Testing the Impossible Turn

[PhatRV]

I was testing the the impossible turn last weekend. I planned to take off and climb to 1000' AGL and tried to land back at the opposite runway heading. This was the first time of me trying to fly this turn by taking off from the runway. All previous simulations were performed at higher altitude.
I waited until late Sunday afternoon to fly this test because my home airport is always very busy with flight training. In this test, I was too high on final and could not land. I lost about 800 feet of altitude but I could have lost a bit less had I flown a bit slower, and bank the airplane at 45deg instead of 35-40 degs
I didn't have the camera recording this flight but I downloaded my Dynon flight logs into Flysto.net. The video was taken from the playback feature on Flysto.

 

[ronrapp]

Thanks for sharing! That's my home airport as well.

I used to test this out at SBD, San Bernardino. The tower was usually pretty accommodating about allowing me to take off and then land downwind. Haven't tried it at Corona, but I'm sure it would be a challenge since the runway is shorter and narrower, and the winds can be both strong and variable in that canyon.

You ended up quite high, it's true. But I would note that once you started the turn around, you'd see you were high and could square the base to final turn. You could also slip aggressively to slow and lose altitude.

Heck, you don't have to land on the runway. You can use a taxiway, a ramp, the grass, whatever you need. If the plane gets bent, it's not a big deal as long as you can walk away. Even if you land fast and have to ground loop it, as long as you avoid a stall/spin, your odds of survival improve dramatically.

Question: based on your experience, what would you set as the minimum altitude for a turn around at AJO? I generally use 600' AGL/1100 MSL at Corona. My airplane has a Sensenich GA prop.

--Ron

 

[PaulvS]

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.

 

[PhatRV]

Question: based on your experience, what would you set as the minimum altitude for a turn around at AJO? I generally use 600' AGL/1100 MSL at Corona. My airplane has a Sensenich GA prop.

--Ron

The RV8 has a high relative climb rate that I could have made it back at 500' AGL. When practice in the pattern, I usually turn to the crosswind leg at about 500'AGL. The sight picture looking toward the runway is even steeper than at 1000' AGL straight out. If the engine fails at 500', I can definitely make it back to the airport property and I would have fly a much steeper descend than normal for landing.

 

[Norman CYYJ]

An engine idling is going to give you a lot of thrust that won't be there in an actual engine out. Don't believe that you can make it back from 300ft in a RV9 or 500ft in a RV8, you will get hurt.

 

[Skykingbob]

I did transition training with the late Jan Bussell. He was a large man and I am big as well. We were fully loaded and his airplanes bore the marks
of numerous transition training episodes and the not super smooth grass strip in Okeechobee Florida. Anyway he was a great trainer and we did several
turnbacks to the runway from 400' altitude.....every one was successful.

 

[PhatRV]

An engine idling is going to give you a lot of thrust that won't be there in an actual engine out. Don't believe that you can make it back from 300ft in a RV9 or 500ft in a RV8, you will get hurt.

From the data, the MAP was about 10 even when idle. I think the key is to judge the angle of the of the airplane relative to the runway. The high climb rate and the short take off roll of my RV8 allow me to gain altitude faster than a normal airplane. Not every airplane is the same, so everybody has to do the exercise to find out. 500' AGL is okay for some airplane but it can be prohibited for some others.

 

[FL Flier]

I did transition training with the late Jan Bussell. He was a large man and I am big as well. We were fully loaded and his airplanes bore the marks
of numerous transition training episodes and the not super smooth grass strip in Okeechobee Florida. Anyway he was a great trainer and we did several
turnbacks to the runway from 400' altitude.....every one was successful.

I did transition with Jan, too. He didn’t just fly that plane - he wore it and it was part of him. We did the same turnbacks, and were also at gross.

 

[swjohnsey]

I consistently make it back in my RV-4 from 500' AGL. The only exception seems to be on calm days. I try to always offset downwind on take-offs and use at least 45 degrees of bank while maintaining best glide (90 mph).

 

[whifof100ll]

I used to have a rubber sheet lining the bottom of my airbox for a better seal in my rv-6. It came loose and completely cut off airflow and the engine quit after takeoff and gaining 1000 feet. I immediately executed the "impossible turn" for real.

