The Impossible Turn...

[Vac]

...isn't. Sometimes. However, it may be the ultimate “it depends” scenario. Foremost, if you have a power loss during initial climb and a suitable landing surface is in front of you, use it! If that’s not the case and you are looking at a face full of trees, or worse, houses and school buses, AND you have sufficient energy to maneuver, then some degree of maneuvering to a suitable off-field landing surface may be warranted. If there are zero point zero options within glide range other than the airport you just departed from, you have the right training, the airplane has sufficient performance, ambient conditions are favorable and you have considered the option pre-flight, you may elect to try to return to the airport or runway. Energy at touchdown (wherever that may be) is also critical. It may be a better choice crash landing off-field at lower speed than trying to land on-field with a significant tailwind.

Here's a look at the factors that impact the ability to turn back to the takeoff runway after losing power. Keep in mind not all aircraft have the performance capability to execute a turn back, regardless of ambient conditions. And ALL aircraft, regardless of how well they perform are impacted by ambient conditions: https://youtu.be/2_Xb3CAXfzM

And to paraphrase Bob Hoover, you must fly the airplane all the way through the crash. Manipulating the controls doesn’t stop until what’s left of the airplane does. Data show that if you maintain aircraft control (that is don’t stall), your odds of surviving the landing are good. If, however, you exceed the critical angle of attack prior to touchdown your odds of becoming a statistic are significant.

The actual physics of the turn back are straight forward, but since so many factors are involved, it’s difficult to make an informed guess as to whether a turn-back is a feasible option. I’ve recently been testing an iPhone-based performance app called “TLAR.” That’s military slang for “that looks about right.” A beta version integrates real-time METAR data (or manual inputs) and actual aircraft performance updated once per second to calculate a “fly/stop” cue (i.e., the point at which I can still land straight ahead on remaining runway) and a “turn back” point if the airplane possesses sufficient performance under ambient conditions. A first-opportunity, low-altitude turnback to a short runway is a “maximum performance” maneuver: https://youtu.be/F_RFKlUhdeE. In this test, you hear me apply flaps—that is purely to compensate for the residual power produced by my fixed pitch prop. My flaps 40 IDLE glide angle is the same as my flaps up, engine off glide angle.

Here's a plot of AOA and stall speed margin from the turnback through touchdown:

In the video, you may have noted the stall warning tone as I “square the corner” (intentionally applying G to bleed some energy). That corresponds with the AOA peak in this figure. Note that my speed margin is reduced to about 4 knots and actual AOA is within 2 degrees of critical AOA.

An important concept in aircraft handling is that AOA correlates directly with G. When we apply G, AOA increases. Optimum bank angle for maneuvering during a turnback is 45 degrees, and even in a glide, that’s about a 1.4 G maneuver. It’s this small increase in G that gets folks in to trouble and can lead to an accelerated stall. This figure plots both AOA and G for the maneuver. Note that every time there is a G peak, AOA peaks as well:

Another way to see that is to plot AOA and G rates. Note how the two marry up:

One of the critical factors impacting the ability to turn back is climb performance. Our RV’s are pretty good climbers, but that’s not the case for all airplanes. Shortly after flying this test, I took off in a Cherokee from the same runway under similar ambient conditions. In this case, the TLAR solution said a turn back simply wasn’t an option:https://youtu.be/t7OwK3LPtBU.

Since stall is the enemy and not everyone is equipped with AOA, nor is everyone trained or comfortable max performing the airplane close to the ground, the app allows you to adjust bank angle and Vref for the turnback calculation. By decreasing bank angle and increasing speed, it may eliminate a turn back option, but it will keep you within your own comfort envelope.

Fly safe,

Vac

 

[Taltruda]

100 feet AGL

I recently tested out my plane, (180hp RV-4, fixed pitch prop) first at altitude, then slowly brought it lower and lower. There are two ways I typically takeoff, one way is staying in ground effect till 110 knots or the end of the runway, then gently climb out, the other way is to climb to 1000 feet at Vy.
Using the Ground Effect method, I can get to the end of the runway around 110 knots indicated (3300 foot length at 2600msl), then gently start a climb, at 100agl, I chopped the power, counted to 3 seconds for the “startle factor” and began a turn back. I make it every time.. anything higher than 100 feet, I actually have to stay straight a little longer before I turn back so I don’t over run the opposite end!

 

[Vac]

Tom,

Gotta love the mighty -4.

You hit upon an important point: energy is a combination of airspeed and altitude. We had to adjust the prediction software to accommodate airplanes that actually zoom after power is lost/reduced. If you are fast enough, and ambient conditions are right, 5' AGL may be sufficient for a turn back. The pre-takeoff roll predicted turn back altitude is based on a combination of ambient conditions and the climb profile you select. In the video, I've selected Vy. And since I'm flying the test without airspeed indications, I'm using L/Dmax as an approximation. Once the airplane starts moving on the takeoff roll, the app changes from a prediction to actual turn back capability based on 1 second updates of real-time performance.

One thing to keep in mind is residual thrust. My -4 ain't a fire-breathing 180, just a milk toast 160 with a two-bladed Catto prop. I'm jealous! Turns out that at IDLE, I've got pretty significant residual thrust:

The takeaway is with the engine actually off, my glide angle is about 20% steeper than it is with the engine at IDLE. We did some additional testing to determine that in my RV-4, if I apply flaps 40 with IDLE power, I can replicate actual engine off glide performance (about 8 degrees, wing's level):

Cheers,

Vac

 

[rv8ch]

Great info, Vac. I really enjoy your videos. It would be interesting if one of your buddies with a hartzell or other constant speed prop would lend you their aircraft to see the differences between idle, windmilling fine pitch, windmilling coarse pitch, and stopped. I don't have the courage to stop my engine in flight.

About the energy - speed vs. altitude - my understanding is if you have enough speed to get you through the "startle factor" without stalling, then that's enough speed and better to have the altitude, since speed comes with drag losses. Is this also your view?

 

[PCHunt]

Even though you are cautioning everyone to test their own airplanes, The vast majority of us probably won't.

I get very concerned when I see comments about turning back at 100' AGL, or even 5' AGL "if you have enough speed" (Energy).

I'm not doubting that it CAN be done in very particular circumstances, I just want to express my concern that this should NOT be tried without being an aeronautical engineer or test pilot with highly instrumented aircraft, after numerous practice flights at altitude. VERY few pilots do that!

Statistics are clear, turning back and screwing it up can be fatal, and often is. Landing while not stalling is statistically safer.

BTW, my "startle factor" is to pull up! (Because I'm usually flying Fast....)

 

[Avanza]

Turning back to the departure airport from below 1000 ft will in many cases
involve an increased risk for a fatal accident. See statistics.
Time and money invested in a thorough preflight check and an airworthy plane
is made on the ground and involves no risk at all.

Good luck

 

[M McGraw]

Tested it!

Hello Vac,
Thank you for this thread. I have done quite a bit of impossible turn testing at my home field which is 2000’ long surrounded with difficult terrain and trees. I created an escape path for both my sailplane and my -14. I always do the same when I fly out west.

