Twin or Single

[6t6]

A twin gets you 1.95 times a single maintenance, twice the fuel burn, higher takeoff and landing speeds plus longer ground roll for each, and you need more recurrent training to stay safe in a twin. Also, your speed increases by the third root of two. Finally, there’s an old saying that losing an engine in a twin means it takes longer to get to the scene of the accident. Once off the ground, they climb better, but as far as I can tell, that’s their main advantage.

You must be a single engine guy. That blanket statement about maintenance and everything is just not accurate. I own a twin Comanche and I'll put the cost of maintenance against any high performance single and probably come out on the winning side. . As far as performance yes you have to know your field length limits. As far a single engine performance in a twin. Its all in the numbers. Plus it's fun runnin' two motors and speed is usually greater.

 

[PaulS]

I think that's probably true — at least for certain types of flying (night in low IMC, over water, above mountains, etc). But if you're considering only competent pilots in twins, then you also need to consider only competent pilots in singles as well in the comparison; otherwise, it's apples to oranges. Unfortunately, pace the late Richard Collins, there's nothing in the stats that really helps us disaggregate the data that far.

We can count the NTSB accident stats a gross level, and say that twins used to have a lot more fatal accidents than singles per hour flown, but it's not so bad now (as Collins pointed out at different times over the years), but any more-nuanced argument will be based on anecdotes, selective readings, personal belief, etc. rather than data. We can keep that going all day, just like low-wing vs high-wing, Garmin vs Avidyne, etc. etc.

I guess my issue, and trust me, I'd love to get a twin, is that based on anecdotal evidence twins should be much safer and much less accident prone than singles, because it removes one of the larger factors that contribute to single crashes, that is complete loss of power. Yet twins are not safer.

There seems to be two issues, proficiency and the appropriateness of the training that is being done. If every pilot addressed those two issues, then accident rates would most likely plummet for both single and multi.

 

[tspear]

@Tantalum

I have about 300 hours in an Aerostar. I love that plane
People called it Deathstar because they largely treated the plane a large C182 mentality. Same for those that flew Barons, it is a simple step up from a Bonanza. The Aerostaris not just a small step up compared to the Baron, C3XX. This is massive jump.
The Aerostar was designed from the start to have jet engines, and even though it has straight wings, it acts more like a traditional swept wing plane.
This is what catches pilots unaware. The Aerostar has by far one of the most honest feedback to the pilot that you can find.

If you are really interested, join the Aerostar Forum.
Tim

 

[Tantalum]

Cape Air operated (still operates?) over 80 Cessna 402 aircraft and has been flying around small piston twins for decades. They've had TONS of engine failures, but up until a freak accident in 2008 caused by spatial disorientation they never had a fatality. Incidentally, this was their only fatality, pilot was sole occupant.

At some point they even grounded their entire 402 fleet because of how many engine failures they were having, but again, no accidents.

Recently, like a few days ago, a cape air plane was doing training touch and goes and the left engine failed.. Guess what, it landed and no one was injured. The engine failed during touch and goes.. so close to the ground, low speed, high power.

TWINS ARE SAFER.. IF FLOWN BY A COMPETENT PILOT. Mind you, the Cape Air flights are single pilot. And at least when I flew them a few years ago the planes were fairly "worn" .. to put it lightly.

 

[tspear]

@PaulS

As much as I like Collins, his article and some of his logic have large holes in them.
For example, he compares absolute numbers of accidents, no normalization for hours flown, or conditions (IMC/VMC/Night/Training...)
Also, the comment that you should not fly a twin in conditions you will not fly a single does not make any logical sense.
At night in IMC, if you are in a single and have a mechanical failure, you are figuratively toast. In a twin, you have options. That is just one example.

Tim

 

[PaulS]

Cape Air operated (still operates?) over 80 Cessna 402 aircraft and has been flying around small piston twins for decades. They've had TONS of engine failures, but up until a freak accident in 2008 caused by spatial disorientation they never had a fatality. Incidentally, this was their only fatality, pilot was sole occupant.

At some point they even grounded their entire 402 fleet because of how many engine failures they were having, but again, no accidents.

Recently, like a few days ago, a cape air plane was doing training touch and goes and the left engine failed.. Guess what, it landed and no one was injured. The engine failed during touch and goes.. so close to the ground, low speed, high power.

TWINS ARE SAFER.. IF FLOWN BY A COMPETENT PILOT. Mind you, the Cape Air flights are single pilot. And at least when I flew them a few years ago the planes were fairly "worn" .. to put it lightly.

Those new technams look sweet though.

