Light twins - single-engine climb performance
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I am going to repeat this as I consider it vitally important to flying LIGHT TWINS!
The other engine gives you more options! With more options come more choices! With more choices the option to make the wrong choice!
Light twins have a bad accident record and frankly I blame the training which is more directed at the pilot moving on to flying aircraft which will climb at 1000 fpm on one.
The majority of the twin rating revolves around shutting down an engine and going for a blue line climb
What happens to the poor pilot desperately flying blue line with minimal climb when the aircraft hits sinking air and everything goes down hill fast?
He sees a descent pulls back and blue line speed is fast gone or the pilot who shuts down an engine still producing 30% power because he is so channel trained that he goes into the blue line mode on automatics?
Light twin training should involve lateral thinking and decision making exploring all the options open to him.
Every engine failure will be different! in different conditions, different weights, different temperatures, different types of failures and the pilot should be trained to being able to identify the best solution even if that means shutting both down and heading to a field.
What does a light twin do best on one engine? It certainly is not climbing! It cruises well on one engine so why not look at setting up a cruise! Take a Seneca Blue line is around 89 kts from memory. Let the aircraft take up level flight it will accelerate to 120 kts, trim it! now trim back and let it step climb till the speed decays to 100 kts. set up level cruise again accelerate to 120 and trim back to 100 kts again. Try it and add this option to flying blue line or closing both .
Only then will we get an improvement in the bad accident stats with twins
Pace
The other engine gives you more options! With more options come more choices! With more choices the option to make the wrong choice!
Light twins have a bad accident record and frankly I blame the training which is more directed at the pilot moving on to flying aircraft which will climb at 1000 fpm on one.
The majority of the twin rating revolves around shutting down an engine and going for a blue line climb
What happens to the poor pilot desperately flying blue line with minimal climb when the aircraft hits sinking air and everything goes down hill fast?
He sees a descent pulls back and blue line speed is fast gone or the pilot who shuts down an engine still producing 30% power because he is so channel trained that he goes into the blue line mode on automatics?
Light twin training should involve lateral thinking and decision making exploring all the options open to him.
Every engine failure will be different! in different conditions, different weights, different temperatures, different types of failures and the pilot should be trained to being able to identify the best solution even if that means shutting both down and heading to a field.
What does a light twin do best on one engine? It certainly is not climbing! It cruises well on one engine so why not look at setting up a cruise! Take a Seneca Blue line is around 89 kts from memory. Let the aircraft take up level flight it will accelerate to 120 kts, trim it! now trim back and let it step climb till the speed decays to 100 kts. set up level cruise again accelerate to 120 and trim back to 100 kts again. Try it and add this option to flying blue line or closing both .
Only then will we get an improvement in the bad accident stats with twins
Pace
Last edited by Pace; 1st Jun 2013 at 19:21.
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Agree Pace, but their are light twins and light twins.
The Seneca, Seminole, Duchess, Couger and Partenavia that I flew, I would not want to lose an engine at or near MTOW. They were pigs for climbing at blue line and your suggestion/s would have been a go'er.
The C310, C421, BE58 and KA200 are a doddle and will happily climb away at blue line.
All horses for courses.
The Seneca, Seminole, Duchess, Couger and Partenavia that I flew, I would not want to lose an engine at or near MTOW. They were pigs for climbing at blue line and your suggestion/s would have been a go'er.
The C310, C421, BE58 and KA200 are a doddle and will happily climb away at blue line.
All horses for courses.
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F900X
Totally agree there is no way an aircraft will climb to its service ceiling for single engine.
Thats it cruise service ceiling and that backs up my argument of why attempt to climb?
Why put the aircraft into having a higher AOA and resulting drag trying to haul a deadweight airframe skywards with one engine.
Unless of course your light and temps are cold.
If a pilot is disciplined enough to peg blue line he is not gurananteed a climb! he is not even guaranteed level flight and maybe even have to fly blue line with a negative reading on the VSI and altimeter.
That is the problem because the training drums it into pilots to climb and when they do not they pull back! Dropping airspeed, more AOA, more drag, more rudder its all going pair shaped fast.
I had an engine failure at 200 feet in a Seneca 4 WITH 100 HRS TT and at grosse.
3 sheared rocker shafts caused by overtorque at manufacture.
The engine was probably still producing 30% power although vibrating badly!
I knew instinctively that if I followed my training by feathering and shutting down the unit i was going to go one way and that was down.
So I kept it going with one hand poised on the prop lever incase there was a bang and coaxed it up to 800 feet where the vibrations got so bad that once level I shut it down, came round and landed.
So I am a firm believer that you have a number of potential ways out! blue line and climb is one but not always the right choice and there are other options which are not taught in the multi engine rating syllabus.