I tested by offsetting my altimeter 100’ before takeoff that provided a safety margin.

I climb at Vx turn 45 degrees after takeoff to reduce the return overshoot. My first attempt resulted in an inability to get low enough for landing even with full flaps and full rudder deflection. From there I incrementally decreased the turn-back altitude to find my optimum.

What I found was Vx and a bank of no less than 45 degrees were required. With that the turn-back altitude is surprising low. I won’t publish it here because each of us need to find our own comfort level. I hope to try your approach.

Marvin

 

[Kyle Boatright]

What I found was Vx and a bank of no less than 45 degrees were required. With that the turn-back altitude is surprising low. I won’t publish it here because each of us need to find our own comfort level. I hope to try your approach.

Marvin

One thing I suggest to people looking for their turnback altitude is to do that investigation at altitude. Start at 5,000', do a "takeoff climb" to (say) 5,500', and see if you can make the impossible turn before the altimeter drops below 5,000 (the simulated ground level) again.

This isn't something to practice at low altitude the first time.

 

[Taltruda]

Hello Vac,
Thank you for this thread. I have done quite a bit of impossible turn testing at my home field which is 2000’ long surrounded with difficult terrain and trees. I created an escape path for both my sailplane and my -14. I always do the same when I fly out west.

I tested by offsetting my altimeter 100’ before takeoff that provided a safety margin.

I climb at Vx turn 45 degrees after takeoff to reduce the return overshoot. My first attempt resulted in an inability to get low enough for landing even with full flaps and full rudder deflection. From there I incrementally decreased the turn-back altitude to find my optimum.

What I found was Vx and a bank of no less than 45 degrees were required. With that the turn-back altitude is surprising low. I won’t publish it here because each of us need to find our own comfort level. I hope to try your approach.

Marvin

Marvin and Vac, I found if I climb to 1000 feet, either at Vx, Vy or high speed and zoom, and I pull to idle, I have to delay my turn back significantly or I overshoot the far end of the runway..
as for my 100 foot AGL, I realize there is residual thrust, I’ll try it pulling the mixture next. For what it’s worth, I have my idle set fairly low, 650 RPM. I also tested timing the 30 seconds from brake release to throttle chop and using high speed climb, Vx, and Vy climbs. Also after throttle chop, I waited 3 seconds and experimented with a level turn and a zoom climb turn. The easiest to return in my plane was after a high speed climb and a level turn. Even then I needed full flaps to land on the first 1/3.

 

[Taltruda]

PCHunt and Avanza, I’m not advocating anybody attempt their turn back at any altitude.. I’m just sharing what I have tested in MY plane with my comfort level. Every landing I do is always power to idle.. every time, so I’m pretty comfortable with it. I also stall, spin, and accelerate stall my plane, so I know what the signs are before it stalls..

For those with a Constant speed prop, if you don’t know if your low pitch stops are set correctly, they probably aren’t. You should be getting 2550 to 2650 or so (something less than 2700) statically, and 2700 at 90 knots. If you get any surging on application of full throttle, they aren’t sweet right. A consequence of them not being set correctly is that your glide ratio will be severely effected, almost half of what you should get if they are adjusted.

 

[Vac]

Great discussion!

Everyone brings up salient points! That's why we are studying this and trying to develop planning and training tools that help a pilot make an informed decision for the airplane they are flying under ambient conditions.

The app updates the math once per second. Not perfect, only "about right" but better than a Mark One Eyeball estimate, even if it's just a model. In 30% of the cases we studied, the pilot attempted a turn back below 200 feet AGL. None of them made it. Obviously we can't know what a pilot was thinking, but if someone attempted this, it's likely they hadn't considered the factors effecting performance prior to making that attempt.

This is a low-frequency event, and will catch any pilot off-guard, plain and simple. A turn back attempt would only be a player if the airplane has sufficient performance, ambient conditions allow, there are simply no other alternatives, the pilot is trained in the maneuver and has considered it before hand. If you choose to go straight ahead with minimum maneuvering and crash in a built up area, trees or foul terrain, we would never second guess that decision. If you crash well, you still have about a 70+% chance of surviving the experience in a built-up area if you don't stall. During any of these tests, I could have departed controlled flight, carried too much energy into the landing transition or simply mis-handled the airplane (insufficient bank, poor energy management, etc.) and had a negative outcome. One reason the test was flow from start to touchdown is that either everything works or it doesn't. You won't get a second chance in real life. I had the luxury of having a set of criteria to assess whether or not things will work and the ability to abort the attempt if it didn't.

We are testing with our instrumented RV-8 with a controllable prop. All we can say is that if you have a controllable prop, and you can't restart, if the prop remains controllable, reduce RPM to reduce drag if conditions don't permit a quick restart attempt or it ain't starting. CAFE flight test shows there isn't any merit to attempting to stop the prop below 3000' AGL. It may or may not. With my light-weight fixed pitch prop, when I slow to on speed AOA, the prop stops. This helps reduce drag. At L/Dmax AOA (best glide speed) it continues to rotate. I fly the maneuver at on speed AOA because it's the best blend of turn performance, glide and energy for touchdown. It's not as optimum as slowing to make the turn, accelerating to glide and decelerating to land, but I'm not a good enough pilot to do all of that in the 60 seconds it takes to execute this maneuver. A single "good enough" cue is the best I can do.

In many cases, there simply isn't an option to turn back. There may be a left or right option that's better than straight ahead, so we've improved the graphic "where I can crash depiction" a bit: https://youtu.be/yUZeN7z5cBo. I turn to the right during this test (counter to what the app directs) to remain over the open field for the turn back. This results in a low energy state as I maneuver to the south side of the field to avoid overflight of the hangars, but sufficient for touchdown--a bit of a different problem than I had in the test in the original post.

Avoid a self-inflicted gun shot wound: 50% of EAB fuel starvation and 70% of EAB fuel contamination power incidents occur on takeoff or during initial climb segment. Consider start, taxi, run-up and takeoff on a tank with a known amount of clean fuel. Changing fuel tanks immediately prior to takeoff can cause problems. If you haven't tested, see how long your engine runs at IDLE after you turn the fuel OFF. Perform the same experiment at wide open throttle...

What a great resource this site is

Vac

 

[rocketman1988]

turn

It is interesting to see the data and hear of people "testing" their individual aircraft.

I would submit, though, that practicing something that you know is going to happen is far different than when it really happens. Everyone accepts a three second delay as a startle factor because you have to assume something. In reality, it may be substantially longer.

A HYPOTHETICAL experiment to actually see the potential difference might look like this:

Assume that you fly with several people on a regular basis. You explain that at some random time and random altitude, an engine failure will occur, and they will pull the power off and note the altitude.


You ask for a random number between 1 and however many people you fly with. Pick unseen numbers from a hat. Whoever draws the matching number is tasked with facilitating the "engine failure" at some random future time.

You then go about your normal routine until the simulated failure occurs. As the pilot you have no way of knowing who, when, or where it will happen. When it does, you will have a realistic approximation of startle factor and data on "the impossible turn".


