Myths of aviation deflated
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Myths of aviation deflated
Flicking through an AOPA Australia Pilot magazine from late last year, the title '8 common aviation myths' caught my eye. Unfortunately most of the myth buster explanations were vague but one in particular I found inaccuate: 'multi-engine airplanes are inherently safer than single-engine airplanes'.
An NTSB report a few years back report that light multi-engine aircraft are involved in fewer engine-related accidents than single-engine aircraft. However, the same report observed that an engine related accident is four times more likely to cause serious or fatal injuries. One could argue that in fact multi-engine aircraft are safer (less accidents), as long as a loss of control situation is not allowed to occur. But anyway, that is not the main point of my post...
The AOPA feature then went on to make the following statement:
Anyone see the inaccuracies in this statement? I'm surprised AOPA printed it. Or maybe my schooling has been incorrect...
An NTSB report a few years back report that light multi-engine aircraft are involved in fewer engine-related accidents than single-engine aircraft. However, the same report observed that an engine related accident is four times more likely to cause serious or fatal injuries. One could argue that in fact multi-engine aircraft are safer (less accidents), as long as a loss of control situation is not allowed to occur. But anyway, that is not the main point of my post...
The AOPA feature then went on to make the following statement:
"...if an engine fails in a multi-engine airplane the pilot must immediately and correctly respond to the situation by identifying the failed engine and feathering its prop. If the pilot does not quickly feather the prop - or worse feather the wrong prop - the airplane will VMC and enter a flat, unrecoverable spin."
Its not rocket science!
Look at the facts - and assume we are talking piston engines light twins vs high performance piston engine singles - eg Aztec, C310, Baron vs Lance, C210, Bonanza!
In the twin you have 2 engines therefore you have twice the chance of having an engine failure - yeah, I figured that bit out for myself! Furthermore, it is well established that an engine failure in a twin is more likely to result in serious injuries or death, than an engine failure in a light twin.
In a high performance single you have half the chance of having an engine failure than you would if flying a twin and should you be unfortunate enough to have an engine failure, your chances of dying or suffering serious injury are substantially less.
Then remove the most common cause of engine failure in singles ie lack of fat for the fire, add a bit of decent maintenance, and an all-cylinder engine monitor - and driving to the aerodrome gets a bit scarey compared to flying a high performance single.
The decision tree for actions following and engine failure in a single are pretty stunted - park it!
Its a no-brainer really! High performance singles are significantly safer than comparable light twins!
Dr
Look at the facts - and assume we are talking piston engines light twins vs high performance piston engine singles - eg Aztec, C310, Baron vs Lance, C210, Bonanza!
In the twin you have 2 engines therefore you have twice the chance of having an engine failure - yeah, I figured that bit out for myself! Furthermore, it is well established that an engine failure in a twin is more likely to result in serious injuries or death, than an engine failure in a light twin.
In a high performance single you have half the chance of having an engine failure than you would if flying a twin and should you be unfortunate enough to have an engine failure, your chances of dying or suffering serious injury are substantially less.
Then remove the most common cause of engine failure in singles ie lack of fat for the fire, add a bit of decent maintenance, and an all-cylinder engine monitor - and driving to the aerodrome gets a bit scarey compared to flying a high performance single.
The decision tree for actions following and engine failure in a single are pretty stunted - park it!
Its a no-brainer really! High performance singles are significantly safer than comparable light twins!
Dr
Last edited by ForkTailedDrKiller; 21st Feb 2009 at 04:06.
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I'm enjoying the way this debate is starting to unfold, but is the pilot's first job really to identify and feather the failed engine/prop? Isn't controlling the aircraft - yaw and airspeed - the first vital action?
Would feathering the wrong engine really cause a flat spin? Feathering the good engine would reduce the large amount of thrust therefore yaw normally generated, particularly at a slow airspeed. The aircraft would then in effect become like a single following an engine failure, however I accept the failed, unfeathered engine would generate some significant yaw. Stall the aircraft while yawing and it will spin, but if you controlled the aircraft in the first place and avoided reaching Vmc or a stall then this won't happen.
Feathering the wrong prop won't cause 'an aircraft to VMC
'. Not maintaining proper control will.
Would feathering the wrong engine really cause a flat spin? Feathering the good engine would reduce the large amount of thrust therefore yaw normally generated, particularly at a slow airspeed. The aircraft would then in effect become like a single following an engine failure, however I accept the failed, unfeathered engine would generate some significant yaw. Stall the aircraft while yawing and it will spin, but if you controlled the aircraft in the first place and avoided reaching Vmc or a stall then this won't happen.
