EFATO, to turn or not to turn.
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From: uk
The point is not whether the prop is stopped or not. It is that the drag from a prop which is still being driven by an idling engine, as in a practice, is a lot less than the drag from a prop/engine which is being driven by the airflow, as in the real thing.
Joined: Dec 2002
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From: UK
This thread is uinbelievable.
As an instructor I would never advocate turning back below circuit height; land straight ahead or within 30-45deg of runway centre line; Hence I get all my students to brief before departure; Normal procedures, departure route, emergency procedures, who is gonna fly the aircraft, where you intend to put it down, rotate speed, climb out speed, glide speed.....trying to turn back is, IMHO the craziest option
Simple fact is that your airspeed is gonna keep you alive; if you start increasing your stall speed by putting on medium to large angles of bank you are going to spin it into the ground;
This was demonstrated by a fairly recent accident at Biggin Hill where the 'examiner' instructor tried to turn back and his stall speed was calculated to be above his glide speed;
I accept some airports don't give you many options and the climb out is over densely populated areas but hey thats the risk of flying single engine.
If the CAA read some of these posts they would be having kittens.
As an instructor I would never advocate turning back below circuit height; land straight ahead or within 30-45deg of runway centre line; Hence I get all my students to brief before departure; Normal procedures, departure route, emergency procedures, who is gonna fly the aircraft, where you intend to put it down, rotate speed, climb out speed, glide speed.....trying to turn back is, IMHO the craziest option
Simple fact is that your airspeed is gonna keep you alive; if you start increasing your stall speed by putting on medium to large angles of bank you are going to spin it into the ground;
This was demonstrated by a fairly recent accident at Biggin Hill where the 'examiner' instructor tried to turn back and his stall speed was calculated to be above his glide speed;
I accept some airports don't give you many options and the climb out is over densely populated areas but hey thats the risk of flying single engine.
If the CAA read some of these posts they would be having kittens.
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From: The 'Bat Cave' @ HLP in the Big Durian Indo
Climb to 3,000 or 4,000 ft in the training area put the aircraft into climb attittude and speed and then pull the mixture , you won't get a 180 deg turn with 400ft , forget the arguements about being at a higher altitude affecting the outcome. You'll lose nearly 100ft while get the nose down and start a turn.
Then add in the fact that in a real engine failure you may be in denial for a second that the engine has failed.
Agree with TurboJ , 30 or 60 deg yes , 180 degrees no way from 400 ft
Then add in the fact that in a real engine failure you may be in denial for a second that the engine has failed.
Agree with TurboJ , 30 or 60 deg yes , 180 degrees no way from 400 ft
Last edited by aseanaero; 24th February 2009 at 11:37.
Joined: Dec 2002
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From: UK
Aseanaero - You put it far better than me !!!
The other point that is not mentioned here is the partial engine failure; Is it going to fail, has it failed, whats it doing?
The engine is still going, but its coughing and spluttering and its sort of loosing power then regaining it again.....what do you do?
Personally, I would climb straight ahead; if its not gonna climb, its going into a field;
Again, the temptation is to turn back; IMHO the craziest option is to turn back; climb away, get the altitude, do the checks; any turn is max 15deg AoB;
The other point that is not mentioned here is the partial engine failure; Is it going to fail, has it failed, whats it doing?
The engine is still going, but its coughing and spluttering and its sort of loosing power then regaining it again.....what do you do?
Personally, I would climb straight ahead; if its not gonna climb, its going into a field;
Again, the temptation is to turn back; IMHO the craziest option is to turn back; climb away, get the altitude, do the checks; any turn is max 15deg AoB;
Joined: Sep 2003
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From: UK,Twighlight Zone
Not to mention that it is not a 180 degree turn it is more like 250 degree. 180 degrees only has you pointing the opposite way, not back at the runway.
I tried to say this on flyer and there followed pages of armchair experts telling us how you could calculate critical speeds and make a turn back etc.
As an Instructor I agree with TurboJ and will continue to teach the same.
I tried to say this on flyer and there followed pages of armchair experts telling us how you could calculate critical speeds and make a turn back etc.
As an Instructor I agree with TurboJ and will continue to teach the same.
