Multi Engine Instruction Dangers
Thread Starter
With all due respect
Thanks for all your input Chuck.
But with all due respect I disagree with some of your arguments.
You're obviously a very experienced pilot but you're in a different ballgame than what I'm talking about.
I mean nobody can prepare you for a broken throttle at Vr on a gravel strip at (or over) MTOW.
You did what you felt was right and lived.
All respect a great display of airmanship.
But the original thread was about the TRAINING environment where we try to train (low time) students to survive the more common of failures.
You cannot expect somebody with maybe a 100hrs TT to perform on the same level as you.
You can only do your best to get them as good as they can get within the limited timeframe you have as an instructor.
I'm talking general aviation level here.
You cannot train for all emergencies, you can only pass on some of your knowledge, eventually they have to develop the airmanship on their own, essentially similar to training for PPL.
As a freshly minted pilot (hell, you were a student only yesterday)
you need to understand your limitations and act accordingly.
As you gain more experience your limitations grow with you.
And maybe somtime you have to make a live or die decision.
Most make it some don't, we read about them.
Comments welcome.....
But with all due respect I disagree with some of your arguments.
You're obviously a very experienced pilot but you're in a different ballgame than what I'm talking about.
I mean nobody can prepare you for a broken throttle at Vr on a gravel strip at (or over) MTOW.
You did what you felt was right and lived.
All respect a great display of airmanship.
But the original thread was about the TRAINING environment where we try to train (low time) students to survive the more common of failures.
You cannot expect somebody with maybe a 100hrs TT to perform on the same level as you.
You can only do your best to get them as good as they can get within the limited timeframe you have as an instructor.
I'm talking general aviation level here.
You cannot train for all emergencies, you can only pass on some of your knowledge, eventually they have to develop the airmanship on their own, essentially similar to training for PPL.
As a freshly minted pilot (hell, you were a student only yesterday)
you need to understand your limitations and act accordingly.
As you gain more experience your limitations grow with you.
And maybe somtime you have to make a live or die decision.
Most make it some don't, we read about them.
Comments welcome.....
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B2N2 thanks for the compliments, however I guess I did not clearly explain my underlying thought process.
So let me try to put it in its simplest form.
I teach "all" my students no matter at what level from their first flight to the most experienced among us a very simple mantra....
Always plan and visualize ahead of the airplane.
No matter what happens be it a sudden stoppage of an engine, a rough engine, a control problem or anything abnormal.....do not do anything until you identify exactly what will best fix the problem... that is why I am not a firm believer in just snapping into rote learned physical actions until there is an intellectual game plan to go with it.
Airplanes in motion have inertia, always ensure that the inertia is vectored in the path which you want the airplane to go in. When something very catastrophic ( to your senses ) goes wrong let inertia drive the airplane in the vector that you have put it in and take a brief few seconds to analize what to do...then go through the actions.
Try something just for the hell of it, at a safe altitude put your airplane in a situation, say just established in the climb and at the recomended climb speed and fail the engine, closely moniter how many seconds you have before airspeed decays to a critical number.
Then always use a speed that will give you several seconds to go through the mental emergancy check of " what in hell is it doing now" that willl give you a chance to maybe recognize something important as to what action is needed.
In short always think before acting....no matter what your experience level.
Respectfully:
Chuck.
So let me try to put it in its simplest form.
I teach "all" my students no matter at what level from their first flight to the most experienced among us a very simple mantra....
Always plan and visualize ahead of the airplane.
No matter what happens be it a sudden stoppage of an engine, a rough engine, a control problem or anything abnormal.....do not do anything until you identify exactly what will best fix the problem... that is why I am not a firm believer in just snapping into rote learned physical actions until there is an intellectual game plan to go with it.
Airplanes in motion have inertia, always ensure that the inertia is vectored in the path which you want the airplane to go in. When something very catastrophic ( to your senses ) goes wrong let inertia drive the airplane in the vector that you have put it in and take a brief few seconds to analize what to do...then go through the actions.
Try something just for the hell of it, at a safe altitude put your airplane in a situation, say just established in the climb and at the recomended climb speed and fail the engine, closely moniter how many seconds you have before airspeed decays to a critical number.