Pace
Totally agree there is no way an aircraft will climb to its service ceiling for single engine.
Thats it cruise service ceiling and that backs up my argument of why attempt to climb?
Why put the aircraft into having a higher AOA and resulting drag trying to haul a deadweight airframe skywards with one engine.
Unless of course your light and temps are cold.
If a pilot is disciplined enough to peg blue line he is not gurananteed a climb! he is not even guaranteed level flight and maybe even have to fly blue line with a negative reading on the VSI and altimeter.
That is the problem because the training drums it into pilots to climb and when they do not they pull back! Dropping airspeed, more AOA, more drag, more rudder its all going pair shaped fast.
I had an engine failure at 200 feet in a Seneca 4 WITH 100 HRS TT and at grosse.
3 sheared rocker shafts caused by overtorque at manufacture.
The engine was probably still producing 30% power although vibrating badly!
I knew instinctively that if I followed my training by feathering and shutting down the unit i was going to go one way and that was down.
So I kept it going with one hand poised on the prop lever incase there was a bang and coaxed it up to 800 feet where the vibrations got so bad that once level I shut it down, came round and landed.
So I am a firm believer that you have a number of potential ways out! blue line and climb is one but not always the right choice and there are other options which are not taught in the multi engine rating syllabus.
Pace
Last edited by Pace; 1st Jun 2013 at 23:22.
A low altitude engine failure in any piston twin is a desperate emergency.
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F900X
200 feet!!! Yes a bit low for a level circuit! Do you have a full failure? Do you keep the damaged engine going? Do you feather and shut down? Blue line at 200 feet are you getting a solid climb? If not look for a reasonable field and use the engine to control your glide into said field.
What are obstructions ahead like? Can you steer a course away from the obstructions? Will you outclimb them on one anyway? 200 feet you have to make a quick decision as you would at 50 feet!
Air below the plane and you have potential energy from the airframe to tap into! room to reduce AOA.
but this is the point you have a number of option not just doggedly going for a blue line come hell or high water as the training seems to concentrate on.
Pace
200 feet!!! Yes a bit low for a level circuit! Do you have a full failure? Do you keep the damaged engine going? Do you feather and shut down? Blue line at 200 feet are you getting a solid climb? If not look for a reasonable field and use the engine to control your glide into said field.
What are obstructions ahead like? Can you steer a course away from the obstructions? Will you outclimb them on one anyway? 200 feet you have to make a quick decision as you would at 50 feet!
Air below the plane and you have potential energy from the airframe to tap into! room to reduce AOA.
but this is the point you have a number of option not just doggedly going for a blue line come hell or high water as the training seems to concentrate on.
Pace
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F900EX
I Know your not getting at anyone
Most twin training has revolved around would be commercial pilots getting multi irs.
They transition to much more capable aircraft where an engine failure is no big deal.
Light twins are a rule to themselves and should have specific training to fly them and respect their limitations
Pace
I Know your not getting at anyone
Most twin training has revolved around would be commercial pilots getting multi irs.They transition to much more capable aircraft where an engine failure is no big deal.
Light twins are a rule to themselves and should have specific training to fly them and respect their limitations
Pace
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BPF.
My statement was probably a bit tongue in cheek and I will rephrase for clarity.
From that bunch, I would happily continue to climb away at blue line knowing that I will achieve a reasonable positive ROC.
It is true, all engine failures are emergencies and it is something I drill myself on for keeping current and ahead of the game.
You have selected the C421. This is not the best aircraft for practice EFAT
due shock loading G520's/reduction gearbox wear etc etc, but I still put myself through the paces with this ship nevertheless.
Full tanks, 4 POB, OAT 10c with simulated EFAT at 300ft, I was achieving 350ft - 450ft min ROC.
My statement was probably a bit tongue in cheek and I will rephrase for clarity.
From that bunch, I would happily continue to climb away at blue line knowing that I will achieve a reasonable positive ROC.
It is true, all engine failures are emergencies and it is something I drill myself on for keeping current and ahead of the game.
You have selected the C421. This is not the best aircraft for practice EFAT
due shock loading G520's/reduction gearbox wear etc etc, but I still put myself through the paces with this ship nevertheless.
Full tanks, 4 POB, OAT 10c with simulated EFAT at 300ft, I was achieving 350ft - 450ft min ROC.
Last edited by Jetblu; 2nd Jun 2013 at 10:53.
I would imagine the 'shock factor' of a real engine power loss would be the biggest problem, those few seconds of disbelief and denial would soon eat up any chance of successfully climbing at blue line after take off. Crashing straight ahead with the wings level is what I try and brief myself on.
