EFATO interesting facts
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Wind Does Not Exist
I think that because we live on the surface we see wind as a dynamic thing. For something that is airborne, though, wind does not exist so there is no head wind cross wind or tail wind. The only airflow is generated by the aircraft itself in flight and, assuming in balanced flight, will always be from 12 o'clock at the indicated airspeed.
Imagine you are airborne in a hot air balloon and not in sight of the surface, above cloud say, so that you are not influenced by your "ground" perspective. Without reference to electronic gadgets you would have no sensation of movement or of any wind. You could light a candle.
You have no idea of any wind velocity, if any, as observed by a ground observer.
You decide to hand launch a model glider. It would not matter in which direction you threw it it would fly equally well.
A powered aircraft orbiting your balloon at a constant distance would have a constant angle of bank, constant airspeed, constant power and constant height and like the balloon crew would have no concept of wind, without reference to gadgets.
So an aircraft can only turn "downwind" to a ground observer. To an airborne observer there is no wind, so there is no "downwind".
The only time a wind exists for an aircraft is on the ground. Immediately prior to touchdown and immediately after take of there is no apparent wind.
Imagine you are airborne in a hot air balloon and not in sight of the surface, above cloud say, so that you are not influenced by your "ground" perspective. Without reference to electronic gadgets you would have no sensation of movement or of any wind. You could light a candle.
You have no idea of any wind velocity, if any, as observed by a ground observer.
You decide to hand launch a model glider. It would not matter in which direction you threw it it would fly equally well.
A powered aircraft orbiting your balloon at a constant distance would have a constant angle of bank, constant airspeed, constant power and constant height and like the balloon crew would have no concept of wind, without reference to gadgets.
So an aircraft can only turn "downwind" to a ground observer. To an airborne observer there is no wind, so there is no "downwind".
The only time a wind exists for an aircraft is on the ground. Immediately prior to touchdown and immediately after take of there is no apparent wind.
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For something that is airborne, though, wind does not exist so there is no head wind cross wind or tail wind
...wind exists to him)If you turn downwind with a fast rate of turn, then I'm convinced the strong headwind you're experiencing on the climbout will have an adverse effect on your flight performance in the real world, maybe it leads to initial loss of altitude becasue you have to put the nose down to keep IAS....
Maybe not in the perfect world, but remember a 75° turn will result in a 180 in around 3 seconds.....
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EA
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Windshear has NOTHING to do with the previous points, with windshear it is the change in wind velocity with respect to the aircraft that makes the difference, when turning in a costant moving mass of air, the velocity change with respect to the aircraft is the same whether the mass of air is stationary w.r. to the ground or not. The thing to watch is the PERCIEVED speed- from looking at the ground.
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Yea I know, my point was that wind can appear to a pilot, and in the case of an engine failure at take off, I'm sure the pilot is not going to make the best, coordinated turn of their life, and therefore wind WILL have an affect on aircraft performance.
In a situation like this it is NO GOOD talking about the ideal world, and 'air masses moving around, no preceived wind to a pilot'. Once the pilot has turned down wind, his next phase is to make contact with the earth again. Now all this tail wind leads to excessive ground speed, possible runway overshoot etc etc...
In a situation like this it is NO GOOD talking about the ideal world, and 'air masses moving around, no preceived wind to a pilot'. Once the pilot has turned down wind, his next phase is to make contact with the earth again. Now all this tail wind leads to excessive ground speed, possible runway overshoot etc etc...
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As a glider pilot flying in hilly country I frequently make thermal turns at low level. If there is any significant wind blowing the apparent speed change when turning into and downwind is very marked and I have had to abandon thermals as a result of disorientation.
For launch failures in a glider I do not usually consider turning back to the reciprocal unless above 300' with calm winds.
In the case of EFATO I would not be thinking about turning back. The visual effects of low level turns and possible gusts make the situation much more interesting than it need be. Use the height you have to gain distance and don't use it up turning.
For launch failures in a glider I do not usually consider turning back to the reciprocal unless above 300' with calm winds.
In the case of EFATO I would not be thinking about turning back. The visual effects of low level turns and possible gusts make the situation much more interesting than it need be. Use the height you have to gain distance and don't use it up turning.
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One point that hasn't been mentioned. A 180deg will not only lose you height but leave you x meters from the runway in a parallell direction.
I don't off hand know the turning circle of a popular GA type ac but I'm pretty sure it's more than the width of a runway!
Surely the height you should allow for is a 270 deg turn followed by 90 the other way to get you onto the runway. Of course, if the airfield is quite spacious, 180 deg will be enough, but you could end up parking in a hangar!
I don't off hand know the turning circle of a popular GA type ac but I'm pretty sure it's more than the width of a runway!