Then always use a speed that will give you several seconds to go through the mental emergancy check of " what in hell is it doing now" that willl give you a chance to maybe recognize something important as to what action is needed.
In short always think before acting....no matter what your experience level.
Respectfully:
Chuck.
G'day Chuck,
I certainly agree with your stance about taking the time to think. It's rare that an instantaneous action would achieve a better result than a considered response.
Sorry about the delay responding to your earlier comments.
You're quite right, a C337 doesn't count for 'standard' multi training. It's probably a bad example however I was trying to highlight that relying on a single symptom without corroboration isn't a 'good thing'.
BMEP is what I had in mind re not using just yaw cues. Also EGT.
Re mixture cuts, Lycoming recommended mixture cuts for their engines in the 'Lycoming Flyer'. They maintain it is less stressful for the engine than a throttle cut. They argue that using the mixture leaves airflow still able to get into the cylinders which, in turn, gives the piston & it's connecting gubbins something to push against. As it was designed to do.
The next issue, I suppose, is whether or not adequate safety can be maintained using mixture. Many of us believe so, many others don't. Fair enough. I believe it's important for the student to have to choose which which engine has failed & test the assumption without having a throttle position cue.
As a slight change of direction: How many here feel that engine power won't be restored when the mixture is returned to full rich (or even less than full rich, if that's more appropriate for the conditions), and how many feel it would be restored?
I certainly agree with your stance about taking the time to think. It's rare that an instantaneous action would achieve a better result than a considered response.
Sorry about the delay responding to your earlier comments.
You're quite right, a C337 doesn't count for 'standard' multi training. It's probably a bad example however I was trying to highlight that relying on a single symptom without corroboration isn't a 'good thing'.
BMEP is what I had in mind re not using just yaw cues. Also EGT.
Re mixture cuts, Lycoming recommended mixture cuts for their engines in the 'Lycoming Flyer'. They maintain it is less stressful for the engine than a throttle cut. They argue that using the mixture leaves airflow still able to get into the cylinders which, in turn, gives the piston & it's connecting gubbins something to push against. As it was designed to do.
The next issue, I suppose, is whether or not adequate safety can be maintained using mixture. Many of us believe so, many others don't. Fair enough. I believe it's important for the student to have to choose which which engine has failed & test the assumption without having a throttle position cue.
As a slight change of direction: How many here feel that engine power won't be restored when the mixture is returned to full rich (or even less than full rich, if that's more appropriate for the conditions), and how many feel it would be restored?
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Tin.....
First to answer your question regarding getting power back with the mixture.... I can see no reason why it would not come back every time...barring something breaking.
However before you return the mixture to the position that restores the fuel flow you have that extra chore of reducing the throttle setting to prevent the engine from surging as fuel flow is restored.
We of course could wear out our fingers discussing our favourite methods of teaching, none of us are perfect and we alll have different ideas molded by our own personal experiences.
Me I go for the least stressful methods of performing any exercise and try and teach it in a manner that will fit more complex engines that can be damaged by sudden power loss.
Engine failures in twin engine aircraft ( one engine failing. ) will result in yaw being induced, I teach them recognize and control yaw and think at the same time.
Chuck
First to answer your question regarding getting power back with the mixture.... I can see no reason why it would not come back every time...barring something breaking.
However before you return the mixture to the position that restores the fuel flow you have that extra chore of reducing the throttle setting to prevent the engine from surging as fuel flow is restored.
We of course could wear out our fingers discussing our favourite methods of teaching, none of us are perfect and we alll have different ideas molded by our own personal experiences.
Me I go for the least stressful methods of performing any exercise and try and teach it in a manner that will fit more complex engines that can be damaged by sudden power loss.
Engine failures in twin engine aircraft ( one engine failing. ) will result in yaw being induced, I teach them recognize and control yaw and think at the same time.
Chuck
This has been a most interesting thread.