I can tell you that after thousands of hours of instruction given, it will NOT end up as it was practiced.

Is it doable? Possibly. I contend that, for most people, it isn't recommended...

 

[wawrzynskivp]

No Fuel Testing

I was curious about the residual thrust so when my engine had plenty of break in hours I tried my glide #s with no fuel.

First off, you are unlikely to ever stop your engine without a much bigger problem, some kind of crazy compression ratio and tiny prop, or a lot of high alpha. Most of us would have to try pretty hard to get our engines to actually stop in a no fuel scenario, and then would have to fly unreasonably slowly to keep them stopped. Well below best glide speed. So know your prop will keep spinning at very nearly the same RPM, you'll still have oil pressure, manifold pressure, engine driven vacuum (God willing), alternator volts, etc.

In my airplane there is no discernable difference in engine feedback when I am at idle with fuel or idle without. Watching EGT is the only feedback tool that gives you assurances the engine is no longer burning fuel. No change in sound, vibrations,...nothing.

With a 3 blade CS prop I can underscore the difference in gliding with idle thrust and no thrust. Don't draw turn back conclusions from testing with idle fuel until you know what no fuel turning glides are in your airplane!

My CS prop setup showed me I can control RPM down to about 1100 in best glide speed ranges. Slower RPM was always better so knob out. Interestingly Manifold Pressure (MP) also makes a measurable difference in my airplane. Yes, I am still talking no fuel MP adjustments. Best MP for me was 16" your setup will probably be different.

Once my best glide was determined I was able to replicate it at idle fuel flow with a prop RPM adjustment, much like Vac's full flap usage.

Two things came from my testing: 1. Some ballpark (NO WIND) numbers for turn back altitudes at various Density Altitudes 2. Some correction numbers adding to those altitudes for runways less than 4,000' long. Keep in mind that at actual no fuel glide #s once you complete the turn around you may not be over the top of the opposite threshold yet. The less excess thrust you have the worse that dynamic. If your overrun is clear then no big deal. If your overrun has a Walmart then it could be problematic. I put a 390 in a -7 and I know that I won't always be back over concrete after a min alt turn if the runway is short.

If you do decide to do no fuel glide testing don't stress about the engine running or not running, but do give some thought to time for it to cool down before you take away the idle heat. (Don't stress but do be smart about doing it over a good landing spot)

Don't do this vicariously! Knowing that you don't know your numbers for this kind of thing is somewhat okay, much better than assuming somebody else's numbers! It's not just how the gear performs, it's also how you perform. In this arena CS prop and fixed will yield much different results depending on where that prop control is.

For the CS folks: Some engine/prop/gov combinations will lose prop control at glide speeds with no engine power. That means your prop is going flat and that is going to really increase your rate of descent (decrease glide). Something to know about before you are in extremis.

"Experience is that quality of knowledge most often achieved just after you needed it"

 

[Vac]

Hi Bob,

Great point! We conducted a simulator experiment with a cross-section of 90 pilots using a typical GA airplane in 2021. Here is a plot of the startle time vs. success of turn back:

Just like factors affecting V1, we had to decide on some time for flight test. You can see the highest probability of success occurred when the pilot reacted within about 3-4 seconds, but average overall reaction time was slower. We discovered with training, pilots reduced reaction time.

That's the basis for the three-second delay during test. Not perfect, obviously.

v/r,

Vac

 

[Dugaru]

One idea

There is endless debate about the so-called impossible turn, and there obviously are a lot of variables that will differ materially for a given aircraft, loading, airport, etc. The physics, human factors, aerodynamics, etc. of this issue are truly fascinating. It's no wonder we love talking about this stuff.

But I think one indisputable and overridingly important fact is that an enormous number of pilots get the required analysis very badly wrong when the event actually occurs.

They misapprehend the physics, they overestimate their own abilities, they remain startled for too long, they fail to make the big push, they otherwise fly badly, whatever. But they get it wrong. We know, for a fact, that they fail over and over and over, year after year, and very frequently do so with awful consequences.

I strongly suspect that if literally NOBODY EVER tried to return to an airport following an engine failure after takeoff, there would be a lot more people walking around today. Maybe we'd have a few more bent aircraft -- maybe -- but I have to believe a lot more people would walk away from these situations.

Pilots seem to have a natural reptile-brain desire to get back to where they came from, and it's very possible they are also just too worried about bending their airplanes.

Let's give them something else to worry about. Here's my proposed "new rule":

1. If you experience an engine failure on takeoff while less than 1200 AGL, you are PROHIBITED from returning to the airport.

2. Insurance companies can deny hull coverage for impossible turn attempts commenced below 1200 AGL.

3. A new FAR will make you lose your license if you try it -- with only one caveat:

4. Caveat: If on a given takeoff the pilot really thinks that literally the only possibility for survival, or avoiding mass casualties on the ground, will be a return to the airport from less than 1200 AGL (and I think this situation is going to be fairly rare), he or she needs to recite this morbid detail before takeoff, and warn any passengers, as part of the required briefing, that an engine failure on takeoff will very likely prove fatal. If a return from below 1200 AGL is subsequently attempted (and the pilot survives...) the FAA will have to agree with the analysis, or else there goes the license and the insurance company can deny coverage.

 

[lr172]

T

Let's give them something else to worry about. Here's my proposed "new rule":

3. A new FAR will make you lose your license if you try it -- with only one caveat:

4. Caveat: If on a given takeoff the pilot really thinks that literally the only possibility for survival, or avoiding mass casualties on the ground, will be a return to the airport from less than 1200 AGL (and I think this situation is going to be fairly rare), he or she needs to recite this morbid detail before takeoff, and warn any passengers, as part of the required briefing, that an engine failure on takeoff will very likely prove fatal. If a return from below 1200 AGL is subsequently attempted (and the pilot survives...) the FAA will have to agree with the analysis, or else there goes the license and the insurance company can deny coverage.

Legislating away the pilots options for safely navigating out of an emergency doesn't seem like a great idea. This not a one size fits all problem. Sorry, but have to go with VAC here that awareness, knowledge, testing and training seem like much better options for reducing accidents. It seems that AOA is great tool for helping in this area, as many pilots do not have an engrained awareness of the relationship between, bank angle, G's and stall speed. Beyond preparing for the PPL written, I doubt many have experimented with this or even think about it.

 

[rocketman1988]

data

Hi Bob,

Great point! We conducted a simulator experiment with a cross-section of 90 pilots using a typical GA airplane in 2021. Here is a plot of the startle time vs. success of turn back:

Just like factors affecting V1, we had to decide on some time for flight test. You can see the highest probability of success occurred when the pilot reacted within about 3-4 seconds, but average overall reaction time was slower. We discovered with training, pilots reduced reaction time.

That's the basis for the three-second delay during test. Not perfect, obviously.

v/r,

Vac

Interesting data.

Yes, you obviously have to make assumption; as we all know, though, the devil is in the details.

