Twin safety record

I think most will agree...

If you have an adequately powered twin, AND MAINTAIN PROPER PROFICIENCY, than the twin will be a safer alternative. Not maintaining profiency blows the equation, and an underpowered twin might blow the the equation. A high performance machine is a whole 'nother ballgame because of increased power. A jet.... Yet another can of worms.
 
I live at 5000' and my DA is probably over 7K a large % of the time.
Anyone know the SE svc ceiling is for most of the common light twins?
 
I don't, but I'd say you're likely screwed.
 
But... That impossible turn / return may not be so impossible depending on exactly where you lost that engine.

My previously analogy was assuming you lost it at rotation, but if you gained maybe 500', you just may be able to get home.
 
Kritchlow said:
That said, I know this is mostly a small airplane forum so I don't want to derail things.
But just for general knowledge, things such as red line and blue line (heck, yellow arcs and white arcs) don't exist on larger airplanes. That is not say we don't have flap speeds and single engine speeds, it's just that the nomenclature is different.
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I am guessing that anyone driving heavier multiengine aircraft probably aren't in need of any hints on multiengine flying, or if they do, they don't think they do.
 
Kristin said:
I am guessing that anyone driving heavier multiengine aircraft probably aren't in need of any hints on multiengine flying, or if they do, they don't think they do.
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Huh??
I think you are devaluing the meaning of professional pilots with that statement. A true pro knows there is always stuff to be learned.
That's very insulting.

Anyway, big airline procedures and training ensure all that stuff is complied with.
 
Kritchlow said:
Huh??
I think you are devaluing the meaning of professional pilots with that statement. A true pro knows there is always stuff to be learned.
That's very insulting.

Anyway, big airline procedures and training ensure all that stuff is complied with.
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Really! I am not a liberal, so feigning insult isn't going to make me feel guilty. That and being a professional myself, I was not trying to insult myself, or anyone else.
 
Kristin said:
Really! I am not a liberal, so feigning insult isn't going to make me feel guilty. That and being a professional myself, I was not trying to insult myself, or anyone else.
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Pardon me, but huh?? I never said anything about being a liberal??

Totally confused by your post.
 
Let me be more blunt. I can't believe you found an insult in my comments in post #87. It struck me like you were manufacturing outrage out of nothing at all. Does that clear it up?
 
Kristin said:
Let me be more blunt. I can't believe you found an insult in my comments in post #87. It struck me like you were manufacturing outrage out of nothing at all. Does that clear it up?
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I'll reread 87 and respond momentarily...
 
It is my opinion there's quite a bit of negative transfer between part 23 twin flying and the part 25 equipment most pro aspirants end up flying. Obviously training departments do a good enough job to re-teach the multi engine wheel to new turbine entrants to become safe and competent, but I've always been puzzled by the sheer inapplicability of stop-oriented de facto single engine piston twins as follow-on trainers...
 
hindsight2020 said:
It is my opinion there's quite a bit of negative transfer between part 23 twin flying and the part 25 equipment most pro aspirants end up flying. Obviously training departments do a good enough job to re-teach the multi engine wheel to new turbine entrants to become safe and competent, but I've always been puzzled by the sheer inapplicability of stop-oriented de facto single engine piston twins as follow-on trainers...
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It is my belief that a multi engine recip aircraft weighing less than 6000 Lbs doesn't need to conform to part 23.
 
Let'sgoflying! said:
I live at 5000' and my DA is probably over 7K a large % of the time.
Anyone know the SE svc ceiling is for most of the common light twins?
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It depends on how its loaded. On one of those purely theoretical standard days at gross the single engine service ceiling of my Aztec is less than 5000'

I fly out of a 4000' ASL airport just east of the Continental Divide. I try to fly the airplane light out of my home airport. I am actually more concerned about single engine service ceiling at altitude over the rocks to the west of me.