I had to use full flaps and aggressive slipping to get it back down but did so. I made a smooth landing on the 7000-foot runway about midfield. The three blade catto kept turning but the engine produced no power. I'm not thinking I would try this at 300 feet.

YOUR MILEAGE MAY VARY!!! I have flown many other RV's that have CS props and they decelerate much faster than my plane. If you were too high this would help, but if I was lower, I would not have wanted the CS prop. My plane usually requires care and early reduction of throttle to get it slow enough to land without slipping, but it does glide pretty well on a loss of power. If I aggressively slip it, it comes down in a hurry.

Not that I had a habit of intersection departures before, but after this incident, I'm a hard advocate for using all the runway you have every time no matter how much it is.

Also make sure you think through anything you put in the airbox and what might happen if it comes loose.

Be safe!

 

[texdog]

Jan taught me as well, he was good at it. Make sure you do the 3 to 5 second recognition delay. At uncontrolled and rural airports, I make a 30 degree turn from the runway heading at 300 ft. It gives you a huge advantage in the turn.

 

[PhatRV]

One observation at the moment the throttle at idle was the rapid loss of speed, especially at the RV high deck angle. Get ready to get the nose down immediately.

 

[Jjackh10]

Jan taught me as well, he was good at it. Make sure you do the 3 to 5 second recognition delay. At uncontrolled and rural airports, I make a 30 degree turn from the runway heading at 300 ft. It gives you a huge advantage in the turn.

Just thinking out loud about this. We were all taught to "maintain centerline". But from a safety perspective I'd think some degree of heading variance from shortly after lift off would be better. The offset would grow with altitude, allowing you trade that altitude to line back up until there's not enough runway left ahead. At that point maybe you'd be in a good spot to just turn around?

I'm sure the smart folks on here could math it out and produce a chart for the POH. Then it's just a matter of getting the FAA on board for controlled airports too haha.

 

[rocketman1988]

I demonstrate the impossible turn to illustrate what NOT to do.

It is a very different thing when you do not know it’s coming. You can say all day that “I can make a successful turn back from 400”.
You are not considering the reality of the startle effect… and no, adding 3-5 seconds doesn’t adequately represent it either, although it helps.

The demonstration I use is to brief the maneuver beforehand and then execute it, proving that it actually can be done. At a later date and unspecified time, I will “fail” the engine and not say a word. By the time the student decides what to do it becomes very apparent to them that successfully completing would be unlikely. Luckily, the airport where I do this has very little traffic and no obstructions to worry about.

Not saying you shouldn’t practice, only that knowing it is going to happen and being prepared for it to begin with, doesn’t give an accurate description of reality.

I understand that in some areas, it can be the best option, as there is nowhere else to go.

My point is, if you actually want to see what happens, have your CFI fail the engine at completely random, unrehearsed times. The outcome will likely surprise you.

Just an observation after many thousands of hours instruction given…

 

[Ralph Inkster]

I'm sure the smart folks on here could math it out and produce a chart for the POH.

The point of practicing this maneuver is to prepare you for the unexpected, to be able to react fast & be precise in your actions to get back safely on the ground. I wouldn't rely on charted POH data to determine my reactions in a emergency 180 back to the runway. I would try & test all possible maneuvers needed to give me the best bank angle / sink rates for any situation I hope to never encounter.
As for glide / sink rates between idle & dead engine, it is very notable! I once (thankfully only once!) had a loss of power on short final. & without 'wearing that plane' probably wouldn't be here today. At about 200' on approach engine died, I definitely would not have made it to the runway, I reacted by pulling the flaps & diving for the tree stump infested swamp below me to pick up speed to try for ground effect lift to get me to the runway. I don't think I've ever read that maneuver in any manual but it got me through.
My point - practice to know your plane, do what you have to to get down safely.

 

[Taltruda]

I used to have a rubber sheet lining the bottom of my airbox for a better seal in my rv-6. It came loose and completely cut off airflow and the engine quit after takeoff and gaining 1000 feet. I immediately executed the "impossible turn" for real.

I had to use full flaps and aggressive slipping to get it back down but did so. I made a smooth landing on the 7000-foot runway about midfield. The three blade catto kept turning but the engine produced no power. I'm not thinking I would try this at 300 feet.

