Mushing in a stall

Richard

Richard

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Ack...city life
You are out practicing some airwork. You pull up to enter a stall. You hold the controls aft to mush in the stall. How would you translate "mushing" to a non-pilot person? How would you explain what the controls feel like? How would you describe control authority is this stall condition?
 
Would need more info on your audience.

Also wondering if we're doing your homework for you. ;)

Hint: There are aircraft that don't mush. They just break and there's no transition "feel" between flying and not flying.

Think about why. "Mush" is something *designed into* modern airfoils and aircraft. Especially training aircraft or aircraft designed for less experienced pilots.
 
What info do you need? How about an educated engineer type who has no first hand experience with anything aviation? No familiarity to aviation terms, or principals other than the understanding of physics as required by his non-aviation career.

I have flown some of those airframes/wings which feature *by design* an absence of pitch change common in stalls in other airframes.

What if you are doing my "homework"? I tried to use the relatable to explain the unrelatable. The best I could do was "driving in deep sand, you still have control authority but it is delayed and control input may not produce the sharp response as if driving on paved asphalt".

EDIT: While I recognize there are designs in which there is little to zero perceptable change between non-stalled and stalled conditions, I am not talking of those types.
 
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Richard said:
How would you explain what the controls feel like? How would you describe control authority is this stall condition?
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Lots of slack in the controls.....
 
We've just had a spate of folks lately asking for folks to feed them info to complete their college level schoolwork or write articles they get paid to write.

It just seems like there's libraries full of really good texts on the topic, thus I question the motivation. Sorry that might not have been a reasonable reply.

I shouldn't jump to that conclusion, but most folks start with what their goal is when asking for detailed assistance describing an experience easily gained with an airplane and a CFI.

No offense intended if you're just asking the question. I just found those other threads where folks only came clean late in the thread that they were using the message board to do their work assigned to them, a little weird and unethical on their part. Actually I found the one where the article writer even stated it right at the beginning slightly uncomfortable too.

Asking out of curiosity to a "community" site is normal. I've seem a lot of online IT communities of old turn into "tell me how to do my job" boards over many years, so I'm probably hyper-sensitive to it at a hobby site.

So I kinda wiggled into the topic very obtusely to see what your reaction was to the implied question. It's probably better left to a different thread titled "Should PoA do student's homework or author's article research for them?" ;)

Sorry. It may become a new pet peeve. But I also understand sometimes we all just need some info to get started on a project too.

My recommendation in all honesty is if you've flown an aircraft to a stall that mushes, you've already got the story you want to tell in the memories of the experience! Tell it your way!

That's probably the best and fairest answer and I should have started there. Apologies.
 
denverpilot said:
We've just had a spate of folks lately asking for folks to feed them info to complete their college level schoolwork or write articles they get paid to write.

It just seems like there's libraries full of really good texts on the topic, thus I question the motivation. Sorry that might not have been a reasonable reply.

I shouldn't jump to that conclusion, but most folks start with what their goal is when asking for detailed assistance describing an experience easily gained with an airplane and a CFI.

No offense intended if you're just asking the question. I just found those other threads where folks only came clean late in the thread that they were using the message board to do their work assigned to them, a little weird and unethical on their part. Actually I found the one where the article writer even stated it right at the beginning slightly uncomfortable too.

Asking out of curiosity to a "community" site is normal. I've seem a lot of online IT communities of old turn into "tell me how to do my job" boards over many years, so I'm probably hyper-sensitive to it at a hobby site.

So I kinda wiggled into the topic very obtusely to see what your reaction was to the implied question. It's probably better left to a different thread titled "Should PoA do student's homework or author's article research for them?" ;)

Sorry. It may become a new pet peeve. But I also understand sometimes we all just need some info to get started on a project too.

My recommendation in all honesty is if you've flown an aircraft to a stall that mushes, you've already got the story you want to tell in the memories of the experience! Tell it your way!

That's probably the best and fairest answer and I should have started there. Apologies.
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Nate, I assure you that Richard is a long time poster on POA (look at his join date) and a CFI and is NOT looking for someone to do his work for him. I'd say he's just reaching out to his fellow POAers as many of us do.
 
For an engineer?

Loss of feedback, lower than normal yoke forces for any given action.
Loss of control authority, higher yoke displacement required for any given aircraft reaction.
 
Been thinking about this and trying to simplify various exhibiting indicators. Perhaps as simple as saying that an aircraft has a low airspeed and very high drag on the back side of the power curve along with higher induced drag from the wingtip vortices. The aircraft requires large control inputs to manoeuvre and results in a slow dissipation of altitude.

