Engine failure turn back.

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Vigilant1

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11 (11%) 21 U-FIT LOTOT Loss of Thrust On Takeoff, stall then spin.
12 (22%) 42 U-FIT Loss of speed Aw. Flight below DMMS not on takeoff results in stall, spin.
Airplanes don't stall because they lose thrust. Power loss does set up a situation that requires action (get the nose down!), but it doesn't cause stalls or spins.
In the terminology favored by this author, his Category 11 and Category 12 should, for consistency, both be categorized as resulting from "flight below DMMS."

I can see the utility of the DMMS ("defined minimum maneuvering speed" ) concept, and it is certainly an improvement over relying on Vs. Very suitable for airline use, or here-to-there GA flying. But it does mask the fact that, fundamentally, stalls are dependent only on AoA, not airspeed (or bank, or thrust, or weight, etc).
 

Hephaestus

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Airplanes don't stall because they lose thrust. Power loss does set up a situation that requires action (get the nose down!), but it doesn't cause stalls or spins.
In the terminology favored by this author, his Category 11 and Category 12 should, for consistency, both be categorized as resulting from "flight below DMMS."

I can see the utility of the DMMS ("defined minimum maneuvering speed" ) concept, and it is certainly an improvement over relying on Vs. Very suitable for airline use, or here-to-there GA flying. But it does mask the fact that, fundamentally, stalls are dependent only on AoA, not airspeed (or bank, or thrust, or weight, etc).
I don't like a lot of what he preaches, or infers... But the Dmms makes sense to me - it's very much a safe fallback position that's easy to reference. With the quality of instructors today - it suits a purpose,
 

BJC

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Having a DMMS masks the issue, especially for sport flying.

Learning one’s airplane allows a pilot to feel (at least in most airplanes) proximity to stall without reference to an AoA indicator, ASI or stall alarm. The benefit of learning spins to lessen the number of stall-spin fatalities is not in learning how to recover from an established spin, rather it is in learning how to recognize an impending spin and take immediate action to avoid the spin.


BJC
 

mquinn

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So to put ridiculous to the extreme - do an outside loop and an aileron roll at the end.... (given enough altitude and correct wind - I might be able to do it in the chaos... but I would really have to channel my inner Bob Hoover before attempting!!!)

I think the KEY to even THINKING about doing anything other than a straight or 45 degree option on takeoff is "have you enough experience in THAT particular aircraft to pull that maneuver off". I practice this at 4000 ft away from an airport a few times a year (not the outside loop thing... the "impossible turn" - I have a set of powerlines that I do aerobatics over as alignment gauge) with various wind conditions. I know what _I_ am capable of doing safely and how much altitude I loose in my various planes. It is in the back of my mind on every takeoff. When I am at an airport that I am less familiar with -- those turn back numbers go way up! With all the construction and changes in the world - the last thing I want to do is stall spiral into an orphanage that is located right off the field...
 

BJC

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So to put ridiculous to the extreme - do an outside loop and an aileron roll at the end.
The only aerobatic maneuver that, at least the first few times for me, felt really weird was a push down outside loop. I’ve never done one from less than about 1,200 feet; it must be really weird at low level.

Push ups seem normal, even the back half.

Yup, knowing your airplane and mastering the turn back at altitude before working down to minimum altitude / airspeed is essential.


BJC
 

Fanhead

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For most airplanes, there is an altitude at which something like a teardrop turn back to the runway to land opposite-direction could be safely flown. Every pilot should have an idea of what that altitude is for the airplane he or she is flying, and think about it for every takeoff. Below xxx' altitude, land ahead with turns of no more than 30 degrees. Above yyy' altitude, a teardrop return to land opposite-direction is possible. Above zzz' turn to downwind, and make a landing in the direction of traffic. Remember that you may not need to take that particular downwind all the way to the numbers before turning base, as long as there's enough runway to stop after landing. Airspeed considerations with engine out is super important. I would not recommend teaching a student to turn back to the runway with the stall warning active. Better to fly L/D max, (and if you err, err on the fast side) - it gives you the best distance to glide and preserves a little speed for a flare at landing. If your flying a tail dragger, remember they don't like landing with tail wind, so an opposite-direction landing could be less than ideal.
 

tallank

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Exactly.

