VIDEO: Testing the urge of attempting the Impossible Turn after Engine failure on takeoff

[challenger_nami]

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Informative Video by AOPA’s Air Safety Institute testing the viability of the 180 degree Turn following an engine failure to land on the runway the aircraft just departed from, AKA the Impossible Turn.

VIDEO: https://youtu.be/dFVFKq3QqXo

Aircrafts tested:
. Piper PA18 SuperCub with one pilot, Full Fuel
. Van’s RV-4 with one pilot, Full Fuel
. Cessna 172N with one pilot, Full Fuel
. Beech Bonanza A36 with one pilot, Full Fuel, PLUS one large male passenger, and PLUS 40 pounds of cargo.

The Bonanza’s loading configuration is the most realistic in my opnion. Would be great if the other 3 aircraft were tested with the same payload to get more scientifically accurate results. <<<< Added: For the sake of those flying with family and friends.


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The following video shows the potential outcome of a failed attempt at the impossible turn:

VIDEO: https://youtu.be/VJAFXLYl2NU
Beechcraft Bonanza crashes just short of the Airport fence, after engine failure on take off and attempting the impossible turn.
Pembroke Pines Florida, 15 March 2021.

Fatalities: 2 occupants of the aircraft . PLUS an innocent 3 year old on the ground who later died in the hospital . He was the passenger of the car that was hit by the aircraft.
Injuries: The driver of the car mentioned above: mother of the deceased 3 year old above.



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[photofly]

If you fly your cub or 172 solo, what’s inaccurate about the results presented?

[StudentPilot]

They should have all been tested at MTOW.

[digits_]

Any idea why they decided on 45 degree bank? They seem to play with other variables, but the 45 degree bank for the turn seems fixed. Is there some reasoning that makes this the most efficient bank angle?

[photofly]

It’s very close to optimal, and it’s easy to recognize. Curiously, the Bonanza pilot never actually seemed to maintain 45 degrees. I wonder if that’s just an artifact of which few seconds of video they included, or whether it contributed to his result.

http://www.campbells.org/BIG_FILES/airp ... leTurn.pdf

I believe it’s a standard result that faster aircraft need more altitude to turn back. Perhaps a more fair comparison between the cub and the bonanza is to consider a failure after x seconds of climb, rather than at some fixed altitude.

Thus, the optimum speed for minimum loss of altitude in a gliding turn to a new heading occurs for CLmax, i.e., at the stall velocity.
Neglecting the small density change with altitude, the second term, 4W/ρSg sin 2φ, is a minimum for sin 2φ = 1 or φ = 45◦, i.e., the optimum bank angle during a gliding turn to a new heading is 45◦.

[challenger_nami]

They should have all been tested at MTOW.

I fully agree.

Any idea why they decided on 45 degree bank? They seem to play with other variables, but the 45 degree bank for the turn seems fixed. Is there some reasoning that makes this the most efficient bank angle?

For Most pilot training standards, PPL and CPL, steep turn is a maximum of 45 degrees of bank. you bank more than 50 degrees, and you potentially fail your check-ride.

Also, you risk a spiral at more than 45 degrees... if you don’t know what you are doing.

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[digits_]

It’s very close to optimal, and it’s easy to recognize. Curiously, the Bonanza pilot never actually seemed to maintain 45 degrees. I wonder if that’s just an artifact of which few seconds of video they included, or whether it contributed to his result.

http://www.campbells.org/BIG_FILES/airp ... leTurn.pdf

I believe it’s a standard result that faster aircraft need more altitude to turn back. Perhaps a more fair comparison between the cub and the bonanza is to consider a failure after x seconds of climb, rather than at some fixed altitude.

I think the main question first should be: why do you need to make the turn back right after takeoff? If the only viable option is the departing runway, then that makes sense. But if the bonanza needs to reach 2000 ft before it can make it back to the runway, surely there are other good options available. The current analysis makes it seem like the bonanza performs the worst of the planes, while in reality it probably has the most choice for a forced landing spot, although the departing runway might not be one.