To a non-pilot? High nose, low airspeed but high power. Large control input required with which the plane responds slowly and over a period of time, you are losing altitude.

Explaining to non-pilots is always a fun thing to do to talk about aviation and get them interested, but I also don't enjoy simplifying something to the point where it is useless information to them. Probably like my above statement on explaining the mush, a very large generalization.
 
Not a problem, Nate. Adam, I do not hold the CFI rating. No one care to provide their answer?
 
I guess I'd say that "Mushing" is where you are still barely able to maintain your pitch, but realize you are no longer climbing and/or perhaps developing a sink rate. It is often accompanied by the ability to make large control movements without significant change (up to a point).

Ryan
 
OzPilot said:
Was mine crap? lol
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Borderline. I feel you introduced so many new terms that you would have to first explain aerodynamics before you could explain what an intentionally prolonged stall is/feels like.

"low airspeed"..."backside of power curve"..."wingtip vortices"...etc

Sure, your audience is an engineer yet by relying on those terms you may have lost him already.

EDIT: I am not trying to direct this thread. I want to know too. I want a good solid answer. Perhaps "mushing" is not a good starting place. So what term would you substitute for "mushing"?
 
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Richard said:
You are out practicing some airwork. You pull up to enter a stall. You hold the controls aft to mush in the stall. How would you translate "mushing" to a non-pilot person?
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Why would a non-pilot person care so much and why is it so important? This non-pilot person can take a discovery flight for cheap and find out themselves. Are you a pilot? All "mushing" is is flight at low airspeed, while likely descending. Hardly different from slow flight, which is hardly different from flying a little faster, etc., etc.

Richard said:
How would you explain what the controls feel like?
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There is less resistance. You will reach the least resistance at zero airspeed (sitting on the tarmac). You will reach most resistance at Vne. The stiffness in the controls increases exponentially with airspeed, but most aircraft operate on the low end of the curve before it really starts to increase rapidly.


Richard said:
How would you describe control authority is this stall condition?
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Less than what you had before you started "mushing"....but more than you have at zero airspeed. Same concept as the previous question.
 
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Richard said:
Borderline. I feel you introduced so many new terms that you would have to first explain aerodynamics before you could explain what an intentionally prolonged stall is/feels like.
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I disagree.. My statement for a non-pilot was

"High nose, low airspeed but high power. Large control input required with which the plane responds slowly and over a period of time, you are losing altitude."

If this isn't simplified enough, I don't know what is
 
AdamZ said:
Nate, I assure you that Richard is a long time poster on POA (look at his join date) and a CFI and is NOT looking for someone to do his work for him. I'd say he's just reaching out to his fellow POAers as many of us do.
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Yeah I was utterly sleep deprived and cranky last night. It's been a week of mostly three hours a night of continuous sleep with ridiculous on-call calls, national CAP communications exercise, planning and execution of a repeater repair trip to the top of Cheyenne Mtn near Colorado Springs today, and OSH coming up. Tomorrow is "catch up on all the little crap" day.

Again apologies. :(
 
Oh. Answer the question, Nate! ;)

For an engineer I'd keep it to discussing flow and pressure. They get that.

Fast forward speed through the air, flow over the wing is high, like sticking your hand out the car window on the Interstate.

Slow through the air is how your hand tilted up out that same window feels like it's not being held up as strongly as you exit the off-ramp.

As you roll up to the stop light and stop, your hand loses all lift and is "fully stalled".

Every kid's done it, and the engineer will get how flow relates to pressure when you tilt your hand up at highway speeds vs side streets. 10-15 MPH for the hand out the window thing is the "mushy" zone I believe. ;)
 
Richard said:
How would you translate "mushing" to a non-pilot person?
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Mushing is when your angle of attack has caused the airflow to create more drag than lift. You still have enough lift to hold the nose up, but the airplane is sinking. Explain AoA, lift/drag, etc.
How would you explain what the controls feel like? How would you describe control authority is this stall condition?
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As the airflow over the controls speeds up or slows down, the controls tighten up or loosen up, like driving a car. A fast speed on the highway needs only a slight wheel movement to cause a turn. When turning at slow speeds into a parking spot, the wheel needs a large turn. Same with the airplane, and also the airplane responds slower when at slower speeds, so control authority is less.
 
In a stall the nose will drop. You can't keep it up. The center of pressure moves aft in the stall and the elevator can't overcome the pitching force.