My naturally-aspirated Aztec has an almost 2000 lb useful load, and full fuel is 1100 lbs. I rarely carry more than 800 lbs of fuel. With 600 lbs of payload it puts me 600 lbs below gross on TO. On that same theoretical standard day with that load the single engine ceiling is 8000'. At altitude with a bit of fuel burned off my single engine ceiling with that payload rises to over 9500'. Most of the time when I am westbound I am lighter than this example.

I deliberated buying a turbocharged airplane, but found the useful loads for most light twins are actually pretty limited. Most of the Seneca's (200 hp turbocharged engines) couldn't carry much of anything so any reasonable fuel+payload left little margin in a single engine event, even if the remaining turbocharged engine was developing full rated output . At the end of the day the trade off of additional complexity, fuel burn, maintenance cost and reduced engine longevity of the turbo lost out to the naturally-aspirated Aztec and its ability to be flow with a margin of safety well below gross.
 
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Let'sgoflying! said:
I live at 5000' and my DA is probably over 7K a large % of the time.
Anyone know the SE svc ceiling is for most of the common light twins?
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I've got a 1000 lb useful load with full fuel in the 310 which will take you 1000 miles. A lot of room to depart significantly under gross. Book says se service ceiling is over 8000ft, 500lbs under gross, and 70* temp.
 
Kritchlow said:
It is my belief that a multi engine recip aircraft weighing less than 6000 Lbs doesn't need to conform to part 23.
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In truth, most of them are CAR3 certified, not Part 23. No SE performance is required in either, IIRC.
 
James_Dean said:
I've got a 1000 lb useful load with full fuel in the 310 which will take you 1000 miles. A lot of room to depart significantly under gross. Book says se service ceiling is over 8000ft, 500lbs under gross, and 70* temp.
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We're way above that -- on the ground -- here in the summertime.

I've always wondered what "the plan" was for engine failure in the Senecas and the Tecnam that are the three most popular ME trainers on the field in those warmer months.

You're coming down whether you want to or not.
 
denverpilot said:
We're way above that -- on the ground -- here in the summertime.

I've always wondered what "the plan" was for engine failure in the Senecas and the Tecnam that are the three most popular ME trainers on the field in those warmer months.

You're coming down whether you want to or not.
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I understand, and you live with the possibility of a gentle drift down.
 
James_Dean said:
I understand, and you live with the possibility of a gentle drift down.
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Yeah wasn't really directed at you, just quoting your numbers for the 310 and pointing out that even though it's a very capable light twin, it's still coming down.

The Senecas and the Tecnam that depart on 80F+ days around here for ME training, I just wonder where they are thinking they'll be landing them when a mill quits.

Maybe one of you steely eyed twin drivers can explain how one of those "gently" drifts down... I get the general feel (without their POH numbers handy) that they're coming down 500 fpm on those days... Or worse.

I can only assume they fly them around at half tanks or less to even get them to perform well enough with two people and no bags on board to be a reasonable risk in the summertime. (Shrug...)

Guess I'll find out one of these days.
 
I learned quite a bit from this post:

#1. Twins and Singles both crash all of the time the most important thing is proficiency.
#2. When taking a trip, have a good flight plan and consider where you would put the plane down if the engine/engines quit.
#3. If you are in a Single or Twin and your engine quits a few hundred feet from take off you are screwed.
 
EdFred said:
Explain it all you want, but you are still explaining it wrong.
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I see nothing wrong with his math. Two engines will will have twice as many failures. It's the same exact failure rate as engines on a single, but you have two of thrm. Odds of them happening at the same time are very small though. Unless someone filled the tanks with jet fuel instead of 100LL.

Having two engines means when one engine does fail, the other is still running leaving the pilot with more options on where to land than they would have in a single when one engine fails.
 
wayne said:
I see nothing wrong with his math. Two engines will will have twice as many failures. It's the same exact failure rate as engines on a single, but you have two of thrm. Odds of them happening at the same time are very small though. Unless someone filled the tanks with jet fuel instead of 100LL.