[2R]

A. Steep Turns
FAA-H-8083-2, FAA-H-8083-3; POH/AFM
The applicant demonstrates understanding of:
Purpose of steep turns.
Aerodynamics associated with steep turns, to include:
a. Coordinated and uncoordinated flight
b. Overbankingtendencies
c. Maneuveringspeed,includingtheimpactofweightchanges d. Load factor and accelerated stalls
e. Rate and radius of turn
The applicant demonstrates the ability to identify, assess and mitigate risks, encompassing:
Failure to divide attention between airplane control and orientation.
Collision hazards, to include aircraft and terrain.
Low altitude maneuvering including, stall, spin, or CFIT.
Distractions, improper task management, loss of situational awareness, or disorientation. Failure to maintain coordinated flight.
The applicant demonstrates the ability to:
Clear the area.
Establish the manufacturer’s recommended airspeed; or if one is not available, an airspeed not to exceed VA.
Roll into a coordinated 360° steep turn with approximately a 50° bank. Perform the Task in the opposite direction.
Maintain the entry altitude ±100 feet, airspeed ±10 knots, bank ±5°, and roll out on the entry heading ±10°.
Objective
To determine that the applicant exhibits satisfactory knowledge, risk management, and skills


FAA commercial standards require 50 degree bank turns . 45 degree steep turns are for private pilots and recreational pilots .

If you cannot control the wing loading in a turn do not attempt a turn around . Cranking and banking low level is a very special skill set not taught to private students . I was very lucky I learned to fly in an aerobat . Second flight was loops and barrel rolls

[challenger_nami]

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I stand corrected

So FAA does not require their pilots to learn spins and how to recover from them, but make them pilots bank 5 degrees more than what we do up here. I got it.

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[photofly]

I think the main question first should be: why do you need to make the turn back right after takeoff? If the only viable option is the departing runway, then that makes sense. But if the bonanza needs to reach 2000 ft before it can make it back to the runway, surely there are other good options available. The current analysis makes it seem like the bonanza performs the worst of the planes, while in reality it probably has the most choice for a forced landing spot, although the departing runway might not be one.

I do agree that a decision about what the most sensible course of action is, very much depends on what you see out of the window: a flat grass meadow ahead to land in is a very different scenario to having to ditch into Toronto harbour in February.

It's also not always necessary to make it back to the runway per se - a 180 might not get you back to the tarmac but it will put you into the airport infield which is a lot nicer and flatter and quicker for ARFF to reach than the built-up areas surrounding many urban small airports.

The Transport Canada PPL flight test standards are for no more than ±10° of deviation from the target 45°, but you don't automatically fail until you reach double the deviation, so you could in theory reach nearly 65° or as little as 25° bank during a steep turn demonstration and still pass the exercise.

Also, you risk a spiral at more than 45 degrees... if you don’t know what you are doing.

I think the key here is that turning back towards the runway is not a manoeuvre that should be attempted for the first time in a real emergency. I think all PPL students should get some practice at it - first at altitude, then in a runway environment, to understand what is, and what is not feasible. Steep turns at 60° of bank are a great exercise too. Beware of reaching 60.1° though - that would be considered aerobatic, and therefore forbidden.

[digits_]

I agree, but I was trying to point out something else. Let me rephrase. Eventually the pipercub which could make the turn back at 200ft, will reach a point where it can not make the runway anymore simply because it is flying away from the airport. At that point, the bonanza might have more options for a safe forced landing, due to its higher speed.

To judge the safety of an airplane or a flight, we shouldn't just focus on those first couple of minutes, but at the flight as a whole. Which makes me wonder what the goal of the researchers was. If it is just a nice test, so be it, it certainly was interesting.

[photofly]

I agree, but I was trying to point out something else. Let me rephrase. Eventually the pipercub which could make the turn back at 200ft, will reach a point where it can not make the runway anymore simply because it is flying away from the airport. At that point, the bonanza might have more options...

