I watched a C150 Spin in today at KWHP. Impossible turn goes very bad.

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BJC

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Two things:
* Test YOUR airplane against the impossible turn. Get into takeoff configuration climbing straight over a straight road. At an even thousand (and with a couple thousand below you) pull power and see how much altitude you loose getting ....
Start practice at altitude, but, if you really want to become proficient, you will need to work your way down to your actual decision height / speed. In my A152, the turn was about a 60 degree bank, and, half way throught, the nose was down enough that the ground filled the windshield. THINGS, ESPECIALLY AEROBATIC MANEUVERS OR THE EXTREME BANK AND PITCH NEEDED TO TURN BACK, LOOK VERY DIFFERENT CLOSE TO THE GROUND. Please read that again. The only way to develop the skills needed is to practice safely. And when you do practice at decision height / speed, and need to add power not to hit the ground, it will frighten you.

(Related comment: Not all airplanes are created equal. I recently flew a fine European, type-certificated, aerobatic category airplane. It was the first airplane that I have flown that I could not feel airspeed changes in the stick. It would take a ton of practice above minimum altitude / speed for me to ever think about attempting a turn-back in that airplane.)

Faking an engine failure at altitude isn't the same as an actual, unexpected failure at 400 feet or whatever.
When I practice, I pull power, then count “one thousand one, one thousand two” before reacting.

Remenber, too, that the decision height at Vy is very different from the decision height at Vx. Assuming that I have cleared any obsticles at the end of the runway, I much prefer to have speed than altitude. So there is not a single decision height; it is a combination of heights and speed that varies with other parameters. I just left a fly-in this morning. Yesterday, I cringed when several pilots flew on takeoff at what appeared to be less than Vx, apparently to ???

Remember that one of those other parameters is airplane weight. I never practice with a passenger, so my decision heights / speeds are for a light airplane only.

Remember, too, to turn into the wind if your intention is to land on the runway that you just left. That means that you need to practice turns in both directions.

Remember, too, to practice the actual landing, because you need to get stopped on the runway. My first minimum decision height / speed turn back in my then-new Sportsman was not comfortable, because it glides and retains energy in steep turns much better than my A152 did. That made it very difficult to get it stopped before the end of the runway. “No sir, I didn’t put those ruts in your nice turf runway.”

Like so many things in life, surviving in an airplane is about risk management. Some things that are perfectly safe for Rob Holland would kill the rest of us. Learn. Practice. Survive. Share.


BJC
 

Highplains

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Last time I horsed around with a 150 I pulled the throttle back to low and also pulled the yoke as far back as it would go to see how it mushed. The airspeed reads around 40 and you bob slightly but nothing much untoward happens other than altitude lost. Saving the plane is not the goal, crashing under control is.
 

BJC

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How have you determined decision points for when you do have a passenger?
I haven’t determined a minimum altitude / airspeed with a passenger. The only person that I would trust not to grab the controls or my arm is my daughter, and I haven’t practiced with her in the airplane.

A potential turn-back from anything below a very comfortable altitude / airspeed, for me, would be a solo event.

Note that I do not advocate turn-backs. I support the idea that they never should be attempted without first having practiced them and having become proficient. I first started seriously considering them when flying from Clearwater Executive, a city-owned airport with high density housing close to both runway ends, but with a golf course beside the runway. I concluded that, were it necessary, I would rather crash on the golf course or runway than into a house.


BJC
 
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TFF

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If the CG is forward on a 150, it is very hard to departure stall because it almost does not have the elevator authority mixed with prop air. It's practically just a hover. Instructors never noticed I would pull the throttle back a little so it would break over. Straight ahead it's easy. Kick some rudder doing that and you have instant spin. Ailerons don't really matter. You can put a 150 in a stall keeping wings level with rudder and it will just mush ahead and down. Kick the rudder to change direction instant spin. The plane is as benign a plane can be, but you can't break the rules. Most people are scared to bank a lot. That is why they end up skidding. 30 deg bank is all they will do, but they will boot the rudder hard. Hello spin below recovery altitude.
 