YOUR MILEAGE MAY VARY!!! I have flown many other RV's that have CS props and they decelerate much faster than my plane. If you were too high this would help, but if I was lower, I would not have wanted the CS prop. My plane usually requires care and early reduction of throttle to get it slow enough to land without slipping, but it does glide pretty well on a loss of power. If I aggressively slip it, it comes down in a hurry.

Not that I had a habit of intersection departures before, but after this incident, I'm a hard advocate for using all the runway you have every time no matter how much it is.

Also make sure you think through anything you put in the airbox and what might happen if it comes loose.

Be safe!

The drag from a CS prop can be minimized greatly by adjusting your low pitch stops under the spinner.. every Hartzell I’ve seen so far has needed adjusting. It’s very easy and increases the glide substantially!

 

[Taltruda]

I was testing the the impossible turn last weekend. I planned to take off and climb to 1000' AGL and tried to land back at the opposite runway heading. This was the first time of me trying to fly this turn by taking off from the runway. All previous simulations were performed at higher altitude.
I waited until late Sunday afternoon to fly this test because my home airport is always very busy with flight training. In this test, I was too high on final and could not land. I lost about 800 feet of altitude but I could have lost a bit less had I flown a bit slower, and bank the airplane at 45deg instead of 35-40 degs
I didn't have the camera recording this flight but I downloaded my Dynon flight logs into Flysto.net. The video was taken from the playback feature on Flysto.

I discovered the same thing with testing my RV-4. It helps if you continue straight out instead of turning back right away. Another variation that I tested in my plane was to stay in ground effect until the end of the runway. I can either get to 1000agl within 30 seconds if I climb at Vy, ot I can take the same 30 seconds and be at 110 knots and 100agl. After 30 seconds, I was able to chop the power, count 3 seconds, and make the turn back from 100 feet and I STILL needed full flaps to make it. I understand that an idling engine and a fixed pitch prop don’t accurately represent a truly dead engine though.

 

[T Mac]

I also did transition training with Jan Bussell in my, new to me, RV-14. We did turn backs at 400’ plus much much more. Seeing these comments about Jan brings back fond memories. I’m pretty sure I was Jan’s last student. He was a sick boy. Climbing in and out of my tailwheel RV was not easy for Jan. During my three days with Jan he drove himself to the hospital and back each day from KOBE to W Palm Beach for blood transfusions. Jan was a kind gentleman, he was an educator who truly loved teaching. What a huge loss for the RV Community!

 

[PhatRV]

The point of practicing this maneuver is to prepare you for the unexpected, to be able to react fast & be precise in your actions to get back safely on the ground.

Agree 100%. I had been practicing emergency landing while flying over the vast mountainous desert in SoCal so turning back at low altitude did not bother me as much. I wanted to develop the muscle memory for this maneuver because everything happened very fast as I found out.

 

[texdog]

A long time ago and far, far away I was practicing a double engine failure in a Cessna 310 from 4000 ft. At 300 ft. on short final I added power and there wasn’t any. I had run both aux tanks dry. I was 22 years old with good reaction time and I switched tanks quick enough to avoid landing short. My reaction time isn’t that good today.

 

[Capt]

Most don’t take in the startle factor, you’d lose a few valuable seconds right there! My personal limit is 800’, that gives me options but only if it’s safe to do so, IE, nothing above 10 kts wind, not a busy drome and I avoid high density built up areas around dromes.

 

[jrs14855]

I am a tired old man and I still don't have a startle factor. When the entire panel goes dark, in the clouds at 200' AGL there is no time for a startle factor.

 

[jrs14855]

Watch the AG pilots working a field for a few minutes and you would realize that a turnback from 300' in a small airplane would just be a very small portion of what they do, every few seconds, all day long. Do not abuse the angle of attack lest the earth rise up and smite thee.

 

[JonJay]

I am a tired old man and I still don't have a startle factor. When the entire panel goes dark, in the clouds at 200' AGL there is no time for a startle factor.

I think that comes with age as we get closer to our maker.