As you stated, the highest probability for success was those who reacted in 3-4 seconds; I would argue that, in reality, the reaction for most people would be longer, in the 4-6 second range. Making that assumption shows that while the turn may be possible, for most people, it will end in failure. Your graph illustrates the point.

Other things I would be interested in hearing is what the test subjects were told, prior to the sim. Were they briefed about test profile, ie "we want you to make the turn back to the runway" or were they left to their own decisions. Obviously, if they were pre briefed that they were to attempt a return, it shortened the reaction time because the decision was already made before the event. Any delay, whatsoever, will push the reaction time into the 4+ second range, with a successful outcome correspondingly lower.

Yes, practice can help reduce the reaction time and improve the skill set necessary to successfully complete the maneuver but I think a 3 second assumption is optimistic.

I also see this in every sim session we do at work. Maneuvers are pre briefed, yet they typically do not go as the briefing specifies. I believe the startle factor is quite a bit more involved than a simple three count. If that wasn't the case, every Upset recovery and V1 cut would end up perfect; in reality, they do not.

One of the best examples is a rejected takeoff. That gets briefed ad infinitum and we KNOW what is supposed to happen and what we supposed to do...and it still doesn't go well every single time.

Again, this is a GREAT discussion with awesome data. I will keep demonstrating "the impossible turn" to my students, however, I use the demonstration to show that in a lot of cases, it may not be the best option.

 

[Taltruda]

Let's give them something else to worry about. Here's my proposed "new rule":

1. If you experience an engine failure on takeoff while less than 1200 AGL, you are PROHIBITED from returning to the airport.

2. Insurance companies can deny hull coverage for impossible turn attempts commenced below 1200 AGL.

3. A new FAR will make you lose your license if you try it -- with only one caveat:

4. Caveat: If on a given takeoff the pilot really thinks that literally the only possibility for survival, or avoiding mass casualties on the ground, will be a return to the airport from less than 1200 AGL (and I think this situation is going to be fairly rare), he or she needs to recite this morbid detail before takeoff, and warn any passengers, as part of the required briefing, that an engine failure on takeoff will very likely prove fatal. If a return from below 1200 AGL is subsequently attempted (and the pilot survives...) the FAA will have to agree with the analysis, or else there goes the license and the insurance company can deny coverage.

I don’t like this proposed “new rule”. My testing at idle (I’ll perform some fuel cutoff testing) in MY plane with a 3 second startle delay, I can easily turn back at 100agl. Actually a worse case would be losing the engine prior to 100 feet, yet past midfield. I would have too much speed to put it back down and get stopped. If I take my 100 feet agl and increase it 5x, is that enough? Do I really need a “rule” to prevent my turn back till 1200 feet? By 700agl, you should be on crosswind, if staying in the pattern, I fly downwind at 800 to 1000 agl, does that mean I can’t turn back to the runway ever?
I propose a new rule, everyone lands power off from abeam the numbers unless ATC extends you out, even then, you hold your pattern altitude until you are ready to go to idle, and proceed to perform every landing power off. Sure there are times when you drag it in with power such as Soft, short, STOL type landings, just another tool in the toolbox. Every BFR should include power off 180s to touchdown within 200 feet or you don’t pass satisfactory until you receive additional instruction. (I also feel the pilot population would be a lot safer if everybody from a student to pro could do this)(also what would make the pilot population safer would be if EVERYONE flying for 5 years or more got their instrument rating, commercial and Tailwheel endorsements)

Edit: I don’t endorse any new “Rules”.. I was just making a point..

 

[Vac]

Hi Doug,

"But I think one indisputable and overridingly important fact is that an enormous number of pilots get the required analysis very badly wrong when the event actually occurs."

This is spot on and borne out in mishap statistics. We would also point out that most pilots would get the pre-flight analysis wrong as well. The physics are such that there is no one "right number." That's why we are assessing a technical solution to assist with decision making and in-flight performance assessment. I turn back when the computer that is updating for actual performance under ambient conditions once per second says I can turn back. Not perfect, but better than even a skilled test pilot can do looking out the window.

When we brief the results of our work, we conduct a real-time straw poll of the room to see what folks use for hip pocket numbers. We typically see a cluster of answers around 800-1200 feet. Some of these pilots are flying airplanes that won't ever turn back, and in some cases 800' is literally too high for a simple turn back with out an extension (not a bad problem to have!); so it's impossible to have a hard and fast rule. As I said, we'd never question anyone that maneuvered straight ahead to the crash, regardless. Not stalling and touching down under control at minimum speed are what ultimately matter.

To emphasize your point, I'll reiterate that fully 30% of the pilots that lose power after takeoff attempt to turn back (lizard brain response) below 200 feet AGL.

v/r,

Vac

 

[Vac]

Hi Bob,

Whole-heartedly agree with you. I was probably one of your sim students . Sounds like my general level of performance....

It was a toss-up between probability of success and observed response. With training, we saw reduced response time. The good news is that as I said in the original post, actual parameters in the app are adjustable. All of my testing so far has been maximum performance to make sure we've got the physics right. We'll be doing future tests under varying ambient conditions (wind has a huge impact) and using different, non-optimum parameters to see what's in the art of the doable.

What I like best is the SA I have pre-takeoff. I can make an informed decision based on a real-time assessment of ambient conditions. Here's a screen shot of the pre-takeoff screen. Notice at the start of the takeoff roll, I have a yellow dot and a green dot. The yellow dot is the go forward, stop in remaining runway point (not strictly abort, I may be airborne at this point) and the green dot is predicted turn back point. Predicted turn back altitude for no-wind conditions is shown in the lower right:

Drop me a PM with an email address and I'll share the test report with you if you are interested.

v/r,

Vac

 

[rvbuilder2002]

Hi Bob,

Great point! We conducted a simulator experiment with a cross-section of 90 pilots using a typical GA airplane in 2021. Here is a plot of the startle time vs. success of turn back:

Just like factors affecting V1, we had to decide on some time for flight test. You can see the highest probability of success occurred when the pilot reacted within about 3-4 seconds, but average overall reaction time was slower. We discovered with training, pilots reduced reaction time.

That's the basis for the three-second delay during test. Not perfect, obviously.

v/r,

Vac

So all of the test subjects had no idea they were being”tested”, and there was no foreknowledge of but they attempted to perform a simulated turn back?

If that was not the case, then my opinion is that the data is skewed.

 

[rvbuilder2002]

Hi Doug,

"But I think one indisputable and overridingly important fact is that an enormous number of pilots get the required analysis very badly wrong when the event actually occurs."

This is spot on and borne out in mishap statistics. We would also point out that most pilots would get the pre-flight analysis wrong as well. The physics are such that there is no one "right number." That's why we are assessing a technical solution to assist with decision making and in-flight performance assessment. I turn back when the computer that is updating for actual performance under ambient conditions once per second says I can turn back. Not perfect, but better than even a skilled test pilot can do looking out the window.