Surely the height you should allow for is a 270 deg turn followed by 90 the other way to get you onto the runway. Of course, if the airfield is quite spacious, 180 deg will be enough, but you could end up parking in a hangar!
Remember that kinetic energy is a function of the square of the speed! - 0.5 x m x v (squared).
Let's say you glide at 60 kt and there is a 30 kt wind blowing down the runway. If you land straight ahead given an EFATO your groundspeed is 30 kt; do a turn back and your groundspeed is 90 kt so if you end up hitting anything you have a lot more energy to lose!
Everything tends to favour not attempting a turn back unless there really is no other choice (housing estates etc.)
Hard aviation experience has shown that you are far more likely to die attempting a turn back than crashing into wind - even the military have come to grief and they have had specific training in turn backs.
My father was a veteran light aircraft instructor and he always used to advise that if you have to crash make sure the wings are level and you are under control (ie not stalling/spinning). He was vehemently against turning back and I think he was right!
Let's say you glide at 60 kt and there is a 30 kt wind blowing down the runway. If you land straight ahead given an EFATO your groundspeed is 30 kt; do a turn back and your groundspeed is 90 kt so if you end up hitting anything you have a lot more energy to lose!
Everything tends to favour not attempting a turn back unless there really is no other choice (housing estates etc.)
Hard aviation experience has shown that you are far more likely to die attempting a turn back than crashing into wind - even the military have come to grief and they have had specific training in turn backs.
My father was a veteran light aircraft instructor and he always used to advise that if you have to crash make sure the wings are level and you are under control (ie not stalling/spinning). He was vehemently against turning back and I think he was right!
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One point that hasn't been mentioned. A 180deg will not only lose you height but leave you x meters from the runway in a parallell direction
Interesting debate, I don't think I would turn back either, unless I had no other option, or a lot of height . Like FFB points out, its better to be in control and land level with relatively low energy, that either hit uncontrolled, or with high speed.
Lets hope we never have to find out !
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I know what you're saying, and you're right in the ideal world....(but tell that to the captain of a 747 at 300' on final that experiences windshear !!!...wind exists to him)
I have been a 747 captain for 11 years and before that military fast jet for 20 years.
I have been a 747 captain for 11 years and before that military fast jet for 20 years.
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QDM
Experts only, in lots of practice. Not for your humble, low-time PPL scum like me.
You don't need to be an expert to perform a turnback, nor do you need lots of practice. (As an aside, I notice UK PPL's seem to have an inferiority complex which does not exist in other places). Flying is not intuitive to most people, and so most people need to be trained how to do weird things, but you should be able to learn how to safely perform a turnback maneuver in less than an hour.
45 degrees bank, just above stall speed, and COORDINATED.
See, easy huh?
I bet the hardest thing is teaching spam-can pilots how to fly coordinated when performing this maneuver, rudders pedals are so misunderstood
It's also the uncoordinated bit which will kill you, trying to tighten the turn with rudder when you are already close to the stall, and skidding into an unrecoverable spin.
The clever bit is to know when to land "sort of ahead", and when to land "not sort of ahead". As WWW said, it helps to know what you are going to do before you begin your roll, so self brief. I depart from some runways where I would not be happy if I had an EF below 300ft, and would definitely perform a turn as described above if any higher. Other places where I would not be too bothered at any altitude. Know this before you head off.
(Nostone has got it right with planes flying in an airmass).
Experts only, in lots of practice. Not for your humble, low-time PPL scum like me.
You don't need to be an expert to perform a turnback, nor do you need lots of practice. (As an aside, I notice UK PPL's seem to have an inferiority complex which does not exist in other places). Flying is not intuitive to most people, and so most people need to be trained how to do weird things, but you should be able to learn how to safely perform a turnback maneuver in less than an hour.
45 degrees bank, just above stall speed, and COORDINATED.
See, easy huh?
I bet the hardest thing is teaching spam-can pilots how to fly coordinated when performing this maneuver, rudders pedals are so misunderstood
It's also the uncoordinated bit which will kill you, trying to tighten the turn with rudder when you are already close to the stall, and skidding into an unrecoverable spin.The clever bit is to know when to land "sort of ahead", and when to land "not sort of ahead". As WWW said, it helps to know what you are going to do before you begin your roll, so self brief. I depart from some runways where I would not be happy if I had an EF below 300ft, and would definitely perform a turn as described above if any higher. Other places where I would not be too bothered at any altitude. Know this before you head off.
(Nostone has got it right with planes flying in an airmass).
Last edited by slim_slag; 2nd Aug 2002 at 20:46.
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I have been a 747 captain for 11 years and before that military fast jet for 20 years.