 

[Roadjunkie1]

Practice; practice; practice. I am a fan of routinely practicing engine-out procedures. That muscle memory thing is amazing when you are used to things going quiet. I can tell by where a field is in relation to something on the airplane whether I could make it there or not. I recently had a valve stick in the Cub which is AMAZING how much of a power loss there is when one cylinder in a C-90-8 quits working. There was no 5 second WTF delay as the nose went down instantly and I was headed for a handy stubble field. I impressed myself with my 'fix this' routine of throttle, mixture, carb heat, switch tanks, mags as it had been previously rehearsed. I was on high alert, feeling what the airplane was telling me and realized I only glanced at the ASI as I was lining up to land. That was about when the valve unstuck and I powered away from that off-field landing. Made it back to home field, which was 2 miles away, without further difficulty but looking at EVERY field available to land in! The cylinder was replaced!

 

[Tankerpilot75]

Remember, as you practice any form on engine out landing procedure with your engine at idle, that even with a prop in front of you, it still takes more than a few “blinks” for power to come back to an engine when pushing the throttle forward. I surprised myself once practicing an engine out landing thinking that application of power would immediately stop my sink rate. It didn’t and I came a lot closer to Terra Firma than planned. Don’t delay making a decision to terminate a “practice engine out” landing and go around when it gets even a little uncomfortable.

 

[Ironflight]

Agree 100%. I had been practicing emergency landing while flying over the vast mountainous desert in SoCal so turning back at low altitude did not bother me as much. I wanted to develop the muscle memory for this maneuver because everything happened very fast as I found out.

Not picking on you directly, I just like to comment in general that for those practicing the maneuver so that they can use it if the engine quits on take-off, remember that every one of the guys that died trying it (and it happens many times per year) thought that they could do it.

Remember that 90% of all pilots believe themselves to be above average…..

(That said, stick and rudder skills are always good to practice and develop just as their own reward, so I have no problem with folks learning what their airplane can do.)

 

[roadrunner20]

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.

Mine did the same thing in his RV6. FWIW, we were heavy too. He had to have weighed easily over 200 lbs. The late Jan Bussell, RIP.

 

[JonJay]

Most fatalities occur as the “urge to stretch it” is extremely powerful. Can’t really practice that.
Your airplane will behave differently with a total loss of power. You will loose power when you do not expect it where you don’t expect it.
While you’re practicing your engine out procedures and trying to tune your sight picture to make that field, practice the mantra “fly the airplane”. This was drilled into me during flight instructions many years ago. It saved my life.
If you fly the airplane to the ground, regardless, your odds are dramatically different than if you don’t. If you learn one thing, learn that. Fly the airplane!
If you practice one thing, say that phrase, over and over and over again.
The impossible turn didn’t just become a phrase for no good reason.

 

[ronrapp]

Not picking on you directly, I just like to comment in general that for those practicing the maneuver so that they can use it if the engine quits on take-off, remember that every one of the guys that died trying it (and it happens many times per year) thought that they could do it.

Remember that 90% of all pilots believe themselves to be above average…..

(That said, stick and rudder skills are always good to practice and develop just as their own reward, so I have no problem with folks learning what their airplane can do.)

What's the old saying? "A man's got to know his limitations." (And I thought he was talking about Section 2 of a POH...)

Seriously, though, this is one area where it's critical to know what you are and are not capable of. We rise or fall to the level of our training and experience. No matter how skilled, those who've never practiced a maneuver like this should probably not attempt it for the first time during an actual emergency.

One thing I really like about the RVs is that they climb so well that the amount of time spent in a zone where there are no good options is relatively limited. I used to borrow a friend's turbo Saratoga, and despite the "turbo" in the name, it was a runway hog and climbed slowly. I always hated that.

And to get back to the OPs post, there are areas around Corona without any good options when departing to the west. Altitude is your friend.

I try to mentally rehearse such an eventuality prior to taking off. What's my minimum altitude to turn around? What's the wind doing, and how will that affect me? Which way will I turn? If I'm below my min altitude, where's my best place to point the aircraft?

--Ron

 

[ronrapp]

YOUR MILEAGE MAY VARY!!! I have flown many other RV's that have CS props and they decelerate much faster than my plane. If you were too high this would help, but if I was lower, I would not have wanted the CS prop. My plane usually requires care and early reduction of throttle to get it slow enough to land without slipping, but it does glide pretty well on a loss of power. If I aggressively slip it, it comes down in a hurry.

So true. CS props create HUGE drag.