It depends what you mean by "at that point" -

"at that point in time": by the time the cub has climbed 200'' the bonanza has climbed 400' and may have more options.
"at that point in space": comparing both at 200' agl, the cub has more options.

You're right in that considering only whether to turn back may be unreasonably obsessing about the chance of losing power in the first minutes of flight vs the chance of losing power over any other two minutes of flight. But, later in the flight the pilot has the psychological comfort of being able to say "well, it has run fine so far, so I'm not worried about the next two minutes". It may be (or may not be) that loss of power right after take off is more likely than at any other time during the flight.

[RedAndWhiteBaron]

I have a new perspective on the impossible turn recently. As part of my return to soaring, I did some rope break training, the scenario being that your tow rope breaks shortly after takeoff - a not altogether scarce occurrence with new pilots, who tend to put a lot of stress on the rope while maneuvering behind a tug at low altitudes.

It's a standard part of glider training in Canada, although I'm not sure if it's legally required. The FAA however, does expect glider pilots to demonstrate a turnback from 200' AGL, I think.

In every case, I did not land on the original runway. I departed from runway 14 and landed on runway 35, making it a roughly 220° right turn, but without the need to turn left again for runway 32.

The turnback itself was easy enough; it's a glider, after all, and it never had an engine to begin with. What really threw me for a loop though was the subsequent downwind landing. I'm guessing I was landing with a 10kt tailwind. The plane could make the impossible turn safely enough, but without a full rudder, full airbrake/spoiler sideslip down to 50'AGL or so, I would have overshot the runway. And the visual perspective of just... not... sinking due to the tailwind is quite unsettling.

It's not just the turnback - landing with a 50% higher groundspeed is also something that can take you by surprise, at least in my case.

[PA32pilot]

Too many things to factor in such a short time eg. wind direction and velocity and trouble shoot.

[‘Bob’]

An aircraft like the Bonanza won’t be successful not because of the altitude.. but the turn radius and track miles. With the gear up and prop coarse it almost certainly glides better than a 172. Heck my King Air if you feather the props does 17:1.

But all of that advantage is lost if it takes you a mile just to maneuver.

Let’s assume 45 degree bank and 1.3 Vs.

Cessna 172

Vs 47 knots.

Safe speed in 45 degree bank: 73 knots.

Track distance for 360 degrees of turn: 2759 feet.

Baron A36

Vs 62 knots.

Safe speed in a 45 degree bank: 97 knots.

Track distance for 360 degrees of turn: 5260 feet.

It doesn’t matter how well the plane glides if you have to eat up almost twice the distance to maneuver.

[pelmet]

I have a new perspective on the impossible turn recently. As part of my return to soaring, I did some rope break training, the scenario being that your tow rope breaks shortly after takeoff - a not altogether scarce occurrence with new pilots, who tend to put a lot of stress on the rope while maneuvering behind a tug at low altitudes.

It's a standard part of glider training in Canada, although I'm not sure if it's legally required. The FAA however, does expect glider pilots to demonstrate a turnback from 200' AGL, I think.

In every case, I did not land on the original runway. I departed from runway 14 and landed on runway 35, making it a roughly 220° right turn, but without the need to turn left again for runway 32.

The turnback itself was easy enough; it's a glider, after all, and it never had an engine to begin with. What really threw me for a loop though was the subsequent downwind landing. I'm guessing I was landing with a 10kt tailwind. The plane could make the impossible turn safely enough, but without a full rudder, full airbrake/spoiler sideslip down to 50'AGL or so, I would have overshot the runway. And the visual perspective of just... not... sinking due to the tailwind is quite unsettling.

It's not just the turnback - landing with a 50% higher groundspeed is also something that can take you by surprise, at least in my case.

That can happen. I used to rent a Piper Sport and there was a case at the school where the turn back after an engine failure resulted in an overrun.