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From: The 'Bat Cave' @ HLP in the Big Durian Indo
The engine is still going, but its coughing and spluttering and its sort of loosing power then regaining it again.....what do you do?
On take off at about 300 ft the whole aircraft started shuddering violently with severe loss of power but still able to hold altitude but not climb , straight ahead landing would of written the aircraft off as it was a small rocky valley so I flew a 300 ft circuit but prepared to put the aircraft down straight ahead at anytime
I got the aircraft and myself down in one piece and the culprit turned out to be a pea sized piece of metal from the previous failure that must have been hiding in the intake manifold and had flattened the spark plug electrodes in the offending cylinder, the ground run ups didnt dislodge it but full power and bouncing down the dirt runway did.
So the answer is depends ... I still had power so I rolled the dice but if I had totally lost power it was into the valley and probably gone home in an ambulance but not to turn back.
Last edited by aseanaero; 24th February 2009 at 13:00.
Fleet Manager
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From: Ontario, Canada
This is an important theme, correctly handled:
These symptoms accurately describe a "stuck valve" which is reasonably common (yes, even on low time engines). When things start shaking up front, it's very important to actually determine has the engine actually stopped developing power entirely, or is it just running rough, and shaking like heck?
"stuck valves" take several forms, but as the pilot, all you need to know is that you have either 25% (4 cyl) or 17% (6 cyl) less power, but the engine is still devoping the rest of the power. The shaking is just because the power is no longer balanced. If the valve stuck open, you have some maintenace in the engine's immediate future, but you're still flying. If it stuck closed, something expensive is now bent, but the engine is still developing power - for a while. (a spark plug blowing out, has a similar effect)
Valves seem to stick a few hundred feet up just after the first takeoff of the day. I suppose that's when the heat of the power being developed finally has it's effect on all of those moving parts. Just because the engine is shaking, don't just abandon remaining airborne! Try and fly! (Okay, if you have a perfect runway right ahead of you, you should land on it, otherwise don't just force land for no good reason!) I've known several aircraft which were carelessly and injuriously crashed, when the only problem was a 17% loss in power and some shaking. All certified aircraft, which are being properly flown, will climb at least somewhat, on 83% power.
At the risk of being resoundingly slagged again, I will suggest that when conditions are suitable and safe, pilots practice a full takeoff and climb with 75% power (knowing that you can go to full power at any time during the practice). You will be surprised how well most aircraft will get airborne doing this, and you'll have a sense of how your aircraft will fly if you do have a partial power loss one day.
If the engine is developing some power, make the best use of it, don't let the shaking bother you, the plane can take it. (It's a "pan" not a "mayday"!) I've climbed away on partial power, to return for a safe landing many more times than I have had a complete engine failure, and force landed. I have been very lucky in never having damaged an aircraft in any of my four forced landings, or landing into a place from which a takeoff later was not possible.
Pilot DAR
On take off at about 300 ft the whole aircraft started shuddering violently with severe loss of power but still able to hold altitude but not climb , straight ahead landing would of written the aircraft off as it was a small rocky valley so I flew a 300 ft circuit but prepared to put the aircraft down straight ahead at anytime
"stuck valves" take several forms, but as the pilot, all you need to know is that you have either 25% (4 cyl) or 17% (6 cyl) less power, but the engine is still devoping the rest of the power. The shaking is just because the power is no longer balanced. If the valve stuck open, you have some maintenace in the engine's immediate future, but you're still flying. If it stuck closed, something expensive is now bent, but the engine is still developing power - for a while. (a spark plug blowing out, has a similar effect)
Valves seem to stick a few hundred feet up just after the first takeoff of the day. I suppose that's when the heat of the power being developed finally has it's effect on all of those moving parts. Just because the engine is shaking, don't just abandon remaining airborne! Try and fly! (Okay, if you have a perfect runway right ahead of you, you should land on it, otherwise don't just force land for no good reason!) I've known several aircraft which were carelessly and injuriously crashed, when the only problem was a 17% loss in power and some shaking. All certified aircraft, which are being properly flown, will climb at least somewhat, on 83% power.