By the way, the KA200 isn't a piston twin and cannot really be compared in the same category as the others, but I'm sure you knew this. It's possibly the easiest of the lot with rudder boost, auto-feather and an excess of power.
By the way, the KA200 isn't a piston twin and cannot really be compared in the same category as the others, but I'm sure you knew this. It's possibly the easiest of the lot with rudder boost, auto-feather and an excess of power.
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YSW
Believe it or not, at every take off, I am always prepared and waiting for a donkey to quit, so I can confidently ascertain a blue line climb out.
I thought that we were talking about light twins ?? Now you tell me.
I guess the biggest clue for me was putting Jet A1 in it.
Even with autofeather, they are far from a walk in the park with EFAT.
Believe it or not, at every take off, I am always prepared and waiting for a donkey to quit, so I can confidently ascertain a blue line climb out.
I thought that we were talking about light twins ?? Now you tell me.
I guess the biggest clue for me was putting Jet A1 in it.
Even with autofeather, they are far from a walk in the park with EFAT.
One of the challenges of twin training is accurately setting zero thrust. My feeling is most of the time more than zero thrust is being set and thus an unrealistic level of performance is achieved.
I did some training for a Navajo operator a while ago. The Chief pilot was sure that he could fly away from a low altitude engine failure and that the airplane climbed "just fine" on one engine. To disabuse him of his opinion we loaded the aircraft to gross weight climbed to 4000 feet AGL and actually shut down and feathered the engine. It was a big eye opener to everyone at just how little climb performance there actually was and as a result the SOP's were changed to require closing the throttles if the aircraft was not already clean and at blue line and even then be aware that the aircraft may still not have adequate performance and a glide landing straight ahead may be the best response to the engine failure.
The other problem with twin training is the engine failure exercise is always taught as a binary problem with only two conditions engine runs perfectly - engine has totally failed. In the real world a partial failure or surging engine is a more likely failure mode and is virtually never addressed in training.
I did some training for a Navajo operator a while ago. The Chief pilot was sure that he could fly away from a low altitude engine failure and that the airplane climbed "just fine" on one engine. To disabuse him of his opinion we loaded the aircraft to gross weight climbed to 4000 feet AGL and actually shut down and feathered the engine. It was a big eye opener to everyone at just how little climb performance there actually was and as a result the SOP's were changed to require closing the throttles if the aircraft was not already clean and at blue line and even then be aware that the aircraft may still not have adequate performance and a glide landing straight ahead may be the best response to the engine failure.
The other problem with twin training is the engine failure exercise is always taught as a binary problem with only two conditions engine runs perfectly - engine has totally failed. In the real world a partial failure or surging engine is a more likely failure mode and is virtually never addressed in training.
A King Air 200 with autofeather is in a whole different league than any piston twin. With that aircraft you have enough real performance that climbing away from a EFATO now becomes a realistic option.
Not all light twins will climb out on one.
This light twin wont. Hence it is subject to single engine rules for many things.
But it could happily take a good chop.
This light twin wont. Hence it is subject to single engine rules for many things.
But it could happily take a good chop.
Last edited by Ejector; 3rd Jun 2013 at 05:45.
A King Air 200 with autofeather is in a whole different league than any piston twin. With that aircraft you have enough real performance that climbing away from a EFATO now becomes a realistic option.
I Agree 100%
I also agree with this post above from Big Pistons Forever. Such a true statement.
I Agree 100%
I also agree with this post above from Big Pistons Forever. Such a true statement.
Last edited by Ejector; 3rd Jun 2013 at 05:50.
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The other problem with twin training is the engine failure exercise is always taught as a binary problem with only two conditions engine runs perfectly - engine has totally failed. In the real world a partial failure or surging engine is a more likely failure mode and is virtually never addressed in training
In my own engine failure at 200 and grosse, 3 rocker shafts complety sheared on a Seneca leaving me with approx 30% power and a very badly vibrating engine.
Training would have meant me feathering and shuitting down the unit and without doubt I would have gone down.
Keeping that unit running for as long as possible gave me a slight climb.
i would recommend pilots experiment more with the options.
Who ever practices PFLs in light twins to get used to the descent profile yet that is an option.
Who practices going from climb to cruise as at 400 feet that is an option.
Who practises when to chuck away trying to fly blue line.
Who actually shuts a unit down!
In the Citation I fly we have flown single engine circuits and even flown a touch and go on one.
Totally different kettle of fish to a light twin.
pace
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Second from last line in your post above, I wouldn't advertise that as it is a very big no no.
Unless of course you mean landing on one engine then take-off on two after a/c is reconfigured
Unless of course you mean landing on one engine then take-off on two after a/c is reconfigured