One should be ready in an engine failure scenario to use very large amounts of sideslip to get down to the desired touchdown point. This may be more likely straight ahead on remaining runway or possibly on a turnaround.

[scdriver]

My instructor made me do the old impossible turn back when I was doing my ppl. In a 172 with 2 guys on board, made it back to the departure rwy with lots of room to spare from 6-800 ft agl. IMO I think it’s something that should be demonstrated and practiced during flight training, especially for cpls and probably for ppls as well if they have the skill

[challenger_nami]

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The surface winds can make a big difference:

If you have 20 knots straight headwind on takeoff, then you will have 20 knots of tailwind helping you get back to the field during and after you make the turn.

If the wind was relatively calm at let’s say 5 knots, then you won’t have that helping tailwind assisting you get back to the field.

The opposite holds true for tailwinds and That is why tailwind takeoffs are a bad idea, IMAO. Not because you or your airplane can not handle them in most cases, but because when Sh*t hits the prop, that wind can make the difference between life and the alternative.


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[pelmet]

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The surface winds can make a big difference:

If you have 20 knots straight headwind on takeoff, then you will have 20 knots of tailwind helping you get back to the field during and after you make the turn.

If the wind was relatively calm at let’s say 5 knots, then you won’t have that helping tailwind assisting you get back to the field.

The opposite holds true for tailwinds and That is why tailwind takeoffs are a bad idea, IMAO. Not because you or your airplane can not handle them in most cases, but because when Sh*t hits the prop, that wind can make the difference between life and the alternative.


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There are a lot of variables including length of runway, aircraft type, weight, etc.

[bodyflyer2]

Any idea why they decided on 45 degree bank? They seem to play with other variables, but the 45 degree bank for the turn seems fixed. Is there some reasoning that makes this the most efficient bank angle?

Various aerodynamics calculations established that pretty clearly, as best I can tell. For example, around the 1990s there were journal papers and articles written by aerospace engineering professors like John T. Lowry or David F. Rogers, who calculated the 45 degree angle as being near optimal. The number does vary with factors like stall speed and can be slightly above 45, but for piloting purposes 45 degrees is what one wants to remember.

[Big Pistons Forever]

What should be: Every time a pilot experiences an EFATO he/she immediately transitions to the correct optimal pitch attitude and then smoothly enters a coordinated steep turn back to the runway, effectively managing the flight path right to touchdown

What is: The shock of the power loss results in a significant delay in establishing the glide attitude leaving the airplane slow. A rushed turn is not fully coordinated and then the ground rush causes the pilot to unconsciously pull back on the wheel.....then the airplane stalls, departs controlled flight and hits the ground in a steep nose down attitude which usually results in fatalities

The accident record shows the turn back is 8 time's more likely to result in an fatal accident than just gliding straight ahead and taking your lumps

There is no way to safely train for this maneuver and IMO practicing it at altitude in the practice area is negative training.

Re glider flying. On the glider I usually fly a rope break at 200 feet AGL means that the flight time to touchdown after a turn back is about the same as it would be for a C 172 or equivalent to have an engine failure at 1000 ft AGL. You are also in a better position because you will be to one side of the runway at 200 ft AGL and so unsurprisingly it is not a particularly demanding maneuver in a glider.

[photofly]

There is no way to safely train for this maneuver=

That's a bold statement, indeed.

I had a completely unexpected power stumble a couple of minutes after takeoff a few months ago, and I had the nose down in a coordinated 45° bank within a couple of seconds. I have it on video. My quick reactions are probably worse than the average person's.

The shock of the power loss results in a significant delay

Well, no, not if you're prepared for it. That's the point of training. But, even if it does take a pilot a few seconds to achieve the appropriate pitch and bank, that doesn't invalidate the manoeuvre.

I actually believe you can, and should - perhaps even must - train for it. I don't know if it's a demanding manoeuvre in a glider, but it's definitely undemanding in a C172.

