Engine failure turn back.

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PagoBay

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Here is a new initiative that addresses how to answer this question with more confidence and help make the Turnback Decision fit your aircraft and local conditions. May have been in an earlier post in this thread but worth a repeat IMHO.

Takeoff Advisor
Takeoff Advisor is a pre-flight planning tool, in development, intended to help a pilot understand the best options in the event of a loss of power on takeoff.


EAA WEBINAR EXPLAINS THIS PROCESS - LINK
EAA
 

Pilot-34

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My point is that academics don’t really matter. What we’re looking at in the situation is reality. Not the calculated wannabes or the formulaic should have beens.

you can have all the academics you want write the book but that book better be based on the real world flying of experienced pilots.

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.
 

Pops

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I had an engine out on take-off in my Piper Cherokee at about 50'. Nose hard down and at the same time full flaps. Got it down and stopped before another intersecting runway on the 5500' long runway. A few feet off the end of the runway was a 200' drop, 45 deg hill down to a river. One of the reasons why I NEVER do an runway intersection takeoff even if ask.
 

BJC

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My point is that academics don’t really matter.
It is a solvable academic problem, but it is much more complex than the simplistic approach taken in the paper. See my previous comments on the stated objective and artificial constraints in the paper.


BJC
 

David L. Downey

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I had an engine out on take-off in my Piper Cherokee at about 50'. Nose hard down and at the same time full flaps. Got it down and stopped before another intersecting runway on the 5500' long runway. A few feet off the end of the runway was a 200' drop, 45 deg hill down to a river. One of the reasons why I NEVER do an runway intersection takeoff even if ask.
wasn't it Bob Hoover that is quoted as saying "there in nothing worth less than the runway behind you and the air above you?"
 

Pilot-34

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It is a solvable academic problem, but it is much more complex than the simplistic approach taken in the paper. See my previous comments on the stated objective and artificial constraints in the paper.


BJC
Perhaps you are right , however I see it as needing a well educated butt.
When That engine quits on departure you’re not likely to be able to measure how rough the bugs are on your wings in the state of dirt wax and polish the engine drag creating propeller drag the exact centers of these references relative to the center of gravity and drag on your aircraft and all the other requirements to reduce it to an academic paper.
Nope at that moment you need a well educated seat of the pants result.
As the Captain Sully accident taught us A return to the field can be possible but not doable.
 

Vigilant1

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wasn't it Bob Hoover that is quoted as saying "there in nothing worth less than the runway behind you and the air above you?"
The way I've heard it most often:

The three most useless things in aviation:
Runway behind you
Altitude above you
Fuel you left on the ground
 

Pilot-34

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In another thread we’re discussing a pilot flying under a bridge.
It would seem like in at least that one case altitude above you is a good thing!
 

Pilot-34

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Come to think of it I was once asked to expedite my departure from a runway which I of course did but when my passenger turned around to see what was coming apparently there was a 747 rapidly closing the gap between us.
i’ve always been grateful for the runway behind me at that point and the fact that he did not need to make a go round.
 

mcrae0104

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Best glide speed + and at 60 degrees you will be gaining speed due to the amount of back pressure required trying to maintain your chosen airspeed. This is with gliders and my RV6.
I'm a little late to this discussion. Help me understand what you are saying.

In the ubiquitous 172 as an example, Vy is about 70 kt and Vs1 is about 47kt. At 60 deg bank, stall speed it 1.41 x 47 kts = 66kt. Holding Vy--70kt--is precious little excess airspeed over stall, isn't it?
 

atypicalguy

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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.
I'm sure the people who had started at the sky for 20k hours thought Galileo was wrong also.

I'm guessing 20k hour pilots are not the majority here

Watch the EAA webinar. Then think about what you are saying. Some of those guys flew the Space Shuttle - the ultimate dead stick glider.