Reminds me of heavily wing-loaded airplanes like the Bonanzas, Lances, etc. which are a whole different breed. They drop like a rock. I've done some commercial certificates with guys who had Bonanzas, Saratogas, and the like, and when you pull the power abeam the numbers for the Power off 180 degree accuracy approach, they come down so quickly. And you have to get the flare just right; get too high on the angle of attack and/or low on airspeed and your only hope of avoiding a hard landing is to go around, even if you were not that close to a stall. Between the CS prop and the wing loading they required a lot of skill for a power off 180.

To illustrate the effect a prop has, I've got a friend with an Edge 540 (or was it an Extra? I forget) who had an engine failure. In aerobatic airplanes, the prop goes to high pitch with a loss of oil pressure, so it suddenly became such an efficient glider that he couldn't get the thing slow enough to land. He had to go up and over several stands of trees in to the 3rd or 4th field before he bled off enough energy to put it down. Even a Pitts S-2B or S-2C becomes a remarkably efficient glider when the prop is at high pitch. I've surprised a lot of high time Pitts pilots by playing that trick on them in the pattern. To a man, they always overshoot the runway badly. They learn a lesson, and I get a hearty laugh. Win/win....

--Ron

 

[blaplante]

I used to have a rubber sheet lining the bottom of my airbox for a better seal in my rv-6. It came loose and completely cut off airflow and the engine quit after takeoff and gaining 1000 feet. I immediately executed the "impossible turn" for real.

I had to use full flaps and aggressive slipping to get it back down but did so. I made a smooth landing on the 7000-foot runway about midfield. The three blade catto kept turning but the engine produced no power. I'm not thinking I would try this at 300 feet.

YOUR MILEAGE MAY VARY!!! I have flown many other RV's that have CS props and they decelerate much faster than my plane. If you were too high this would help, but if I was lower, I would not have wanted the CS prop. My plane usually requires care and early reduction of throttle to get it slow enough to land without slipping, but it does glide pretty well on a loss of power. If I aggressively slip it, it comes down in a hurry.

Not that I had a habit of intersection departures before, but after this incident, I'm a hard advocate for using all the runway you have every time no matter how much it is.

Also make sure you think through anything you put in the airbox and what might happen if it comes loose.

Be safe!

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!

 

[rocketman1988]

I am a tired old man and I still don't have a startle factor. When the entire panel goes dark, in the clouds at 200' AGL there is no time for a startle factor.

That's not really relevant to this discussion, though. This discussion is about the impossible turn...

As far as not having a startle factor...I have to call BS. It is inevitable and unavoidable; and it doesn't matter if you have 30 hours or 30,000 hours. It is there and the only difference between the experience levels is how you react AFTER the startle.

 

[rocketman1988]

Watch the AG pilots working a field for a few minutes and you would realize that a turnback from 300' in a small airplane would just be a very small portion of what they do, every few seconds, all day long. Do not abuse the angle of attack lest the earth rise up and smite thee.

Yes, the turn back is a part of what they do. The DIFFERENCE is that that they KNOW, in advance, what they are doing and there is no startle or delay in what they are doing because it is a planned part of the flight.

 

[PhatRV]

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!

There are a lot of discussions like this at my local airport. Lots of pilots gave their opinions. Until I found out that none of them have ever tried to test fly the impossible turn just to see how their airplane behave while doing the turn at low altitude, or at least to verify their assumptions. They don't know how far from the airport when they are at 1000' AGL, how the airplane behaves when the engine quits, or in my case, the engine was at idle during takeoff. This was why I did the test to verify if my hunch was correct, that my RV8 could climb well enough to have the possibility of making the impossible turn. Each airplane is different, each airport is different. At least when test flying this maneuver, if you don't feel comfortable, just power up and go around. At least each of us know how we react to the maneuver rather than doing for the very first time in an actual emergency.