Chuck
At the risk of placing words in your mouth I would argue that in fact you did use a rote procedure when the throtle snaped off, because you rejected the TO primarily based on the fact that you were below V1. I would also wager that your initial instinctive action was to pull back the throttles and you used critical thinking to override that action with a better one. I think B2N2's point about the challenges faced by low time new twin rated pilots is very important. I believe the best way to train new pilots is to give them a framework of standard actions as place to start. But you are right Chuck, they must be used in conjunction with critical thinking. One point nobody has addressed yet is the point that a mixture cut simulates a instant total engine failure. However I think this is the least likely failure scenario in a light twin. A slow run down in power and/or rough running caused by internal mechanical failure or a ignition problem , or a surging engine caused by a fuel problem is IMO a more likely real world event.
Yet from what I have seen many students complete the multi rating course with out any exposure to these situations.
When I teach the muti rating I always make sure to distract the student when the aircraft is in a turn and then slowly pull the inside throttle back. I also hide the quandrant on final approach and reduce power on one engine. These exercises provide a good example of ther fact that a engine failures can be subtle and the massive yaw experienced with a high power low airspeed rapid throttle cut is not the only way engines fail.
To simulate a surging engine I cover the throttle quadrant and then rapidly move one throttle back and forth from idle to cruise. This demonstrates that with a surging engine, It may not initially be obvious which engine is acting up. Careful observation of the engine quages is vital before any actions are taken.
Finally one of my concerns with the standard multi curiculum is that the prop overspeed scenario seemes to be at best glossed over. A prop overspeed could cause a yaw away from the malfunctioning engine, so instead of reducing power and airspeed and flying away on two engines the pilot could feather the good engine and crash. This execise is very difficult to simulate in flight. The best I have come up with is to cover both RPM guages . hide the quandrant with my clipboard and reduce the RPM on one engine to the minimum allowed. I expect the student to call " suspected prop over/underspeed", point to the RPM guages and verbalize his corrective actions. Its not a great exercise but at least it does provide the tactile cues of yaw combined with the sound of the engines going massively out of sync, and will hopefully mean the student will not consider every power abnormality only within the context of a engine failure.
I believe the instructor must adequately prepare their students for the real dangers of multi engine flight, but in a way that does not put the instructor or the student deliberately in danger.
Finally I bet that virtually all those instructors who do mixture cuts at takeoff are low time themselves and have probably
little or no time as a working line pilot. I tell all my students that the yellow stripe down my back has gotten a lot bigger since I started flying 27 years ago
Chuck
At the risk of placing words in your mouth I would argue that in fact you did use a rote procedure when the throtle snaped off, because you rejected the TO primarily based on the fact that you were below V1. I would also wager that your initial instinctive action was to pull back the throttles and you used critical thinking to override that action with a better one. I think B2N2's point about the challenges faced by low time new twin rated pilots is very important. I believe the best way to train new pilots is to give them a framework of standard actions as place to start. But you are right Chuck, they must be used in conjunction with critical thinking. One point nobody has addressed yet is the point that a mixture cut simulates a instant total engine failure. However I think this is the least likely failure scenario in a light twin. A slow run down in power and/or rough running caused by internal mechanical failure or a ignition problem , or a surging engine caused by a fuel problem is IMO a more likely real world event.
Yet from what I have seen many students complete the multi rating course with out any exposure to these situations.
When I teach the muti rating I always make sure to distract the student when the aircraft is in a turn and then slowly pull the inside throttle back. I also hide the quandrant on final approach and reduce power on one engine. These exercises provide a good example of ther fact that a engine failures can be subtle and the massive yaw experienced with a high power low airspeed rapid throttle cut is not the only way engines fail.
To simulate a surging engine I cover the throttle quadrant and then rapidly move one throttle back and forth from idle to cruise. This demonstrates that with a surging engine, It may not initially be obvious which engine is acting up. Careful observation of the engine quages is vital before any actions are taken.