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Good for you, I'm not doubting your abilities, I'm making the point that although in the ideal world, there is no 'wind' to someone airborne flying through an airmass, in the real world, things can appear different. I think those most quaified to talk about air masses and their apparent effect on flying, is a Glider pilot, who, lets face it, land every time without an engine....
Evan a glider pilot cant change physics. :-)
The facts are that whether you are flying a glider or a space shuttle any turn made in a steady airmass is not affected by the velocity of that airmass relative to the ground. I only have to harp back to my analogy of flying a model glider in the cabin of a B747 travelling at 500 kts.
Where this "downwind turn" myth came from I don't know. I did not come across it in the military but was amazed to hear it from some very senior, civilian trained, airline pilots.
Sorry to harp on about this subject but it is not good to have such a misconception being accepted as fact. I only mentioned my experience in an effort to show that I might know what I am talking about.
Good for you, I'm not doubting your abilities, I'm making the point that although in the ideal world, there is no 'wind' to someone airborne flying through an airmass, in the real world, things can appear different. I think those most quaified to talk about air masses and their apparent effect on flying, is a Glider pilot, who, lets face it, land every time without an engine....
Evan a glider pilot cant change physics. :-)
The facts are that whether you are flying a glider or a space shuttle any turn made in a steady airmass is not affected by the velocity of that airmass relative to the ground. I only have to harp back to my analogy of flying a model glider in the cabin of a B747 travelling at 500 kts.
Where this "downwind turn" myth came from I don't know. I did not come across it in the military but was amazed to hear it from some very senior, civilian trained, airline pilots.
Sorry to harp on about this subject but it is not good to have such a misconception being accepted as fact. I only mentioned my experience in an effort to show that I might know what I am talking about.
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Evan a glider pilot cant change physics
(Though apparently in the remaining 7 spacial dimensions, which are curled up into an incredibly small space, the laws of Phisics apparently break down 
)...or something like that, seem to remember having a conversation to this effect while sitting in a coffee shop in Amsterdam)I Know what you're saying Nostone, and I know you're right
However, I'm still peeved about my radio controlled glider which fell out of the sky and landed nose first on that rock Cheers
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As an aside, I notice UK PPL's seem to have an inferiority complex which does not exist in other places
No, that should read 'UK people'.
45 degrees bank, just above stall speed, and COORDINATED.
I bet the hardest thing is teaching spam-can pilots how to fly coordinated when performing this maneuver, rudders pedals are so misunderstood It's also the uncoordinated bit which will kill you, trying to tighten the turn with rudder when you are already close to the stall, and skidding into an unrecoverable spin.
QDM
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Yep. This is usually quoted in the context of maintaining altitude in the turn. We are engine out and not maintaining altitude, so how does stall speed change now? I need more coffee to work that out......
Can you spin if you are beyond the stall, yet remain coordinated????? You can certainly turn a plane to where you want it to go when on the 'wrong' side of the critical AOA!
Should you turnback has probably been cited before, and excuse my rough extracting. I think this says that 19 of 20 pilots, of varying experience including students, can be taught how to succesfully turn back to the runway in fewer than ten attempts on a sim. Some a lot less. Do you mean high level?
Indeed, landing ahead when you could have turned back can also kill. The hard part is knowing when to do it. But knowing "I need to turn back, but I don't know how to" is a fat lot of good.
No, that should read 'UK people'.
I actually find UK people have a superiority complex, just like all countries do. I get the feeling that many PPLs in the UK don't think they are real pilots, you need to be an almighty CPL to be one of those, which is absolute nonsense. All part of the class system I guess
Stall speed increases in the bank and with increasing weight.
Can you spin if you are beyond the stall, yet remain coordinated????? You can certainly turn a plane to where you want it to go when on the 'wrong' side of the critical AOA!
This is a manoeuvre that needs a lot of practice at low level to get right.
Not getting it right = dying.
No, that should read 'UK people'.
I actually find UK people have a superiority complex, just like all countries do. I get the feeling that many PPLs in the UK don't think they are real pilots, you need to be an almighty CPL to be one of those, which is absolute nonsense. All part of the class system I guess
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On the subject of stall speed...it increases with angle of bank as has been said. Up to 45 deg the increase is quite small (less than 20%). After that it increases fairly dramaticly and at 60 deg it increases by 40% (like wise with load factor 60 deg angle of bank = 2g's).
(assuming you keep the turn perfectly coordinated)
I think personaly unless there is no other option I would land straight ahead making shallow turns to avoid objects as per my trainning.
I did once have to make a couple of drastic turns on final at approach speed, with a rough running engine due to an aircraft dawdling about on the runway despite the fact he knew my situation (before turning final there was in my opinion more than adequate spacing but you live and learn). It's not something I'd like to do on a regular basis.