At the risk of being resoundingly slagged again, I will suggest that when conditions are suitable and safe, pilots practice a full takeoff and climb with 75% power (knowing that you can go to full power at any time during the practice). You will be surprised how well most aircraft will get airborne doing this, and you'll have a sense of how your aircraft will fly if you do have a partial power loss one day.
If the engine is developing some power, make the best use of it, don't let the shaking bother you, the plane can take it. (It's a "pan" not a "mayday"!) I've climbed away on partial power, to return for a safe landing many more times than I have had a complete engine failure, and force landed. I have been very lucky in never having damaged an aircraft in any of my four forced landings, or landing into a place from which a takeoff later was not possible.
Pilot DAR
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From: Amsterdam
don't let the shaking bother you, the plane can take it.
On a lighter note, I can confirm from experience that a first-generation Alfa Romeo 145, with the flat-four 1.4 engine and two distribution belts, can continue running on two cylinders when one of the distribution belts breaks. Lots of shaking and a maximum of 60 km/h, but it got me to a garage. (The same garage who was responsible for installing the distribution belt wrongly in the first place, leading to its failure after only 16.000 km.)
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From: Europe
if you start increasing your stall speed by putting on medium to large angles of bank you are going to spin it into the ground;
Some more "mince" to add to the pie - The above is a popular misconception
You are in a descending turn (not maintaining straight and level) so your stall speed increase is not the same as if you were trying to maintain level flight.
I fly with many students who have a fear of banking when descending base to final - they are always happy to discover that you can bank at 45degrees or even 60 degrees quite safely if you want to, (not so when climbing obviously).
Some more "mince" to add to the pie - The above is a popular misconception
You are in a descending turn (not maintaining straight and level) so your stall speed increase is not the same as if you were trying to maintain level flight.
I fly with many students who have a fear of banking when descending base to final - they are always happy to discover that you can bank at 45degrees or even 60 degrees quite safely if you want to, (not so when climbing obviously).
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From: UK,Twighlight Zone
You are in a descending turn (not maintaining straight and level) so your stall speed increase is not the same as if you were trying to maintain level flight.
Hence we get in a situation where the natural instinct is to try and make the bank angle without losing height, this is where we get the stall and spin. The evidence is quite clearly out there that shows this is the case. Just read the AIB reports of the stall and spin incidents.
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From: South Norfolk, England
Actually, it's more likely that you'll be frightened to bank steeply as the ground appears to be rushing up. You then realise you're not going to get around, and feed in more and more rudder without thinking ..................... Oh dear!
SS
SS
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From: UK
Bose
Here and on Flyer most of you are missing the point.
If you fly an aircraft and fly aerobatics and are flying 100s of hours a year including some low level stuff there is a very good chance you know exactly what the aircraft will and will not do. You are very comfortable with high angles of bank and the required control inputs. When I was flying aeros most weeks I reckon I would have known exactly where and when I could turn back.
If you know you dont need to be reading this thread or thinking about the question.
I would hazard that the vast majority of pilots do not fall into this category for the reasons I gave earlier. I would even go as far as to say IF they completed the turn back successfully the result of a 20 knot tail wind might in itself result in a less than pretty outcome.
The collected wisdom of so many does not come cheap, and it would be surprising if it were wrong. Be very sure of what you are doing if you turn back, if you find yourself hesitating, I wouldnt hesitate a moment longer - land straight ahead.
I recall quite some while ago a pilot landing a twin literally through the roof of a house into a back yard barely large enough in which to swing a cat. All he did was maintain control - he barely suffered a scratch, ok, he was lucky BUT it is interesting if you read the accident reports how many aircraft that land straight ahead and under control achieve a satisfactory outcome. The outcome of a stall and spin is very rarely satisfactory.
(Mind you so far as the lot on Flyer is concerned I recall the arm chair experts wanting to fly their twins around the country on one engine after the other had failed - do I recall you might have been one of them Bose? It is a great idea, but I will pass on both turning back and flying on one engine if I started out with two if you dont mind, thank you
)
Here and on Flyer most of you are missing the point.