When we brief the results of our work, we conduct a real-time straw poll of the room to see what folks use for hip pocket numbers. We typically see a cluster of answers around 800-1200 feet. Some of these pilots are flying airplanes that won't ever turn back, and in some cases 800' is literally too high for a simple turn back with out an extension (not a bad problem to have!); so it's impossible to have a hard and fast rule. As I said, we'd never question anyone that maneuvered straight ahead to the crash, regardless. Not stalling and touching down under control at minimum speed are what ultimately matter.

To emphasize your point, I'll reiterate that fully 30% of the pilots that lose power after takeoff attempt to turn back (lizard brain response) below 200 feet AGL.

v/r,

Vac

I can’t help but wonder how many people have attempted and failed because of all the high profile promotion of success on YouTube and by other means.

If not trained for in advance, no one should attempt something they have only seen or read about but in desperate times the human mind can go many different directions.
It is hard not to believe it has all had a negative influence when compared to decades ago when the pilot community pretty universally said “don’t do it” ( and people still did).

 

[rocketman1988]

skill set

So all of the test subjects had no idea they were being”tested”, and there was no foreknowledge of but they attempted to perform a simulated turn back?

If that was not the case, then my opinion is that the data is skewed.

I tend to agree, which is why I proposed a hypothetical scenario that would lead to a truly "real" outcome.

Unfortunately, without specifying that the return was to be attempted, it would be much more difficult to collect representative data. You would never know what each person was going to do each time, in fact, the same person may choose to do it differently every time...

I do appreciate the data and discussion, while realizing the assumptions and limitations of the results.

 

[swjohnsey]

I conduct a turn back from 500 AGL using 3 second startle factor on the first landing of nearly every flight in my IO-360-EXP CS RV-4 to a full stop landing. Alway end up at least 100' high.

 

[Vac]

Hi Scott,

That is correct. Study participants knew that they were participating in an experiment, and they would encounter an emergency but they had no foreknowledge of the nature of the emergency prior to the first data run (profile 2).

The experiment was designed to not only gather the "going in cold data," it was also designed to evaluate the ability to teach the turn back maneuver. The first profile was simply sim and visual environment orientation. The 2-5th profiles were test runs. The engine failed automatically at a designated altitude. The distance from the field was dependent on the climb profile flown by the test subject. While directed to use a specific takeoff and climb technique, performance varied. Plenty of off-airport landing sites were available, and some folks elected to simply go straight ahead, but a surprisingly large number of folks attempted turn back of their own accord. For the 3rd profile, subjects knew the nature of the emergency, but were given no further guidance. Again, some elected to turn back, others did not. On the 4th profile, subjects were directed to turn back and told what bank angle to use for the turn and what airspeed to fly. A short debrief was conducted after the 4th test run and a 5th run was flown. No instruction was given during any of the runs.

The sim flight model posed some challenges, so the engine failure altitude was selected based on simulator performance. If the subject followed takeoff and climb instructions, ambient conditions were sufficient to allow a successful turn back. The simulator had poor stall modeling (i.e., more forgiving than an actual airplane), and this was reflected in results. Only 15% of turn back attempts during the study resulted in stall, whereas more that 50% of documented mishap turn back attempts result in stall.

These four plots are a good 30K foot overview of results. These plots only show the pilots that turned back on run 2 and 3. All pilots were directed to turn back on runs 4 and 5:

v/r,

Vac

 

[wawrzynskivp]

Foreknowledge and reaction time

Interesting feedback,

Should it be any different to tell someone in a simulator that their engine may fail than it is any time we launch for an actual flight? Shouldn't we be thinking on each and every launch that our single engines may fail at the worst possible moment?

Gotta multi-task a few things but the possibility of an engine failure at that phase should be in each and every mind yes? Is it not the closest gator to the boat?

 

[rvbuilder2002]

Interesting feedback,

Should it be any different to tell someone in a simulator that their engine may fail than it is any time we launch for an actual flight? Shouldn't we be thinking on each and every launch that our single engines may fail at the worst possible moment?

Gotta multi-task a few things but the possibility of an engine failure at that phase should be in each and every mind yes? Is it not the closest gator to the boat?

I agree on ever point, but the way the average recreational pilot approaches aviation is far different than someone like yourself who has operated a large portion of their flying career within the professional realm (which I think a multitude of different accident types, not just turn back accidents, shows evidence of).

 

[Ironflight]

Should it be any different to tell someone in a simulator that their engine may fail than it is any time we launch for an actual flight? Shouldn't we be thinking on each and every launch that our single engines may fail at the worst possible moment?

Gotta multi-task a few things but the possibility of an engine failure at that phase should be in each and every mind yes? Is it not the closest gator to the boat?

Yes - In theory, every pilot should think like the professional pilots on this thread, going through options before every take-off and keying themselves up for the failures. Unfortunately, the vast majority of GA aviators under the bell-shaped curve don’t think or fly like professional risk managers, and a century of experience tells us that we probably won’t get them to change.

That means that those of us working in aviation safety and risk management, developing initiatives to decrease mishaps have to think about what realistic changes we can make - if you can’t change the psychology of the pilot community, and no one wants to increase the regulatory or financial burden, then how CAN we help folks fly more safely, despite themselves?

As much as we want folks to be sharp as tacks on every flight, the sad fact is that a huge number of E-AB pilots log most of their annual hours flying to and from Oshkosh in July, and they treat their flying like they treat driving a car…..

Paul

 

[rv8ch]

Interesting feedback,

Should it be any different to tell someone in a simulator that their engine may fail than it is any time we launch for an actual flight? Shouldn't we be thinking on each and every launch that our single engines may fail at the worst possible moment?

Gotta multi-task a few things but the possibility of an engine failure at that phase should be in each and every mind yes? Is it not the closest gator to the boat?

I agree - I was taught from primary flight training to expect an engine failure, and to brief exact actions when it fails. I still do this on every takeoff.

What seems to happen to some pilots is that they don't have a total engine failure, and the partial power lures them into thinking they can make it back.

I've done dozens of simulated engine failures in a VR sim, and I rarely make it back to the runway, but can often get it to airport property. If I go for a field, I "walk away" almost every time.

 

[swjohnsey]

If you offset downwind after landing on the remaining runway is no longer an option you make the turnback much more doable. Also if you lose power at 100 - 200 AGL it is possible for me to get back down and stopped on 6,000' runway by using full flaps and slip to get back down and stopped. Even if I don't get stopped the run-off area is very benign.

 

[rocketman1988]

But

“…I agree - I was taught from primary flight training to expect an engine failure, and to brief exact actions when it fails. I still do this on every takeoff…”

…and I would argue that this mindset leads to expectation bias, which can and often does, end up in a more challenging situation.

There is no “exact actions” that will cover every conceivable scenario. I would give two prime examples:

The first involves pre briefing an expected taxi route. Often that is not what you get, and the pre brief causes an expectation bias. When ground gives something different, many times the pilot will start out on the prebriefed route instead of the actual clearance.