In my case, glider training was done by people who were paid by the government (military), which also provided the hardware. So, the training rules and procedures were fairly rigid and uniform throughout the country. Until the mid-1980s, joining an aero club was free, as was glider training. As the military was tightening the budgets (amid the political turmoils of the late 1980s in the Balkans), the clubs started charging for glider training, but it was still fairly cheap. We got a lot of winch launches/landings (about 15 per hour), which rapidly built stick&rudder skills.

Back on the subject, the 180º turn was for a fairly narrow set of cases, but it was available. Blaník does have spoilers, which significantly increase rate of descent, and which you would usually deploy on your final approach, so once you're lined up with the runway after that 180º turn, the speed brakes would quickly get you down well before running out of runway (even with a strong tailwind). Another minor benefit of such a landing is that the glider is then neatly positioned for the next launch (once the winch team completes the splicing of the cable, that is, which usually took 45 minutes...).
180 degree turn does not get you lined up with the runway. You are offset from it. Takes two 90 degree turns to get lined up with the runway. Bottom line, it takes 360 degree of turns to get back to the runway.
 

tallank

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Flying the greatest distance is not the objective: positioning the aircraft for a return to the runway is the objective, and what we are discussing.
Why? Spinning is the result of stalling in uncoordinated flight.
I wasn't aware of that statistic. Can you provide a citation?

According to the FAA, most stall-spin fatalities occur from the turn to crosswind on takeoff.


BJC
I am aware that more spins accidents happen on takeoff than engine out turn arounds. The fact is that there are more takeoffs than engine outs on takeoff. Just pay attention to the news and you will be shocked of how many engine out return to airport end in fatal spins. One take away from this, do no takeoff at VX.
 

Vigilant1

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For those pilots concerned about climbs at Vx, I'd urge you to get some altitude, apply full power, pull the nose up to attain Vx, reduce power to idle, practice pushing the nose over to keep the wing flying and attain a "best glide" attitude. Obviously, do this only if you are comfortable with it, and with stall recoveries. In the planes I've flown there is plenty of time to get the nose down before the airspeed degrades to Vso. More importantly, Vso isn't relevant once you unload the wing sufficiently by pushing forward on the stick/yoke. When you unload the wing any imminent stall will cease well before you've regained any airspeed. Vso applies to 1g conditions. Get light in the seat and your "stall speed" (giggle) is less than Vso.
Promptly recognizing the loss of engine power and then acting to keep the wing flying by lowering nose is critical, regardless of the chosen climbout speed.
 
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rick9mjn

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180 degree turn does not get you lined up with the runway. You are offset from it. Takes two 90 degree turns to get lined up with the runway. Bottom line, it takes 360 degree of turns to get back to the runway.
To the poster of post #108...Please go to a club glider field , and go for 2 flights , one being a standard , demo flight , and one being a simulated rope break . One reason for doing is to meet some nice people at the glider club. And the other is to learn something. About doing a turn back to the runway, after take off. The main thing you will learn ,if a turn back is a safe, thing to do. If you do the turn back correctly....


good day / rick
 

PredragVasic

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180 degree turn does not get you lined up with the runway. You are offset from it. Takes two 90 degree turns to get lined up with the runway. Bottom line, it takes 360 degree of turns to get back to the runway.
I'm not sure you understood correctly. The 180º turn after the winch launch cable snap implies a teardrop turn, where you essentially make a U-turn, in the direction of the crosswind component, and land on the same runway downwind. We have already discussed the teardrop turn before, and it is also commonly (albeit a bit imprecisely) called a 180º turn. Technically, it would probably be a 210º turn, followed by an opposite 30º turn, if I were to pick nits or split hairs...

But even that wouldn't be quite that precise, since the crosswind component might require shortening that 210º turn to perhaps 200º or even less, as well as reducing the subsequent turn from 30º to 20º or even less. And if the crosswind is strong enough, a 180º turn may well be enough to return to the runway in the opposite direction...
 