 

[Mikeyb]

I like you and Ron dreaded the thought of an engine failure on takeoff at Corona but If you consider the statistics about engine failures:
1) the FAA thinks a piston engine failure occurs once every 3200 hours of flight time
2) only a third of those failures occur at takeoff (from AV web)
3) as you noted RV’s climb pretty fast. My -8 takes 40 seconds from throttle up to 1000 AGL at 300 MSL @ 1450# GW
Probably we should find something else to worry about besides the impossible turn. It’s also the improbable turn.
It would take a lot of practice to commit it to muscle memory. Most estimates suggest it takes more than 1000 repetitions, more like 5000 to 10000

 

[PhatRV]

This engine failure case was recently posted on Reddit. The engine didn't die completely. It was making partial power and the CFI landed the airplane safely with the student pilot onboard. It wasn't an impossible turn but the symptom of the engine failure is common in that it wasn't making sufficient power for the airplane to climb. The CFI nursed the airplane until it climbed to 550' AGL and performed a PO 180.

https://www.reddit.com/r/flying/comments/1h7p1ne/had_my_first_failure_today

 

[ronrapp]

I like you and Ron dreaded the thought of an engine failure at Corona but If you consider the statistics about engine failures:
1) the FAA thinks an engine failure occurs 1 every 3200 hours of flight time
2) only a third of those failures occur at takeoff (from AV web)
3) like people described here RV’s climb pretty fast. My -8 takes 40 seconds from throttle up to 1000 AGL at 300 MSL @ 1450# GW
Probably you should find something else to practice besides the impossible turn.
Most estimates for committing something to muscle memory suggest it takes more than 1000 repetitions, more like 10000

Now you're making me nervous. 3*3200=~10,000 so I'm overdue for a Bad Day -- statistically speaking, of course.

This engine failure case was recently posted on Reddit. The engine didn't die completely. It was making partial power and the CFI landed the airplane safely with the student pilot onboard. It wasn't an impossible turn but the symptom of the engine failure is common in that it wasn't making sufficient power for the airplane to climb. The CFI nursed the airplane until it climbed to 550' AGL and performed a PO 180.

I think this points out something that's missing from flight training. Most instructors simulate engine failures as sudden and total losses of power. No mistaking it.

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. Do I fly the pattern? Land downwind? Land off-airport? Continue to an open area? Can I hold altitude? Is the problem getting/going to get worse? Etc.

I enjoy simulating those with students, for the discussion and thought process if nothing else. How often do partial failures happen? I don't think there are any statistics on it. if the plane lands successfully, it doesn't typically end up in the stats. Personally, I've never had a total an complete catastrophic failure, but I've had a number of partial failures over the years.

--Ron

 

[blaplante]

There are a lot of discussions like this at my local airport. Lots of pilots gave their opinions. Until I found out that none of them have ever tried to test fly the impossible turn just to see how their airplane behave while doing the turn at low altitude, or at least to verify their assumptions. They don't know how far from the airport when they are at 1000' AGL, how the airplane behaves when the engine quits, or in my case, the engine was at idle during takeoff. This was why I did the test to verify if my hunch was correct, that my RV8 could climb well enough to have the possibility of making the impossible turn. Each airplane is different, each airport is different. At least when test flying this maneuver, if you don't feel comfortable, just power up and go around. At least each of us know how we react to the maneuver rather than doing for the very first time in an actual emergency.

Not much discussion at L18 at all.

 

[swjohnsey]

Better than an oil thread! I fly an old RV-4 with CS prop and lots of power. My ground roll is usually about 12 seconds using 75% power. I accelerate up to around 80 mph in ground effect then climb at 100 - 110. I turn crosswind at around 500' AGL. I also offset downwind after I don't have enough runway to reject and stop. I usually do a turn back to a full stop from 500' AGL most days first take-off. All that said, getting back to the runway is just the cherry on top. Once you are pointed back at the airport you are in much better shape to survive. Most stuff around an airport is safer to hit. How much skill does it take not to stall in a steep turn? When you get close to the ground level the wings, dump the flaps and get it as slow as possible, try to hit something soft and cheap. You will also be making a downwind landing. You probably won't be able to pull this off on your first try so it pays to practice. On my RV-4 my gliding distance is about doubled when I pull the prop back to low rpm.