The second is something I like to illustrate to students. While transiting to and from the practice area, I will simulate an engine failure or partial engine failure. There is plenty of altitude and time to decide what to do. The students typically do quite well with their procedures, pick a field, and begin to position themselves for an off airport landing. That’s great. The problem is that the engine failure is usually triggered basically over a perfectly good runway. The students almost never look anywhere except away from the airplane, and usually too far. They are trained that way; instead of assessing the problem and possible solutions, they automatically go to what they learned by rote. The expectation bias is to pick a field and land, and they lose sight of an obvious solution because of it.

It is interesting to sit back and watch these things unfold and even more interesting to see what they were thinking while debriefing the flight…

 

[JonJay]

Flight training some odd thirty years ago:

Flight Instructor - Ok, Engine Out! Pulls throttle.

Me- Push throttle back in.

Flight Instructor - Ok, we are going to simulate an engine out. Pulls throttle.

Me - Push throttle back in.

Flight Instructor- I’ve never had a student do that. Ok, I’m going to pull the throttle, you’re going to leave it there, and you’re going to demonstrate an engine out. Ok?

Me - Got it.

 

[Terry Lutz]

Turnback on AOA

At the beginning of this thread, Vac is doing a turnback using guidance from the TLAR app. Although I'm sure you heard the audio, with the FlyOnSpeed system talking away to indicate optimum AOA, perhaps you should notice two other things. First, his airspeed indicator (round dial to the left of the Dynon D10), and the Dynon D10 itself were both covered over. So he had no airspeed reference. If you view the video again, focus on the AOA display at the bottom of the screen, and watch how the tones change with AOA. Then take another look at the AOA display and look at the number above the indexer. That number indicates the energy state of the airplane, in terms of percent lift being used. There are two points where he uses all the lift, at one point during the turn, and right at touchdown. Here is the link again: https://youtu.be/F_RFKlUhdeE Also, you can click on CC at the bottom for all of Vac's narrative.

 

[rv8ch]

Yes - In theory, every pilot should think like the professional pilots on this thread, going through options before every take-off and keying themselves up for the failures. Unfortunately, the vast majority of GA aviators under the bell-shaped curve don’t think or fly like professional risk managers, and a century of experience tells us that we probably won’t get them to change.

That means that those of us working in aviation safety and risk management, developing initiatives to decrease mishaps have to think about what realistic changes we can make - if you can’t change the psychology of the pilot community, and no one wants to increase the regulatory or financial burden, then how CAN we help folks fly more safely, despite themselves?

As much as we want folks to be sharp as tacks on every flight, the sad fact is that a huge number of E-AB pilots log most of their annual hours flying to and from Oshkosh in July, and they treat their flying like they treat driving a car…..

Paul

Totally agree. Eventually, with technology, if the engine stops the automatic landing system will take over, ignore inputs from the pilot, and land in the safest place. We all know this is possible, but for various reasons, it won't happen any time soon.

The question is "how do we deal with the systems we have today, and the people we have today?"

What I understand Vac and team are doing is providing another tool for a pilot to find a safe place and safe way to land. If this is installed in 100 aircraft, it might save a life - a very laudable achievement!

The challenge in discussing the turnback is that we have some who will try and die, some who will try and succeed, but we'll rarely hear about the successes. If we count total fatality impact on the community, is the turnback net positive or negative? We don't have data to say. Turnback failures are spectacular.

As a former renter, if I saw an OnSpeed with tone in my rental aircraft it would certainly prompt me to ask "hey, what is this?" and hopefully open a discussion with the chief pilot to learn about the turnback, and its risks.

I am convinced that pilots can learn. A recent video I saw with two pilots who found themselves with a failed engine at night in a PA28 was heartening - they both kept telling each other "keep the nose down - don't stall the aircraft" and they flew into some trees just above stall, and survived.

I think the best advice, until we get better training and better tools, is "Keep the nose down - don't stall the aircraft."

 

[Dugaru]

Good points

The challenge in discussing the turnback is that we have some who will try and die, some who will try and succeed, but we'll rarely hear about the successes. If we count total fatality impact on the community, is the turnback net positive or negative? We don't have data to say. Turnback failures are spectacular.

…

I think the best advice, until we get better training and better tools, is "Keep the nose down - don't stall the aircraft."

That’s the advice, to be sure.

It’s true that we don’t hear a lot about successful turnbacks. But of course, successful straight-ahead off airport landings probably aren’t headlines most of the time either.

My bottom line is that I find it very, very hard to believe that turnbacks below 1200 AGL have saved more lives than they have cost. I suspect it’s actually wildly disproportionate. In light of how little we’ve accomplished solving this problem over many years, and until we get better technology - kudos to those working on it! - I continue to think we should teach pilots that turning back below 1200 AGL is a decision on par with flying while intoxicated.

Not sure 1200 is the perfect number, but I bet it’s in the ballpark.

 

[maxmirot]

Totally agree. Eventually, with technology, if the engine stops the automatic landing system will take over, ignore inputs from the pilot, and land in the safest place. We all know this is possible, but for various reasons, it won't happen any time soon.

The question is "how do we deal with the systems we have today, and the people we have today?"

What I understand Vac and team are doing is providing another tool for a pilot to find a safe place and safe way to land. If this is installed in 100 aircraft, it might save a life - a very laudable achievement!

The challenge in discussing the turnback is that we have some who will try and die, some who will try and succeed, but we'll rarely hear about the successes. If we count total fatality impact on the community, is the turnback net positive or negative? We don't have data to say. Turnback failures are spectacular.

As a former renter, if I saw an OnSpeed with tone in my rental aircraft it would certainly prompt me to ask "hey, what is this?" and hopefully open a discussion with the chief pilot to learn about the turnback, and its risks.

I am convinced that pilots can learn. A recent video I saw with two pilots who found themselves with a failed engine at night in a PA28 was heartening - they both kept telling each other "keep the nose down - don't stall the aircraft" and they flew into some trees just above stall, and survived.

I think the best advice, until we get better training and better tools, is "Keep the nose down - don't stall the aircraft."

AOA and OnSpeed is not a turn back tool.

It can help you understand the limits of the flight envelope.

The TLAR software has a feature to indicate a possible turn back. Vac is testing this as an extra tool. It has nothing to do with AOA or the OnSpeed

Any turn back requires training and currency. I built and fly an OnSpeed AOA.

It would not try a turn back below 1000 ft AGL unless I mastered it with a instructor.

Any AOA should keep you from stalling if you know how to use it.
I like the tone system on that OnSpeed uses better than my AFS AOA.

 

[pvalovich]

Impossible Turn - Overlooked Factor: Immediate Bank

RV-8A; IO-360; AFS AOA - and former Navy carrier guy who is AOA experienced. This works for me - your outcome may vary.

I practice the turn back regularly. Climb at 110 kts to safe practice altitude. I've decided 600' AGL is a reasonable altitude taking off into the very hilly landscape around AFJ to attempt the turn, so use 600 ft above a simulated ground for practice.

Use 5-second startle factor, lower the nose and immediately crank hard into 60 degrees of bank and pull, monitoring AOA and airspeed. Hard maneuvering getting through as many angles as possible before airspeed is reduced. Adjust angle of bank, g, and nose attitude as necessary to maintain AOA above stall.

