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Testing the Impossible Turn

As a long time aerobatic pilot I find it disappointing that many posters here appear to think that a stall at low altitude inevitably leads to a spin and crash.

To my internal g meter the sensation of stalling is unmistakeable and that sensation comes a long time before autorotation develops. There is always plenty of time to reduce the angle of attack and get the wing flying again, even in planes that give no detectable warning of an impending stall. Since RVs tend to give some warning of impending stall there are no excuses other than inexperience and lack of focus on what is important for a stall to turn into a spin.

I developed my sense of the wing stalling flying airplanes that could just barely manage the required aerobatic sequences - a Decathlon in Intermediate and a Pitts S-1S in Unlimited. While leaning to fly figures starting with the least possible energy I've stalled unintentionally several hundred times in every possible attitude and never once did the stall turn into a spin. There's no reason why stall detection and mitigation can't be automatic even while concentrating on many other issues. All it takes is practice.

I concur with jonjay's suggestion that practicing stalls out of steep power off turns is probably the best way to get comfortable with doing the impossible turn. Once you are sure you can detect a stall and stop it without losing much altitude, you can move on to deciding how close to stalling you are willing to pull and then to optimizing speed and bank angle.

If you're not willing to do this sort of familiarization and practice, you might well be better off landing somewhere ahead of you after an engine fails on takeoff.
 
The CFI who did my RV transition training demonstrated the "impossible turn". At 300' AGL I closed the throttle (as instructed) and he made a very steep diving turn back and landed on the runway we'd just left. The performance of the -9A in his hands was truly amazing.
I did a bunch of test also...I found the same thing anything over 400' AGL I would be high and need to slip to get down. I use 300-400' as my transition to cruise climb based on surrounding close-in obstacles.
 
The reality is that many of them -- perhaps most -- are partial failures from a bad plug, a partially blocked filter or air inlet, a stuck valve, slow onset of carb or induction icing, or something else that will leave you with partial power, maybe a lot of vibration, and a much more complex decision making process.
This! I had a partial power loss some years back departing from Allentown in my old Warrior. After nursing it back to the airport, landing safely, and removing the seat cushion from… it occurred to me that I had neither trained for, nor thought about, this scenario. And as you say, I suspect it’s MUCH more common than a total power loss on takeoff.

My current thinking is, if it happens after takeoff, and you DO have enough continuous power to maintain altitude, don’t touch anything and just set up for a power-off landing. Seems to me that troubleshooting is less important than landing (and might make things worse!). Not sure if that’s the right approach.

As you say, the other alternative gets complicated fast.
 
If 50% is the average, then half of us are better than that, and half are... well... below...
Could be, but not necessarily. Just for example, we could ALL be 50 percent, and the average would be 50 percent. Or there could be just a few really hotshot pilots (like us) and a ton of terrible ones, with the average “test score” still being a 50. The middle value in a set of scores, arranged smallest to largest (or vice versa I suppose) is the median, not the average (aka mean).
 
Now we're getting to some REAL information. In the S2B I would do a one turn spin and recover to level flight with power at idle. Consistent 450', full buffet from stoppage of rotation to level flight. A VERY fine line on managing angle of attack. Could I do that from pattern altitude? I don't know.
In the B and later the SU29 I demonstrated stall recovery with the nose raised a few degrees in the Pitts and around 10 degrees in the Sukhoi from the stall pitch angle. Just a demo of how much performance both airplanes have. Very easy to maintain control with rudder only.
I rode thru one spin demo in the Cub just before I got my Private. Over the next 12 years I continued to do spins in a variety of airplanes. Then one day a friend said to me "I would like you to race my Cassutt". I had never been upside down in an airplane and detested the idea of hanging upside down from the belts. BUT I had to demonstrate rolls in both directions for F1 Racing qualifications. So I spent a couple of months stumbling all over the sky learning rolls in the Cassutt. Several years of no aerobatics followed by aerobatics in another Cassutt. I then took two hours of dual in a Pitts S2A. Then someone handed me the keys to a brand new kit built Pitts S1S. My previous life ended and I emerged into a new life that lasted 22 years. two years later I test flew my brand new built from scratch S1S. I went from Sportsman to Unlimited in the S1S and won at the regional level in Int thru Unlimited. I never once lost control of any airplane doing aerobatics. Had that occurred my recovery was very simple: center the rudder and very gently pitch to the nearest horizon.
I instructed aerobatics full time for two years. One day off a month and a few days lost to weather. S2B, T34 and a bit later the Sukhoi SU29. I had access to Extra 230 and SU26.
Back to RV's, I have studied US registry fatal accidents in the RV3,4,6,7 and 8. My primary goal was to identify structural failures. I don't recall a single fatal accident involving an attempted return to the runway following an engine failure on takeoff. As I have stated before we have no idea how many successful turnbacks there have been. I know of one in a Wittman Tailwind that was successful. That airport is surrounded by big trees and rocks. No place to go off airport.
 
This! I had a partial power loss some years back departing from Allentown in my old Warrior. After nursing it back to the airport, landing safely, and removing the seat cushion from… it occurred to me that I had neither trained for, nor thought about, this scenario. And as you say, I suspect it’s MUCH more common than a total power loss on takeoff.