Vigilant1

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I have been wondering why most of you actual pilots are saying that there is a huge temptation to make flat, skidding turns when altitude is in short supply.
This:
Most people are scared to bank a lot. That is why they end up skidding. 30 deg bank is all they will do, but they will boot the rudder hard.
Plus, as the wing stalls the ailerons just aren't as effective as they are at typical cruise speeds/AoA, so the input pilots are used to providing just doesn't produce as much roll as they want (well, at least at first--after the stall break there may be PLENTY of roll!). But the rudder generally remains effective even at low airspeed, and it's possible to push the nose around in a skidding turn, for a little while.

When spins were covered in the flight training for a PPL, students got a good appreciation for how they were caused (including uncoordinated flight at the stall). Now that training concentrates instead on avoiding stalls, that is what new pilots may tend to do (including the tactic of avoiding high bank angles at low speeds). They may be less shy about using heavy rudder just because they haven't experienced the untoward consequences firsthand.

Just to make clear, this is just addressing the general question about why someone would use rudder to turn when at high AoA, it is not about the specifics of the crash at KWHP. Every accident is different, and I know nothing about the chain of events that led to that tragic result. We'll know more eventually after the facts are in and have been analyzed.
 
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Turd Ferguson

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Last time I horsed around with a 150 I pulled the throttle back to low and also pulled the yoke as far back as it would go to see how it mushed. The airspeed reads around 40 and you bob slightly but nothing much untoward happens other than altitude lost. Saving the plane is not the goal, crashing under control is.
You can hit the ground under complete control but if vertical velocity is more than 30 fps survival is questionable.
 

Turd Ferguson

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I have flown a lot of hrs with students and other pilots in C-150's. I can count on 2 fingers the number of people that skidded the plane. One was an ag pilot, the other was an ex-Hun driver.

Even purposely having students and pilots correct for base to final overshoot, almost never would someone push on the rudder to slide the nose around. I've always been curious about that because that's how spins in the pattern occur, or so at least that is what we are told. I believe spins in the pattern are always preceded by pulling on the elevator, the lower AGL the more they pull. At the point the plane departs controlled flight, roll is almost always countered with aileron - which is a pro spin control input.
 
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Dan Thomas

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I just left a fly-in this morning. Yesterday, I cringed when several pilots flew on takeoff at what appeared to be less than Vx, apparently to ???
Trying to show off the performance of their airplanes, maybe. Showing off breaks a lot of airplanes.
 

BBerson

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I believe spins in the pattern are always preceded by pulling on the elevator, the lower AGL the more they pull. At the point the plane departs controlled flight, roll is almost always countered with aileron - which is a pro spin control input.
So they roll out of the base turn to final with rapid aileron and no rudder? (which is strong pro-spin)
The problem is not learning to get out of the stalled turn with enough rudder to recover before the spin.
 

Highplains

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One should learn how to fly on the backside of the curve. Very useful for controlling glide distance. But you do have to relax the excessive elevator to get back enough flying speed to flair. The problem for many is they can be unaware that they are on the backside. When they attempt to flair, they drop faster.
 

pictsidhe

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Trying to show off the performance of their airplanes, maybe. Showing off breaks a lot of airplanes.
But if you are under Vx, you are merely demonstrating a lack of flying skills? To me, Vx is most impressive. I can see Vy being more impressive to others. <Vx has poor speed, climb angle and climb speed. Hey, look how I slowly I can climb out!
 

Dan Thomas

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But if you are under Vx, you are merely demonstrating a lack of flying skills?
Wishful thinking. The same thing that makes the pilot pull back more when the trees are approaching after a takeoff where he did not first properly assess the required takeoff and obstacle clearance distance required for the gross weight, DA and surface conditions.
 

rdj

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I have flown a lot of hrs with students and other pilots in C-150's. I can count on 2 fingers the number of people that skidded the plane. One was an ag pilot, the other was an ex-Hun driver.

Even purposely having students and pilots correct for base to final overshoot, almost never would someone push on the rudder to slide the nose around. I've always been curious about that because that's how spins in the pattern occur, or so at least that is what we are told. I believe spins in the pattern are always preceded by pulling on the elevator, the lower AGL the more they pull. At the point the plane departs controlled flight, roll is almost always countered with aileron - which is a pro spin control input.
I've always wondered how much unusual configurations play a role in these sorts of accidents (although probably not a factor in the OP). By 'unusual configurations', I simply mean something like a passenger in the right seat and another in the aft seats, or something like that. Our light GA planes behave so differently with different loadings that perhaps that approach you've flown solo dozens of times before--slightly uncoordinated--with no ill effects suddenly turns hairy with 380 lbs of aft-cg useful load gone.
 