Hephaestus

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My experiences practicing - pretty much mirrors scott purdue's findings on his bonanza. My skills might be a bit weaker, and I'm always practicing tanks full - because that's normal takeoff for me. If I'm not making the asphalt - There's no reason for me to turn back. No emergency services onsite. Farmer Joe's field is no worse than the back 40 at the airport. At pattern altitude - I can definitely make it, below - I'll take the extra time to prep for off field properly.
 

Pilot-34

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Answering the question does not require any experience. It requires reading the research that has been done on the topic by astronauts and ATPs with phds
Lol
Just exactly why is a PhD required to answer that question?

In flying that PhD is going to have zero value at all.
Set two airplanes at the terminal in side by side gates.
Passengers have their choice of plane A or plane B.
Plane A a has a little sign on it that Captain Pete Smith will be flying this plane , he has flown the same route for 20,000 hours.
Plane B has a little sign that says Captain Bob Smith who graduated this morning with a PhD in flying but has never actually seen an airplane before will be flying .
Which plane do you think is going to fill up first?
 
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Pilot-34

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The mitigating factor is you *don't* have to land back on the runway. In a true engine failure, it is still a "win" if you put it down on a nice flat space on the airfield - there's a lot of area that isn't technically the runway.
A Technicality that many pilots get hung up on.
 

BJC

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I am aware that more spins accidents happen on takeoff than engine out turn arounds. The fact is that there are more takeoffs than engine outs on takeoff. Just pay attention to the news and you will be shocked of how many engine out return to airport end in fatal spins. One take away from this, do no takeoff at VX.
Vx is useful for clearing obstacles on shorter runways. That doesn’t mean that, once the obstacle has been cleared, the pilot should continue at Vx. Most of us will transition to Vy after clearing the obstacle.

Note, also, that some aircraft have a considerable airspeed margin between Vx and stall, so a loss of power doesn't present an immediate stall hazard. See post #66. Still, airspeed management is important because Vx and lower is below best glide sp


BJC
 

BJC

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My experiences practicing - pretty much mirrors scott purdue's findings on his bonanza.
Hep, did Scott pull out the propeller control to low RPM? I don’t do it in my airplane when turning at minimum altitude, but it makes a difference in the glide angle in my airplane, and I would expect that it would in most GA aircraft. His leisurely turn left an opportunity to reset the propeller to improve his long trip back to the airport.


BJC
 
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PredragVasic

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I’ll just exactly why has a PhD required to answer that question?
If you look at the text you quoted, it isn't talking about flying; it is talking about research that has been done on the topic in question. A PhD in the subject field may well be very useful in figuring out the aerodynamic forces and kinetic energy, how they interact and affect the performance in an aircraft, and how this applies to an emergency. Nobody here was suggesting putting a random PhD at the controls of an airliner.

An experienced pilot with 20k hours may have never experienced engine-out emergency (very unlikely, but possible), and the only thing that would help him make the correct decision is recent enough training. Now, if such a pilot has gone through dozens of such emergencies, (s)he may well have extensive experience to rely on.

I don't have many hours of fight time, but about two of them were in a glider, almost all of it on winch launches. In those two hours, I have experienced at least five simulated and one real cable snap emergency (roughly equivalent to the loss of thrust on take-off in a powered aircraft). In a very short time, I'd like to think I have developed a pretty solid proper response for such a situation. Not every pilot goes through such training, though.
 

Hephaestus

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Hep, did Scott pull out the propeller control to low RPM? I don’t do it in my airplane when turning at minimum altitude, but it makes a difference in the glide angle in my airplane, and I would expect that it would in most GA aircraft. His leisurely turn left an opportunity to reset the propeller to improve his long trip back to the airport.
Haven't watched the video in a couple years. I know in my practicing we went full fine to exasperate the drag - practice worst case scenario - not best.
 

Vigilant1

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IIRC he said he didn't change pitch. This was to partially compensate for leaving the engine at idle (vs shut down). So, not best glide he could get at idle, but a better analogue to a dead engine.
 
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