[Big Pistons Forever]

I actually believe you can, and should - perhaps even must - train for it. I don't know if it's a demanding manoeuvre in a glider, but it's definitely undemanding in a C172.

You can’t train for the shock of a sudden loss of power near the ground and you can’t train for ground rush unless you actually do a low altitude turn back for real which IMO is situation where the actual danger far exceeds the training value.

I have 16 years of experience flying the bird dog and fire bomber. I am use to working close to the ground at high bank angles. That experience has heightened my respect for the dangers of low altitude maneuvering, not diminished it.

That been said there is absolutely a need for good training in dealing with the EFATO. That training should be built around the importance of having a plan of where you are going to point the airplane in the event of an EFATO, including an admonition to avoid the turn back below a target altitude ( 1000 ft AGL for a low time pilot) and that the first action in the event of a EFATO will be a positive pitch down including actually pushing the wheel forward as the action is verbalized to build muscle memory.

Sadly the accident statistics are pretty clear, too many turn backs end in the stall-spin-die trifecta.

[photofly]

You can’t train for the shock of a sudden loss of power near the ground and you can’t train for ground rush unless you actually do a low altitude turn back for real which IMO is situation where the actual danger far exceeds the training value.

Respectfully, I don't agree. We experience approaching the ground in low altitude power-off manoeuvring every time we practice a forced approach to land from the circuit.

A low altitude turnback for real is a very straightforward and safe manoeuvre and every pilot should do it as part of their PPL training, if circumstances permit. Even if it's not possible to complete a landing, the turn can be flown down to a couple of hundred feet above the ground at which point it is very clear whether a safe touchdown would have been achieved or not.

I also disagree that the yoke needs to be pushed forward, or that it should be trained as such. If the aircraft is trimmed correctly and flown in trim, the nose will drop on its own, and it should be permitted to do so. Thereafter It will need positive back pressure and very very significant nose up trim to avoid overspeeding and excessive loss of altitude.

The key is to learn the correct pitch attitude (and therefore horizon position) for the manoeuvre at hand, and not to teach "pushes" or "pulls".

Whether you should turn, and if so at what altitude, would form part of a pre-takeoff briefing, which is an important part of avoiding a tendency to freeze or grab at the controls. If the pilot has such a tendency to freeze and become a passenger in his or her own airplane then they need better training. The details of minimum altitudes, direction to turn would depend entirely on things like the winds and environment around the runway in use; it's a bit useless trying to give advice without that knowledge.

[‘Bob’]

You can’t train for the shock of a sudden loss of power near the ground and you can’t train for ground rush unless you actually do a low altitude turn back for real which IMO is situation where the actual danger far exceeds the training value.

Respectfully, I don't agree. We experience approaching the ground in low altitude power-off manoeuvring every time we practice a forced approach to land from the circuit.

About as comparable as rolls at 3000 feet vs surface level vertical aerobatics.

A low altitude turnback for real is a very straightforward and safe manoeuvre and every pilot should do it as part of their PPL training

No... it’s not. And no... they shouldn’t.

I also disagree that the yoke needs to be pushed forward, or that it should be trained as such. If the aircraft is trimmed correctly and flown in trim, the nose will drop on its own, and it should be permitted to do so. Thereafter It will need positive back pressure and very very significant nose up trim to avoid overspeeding and excessive loss of altitude.

Sure it will...... eventually. By the time it does, vital airspeed will be lost while it continues to climb. Potential energy, it has to come from somewhere and it sure ain’t the engine.

Now you have to sacrifice even more altitude to get airspeed back. No.. ...push forward.. right away. It doesn’t matter to where as long as it is a nose down attitude. The correct attitude is preferable, but anything is better than what you suggest. Try your method on a Vx climb out and you’re going to be in for a huge surprise.


I agree with Big Pistons Forever. This is far too complex and risky to be taught. PPLs have enough trouble with regular forced approaches. Time would be better spent improving those. Land straight ahead... ...and live.