If you fly an aircraft and fly aerobatics and are flying 100s of hours a year including some low level stuff there is a very good chance you know exactly what the aircraft will and will not do. You are very comfortable with high angles of bank and the required control inputs. When I was flying aeros most weeks I reckon I would have known exactly where and when I could turn back.
If you know you dont need to be reading this thread or thinking about the question.
I would hazard that the vast majority of pilots do not fall into this category for the reasons I gave earlier. I would even go as far as to say IF they completed the turn back successfully the result of a 20 knot tail wind might in itself result in a less than pretty outcome.
The collected wisdom of so many does not come cheap, and it would be surprising if it were wrong. Be very sure of what you are doing if you turn back, if you find yourself hesitating, I wouldnt hesitate a moment longer - land straight ahead.
I recall quite some while ago a pilot landing a twin literally through the roof of a house into a back yard barely large enough in which to swing a cat. All he did was maintain control - he barely suffered a scratch, ok, he was lucky BUT it is interesting if you read the accident reports how many aircraft that land straight ahead and under control achieve a satisfactory outcome. The outcome of a stall and spin is very rarely satisfactory.
(Mind you so far as the lot on Flyer is concerned I recall the arm chair experts wanting to fly their twins around the country on one engine after the other had failed - do I recall you might have been one of them Bose? It is a great idea, but I will pass on both turning back and flying on one engine if I started out with two if you dont mind, thank you
)
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From: UK,Twighlight Zone
Well as we are mentioning your Gatwick debacle I think you will find that I was not advocating 'flying around the country on one engine' but rather that I would not have shut Gatwick down and chosen one of the other more suitable options like Redhill or Biggin Hill...... 
If you also take the time to read my comments on EFATO I quite clearly make the point that we are not talking about high hour aerobatic sky gods like yourself, we are talking about average joe in a spamcan who probably only fly's 20-30 hours a year. I am quite sure there are many sky gods who can quite easily do a turn back in there hot ships. But do I think the average PPL is capable of doing so? Nope, I think that trying it is likely to get them killed. I have a little instructional time under my belt and watching people at the 2 year instructional flight is enough to convince me that average joe will end up in a smoking pile attempting a low level turn back. I am pretty sure the AIB stats back it up as well.
If you also take the time to read my comments on EFATO I quite clearly make the point that we are not talking about high hour aerobatic sky gods like yourself, we are talking about average joe in a spamcan who probably only fly's 20-30 hours a year. I am quite sure there are many sky gods who can quite easily do a turn back in there hot ships. But do I think the average PPL is capable of doing so? Nope, I think that trying it is likely to get them killed. I have a little instructional time under my belt and watching people at the 2 year instructional flight is enough to convince me that average joe will end up in a smoking pile attempting a low level turn back. I am pretty sure the AIB stats back it up as well.
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From: UK
Bose
Are you having a really bad day? I was COMPLETELY agreeing with you (for once ).
.. .. .. this is part of the problem on Flyer and a trap, if set, all to easy to fall into. We judge the actions of others based on our own perception, often without knowing the circumstances. Some of those Sky Gods advocating a turn back might do so safetly but they are applying their own skill set to others, or to circumstances of which they have no knowledge.
If you also take the time to read my comments on EFATO
).
but rather that I would not have shut Gatwick down and chosen one of the other more suitable options like Redhill or Biggin Hill
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From: Right here
In such a situation my main worry would be that the engine would tear itself off its engine mount. Is there a formal certification requirement or something that would require the mount to be strong enough for an unbalanced engine running on all minus one cylinders, either through a stuck valve or blown-out spark plug, at full throttle?
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From: France
The point is not whether the prop is stopped or not. It is that the drag from a prop which is still being driven by an idling engine, as in a practice, is a lot less than the drag from a prop/engine which is being driven by the airflow, as in the real thing.
So, the point is at least partially whether the prop is stopped, is it not? Because some engine failures the prop will windmill, and some it won't. So that is another thing to factor in to the calculations, as is the rate of climb, the glide angle, the wind, the type of circuit you are flying, the length of runway, what lies ahead, how current you are, how much oil there is on the windscreen, what cross runways are available, and probably how well you slept last night. I am not saying to turn back or go in straight ahead, I am saying that there is no one size fits all answer.