Being close to the ground in a butt clenching situation may focus the mind but doesn't necessarily improve your flying ability. (IMHO)
(assuming you keep the turn perfectly coordinated)
I think personaly unless there is no other option I would land straight ahead making shallow turns to avoid objects as per my trainning.
I did once have to make a couple of drastic turns on final at approach speed, with a rough running engine due to an aircraft dawdling about on the runway despite the fact he knew my situation (before turning final there was in my opinion more than adequate spacing but you live and learn). It's not something I'd like to do on a regular basis.
Being close to the ground in a butt clenching situation may focus the mind but doesn't necessarily improve your flying ability. (IMHO)
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We are engine out and not maintaining altitude, so how does stall speed change now? I need more coffee to work that out......
It will be a function of G, whether you're losing height or not.
Can you spin if you are beyond the stall, yet remain coordinated
In practice, I think it's irrelevant.
Do you mean high level?
Indeed, landing ahead when you could have turned back can also kill. The hard part is knowing when to do it. But knowing "I need to turn back, but I don't know how to" is a fat lot of good
QDM
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Stall speed can increase if you bank, definitely if you maintain altitude, but as QDM said, it's a totally related to the (small) g you experience, and you can turn/bank a plane and experience less than 1g. i.e you descend.
I said Can you spin if you are beyond the stall, yet remain coordinated
QDM said An interesting question, but not one to consider at under 500 ft agl. In practice, I think it's irrelevant.
I'ts totally relevant, it's the skid/stall/spin that will kill you. To answer my own question, I don't believe you can, but in a 45 deg bank where each wing is "doing its own thing" wrt AOA, you would be very clever to pull it off. I defer to those with expertise I do not posess.
Yes, one must never be too dogmatic about things
Indeed!
So from another thread, I see you are a GP in Devon. Heard of the Spirochaetes?
I said Can you spin if you are beyond the stall, yet remain coordinated
QDM said An interesting question, but not one to consider at under 500 ft agl. In practice, I think it's irrelevant.
I'ts totally relevant, it's the skid/stall/spin that will kill you. To answer my own question, I don't believe you can, but in a 45 deg bank where each wing is "doing its own thing" wrt AOA, you would be very clever to pull it off. I defer to those with expertise I do not posess.
Yes, one must never be too dogmatic about things
Indeed!
So from another thread, I see you are a GP in Devon. Heard of the Spirochaetes?
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Not building g when entering a turn is a good spiral dive entry and therefore a good way of losing height.
If you climb away at 500fpm and 60kt you would be 1 mile away from your takeoff point if the fan stopped at 500feet assuming still air. The experiments noted in the thread suggest a 380foot loss in a 180 turn which would put you a mile from your start point at 120feet. This would require a 1/50 glide to get back which is a figure only reached by very goo sailplanes. Cessna/Piper figures are about 1/10. OK on big airfields but very marginal anywhere else.
If you have GPS why not try the following on a still day away from traffic, probably also above 2000' agl. Set the aircraft up in a takeoff configuration at about normal climb speed. When ready set a waypoint into the GPS and initiate a climb as if the waypoint was you take off point. Climb 500', pull the throttle to simulate EFATO and try to turn back to your waypoint. Note height passing the waypoint, if less than your initial height, you've crashed. You could note how far short you came down.
If you climb away at 500fpm and 60kt you would be 1 mile away from your takeoff point if the fan stopped at 500feet assuming still air. The experiments noted in the thread suggest a 380foot loss in a 180 turn which would put you a mile from your start point at 120feet. This would require a 1/50 glide to get back which is a figure only reached by very goo sailplanes. Cessna/Piper figures are about 1/10. OK on big airfields but very marginal anywhere else.
If you have GPS why not try the following on a still day away from traffic, probably also above 2000' agl. Set the aircraft up in a takeoff configuration at about normal climb speed. When ready set a waypoint into the GPS and initiate a climb as if the waypoint was you take off point. Climb 500', pull the throttle to simulate EFATO and try to turn back to your waypoint. Note height passing the waypoint, if less than your initial height, you've crashed. You could note how far short you came down.
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At a safe hight try climbing at initial climb speed, chop the throttle, stuff the nose down at the same time rolling on about 60 deg bank, and pulling enough to just blink the stall warning and when you are coming to 180 heading, roll level and you should have lost 180 to 200ft. Look out all the time. You would only be doing a 180 if you had nothing but houses ahead, and it is not fair to the unsuspecting public to have an aircraft in their bedroom window, or worse still to have their children wiped out as the play in the back yard.
PS this even works with a Pitts.
PS this even works with a Pitts.
