'd be real tempted to look at the turn coordinator and use whichever rudder was indicated by that, with the obvious goal of keeping the ball centered.
Others have already addressed most of this already I think, so let me zero in on the above temptation:
Don't do it!
This exercise, and the time period immediately surrounding any stall departure for that matter, is highly dynamic. And if you're VFR anyway (which is where most of us are most of the time), looking outside provides far more immediate and accurate information than those instruments, which are lagging more and more the more dynamic the scenario. Plus, you won't be as likely to get sick staring inside the cockpit with all of the sensory commotion going on outside.
The slip/skid ball is the least reliable at this point, too! In fact, the closer you get to an actual spin departure (the rudder stall exercise is a series of mini-spin departures rapidly corrected by the pilot), the less reliable the ball.
Moreover, once a true spin departure has occurred, the ball becomes a totally unreliable indicator of yaw/spin direction.
Whenever it's available, look outside for information.
BTW, power-idle rudder stalls tend to be quite benign in most airplanes, so I do them with students with the power set at around 1300-1500 rpm -- much more interesting and dynamic. Plus the little bit of engine effects contribute more to the mix.
Rich
www.richstowell.com