 

[Taltruda]

Better than an oil thread! I fly an old RV-4 with CS prop and lots of power. My ground roll is usually about 12 seconds using 75% power. I accelerate up to around 80 mph in ground effect then climb at 100 - 110. I turn crosswind at around 500' AGL. I also offset downwind after I don't have enough runway to reject and stop. I usually do a turn back to a full stop from 500' AGL most days first take-off. All that said, getting back to the runway is just the cherry on top. Once you are pointed back at the airport you are in much better shape to survive. Most stuff around an airport is safer to hit. How much skill does it take not to stall in a steep turn? When you get close to the ground level the wings, dump the flaps and get it as slow as possible, try to hit something soft and cheap. You will also be making a downwind landing. You probably won't be able to pull this off on your first try so it pays to practice. On my RV-4 my gliding distance is about doubled when I pull the prop back to low rpm.

Sounds like your CS prop is a perfect candidate for a low pitch adjustment.. if you are doubling your glide by pulling your prop back, I guarantee that your plane will respond very nicely to an adjustment! Pm me and I can talk you though it. I fly a lot of CS equipt RVs, and a with a proper low Pitch stop adjustment, there is almost nothing to gain by pulling the prop back around 90 knots because the plane will be already gliding as if it’s back! At 110 or more, you’ll still benefit from the pull, but the slower you go, the less dramatic it becomes (because you will already be efficient)

 

[flyingpreacher]

I have not done the Impossible turn in an RV yet, but I did it recently in a 172 from 700' and had to land long. I did it again at 500' and that was as low as I was comfortable going. The name "Impossible Turn" is simply a misnomer. Yes, there is an altitude at which it is not possible, but as you all have seen with your various experiments and experiences it can, in fact, be done.

 

[sailvi767]

There has been some discussion about ground effect in this thread. Ground effect in a RV starts at about 12 feet AGL. Its effect on glide range will be very minimal.

 

[Roadjunkie1]

Probably we should find something else to worry about besides the impossible turn. It’s also the improbable turn.

Probably a better term....... It isn't so much worrying about it than figuring out a 'what if' set of procedures that might make for a better outcome.

It would take a lot of practice to commit it to muscle memory. Most estimates suggest it takes more than 1000 repetitions, more like 5000 to 10000

Hmmmmmmmmmm.....in medicine we would say 'state your source'. In law it would perhaps be 'rumor and conjecture'.

SO: Maybe it isn't true 'muscle memory' but rather everything it takes to get used to the sight picture, reactions of the aircraft, pilot reaction and everything that goes in to practicing those things we want to be good at doing. Why do we do touch-and-goes (I do stop-and-goes)? To get used to what that takes to learn and be good or better at getting an airplane back on the ground where we wanted it to be and in one piece. Muscle memory? Maybe not but PRACTICE to have things be familiar when the unexpected happens: there is no substitute. Practice also makes us better at the normal things we do as pilots. As our hours increase, we tend to get further away from The Basics and sometimes need to go back and practice those. That word keeps coming up.......... That is one of the benefits Unusual Attitude or Aerobatic training comes in: basics are needed to be good at those!

I recently flew with my old instructor (who was not old at the time; well he SEEMED old because I was 20) who is now in his upper 80's still flying his PA-12 and probably has 60,000+ hours of flying pipelines at low-level. I was amazed at how he commanded that aircraft! If there was true muscle memory in flying, that was it!

 

[ve0kog]

@Vac posted quite a few turnback videos demonstrating the perfectly tuned AOA instrumentation. The airplane sure looks more than capable to make the field from a low altitude. But it also helps to have the skill set of a test pilot. When I learned PPL in a 172 the CFI insisted to not even consider turning back from below 1000 AGL. I think this is still true for the RV until i have at least 500 RV PIC hours . I've got only about 50 right now - I would not attempt anything dramatic for a while and more practice/dual time.

 

[JonJay]

The “impossible turn” was coined as a training tool to try to prevent stall/spin accidents. It had nothing to do with making the field. It had everything to do with our human instincts in a stressful surprise situation to try.
No power, steep turn back into a tailwind, stall/spin.
Can’t argue with practicing anything, but I agree, focus on something more likely to happen like stall awarenss in a turn. At altitude of course, and properly instructed. Not the same when your engine is still running but still has value.
A few years ago, we set a hard deck at something like 3,000’ and aggressively practiced this, for some of us, all the way to the stall. Most were shocked at the noises that your airplane makes right before it stalls and a wing drops. Down right scary. This was more for overshoot practice than anything, but still applies here.
At 500ft per turn in a spin, you don’t have to be that close to the ground to have a bad result. The odds for a new pilot were much better to fly straight and land where you could, if you could. I know that doesn’t fit all scenarios, but that is what was taught.