Finally one of my concerns with the standard multi curiculum is that the prop overspeed scenario seemes to be at best glossed over. A prop overspeed could cause a yaw away from the malfunctioning engine, so instead of reducing power and airspeed and flying away on two engines the pilot could feather the good engine and crash. This execise is very difficult to simulate in flight. The best I have come up with is to cover both RPM guages . hide the quandrant with my clipboard and reduce the RPM on one engine to the minimum allowed. I expect the student to call " suspected prop over/underspeed", point to the RPM guages and verbalize his corrective actions. Its not a great exercise but at least it does provide the tactile cues of yaw combined with the sound of the engines going massively out of sync, and will hopefully mean the student will not consider every power abnormality only within the context of a engine failure.
I believe the instructor must adequately prepare their students for the real dangers of multi engine flight, but in a way that does not put the instructor or the student deliberately in danger.
Finally I bet that virtually all those instructors who do mixture cuts at takeoff are low time themselves and have probably
little or no time as a working line pilot. I tell all my students that the yellow stripe down my back has gotten a lot bigger since I started flying 27 years ago
Chuck
I was never your student
I was never your student
Thread Starter
Crossfeeding
Saw a program on TV last night about the airplane crash that killed half of the rock band Lynnard Skinnard(?) in the '70-ties.
Convair 240, lost the left engine somewhere over Alabama,
pilots didn't get the crossfeeding quite right and the right engine quit also.....
Must admit don't know anything about the fuel system of a Convair bit I bet it's a little more conplicated than the average twin.
Chuck or Big Pistons any experience on this type of plane?
Convair 240, lost the left engine somewhere over Alabama,
pilots didn't get the crossfeeding quite right and the right engine quit also.....
Must admit don't know anything about the fuel system of a Convair bit I bet it's a little more conplicated than the average twin.
Chuck or Big Pistons any experience on this type of plane?
The piston Convair fuel system is I believe the same as the turbine 580 series which is very simple. Each wing is one big wet wing fuel tank which feeds its respective engine. The fuel controls are 5 switches. 2 fuel on/off, 2 fuel dump, and one fuel crossfeed on/off. I have not sen the report of the crash you mentioned but I would guess there were other factors which contributed to the crash.
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Horror stories (from the infamous cabbage patch field of Jandakot, Western Australia)
- Applied incorrect rudder: aircraft then flick rolled upside down
- Rejected takeoff: Applied opposite brake pedal and continued! Resulted in tyre replacement, and instructor blood pressure check...
-Applied incorrect rudder during EFATO: not a repeat effort of the first, but those power lines came awful close in the recovery! (or at least thats the way they looked)
- Excursions below blue line whilst on crosswind, downwind, base...
- Negative climb peformance after takeoff during practice EFATO (had to give the student a little more "zero thrust" on "failed engine)
- Decided Vmca practice recovery was fun so turned into wingover session...
- Decided drill is actually gear and flap down whilst given an E/F on crosswind.
The biggest advice to those getting there multi training approval, but also applies to all instructing...
PUSH THE STUDENT TO THEIR LIMIT, NOT TO YOURS...
Not really a horror story, but my favourite:
Established on YPPH 03 ILS, at dusk, student asks to turn cockpit lights up (they were already giving me a healthy tan). Chief instructor observing in back asks if the student would prefer to take his sunglasses off from under the IFR hood...
- Applied incorrect rudder: aircraft then flick rolled upside down
- Rejected takeoff: Applied opposite brake pedal and continued! Resulted in tyre replacement, and instructor blood pressure check...
-Applied incorrect rudder during EFATO: not a repeat effort of the first, but those power lines came awful close in the recovery! (or at least thats the way they looked)
- Excursions below blue line whilst on crosswind, downwind, base...
- Negative climb peformance after takeoff during practice EFATO (had to give the student a little more "zero thrust" on "failed engine)
- Decided Vmca practice recovery was fun so turned into wingover session...
- Decided drill is actually gear and flap down whilst given an E/F on crosswind.
The biggest advice to those getting there multi training approval, but also applies to all instructing...
PUSH THE STUDENT TO THEIR LIMIT, NOT TO YOURS...
Not really a horror story, but my favourite:
Established on YPPH 03 ILS, at dusk, student asks to turn cockpit lights up (they were already giving me a healthy tan). Chief instructor observing in back asks if the student would prefer to take his sunglasses off from under the IFR hood...