Having two engines means when one engine does fail, the other is still running leaving the pilot with more options on where to land than they would have in a single when one engine fails.
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this......:yes:
 
denverpilot said:
Yeah wasn't really directed at you, just quoting your numbers for the 310 and pointing out that even though it's a very capable light twin, it's still coming down.

The Senecas and the Tecnam that depart on 80F+ days around here for ME training, I just wonder where they are thinking they'll be landing them when a mill quits.

Maybe one of you steely eyed twin drivers can explain how one of those "gently" drifts down... I get the general feel (without their POH numbers handy) that they're coming down 500 fpm on those days... Or worse.

I can only assume they fly them around at half tanks or less to even get them to perform well enough with two people and no bags on board to be a reasonable risk in the summertime. (Shrug...)

Guess I'll find out one of these days.
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Take off options with an engine failure are not much different than being in a single. Still on the ground, close the throttles and get on the brakes. Just off the ground before establishing +'ve rate of climb, with the gear still out, same thing (Vmca = 0 when the throttle on the good engine is closed & better to land wings level under control than a futile attempt to accelerate the airplane with asymmetric thrust). Once I have +'ve rate I don't waste time getting the gear up and climbing the first 1000 ft, after which there are more options, but I know before I leave the ground what the airplane should be able to do in the specific loading and DA circumstance. I had that drilled into me by an instructor early in my twin training. One of the perversely satisfying things I find about the Aztec is the enormous amount of performance information/charts in the PoH; part of that is the airplane is newer than any single I've owned and the PoH info for all airplanes got more complete with time.

At altitude I've done actual single engine shutdowns on each side in training to see how the airplane really responds and it's nothing dramatic. Depending on conditions and loading the plane seems to typically do anywhere from 200 fpm down to 200 fpm up on the VSE.

There are a couple of Rotax powered Tecnam twins used as trainers out of our 4000 ASL airport now, but I am not sure I would actually want to fly one of those. Our flying club has a twin Comanche which I think is a better choice at our altitude.
 
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Kritchlow said:
It is my belief that a multi engine recip aircraft weighing less than 6000 Lbs doesn't need to conform to part 23.
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Clearly you don't understand how certification works. Most of the light twins out there were type certificated before Part 23 existed. If certified to 1956 regulations it was still built basically to the same regulations a decade later with very minor tweaks.


Twin Comanche production started in 1962ish and ended 1973ish.


(Parts 23.1557, 23.1401, 23.145, 23.161 and 23.175 listed there have nothing to do with climb minimums)

§ 3.85a Climb requirements - airplane of 6,000 lbs. or less . Airplanes having a maximum certificated take-off weight of 6,000 lbs. or less shall comply with the requirements of this section.

(a) Climb - take-off climb condition. The steady rate of climb as sea level shall not be less than 10 Vs1 or 300 feet per minute, whichever is the greater, with:

(1) Take-off power,

(2) Landing gear extended,

(3) Wing flaps in take-off position,

(4) Cowl flaps in the position used in cooling tests specified in §§ 3.581 through 3.596.

(b) Climb with inoperative engine. All multiengine airplanes having a stalling speed Vso greater than 70 miles per hour shall have a steady rate of climb of at least 0.02 Vso in feet per minute at an altitude of 5,000 feet with the critical engine inoperative and:

(1) The remaining engines operating at not more than maximum continuous power,

(2) The inoperative propeller in the minimum drag position,

(3) Landing gear retracted,

(4) Wing flaps in the most favorable position,

(5) Cowl flaps in the position used in cooling tests specified in §§ 3.581 through 3.596.

(c) Climb - balked landing conditions. The steady rate of climb at sea level shall not be less than 5 Vso or 200 feet per minute, whichever is the greater, with:

(1) Take-off power,

(2) Landing gear extended,

(3) Wing flaps in the landing position. If rapid retraction is possible with safety, without loss of altitude and without requiring sudden changes of angle of attack or exceptional skill on the part of the pilot, wing flaps may be retracted.
 