My current thinking is, if it happens after takeoff, and you DO have enough continuous power to maintain altitude, don’t touch anything and just set up for a power-off landing. Seems to me that troubleshooting is less important than landing (and might make things worse!). Not sure if that’s the right approach.

As you say, the other alternative gets complicated fast.
The other nice thing about an RV is it takes little power to keep it in level flight
My -8 will fly nicely at 88 mph with 40 horsepower, 20% power
 
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I concur with jonjay's suggestion that practicing stalls out of steep power off turns is probably the best way to get comfortable with doing the impossible turn. Once you are sure you can detect a stall and stop it without losing much altitude, you can move on to deciding how close to stalling you are willing to pull and then to optimizing speed and bank angle.
This is a great suggestion, thanks!
 
Obtaining and reading Steve Krog's articles from the past several years would provide a great deal of insight into how pathetic knowledge, skill and proficiency is, especially at the entry level.
The next part of education is reading accident reports.
One example: recent fatal at N Vegas involving, I think a Jetprop conversion of a Malibu. Husband and wife retuning from a safety seminar, operating in violation of basic med limitations. The Jetprop ran over a 172 on short final, fatal to two in each airplane.
 
Now we're getting to some REAL information. In the S2B I would do a one turn spin and recover to level flight with power at idle. Consistent 450', full buffet from stoppage of rotation to level flight. A VERY fine line on managing angle of attack. Could I do that from pattern altitude? I don't know.
In the B and later the SU29 I demonstrated stall recovery with the nose raised a few degrees in the Pitts and around 10 degrees in the Sukhoi from the stall pitch angle. Just a demo of how much performance both airplanes have. Very easy to maintain control with rudder only.
I rode thru one spin demo in the Cub just before I got my Private. Over the next 12 years I continued to do spins in a variety of airplanes. Then one day a friend said to me "I would like you to race my Cassutt". I had never been upside down in an airplane and detested the idea of hanging upside down from the belts. BUT I had to demonstrate rolls in both directions for F1 Racing qualifications. So I spent a couple of months stumbling all over the sky learning rolls in the Cassutt. Several years of no aerobatics followed by aerobatics in another Cassutt. I then took two hours of dual in a Pitts S2A. Then someone handed me the keys to a brand new kit built Pitts S1S. My previous life ended and I emerged into a new life that lasted 22 years. two years later I test flew my brand new built from scratch S1S. I went from Sportsman to Unlimited in the S1S and won at the regional level in Int thru Unlimited. I never once lost control of any airplane doing aerobatics. Had that occurred my recovery was very simple: center the rudder and very gently pitch to the nearest horizon.
I instructed aerobatics full time for two years. One day off a month and a few days lost to weather. S2B, T34 and a bit later the Sukhoi SU29. I had access to Extra 230 and SU26.
Back to RV's, I have studied US registry fatal accidents in the RV3,4,6,7 and 8. My primary goal was to identify structural failures. I don't recall a single fatal accident involving an attempted return to the runway following an engine failure on takeoff. As I have stated before we have no idea how many successful turnbacks there have been. I know of one in a Wittman Tailwind that was successful. That airport is surrounded by big trees and rocks. No place to go off airport.
So what do the first four paragraphs have to do with RVs? Only the last paragraph even referenced an RV, and the information contained within that last paragraph would read the same without the first four.
 
Here’s an outbrief of what the EAA Power Loss on Takeoff working group learned in two years of mishap analysis, simulator and flight tests. Jeff and I presented this in. NAFI mentor live in September: September Mentor Live Brief.

We also had a good discussion with lessons learned in this forum as well: https://www.vansairforce.net/threads/the-impossible-turn.221622/

The bottom line is it’s highly scenario dependent, a technical aid (airline “APS” [aircraft performance system]) and preflight planning/brief approach are required. Although the performance software uses airspeed and bank angle inputs, the “hack” I use during execution is flying a single reference angle of attack that is a “best blend” of turn/glide performance and emergency maneuverability for touchdown.

It’s great to see folks practicing and discussing this at 1 g and zero knots since there isn’t one correct answer :).

Fly safe,

Vac
 
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On departure were you flying Vx, Vy, or something faster?
A ton of us end up flying faster than Vy for cooling reasons (especially in the summer). From my reading of the various impossible turn articles/testing, if you aren't doing a steep climb... by the time you get to 1000' you can't get turned around and make the field (unless you have a helpful wind). Just too far away. Unless your runway is 5000' or something. My 0.02, quite possibly incorrect!
Because engine failures are a function of time and I don't have cooling problems, Vy as always unless I need Vx for some obstacle clearance reason. My airplane gets to 1000 feet close enough to turn around and land on at my home airport (5000ft) with no wind. In this particular case I had a good headwind and a 7000 ft runway and I was higher than I wanted to be when I got turned around.
 
Because engine failures are a function of time and I don't have cooling problems, Vy as always unless I need Vx for some obstacle clearance reason. My airplane gets to 1000 feet close enough to turn around and land on at my home airport (5000ft) with no wind. In this particular case I had a good headwind and a 7000 ft runway and I was higher than I wanted to be when I got turned around.
My home airport runway is 2160'. Typically a 45 degree crosswind.
 
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