Feathering the wrong prop won't cause 'an aircraft to VMC
'. Not maintaining proper control will.
Yeah there's no reason why poor engine handling following an engine failure will cause a stall/spin/crash/burn/die situation. Provided the pilot pops the nose forward to maintain a safe airspeed, (s)he can arrive in a controlled fashion to the scene of the accident just as well as any single pilot can.
The danger with light twins is that they don't have a lot of single engine performance and pilots generally have the expectation that they'll be able to fly away from an engine failure even though that's not always the case. The multi-engine pilot has options, and when there are options there is always a chance that you'll take the wrong one. When things go pear shaped in a single though, you don't have any option other than finding a good place to crash.
Our after take-off engine failure drill was to control the aircraft, secure the engine, clean up the airframe and assess performance. If the performance is adequate, continue for a reland, if the performance is not adequate, use available power to make your way to a suitable crash site ahead of you.
The danger with light twins is that they don't have a lot of single engine performance and pilots generally have the expectation that they'll be able to fly away from an engine failure even though that's not always the case. The multi-engine pilot has options, and when there are options there is always a chance that you'll take the wrong one. When things go pear shaped in a single though, you don't have any option other than finding a good place to crash.
Our after take-off engine failure drill was to control the aircraft, secure the engine, clean up the airframe and assess performance. If the performance is adequate, continue for a reland, if the performance is not adequate, use available power to make your way to a suitable crash site ahead of you.
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Isn't controlling the aircraft - yaw and airspeed - the first vital action?
I would go for airspeed first followed by directional control, without these two whether you feather the prop or not, you are probably gonna end up in a smouldering heap!
puff, its all about risk management! Unfortunately, by chosing to fly a Baron, you accepted double the risk of having an engine failure - and your marble came up. I on the other hand, with half the risk that you accepted, didn't have an engine failure and had a totally uneventful flight over the tiger country!
Dr
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Twins are safer if the pilot is.
Many of todays pilots have some strange ideas about flying twins, and many should stick to singles. American figures showed that people were less likely to die in twins as a result of an engine failure, but they were more likely to die in twins. These figures would almost certainly be different if the survey had been restricted to commercial pilots, as America had lots of business man pilots and they were using aeroplanes like cars. (the doctor in his bonanza was often quoted)
The workload is much higher in a twin, they are more complex and they often fly in conditions that single pilots would avoid. And when an engine fails they can get nasty if you don't do it right. (some singles can too)
It is necessary to practise engine failure drills and remain current, so you can prevent the nasty behaviour.
The same thinking that tells us to have lots of governments and 1500 politician in this country instead of one government and 100 pollies, also tells us to make twin training very complicated and intimidating, and this is counterproductive. We hear twin pilots saying "if an engine fails i will land straight ahead" and " don't practise that assymetric stuff, it's too dangerous"
If you are one of those, then stick to singles, and you will be safer.
But a twin, flown by a properly trained, current, competent pilot is more likely to reach it's destination safely than a single. That's why our airliners are multi engined.
In Alice Springs where the airfield elevation is 1800 ft AMSL and temperatures are often over 40 we had the humble Partenavia fly home on one ngine on two occasions, and I personally brought a chieftain home on one on a couple of occasions.
Twins CAN do it if the pilot is up to it. Singles cannot fly beyond their gliding range after an engine failure.
Accidents are nearly always caused by people, not aeroplanes.
The workload is much higher in a twin, they are more complex and they often fly in conditions that single pilots would avoid. And when an engine fails they can get nasty if you don't do it right. (some singles can too)
It is necessary to practise engine failure drills and remain current, so you can prevent the nasty behaviour.
The same thinking that tells us to have lots of governments and 1500 politician in this country instead of one government and 100 pollies, also tells us to make twin training very complicated and intimidating, and this is counterproductive. We hear twin pilots saying "if an engine fails i will land straight ahead" and " don't practise that assymetric stuff, it's too dangerous"
If you are one of those, then stick to singles, and you will be safer.
But a twin, flown by a properly trained, current, competent pilot is more likely to reach it's destination safely than a single. That's why our airliners are multi engined.
In Alice Springs where the airfield elevation is 1800 ft AMSL and temperatures are often over 40 we had the humble Partenavia fly home on one ngine on two occasions, and I personally brought a chieftain home on one on a couple of occasions.