Basically some planes, including 172s, will never make it back to the field, no matter how skilled the pilot. There may be some aerobatic guys who can do a super aggressive turn and get back faster than a 45; my CFI claims to be one. But I will wait for you to show me where the drag curve math is wrong before I will be trying anything other than 45 in practice. That paper is not rocket science. You can pick it apart on math grounds, or say you don't understand it. But you dont get to say it is wrong just because you think it is wrong. I know a lot of people who think they are right. This happens to be an area of inquiry that lends itself to empirical analysis
Perhaps you are right , however I see it as needing a well educated butt.
When That engine quits on departure you’re not likely to be able to measure how rough the bugs are on your wings in the state of dirt wax and polish the engine drag creating propeller drag the exact centers of these references relative to the center of gravity and drag on your aircraft and all the other requirements to reduce it to an academic paper.
Nope at that moment you need a well educated seat of the pants result.
As the Captain Sully accident taught us A return to the field can be possible but not doable.
I don't think anyone would argue that pilot experience is irrelevant, but these parameters have never been more measurable. Everyone on this thread should watch the EAA webinar above, go record you airplane's best climb, fly their best attempt at a sharp turn back at altitude, record several attempts in fore flight or whatever app, download the data card from the website above, and fill it out. Then please come back here and post the results for your piloting skills and your airplane. If you send the tracking data to them, they will overlay the kml data on your local airfield for you and tell you if you would have made it back to the field or the runway. That is all. If you can do it better at 60 degrees than 45 because you are an ace acro guy, the data will show that. No guessing or academic papers. Go out and prove it. I am going to ask my CFI to help me try all the options also and will report back.
 

Pilot-34

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I'm sure the people who had started at the sky for 20k hours thought Galileo was wrong also.

I'm guessing 20k hour pilots are not the majority here

Watch the EAA webinar. Then think about what you are saying. Some of those guys flew the Space Shuttle - the ultimate dead stick glider.

Basically some planes, including 172s, will never make it back to the field, no matter how skilled the pilot. There may be some aerobatic guys who can do a super aggressive turn and get back faster than a 45; my CFI claims to be one. But I will wait for you to show me where the drag curve math is wrong before I will be trying anything other than 45 in practice. That paper is not rocket science. You can pick it apart on math grounds, or say you don't understand it. But you dont get to say it is wrong just because you think it is wrong. I know a lot of people who think they are right. This happens to be an area of inquiry that lends itself to empirical analysis

I don't think anyone would argue that pilot experience is irrelevant, but these parameters have never been more measurable. Everyone on this thread should watch the EAA webinar above, go record you airplane's best climb, fly their best attempt at a sharp turn back at altitude, record several attempts in fore flight or whatever app, download the data card from the website above, and fill it out. Then please come back here and post the results for your piloting skills and your airplane. If you send the tracking data to them, they will overlay the kml data on your local airfield for you and tell you if you would have made it back to the field or the runway. That is all. If you can do it better at 60 degrees than 45 because you are an ace acro guy, the data will show that. No guessing or academic papers. Go out and prove it. I am going to ask my CFI to help me try all the options also and will report back.
That’s all fine but if you do that on purpose by yourself one day after washing and waxing your plane you’re going to get a whole different answer than when that thing is loaded past gross with a moose coming out of a mud field with splatters all over it.
 

tallank

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I'm sure the people who had started at the sky for 20k hours thought Galileo was wrong also.

I'm guessing 20k hour pilots are not the majority here

Watch the EAA webinar. Then think about what you are saying. Some of those guys flew the Space Shuttle - the ultimate dead stick glider.

Basically some planes, including 172s, will never make it back to the field, no matter how skilled the pilot. There may be some aerobatic guys who can do a super aggressive turn and get back faster than a 45; my CFI claims to be one. But I will wait for you to show me where the drag curve math is wrong before I will be trying anything other than 45 in practice. That paper is not rocket science. You can pick it apart on math grounds, or say you don't understand it. But you dont get to say it is wrong just because you think it is wrong. I know a lot of people who think they are right. This happens to be an area of inquiry that lends itself to empirical analysis