FloridaPilot said:
I learned quite a bit from this post:

#1. Twins and Singles both crash all of the time the most important thing is proficiency.
#2. When taking a trip, have a good flight plan and consider where you would put the plane down if the engine/engines quit.
#3. If you are in a Single or Twin and your engine quits a few hundred feet from take off you are screwed.
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Basically, yes! ;):)

late edit: agree with EggMan on #3 :)
 
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denverpilot said:
Yeah wasn't really directed at you, just quoting your numbers for the 310 and pointing out that even though it's a very capable light twin, it's still coming down.

The Senecas and the Tecnam that depart on 80F+ days around here for ME training, I just wonder where they are thinking they'll be landing them when a mill quits.

Maybe one of you steely eyed twin drivers can explain how one of those "gently" drifts down... I get the general feel (without their POH numbers handy) that they're coming down 500 fpm on those days... Or worse.

I can only assume they fly them around at half tanks or less to even get them to perform well enough with two people and no bags on board to be a reasonable risk in the summertime. (Shrug...)

Guess I'll find out one of these days.
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I accepted the fact that the turbocharged twin I flew out of here was a glorified single because we almost always took off close to gross.
 
FloridaPilot said:
I learned quite a bit from this post:

#1. Twins and Singles both crash all of the time the most important thing is proficiency.
#2. When taking a trip, have a good flight plan and consider where you would put the plane down if the engine/engines quit.
#3. If you are in a Single or Twin and your engine quits a few hundred feet from take off you are screwed.
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I don't agree with #3 if the pilot has heeded #1 and #2.
 
James_Dean said:
I don't agree with #3 if the pilot has heeded #1 and #2.
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Correct. I know several people who've had engine failures at 400 AGL and successfully made it around the pattern for landing.
 
denverpilot said:
Maybe one of you steely eyed twin drivers can explain how one of those "gently" drifts down...
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You fly along with one engine at full power and the other caged. Get it trimmed properly to maintain about 5* of bank and half a ball out. You sit there and fly along slowly drifting down at whatever she will give you which will improve with lower altitude. So, for example if I'm at 10,000 ft on a standard day at gross the poh says I will be coming down at about 50 fpm. It really isn't a big deal at altitude.


 

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The 5 degree bank is to prevent Vmc roll, zero-sideslip (minimum drag) is less than that.
 
Ted DuPuis said:
Correct. I know several people who've had engine failures at 400 AGL and successfully made it around the pattern for landing.
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...but let's not talk about the several hundred who didn't make it.
 
James_Dean said:
You fly along with one engine at full power and the other caged. Get it trimmed properly to maintain about 5* of bank and half a ball out. You sit there and fly along slowly drifting down at whatever she will give you which will improve with lower altitude. So, for example if I'm at 10,000 ft on a standard day at gross the poh says I will be coming down at about 50 fpm. It really isn't a big deal at altitude.


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I see. I was thinking the sink rate would be higher.

(I could go read up on these things if I wasn't so terribly busy right at the moment. Heh. And you guys already know. The impression folks -- who probably don't know jack -- around here give is that it's a lot more "urgent" in the smaller light twins...)

And I phrased the question poorly. What I was really attempting to ask is: If you know you're going to have to "drift down", do you plan an altitude where a runway or other suitable landing spot is available to you within "drift down" range, similar to the technique of flying higher at night in a single?

But at 50 fpm my guess is the answer is probably "no". ;) The risk is "acceptable" over most places during the climb and descent phases considering the altitudes y'all like to climb up to in order to go somewhere.
 
The safety of a twin is what you make it. I fly a single, on takeoff I pretty much just firewall it and hope for the best. If the engine fails, all I have to do is not stall, and steer it left or right to the most suitable crashing area.
 
One issue is, when a pilot has one engine fail on a twin, he has to make some decisions, like whether to land at the closest airport, closest airport with services or continue to his destination.
 
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