Twins CAN do it if the pilot is up to it. Singles cannot fly beyond their gliding range after an engine failure.
Accidents are nearly always caused by people, not aeroplanes.
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An interesting thread but I find it somewhat curious that no-one has as of yet picked up on one thing...
Other than the obvious error, which should read VMCa it should be quite apparent that the latter part of the statement is somewhat erroneous, ie the flat spin part.
As someone who as part of his initial twin endorsement in a Seneca 1, had VMCa very well demonstrated (Thanks TK! It was a lesson well learned.)... a flat spin? No it fecking will not!!
What will happen is that the aircraft will, upon getting below VMCa, rapidly roll inverted!
After that, well, a spin may indeed develop. But it won't be flat! And if at low altitude....well the results can be imagined.
the airplane will VMC and enter a flat, unrecoverable spin."
As someone who as part of his initial twin endorsement in a Seneca 1, had VMCa very well demonstrated (Thanks TK! It was a lesson well learned.
)... a flat spin? No it fecking will not!! What will happen is that the aircraft will, upon getting below VMCa, rapidly roll inverted!
After that, well, a spin may indeed develop. But it won't be flat! And if at low altitude....well the results can be imagined.
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Pinky, I agree with your comments and was waiting for someone else to pick it up. The original quote I posted from Austin S. Collins I find amazing given he is an 'expert':
More of his myth busters are in the Nov/Dec 2008 edition of Australia Pilot. I find AOPA's publication disappointing, and Austin's article didn't exactly help to change my mind.
Austin is the chief pilot of Flight Express, a US based on-demand carrier specialising in light cargo, such as bank checks and medical specimens. He supervises about 50 full-time pilots and 85 airplanes (all Cessna 210s and Beech Barons).
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Re light twin safety and engine failure after lift off. Now this is very much a personal viewpoint and it is a comment or better still a point to ponder. Easy on the criticism please if you are inclined to comment>
Once the landing gear is selected up and suddenly you lose an engine, the chances are you will climb away albeit a slow rate of climb, providing you feather the dead engine immediately. For every second you delay feathering and the prop is windmilling you will lose airspeed at the rate of around 1.5 knots per second. These are not hard and fast figures because it also depends how quickly you lower the nose toward level flight.
The flying school mantra of mixture, pitch and power up - identify the failed engine by dead side dead leg (or whatever ) then slowly pull back the throttle on the dead engine to confirm it is the correct one - is fine for initial twin training.
But going through all that with the airspeed decaying at 1.5 knots per second because the prop is windmilling, reduces your chances of a successful climb. The pulling back the throttle to confirm you have the correct dead engine was historically a procedure for a four engined aircraft. Not a twin.
Why? Because dead leg dead side gave you the side (port or starboard) but you still had to positively identify by other means, which engine of the two had given up the ghost. So NOW you slowly pull back the offending throttle to confirm which engine and you did it slowly so if you had the wrong engine you didn't crash due to a two engine VMCA event which is usually much higher than a one engine VMCA event.
Unless the POH states specifically to slowly retard the suspected engine throttle as a means of confirmation, then the act of slowly pulling back the throttle still loses you valuable feathering time and at a speed decay of a windmilling prop at 1.5 knots per second of delay the situation gets deadly serious.
You must get the action right first time. Dead side dead leg in a twin is a natural reaction to prevent further yaw and that is the primary instant means of identification. You then feather immediately.
If you have done your before take off checks correctly then no need to "confirm" full power on the live engine as presumably when the crook engine goes shortly after gear up you will already have full throttle anyway. It is essential to the success of the one engine inoperative initial climb that you dispense with the niceties of flying school training and get the dead engine feathered instantly and that you don't stuff around fiddling with mixtures, pitch controls and throttles and talking to yourself to ensure you get the order right.
No hysterical criticism please - just constructive comments.
Once the landing gear is selected up and suddenly you lose an engine, the chances are you will climb away albeit a slow rate of climb, providing you feather the dead engine immediately. For every second you delay feathering and the prop is windmilling you will lose airspeed at the rate of around 1.5 knots per second. These are not hard and fast figures because it also depends how quickly you lower the nose toward level flight.
The flying school mantra of mixture, pitch and power up - identify the failed engine by dead side dead leg (or whatever ) then slowly pull back the throttle on the dead engine to confirm it is the correct one - is fine for initial twin training.