I don't think anyone would argue that pilot experience is irrelevant, but these parameters have never been more measurable. Everyone on this thread should watch the EAA webinar above, go record you airplane's best climb, fly their best attempt at a sharp turn back at altitude, record several attempts in fore flight or whatever app, download the data card from the website above, and fill it out. Then please come back here and post the results for your piloting skills and your airplane. If you send the tracking data to them, they will overlay the kml data on your local airfield for you and tell you if you would have made it back to the field or the runway. That is all. If you can do it better at 60 degrees than 45 because you are an ace acro guy, the data will show that. No guessing or academic papers. Go out and prove it. I am going to ask my CFI to help me try all the options also and will report back.
There is another way to check the performance of your aircraft for an engine out turnaround. First understand we are not talking about 180 degree turn which results in you being well offset from the centerline of the runway. To get lined up with the centerline requires two more 90 degree turns. So we are talking about a 360 degree turn. Take someone with you and go up to a good safe altitude. On my test flights I went up to 6000 feet. I picked an airspeed that I wanted to do the test at, best glide plus a little, went to idle power and let the aircraft stabilize for a thousand feet and started a 360 degree turn at 5000 with a selected bank angle. My passenger noted the altitude at the completion of the 360 degree turn. I repeated the whole procedure for 20, 30, 45, and 60 degree bank angles. My numbers altitude loss for my RV6 at 90 kts were 1100 ft, 1000ft, 900 ft, 750ft. As a side note, I could not hold a steady airspeed at near 60 degree bank. I ended up around 110 kts. My self imposed minimum turnaround altitude is 1000 ft.
 

Wolfen1176

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One other thing to consider when practicing this maneuver is that an engine at idle power is still producing some thrust all be it very little. Much different than a windmilling prop which robs energy or a dead prop which might as well be a speed brake.
 

BJC

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My CS prop, at idle, produces more drag at high RPM pitch (as it would be set for takeoff and initial climb) than it does at idle and set for low RPM.

When I practice low altitude return to the runway turns, I leave the propeller set to high RPM. I need the drag to avoid landing too long. As soon as I complete the turn, I add full flaps and full rudder slip.

From higher than minimum altitudes still in the traffic pattern, the propeller typically will be set for 2,600 RPM. If I need maximum glide, I pull the propeller control to minimum RPM.

Note, also, as previously discussed, a stopped prop has less drag than a windmilling prop.


BJC
 

Vigilant1

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There is another way to check the performance of your aircraft for an engine out turnaround. First understand we are not talking about 180 degree turn which results in you being well offset from the centerline of the runway. To get lined up with the centerline requires two more 90 degree turns.
Assuming we are past the departure threshold when the engine quits, we need an approx 225 degree turn (to a teardrop) then an approx 45 degree opposite direction turn to the runway heading, right? So, less than 300 degrees in the turn (more if you start closer to the runway, less if you are farther away).
On my test flights I went up to 6000 feet. I picked an airspeed that I wanted to do the test at, best glide plus a little, went to idle power and let the aircraft stabilize for a thousand feet and started a 360 degree turn at 5000 with a selected bank angle. My passenger noted the altitude at the completion of the 360 degree turn. I repeated the whole procedure for 20, 30, 45, and 60 degree bank angles. My numbers altitude loss for my RV6 at 90 kts were 1100 ft, 1000ft, 900 ft, 750ft. As a side note, I could not hold a steady airspeed at near 60 degree bank. I ended up around 110 kts. My self imposed minimum turnaround altitude is 1000 ft.
Your tests told you how much altitude you'd lose in the turn, but will you be over the pavement, or within the airfield boundaries, at that point based on your typical distance from the runway when you reach your min turn around altitude of 1000' during a typical climbout at your airfield?
 
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Kyle Boatright

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There is another way to check the performance of your aircraft for an engine out turnaround. First understand we are not talking about 180 degree turn which results in you being well offset from the centerline of the runway. To get lined up with the centerline requires two more 90 degree turns. So we are talking about a 360 degree turn.
You’re locked into a mistaken paradigm. Your intent isn’t to land on the runway. It is to set the airplane down somewhere relatively flat. Most anywhere in the vicinity of the runway is fine. A 200 degree turn is probably adequate in most cases.
 

PredragVasic

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... when flying from a public airport.
or private one. If you turn into the crosswind, and that crosswind component is strong enough, that turn may well be barely over 180°, and even if it is quite low, it will still reduce the size of the turn.
 

Rhino

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...Just exactly why is a PhD required to answer that question?

In flying that PhD is going to have zero value at all...
Have to agree. Had some PhDs assist with the engineering on a plane I flew on in the Air Force. I assume they were stellar in that tiny little niche of the world in which they worked, but they were absolutely clueless in everything else, and I mean everything. One of them couldn't even figure out how to use an aircraft toilet. Several similar experiences have followed over the years that reaffirm that observation. I'm not saying they can't be smart, but for many of them their intelligence is confined to a highly limited area. For some of them though, they're just idiots who were good at studying and taking tests. The term PhDuh has very significant meaning for me.
 
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