I also regularly practice accelerated stalls so am familiar with how the plane feels before stall. I've found that regardless of bank angle unloading at first hint of stall immediately leads to stall recovery. If I've screwed up it's then back to more carefully executing the turn.

Don't stall! If the turn isn't completely successful, the unstalled controlled crash will be closer to the airport in somewhat more friendly terrain than that off the departure ends.

 

[Pilot135pd]

AOA and OnSpeed is not a turn back tool.

It can help you understand the limits of the flight envelope.

The TLAR software has a feature to indicate a possible turn back. Vac is testing this as an extra tool. It has nothing to do with AOA or the OnSpeed

Any turn back requires training and currency. I built and fly an OnSpeed AOA.

It would not try a turn back below 1000 ft AGL unless I mastered it with a instructor.

Any AOA should keep you from stalling if you know how to use it.
I like the tone system on that OnSpeed uses better than my AFS AOA.

As I read his comment I was about to write pretty much the same thing you wrote, then I reached and read your comment. I agree.

 

[Desert Rat]

Totally agree. Eventually, with technology, if the engine stops the automatic landing system will take over, ignore inputs from the pilot, and land in the safest place. We all know this is possible, but for various reasons, it won't happen any time soon.

I'm sorry, but I don't see how this will be feasible within my lifetime. If there's an airport within gliding distance then sure, that's great. But if not, who gets to define "safest place?"

Garmin will tell you that their terrain database is to the dirt. It doesn't include trees, houses, or pretty much anything else that isn't dirt. Even if technology advances to a point that every semi-permanent feature is noted down to the inch, what about a field that was empty last week but is full of 800 lb round hay bales this week? Or a parking lot that may or may not be full of school busses? Is the auto land system going to be smart enough to know whether those giant soccer fields in front of you are empty or if there's a little kid tournament gong on?

I'll hand fly to the scene of the crash, thanks anyway

 

[Pilot135pd]

Garmin will tell you that their terrain database is to the dirt. It doesn't include trees, houses, or pretty much anything else that isn't dirt. Even if technology advances to a point that every semi-permanent feature is noted down to the inch, what about a field that was empty last week but is full of 800 lb round hay bales this week? Or a parking lot that may or may not be full of school busses? Is the auto land system going to be smart enough to know whether those giant soccer fields in front of you are empty or if there's a little kid tournament gong on?

Short answer is that by the time it's ready to use, YES. I believe AI (which is basically lots of fancy code) and a cheap camera will be able to determine if there are obstacles on that land and where to point the plane for a safer outcome, but I'm a glass half full kind of guy.

 

[Desert Rat]

We shall see. I’m one of the crunchy old guys who thought glass cockpits in training airplanes was a bad idea as well, so perhaps you’re right

 

[Vac]

Wow, thanks to everyone for engaging in good discussion!

I have the privilege to work with a group of experts studying the various facets of power loss on takeoff. The turn back maneuver itself and the documented unsuccessful events tend to illicit a visceral response from most pilots. As Mickey wisely points out, we have very little data or documented successful attempts. There are a few, and we've looked at those as well as ballistic chute recoveries (the civilian version of an ejection seat) as well.

To reiterate, if there is a suitable off-field option ahead or with limited maneuvering, take it. The fact that fully a third of turn back mishaps are initiated under 200' AGL, means the pilot likely put zero point zero brain cells on it prior to attempting the last thing they did. A turn back is simply a "I literally have no other good options," have trained and planned for it prior to takeoff and, if in doubt, readjust your game plan real time and crash under control doing your best not to hit anything on the ground while not stalling. You'll notice in the test, I'm over a pine forest (that's why it's the designated test area). If I had insufficient energy and the engine was off, I'd be committed to fly into the trees just like the guys referenced above. You may train, test your airplane and still decide "I'm never doing that." I would also commend anyone that stipulates "I'm not trained and not going there." Training (and/or testing) experience is critical. Another part of the effort is developing techniques and tools for instructors to teach power loss on take off, including the proper conduct of a turn back maneuver. The purpose of starting this discussion is to share our lesson's learned with our VAF family.

One of the important "learnings" our team discovered is that the ability to conduct a turn back is a physics problem, and many pilots have some sort of hip pocket number that is metaphysical. There simply isn't a boiler plate altitude. Period. Dot. If you were to conduct extensive testing with your airplane under calm conditions, you would have an approximate altitude for that airport under similar conditions. You'd also have a pretty well developed Mark 1 eyeball calibration, which will go a long way--it's the testing and training piece. The app was developed to actually do the math, and even allows the pilot to adjust the parameters to remain in their comfort zone (at the risk of reducing performance). The two examples I posted in the original thread bookend the problem nicely: the RV-4 is a relatively high performance airplane with excellent handling characteristics that's capable of "edge case" maneuvering and shoehorning itself back into a relatively short landing strip using maximum performance maneuvering (270 degree turn back with a 90+ degree reposition). On the other hand, if you watch me takeoff in a Cherokee shortly after the first test from same field, a turn back simply wasn't an option at any altitude.

The factors that Charlie explains in the video in the original post all impact the minimum turn back altitude for the RV-4. It will always vary with ambient conditions and some days, it simply wouldn't be practical. Just like I need a tool to manage energy. As an ape (albeit a mostly bald one!) sitting in the cockpit, I need some help figuring out if a) a turn back may be practical; and b) some help flying it without losing aircraft control and effectively managing my flight path simultaneously.

Everyone is correct in the first step is "do not stall." An airplane stalls when it exceeds critical angle of attack. The only system that provides direct feedback to a pilot that critical angle of attack is approaching is an accurate, properly calibrated AOA system that has good linear performance across the speed band of the airplane, good filtering, transient response and is designed to provide trend information to the pilot. I know that my AOA responds to G, so if I can hear (preferably) or see AOA (better than nothing), I know exactly how far from the stall I am. Obviously, I wouldn't take the wing to near 100% capacity close to the ground while maneuvering if I didn't have that SA--I'd keep some extra energy (speed in this case) "in the bank" and I'd also extend the re-alignment maneuver to the runway and likely over-shoot my intended/safe landing point. Some airplanes provide marvelous buffet cues, and pilot can "max perform" the wing by the seat of his trained and exerienced pants. My RV-4 doesn't provide those cues, I need help with determining my energy state, just like I need help determining minimum turn back altitude.

v/r,

Vac

 

[N8RV]

Before I built my RV-8, I owned an American Aviation AA-1A "Trainer" (think Grumman Yankee.) Great little plane, and a really good training platform to get me ready for flying an RV. However, with its stubby little wings, high loading, small engine, and two full-sized guys on board, maneuverability was ... marginal at best.

During a flight review, the instructor reached over when we were over the end of the 2500' runway and pulled the power. I immediately shoved it back in.

"I want you to execute a turn to return to the airport," he said.

"Nope. Not gonna happen. We're going straight into that cornfield ahead if you do that again," I said. During the rest of the flight review, I educated him on what the Yankee can and can't do. I gave him the controls at altitude and made him a believer.