Turd Ferguson

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So they roll out of the base turn to final with rapid aileron and no rudder? (which is strong pro-spin)
The problem is not learning to get out of the stalled turn with enough rudder to recover before the spin.
No, I'm talking once the stall envelope has been penetrated, very few will counter roll with rudder. It will invariably be aileron while still pulling on the elevator. Relaxing back pressure or pushing forward on the elevator is NOT the intuitive response when low to the ground.

This is how I envision it playing out: Pilot is on base, makes his turn to final, bank gets a little excessive which causes the nose to drop, ground is rushing up so pilot hauls back on the elevator without reducing bank (he is totally confused by the turn dynamics at this point) penetrates the stall envelope, plane departs controlled flight with a roll, roll is countered with aileron while stick is still pulled back to pilots chest and the spin setup is complete with no room for recovery.
 

pwood66889

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THINGS, ESPECIALLY AEROBATIC MANEUVERS OR THE EXTREME BANK AND PITCH NEEDED TO TURN BACK, LOOK VERY DIFFERENT CLOSE TO THE GROUND.
BJC
Thanks for the tip, BJC. This probably is going to be moved to it's own thread but I believe it should be a continuing discussion for all those who fly.
Percy in NW FL, USA
 

pwood66889

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If a person has any way to believe that they have reached the altitude/energy state where a turnback is possible, then they are at serious risk of talking themselves into that option. On the other hand, if they have a hard number in their head, based on personal experience with their airplane, that can serve as a rational basis for abandoning any hope of the turnback option, then there's a better chance more pilots will choose to set down in the safest place available near their present heading. It won't be possible to have a precise altitude (due to winds, etc), but some pre-established criteria/decision point/mark-on-the-wall would seem better than nothing.
Thanks, Vig. That is my point, very well put.
Percy in NW FL, USA
 

BBerson

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No, I'm talking once the stall envelope has been penetrated, very few will counter roll with rudder. It will invariably be aileron while still pulling on the elevator. Relaxing back pressure or pushing forward on the elevator is NOT the intuitive response when low to the ground.

This is how I envision it playing out: Pilot is on base, makes his turn to final, bank gets a little excessive which causes the nose to drop, ground is rushing up so pilot hauls back on the elevator without reducing bank (he is totally confused by the turn dynamics at this point) penetrates the stall envelope, plane departs controlled flight with a roll, roll is countered with aileron while stick is still pulled back to pilots chest and the spin setup is complete with no room for recovery.
I think I am saying the same as you. Pilots are more likely to shallow the bank solely with ailerons and aft stick. Instead of using top rudder (anti spin) to nip the incipient spin before it happens while they attempt to shallow the bank.

On my commercial glider check ride during unpowered stall turning demonstrations, the examiner made sure I used rudder only to "raise" the stalled wing.
So a smart pilot would need to remember to use appropriate amount of rudder to " raise" the wing at all times in order to stay in practice with a proper reaction when needed.
 
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Turd Ferguson

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When spins were covered in the flight training for a PPL, students got a good appreciation for how they were caused (including uncoordinated flight at the stall). Now that training concentrates instead on avoiding stalls, that is what new pilots may tend to do (including the tactic of avoiding high bank angles at low speeds). They may be less shy about using heavy rudder just because they haven't experienced the untoward consequences firsthand.
The current regulations for a private pilot certificate requires ground training, flight training and flight proficiency in: (viii) Slow flight and stalls;

Does that not provide an appreciation for what causes loss of control during low speed maneuvering, including spins?

Also, what is meant by "new pilots?" Spins have not been part of PPL training for 70 yrs so we have gone a couple of generations without spin training. The number of spin accidents has decreased over that time period. I would say current methods have had a positive impact on reducing spin accidents.
 

Tiger Tim

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I would say current methods have had a positive impact on reducing spin accidents.
Current equipment helps too. The sloppy flying planes of yore needed the pilot to actively coordinate turns (to be clear I love that about them) while now a set of rudder pedals can be used as foot rests in flight. If you never use the rudder anyways, it’s hard to use it wrong.
 
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