 

[ronrapp]

I recently flew with my old instructor (who was not old at the time; well he SEEMED old because I was 20) who is now in his upper 80's still flying his PA-12 and probably has 60,000+ hours of flying pipelines at low-level. I was amazed at how he commanded that aircraft! If there was true muscle memory in flying, that was it!

I took a Cub with the Reed clipped-wing mod up to Lompoc for the fly-in one year. Cubs as far as the eye could see in every direction. Anyway, I thought I did pretty well in the spot landing contest; my best effort was within a foot of the line.

Then I saw an 80-something guy who had owned his Cub since he bought it new from the factory make his three attempts. He put the wheels ON the line every. single. time. And I came to the realization that a) it was completely effortless, and b) he could do this all. day. long.

Oh, and my best effort wasn't even in the top 10 when the final results were published.

I won't even get into the flour bomb drop. I realized that 90% may think they're above average, but I'm probably on the inverted side of that curve!

--Ron

 

[jrs14855]

One of the first things I read in Sport Aviation is Steve Krog's column. Recently he has been focused on the lack of experience of many instructors. This leads to grossly inadequate training and totally unprepared candidates showing up for Private Checkrides.
I don't think this is anything new, just that the volume of inadequate training has increased.
So the starting point is far too many pilots that don't know much about stalls and spins.
Barry Schiff and his son Brian are both strong advocates of the turnback maneuver.
The flight school at John Wayne teaches turn backs to pre solo students. Using the short runway there is no other reasonable option.
NO ONE has any valid information on successful turnback's because they never get reported.
My previous post about instrument failure on takeoff is pertinent to this discussion because the instrument failure left zero time for "startle factor". I believe that in the case of an engine failure on takeoff lowering the nose immediately should be an automatic reaction. No startle factor involved.

 

[rocketman1988]

One of the first things I read in Sport Aviation is Steve Krog's column. Recently he has been focused on the lack of experience of many instructors. This leads to grossly inadequate training and totally unprepared candidates showing up for Private Checkrides.
I don't think this is anything new, just that the volume of inadequate training has increased.
So the starting point is far too many pilots that don't know much about stalls and spins.
Barry Schiff and his son Brian are both strong advocates of the turnback maneuver.
The flight school at John Wayne teaches turn backs to pre solo students. Using the short runway there is no other reasonable option.
NO ONE has any valid information on successful turnback's because they never get reported.
My previous post about instrument failure on takeoff is pertinent to this discussion because the instrument failure left zero time for "startle factor". I believe that in the case of an engine failure on takeoff lowering the nose immediately should be an automatic reaction. No startle factor involved.

…and you would be surprised at the number of pilots do not do it, ie startle factor.

My Dad is one of those 80 something guys, he actively instructs for Steve K, and he would talk your ear off about startle factor. Actually, he is also instructing for EAA, and their current scenario illustrate startle factor perfectly. They have run the scenario on all sorts of pilots, from solo through professional ATP pilots. There is always a startle factor, and it is measurable. What happens AFTER the startle, is definitely different based on experience but the point is, there is ALWAYS a startle factor.

 

[ronrapp]

The flight school at John Wayne teaches turn backs to pre solo students. Using the short runway there is no other reasonable option.

I learned to fly at the flight school you're referring to. Got most of my ratings and certificates there, along with aerobatic and tailwheel training. And then spent a decade instructing there as well.

They will not solo anyone who hasn't had *practical* spin training. Before I soloed as a student pilot, I had done multiple 1, 2, and 3 turn spins in both directions and had to get in and out of them by myself. They take that stuff very seriously, and as a result turn out pilots with above average basic flying skills.

(They also take wake turbulence seriously, because they have short runways and lots of 757s (and the occasional heavy) landing 100' away from you.). Time to solo is greater than average, but when you're done training, you can fly into any Class B airport with 60 hours total time in your logbook and think it's no big deal. Because it's not.

--Ron

P.S. I believe it's the only flight school in world which will allow pilots to rent an Extra 300 and Pitts solo. I always took checking people out in those airplanes very seriously. A mid-wing Extra makes a tailwheel RV look like it has the visibility of an AirCam.