But going through all that with the airspeed decaying at 1.5 knots per second because the prop is windmilling, reduces your chances of a successful climb. The pulling back the throttle to confirm you have the correct dead engine was historically a procedure for a four engined aircraft. Not a twin.
Why? Because dead leg dead side gave you the side (port or starboard) but you still had to positively identify by other means, which engine of the two had given up the ghost. So NOW you slowly pull back the offending throttle to confirm which engine and you did it slowly so if you had the wrong engine you didn't crash due to a two engine VMCA event which is usually much higher than a one engine VMCA event.
Unless the POH states specifically to slowly retard the suspected engine throttle as a means of confirmation, then the act of slowly pulling back the throttle still loses you valuable feathering time and at a speed decay of a windmilling prop at 1.5 knots per second of delay the situation gets deadly serious.
You must get the action right first time. Dead side dead leg in a twin is a natural reaction to prevent further yaw and that is the primary instant means of identification. You then feather immediately.
If you have done your before take off checks correctly then no need to "confirm" full power on the live engine as presumably when the crook engine goes shortly after gear up you will already have full throttle anyway. It is essential to the success of the one engine inoperative initial climb that you dispense with the niceties of flying school training and get the dead engine feathered instantly and that you don't stuff around fiddling with mixtures, pitch controls and throttles and talking to yourself to ensure you get the order right.
No hysterical criticism please - just constructive comments.
Not sure I agree with you A37 but as you said it is food for thought.
I think the actions of stepping on the ball (balance that is), and reducing pitch attitude to
to prevent airspeed decaying below your current Vyse if neccesarry, should be automatic and occur pretty much simultaneously with "rich pitch power gear up flap up" (assuming that taking the flap up is appropriate in that a/c) , and then you are left with "dead right leg dead right engine" or whatever you use, then feather. It's not much good addressing the drag factor of the prop if you have missed the drag factor of flap or gear. I have seen a pilot lose an engine in a hold and forget that they had flap out (cleared for the approach) because they didn't have a proceedure that addressed the different configuarations possible. He was highly loaded up and couldn't figure out the reason for the poor performance until he had lost 300ft.
So although I agree that feathering the prop qucikly is highly desireable, I think the risks of jumping straight into it without going through
pose more of a threat than the extra 2 seconds it takes to go through it. Just my thoughts, Regards Framer.
I think the actions of stepping on the ball (balance that is), and reducing pitch attitude to
to prevent airspeed decaying below your current Vyse if neccesarry, should be automatic and occur pretty much simultaneously with "rich pitch power gear up flap up" (assuming that taking the flap up is appropriate in that a/c) , and then you are left with "dead right leg dead right engine" or whatever you use, then feather. It's not much good addressing the drag factor of the prop if you have missed the drag factor of flap or gear. I have seen a pilot lose an engine in a hold and forget that they had flap out (cleared for the approach) because they didn't have a proceedure that addressed the different configuarations possible. He was highly loaded up and couldn't figure out the reason for the poor performance until he had lost 300ft.
So although I agree that feathering the prop qucikly is highly desireable, I think the risks of jumping straight into it without going through
The flying school mantra
Silly Old Git
Exactly Mr 37375, DEAD LEG,DEAD ENGINE, CORRECT LEVER? FEATHER,is all thats required initially
After you have stopped shaking, and the pax have turned back to a nice pax colour, all the other mumbo jumbo can be applied
I say it again, a Chieftan will climb on one at gross weight IF ITS CLEANED UP SMARTISH.If a pilot told me he was gonna land it straight ahead I would fire him
After you have stopped shaking, and the pax have turned back to a nice pax colour, all the other mumbo jumbo can be applied
I say it again, a Chieftan will climb on one at gross weight IF ITS CLEANED UP SMARTISH.If a pilot told me he was gonna land it straight ahead I would fire him
While statistics might suggest that increasing the number of engines increases the chance of an engine problem occurring I bet that Capt Sully would have given his left one for a couple more engines on his aircraft.
Bushy is right, flying piston twins DEMANDS a higher level of skills in an engine out situation. Many pilots flying multi engine have no business being there....yet.
Bushy is right, flying piston twins DEMANDS a higher level of skills in an engine out situation. Many pilots flying multi engine have no business being there....yet.
I say it again, a Chieftan will climb on one at gross weight IF ITS CLEANED UP SMARTISH.If a pilot told me he was gonna land it straight ahead I would fire him
PS I'd like to see a V1 cut in a Chieftan at MAUW on a hot day that climbed out, if you were on a massive billiard table you might reach circuit height at 30 miles.