While I didn't dwell on takeoff failures every time I flew, I was never really relaxed until the airport was well behind me, everything was in the green, and nothing sounded weird.

 

[jrs14855]

Turn Back

Mike has covered most of what I wanted to say. My important point is the vast difference in performance between two near identical airplanes except one has a fixed pitch prop and one has a constant speed. A windmilling constant speed will result in a HUGE degradation in performance. There will also be significant variations in performance between different make/model constant speeds.
I believe I can do the turnaround at 300' in my Wittman Tailwind using less than optical numbers for speed and bank angle. The optimum bank angle is 60 degrees. The compromise in performance using 45 degree bank is very small.
A Pitts S2B with Hartzell two blade needs 1200' to make a 180 to the runway from abeam the numbers on downwind. A A36 Bonanza requires about the same. The nice thing about the Pitts is that you can be at 1500' AGL at the end of a 4000' runway on takeoff. If one is really good on that same runway it is possible to land straight ahead if the engine quits at 500' AGL.
Finally I am repeating myself but Sunrise Aviation at John Wayne Airport trains pre solo pilots on the turnback maneuver because the area around the airport has almost zero options for putting the airplane down and surviving.

 

[ronrapp]

Finally I am repeating myself but Sunrise Aviation at John Wayne Airport trains pre solo pilots on the turnback maneuver because the area around the airport has almost zero options for putting the airplane down and surviving.

I learned to fly there. I also taught there for many years, especially tailwheel and aerobatic courses. I'd say a third of my 10,000 hours of flight time is in and out of SNA.

Sunrise doesn't solo student pilots until they've completed practical spin training in the Decathlon. It's a unique and -- in my opinion -- invaluable characteristic of that FBO.

I could write a book about this, but spin training is important. People are afraid of the unknown -- that's just a human characteristic. If you've never experienced spins, you'll be wary of them. You won't be comfortable with stalls. Or high angles of attack, and we all have to fly at high AOA as part of every takeoff and landing. My theory is that this plays a factor in loss of control accidents on landing... but that's for another post.

You definitely have to bring your A game when flying at John Wayne Airport. Two closely spaced parallel runways with heavy airline traffic, helicopters, warbirds, aerobatic planes, and a lot of student activity, plus a prevailing wind that pushes the wake turbulence toward the smaller runway. But if they're trained properly, it's entirely possible for students to fly there. And it turns them into excellent pilots with the skills and experience to fly anywhere.

--Ron

 

[jrs14855]

Sunrise Aviation

Forgot to mention that Sunrise has an excellent video showing various bank angles etc on practice turn backs in a 172 at some remote dirt strip.
There was one successful off airport landing at John Wayne. Cherokee 140 with instructor landed on a wide city street with no damage to airplane.
For an education in energy management find a video of Bob Hoover in the Shrike Commander. Ten ft. off the ground at Vne, feather both engines and do a loop, four point roll and landing. He usually had the announcer stand on the taxiway and stopped with the announcers hand on the nose of the airplane. There is also video of him pouring ice tea while doing a aileron roll.

 

[skylor]

Spin Training, Spin Awareness, Rudder Control-

I learned to fly there. I also taught there for many years, especially tailwheel and aerobatic courses. I'd say a third of my 10,000 hours of flight time is in and out of SNA.

Sunrise doesn't solo student pilots until they've completed practical spin training in the Decathlon. It's a unique and -- in my opinion -- invaluable characteristic of that FBO.

I could write a book about this, but spin training is important. People are afraid of the unknown -- that's just a human characteristic. If you've never experienced spins, you'll be wary of them. You won't be comfortable with stalls. Or high angles of attack, and we all have to fly at high AOA as part of every takeoff and landing. My theory is that this plays a factor in loss of control accidents on landing... but that's for another post.

You definitely have to bring your A game when flying at John Wayne Airport. Two closely spaced parallel runways with heavy airline traffic, helicopters, warbirds, aerobatic planes, and a lot of student activity, plus a prevailing wind that pushes the wake turbulence toward the smaller runway. But if they're trained properly, it's entirely possible for students to fly there. And it turns them into excellent pilots with the skills and experience to fly anywhere.

--Ron

I took the Sunrise basic aerobatic course and flew their D's and Super D on solo aerobatic flights for a period of time (and even flew with you once ). In my opinion, one of the main values of spin training and aerobatic practice, particularly low speed vertical maneuver's such as Immelmanns in a lower powered plane, is to learn instinctive, correct rudder and elevator usage at high alpha and stall/incipient spin stages of flight.

I've seen a number of videos, and even witnessed in real life, failed turn back's or stall spin accidents where it is quite obvious that incorrect rudder usage is being made from the very start of the turn and no reduction of angle of attack or anti-spin rudder input is being made when the plane is clearly beginning to stall and "auto-rotate". This tells me that many pilots are simply not learning to use the rudder correctly and have not developed any natural instinct to stop the stall and/or spin before it fully develops in the first place. In one particular video of a fatal failed engine out turn-back, the plane goes from a straight out climb into a bank and immediate spin in a single fluid motion! Another accident report has an RV6 turning back after engine failure and entering a 7 turn spin from 800'. And this with a golf course straight ahead!

Skylor

 

[ronrapp]

Improper rudder usage will definitely make a bad day worse. The other thing about RVs is that they develop high sink rates when the angle of attack gets to a certain point. I could see a situation where someone turned back successfully but lacked enough residual energy to round out and flare. Might not sound too bad, a hard landing, but those can be forceful enough to cause serious injury.

Regarding the golf course, that one I've seen quite a bit. Humans can develop tunnel vision under stress and miss the most obvious things.

I once had a student on a lost-and-diversion exercise circle over a landmark while trying to figure out where he was. His destination was Cable Airport (CCB). The landmark he chose circle while figuring out where he was? Cable Airport. It even said "Cable Airport" in huge white letters right on the taxiway. He circled around it for like 10 minutes while trying to figure out where he was and how he could navigate to Cable Airport. I even had him read the text on the taxiway. He actually said "Cable Airport" without realizing what the words meant. It was surreal.

--Ron

 

[F1R]

Some(if not most) engine failures and loss of thrust after take off events are not instant or complete events. Adding complexity to the human factors is how long does it take to notice and decide that " This thing is not climbing quite right", or "My RPM is 100 low." Following the time elapsed in recognition that there is a problem and the decision to return or land, the power loss decays further or may become complete.

 

[ronrapp]

Very true. I've had a few partial engine failures (single cylinder gone bad, partial blockage of the fuel filter, etc), and it can be a complex decision-making process. If you've got SOME power and the engine is still running, there are multiple options. Do I make a 180 and land? Make a precautionary off field landing somewhere straight ahead? Can I hold altitude well enough to fly the pattern? Is the engine going to keep running this way or completely stop? Should I take any time to troubleshoot?

It's best to train the way we fly, but not many light GA powerplant failure training scenarios involve anything except a total, instantaneous failure of the engine.

--Ron