If it's mushing it's not fully stalled. In most light airplanes the stall starts at the wing roots and progresses outward. You can get a mush going and still only have a portion of the wing stalled. What you have is sink, not stall. That's how the Ercoupe was designed: Not enough elevator to stall it (so it wouldn't spin) but it sure would sink badly and more than a few got busted on landing when the pilot got too slow. Idiot-proof airplanes just breed better idiots.

Dan
 
I think of mushing along the lines of what Dan just mentioned above - the airplane is only partially stalled.

It is a condition where the airplane is not generating enough lift to maintain altitude at a given angle of attack, but the wing is not fully stalled.
 
Who likes mushing?:dunno:

Pull full up elevator--Kick full right or left rudder--and go along for a much more interesting ride!:goofy:

p.s. Do not do this close to the ground!
 
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B2Soar said:
Who likes mushing?:dunno:

Pull full up elevator--Kick full right or left rudder--and go along for a much more interesting ride!:goofy:

p.s. Do not do this close to the ground!
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Actually, what got me going to start this thread was a demo of the docile nature of the C-208 Caravan. The thing is a puppy.

Ahyup, stay in the middle of the air.
 
How about describing a boat up on plane, vs a boat at slow speed with the nose high up and displacing lots of water, requiring more power to maintain speed, and less maneuverable and slow to respond.
 
I would say that "mushing" is flight at a high angle of attack, often in a descent, with controls that are often rather unresponsive and delayed. Recovery from this "mushy" flight is most easily accomplished by a reduction in angle of attack, which often translates to lowering the nose.

A similar control feeling can be had on a wave runner at a speed somewhere between slow and comfortable. I'm not a boat guy so I can't explain what this is exactly but it's before the waverunner is really "on" the water.
 
Richard said:
You are out practicing some airwork. You pull up to enter a stall. You hold the controls aft to mush in the stall. How would you translate "mushing" to a non-pilot person? How would you explain what the controls feel like? How would you describe control authority is this stall condition?
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It's real easy.... When you are about to enter a stall the controls feel like a stretchy rubber band. It's like trying to steer a car on an icy road just before the stall.
 
Stretchy? Huh? The controls do not feel like they want to pull back to neutral.
 
Aviation texts have been striving to describe this feeling for decades. Being fresh from training, I've done plenty of stalls, but I truly didn't understand what a stall feels like until about 3 weeks ago, when I had to opportunity to do a few full up-elevator stalls in a Citabria 7KCAB. Then, it clicked.
 
Jaybird180 said:
Aviation texts have been striving to describe this feeling for decades. Being fresh from training, I've done plenty of stalls, but I truly didn't understand what a stall feels like until about 3 weeks ago, when I had to opportunity to do a few full up-elevator stalls in a Citabria 7KCAB. Then, it clicked.
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~~~~~~~~ and since you were in a Citabria did you apply full rudder just at the stall and get to spin too ? :)
 
bob_albertson said:
It's like trying to steer a car on an icy road just before the stall.
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That is one of the examples I used. But you know, driving in those conditions leaves little control...which immediately prompted the question, "So mushing means you are out of control?" rolls eyes..."No, I did not say that."

Try again, Bob.
 
dmccormack said:
All good descriptions, but I concur with those who said "mushing" implies some residual lift -- that some part of the wing is still flying.
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Yes, but airsflow is less than Vs, right?

BTW: Vs is an engineering term whereas Vsi, Vso is an aeronautical term. Or so I have been told by an aircraft designer.
 
Richard said:
Yes, but airsflow is less than Vs, right?

BTW: Vs is an engineering term whereas Vsi, Vso is an aeronautical term. Or so I have been told by an aircraft designer.
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"Airflow" at what part of the wing?

Simply -- The wings are designed so that aileron authority is maintained even while the roots are stalled. Therefore the outer portions of the wing is still providing lift.

EDIT: Not so for older airplanes or certain trainers.
 
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dmccormack said:
"Airflow" at what part of the wing?

Simply -- The wings are designed so that aileron authority is maintained even while the roots are stalled. Therefore the outer portions of the wing is still providing lift.

EDIT: Not so for older airplanes or certain trainers.
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Even most older airplanes, with rectangular wing planform and no washout, will still start stalling at the roots first. It just progresses outward much more quickly as drag builds and speed falls off. Tapered and elliptical wings tend to start at midspan and are usually washed out some to force the stall inboard, or stall strips are used, or the airfoil at the tip is different than the inboard airfoil.

StallProgression.png


Dan
 
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