 

[PaulS]

@PaulS

As much as I like Collins, his article and some of his logic have large holes in them.
For example, he compares absolute numbers of accidents, no normalization for hours flown, or conditions (IMC/VMC/Night/Training...)
Also, the comment that you should not fly a twin in conditions you will not fly a single does not make any logical sense.
At night in IMC, if you are in a single and have a mechanical failure, you are figuratively toast. In a twin, you have options. That is just one example.

Tim

I thought he delved into fatalities per hours flown, he had written a few articles about this. But I'm no expert, nor do I care to become one. At the end of the day if you do the training and stay proficient and the training is good, then logically it seems better to have two engines versus one. Remove any one of those things, then it seems they are more dangerous, more so than a single pilot with one missing due to the inherent issues of asymmetrical thrust.

 

[tspear]

I thought he delved into fatalities per hours flown, he had written a few articles about this. But I'm no expert, nor do I care to become one. At the end of the day if you do the training and stay proficient and the training is good, then logically it seems better to have two engines versus one. Remove any one of those things, then it seems they are more dangerous, more so than a single pilot with one missing due to the inherent issues of asymmetrical thrust.

I have read a fair number of his articles, including the ones you linked too. And no, I did not find the hour breakdown.
What he rightly challenged was the assumption twin was safer. But there is no data to back the claim either way.

Tim

 

[EdFred]

I thought he delved into fatalities per hours flown, he had written a few articles about this. But I'm no expert, nor do I care to become one. At the end of the day if you do the training and stay proficient and the training is good, then logically it seems better to have two engines versus one. Remove any one of those things, then it seems they are more dangerous, more so than a single pilot with one missing due to the inherent issues of asymmetrical thrust.

Accidents/Hours flown might not be the best metric to use.

How long does it take to go 200nm in a cabin class twin?
How long does it take to go that far in a Cub?

 

[Tantalum]

@Tantalum

I have about 300 hours in an Aerostar. I love that plane
People called it Deathstar because they largely treated the plane a large C182 mentality. Same for those that flew Barons, it is a simple step up from a Bonanza. The Aerostaris not just a small step up compared to the Baron, C3XX. This is massive jump.
The Aerostar was designed from the start to have jet engines, and even though it has straight wings, it acts more like a traditional swept wing plane.
This is what catches pilots unaware. The Aerostar has by far one of the most honest feedback to the pilot that you can find.

If you are really interested, join the Aerostar Forum.
Tim

Thanks man! I really am interested. We'll see what the landscape looks like like in 2-3 years, both for myself financially personally and for what's out there on the market. I'll check out the forum. Every now and then I see one at the ramp around my parts either at MYF or RNM

 

[Tantalum]

Those new technams look sweet though.

They do! I believe they're FADEC engines too.

 

[tspear]

Accidents/Hours flown might not be the best metric to use.

How long does it take to go 200nm in a cabin class twin?
How long does it take to go that far in a Cub?

Not just hours, but mission plays a factor.
What is more likely to have a fatal flight? A training flight in daylight, or night IMC over the mountains at MTOW.

Tim

 

[EdFred]

Not just hours, but mission plays a factor.
What is more likely to have a fatal flight? A training flight in daylight, or night IMC over the mountains at MTOW.

Tim

*The latter, because if you are at MTOW and already en route, you're probably doing a bunch of other stuff to contribute to your demise, as well.

* - Planes that can refuel in the air not included.

 

[GRG55]

I'm going to sound like a Gryder groupie again, but he covers the twin issue pretty well IMO. There have been a few departure rollover crashes in the past year or two and a couple loss of control enroute to an airport, all after an engine failure, none should have occurred. All point to pilot error, lack of proficiency, getting too slow.

I'm not trying to talk anybody out of getting a twin, personally, from what I see of you and how you post I think you'd be a safe twin pilot.

I'm just pointing out that twins don't have a better safety record than singles, even though they probably should. I think pilots that understand this, and train to avoid what gets other pilots killed will have a twin with a better safety potential than a single. It's sad that historically this is not the case.

Twins require more knowledge than singles and they are not as forgiving of forgetting that extra knowledge as forgetting something in a single would be.

I'm not ever going to argue that a twin is "safer" or "less safe" than a single engine airplane.

What I will argue is NO airplane is "safe" in the hands of a pilot that tries to fly it outside it's known flight envelope. Even a Cessna 150 will try to kill you if you disrespect this fact - but the faster, higher performance airplanes generally try to kill you faster, and in a wider variety of ways than a 150 might. There's just no substitute for pilot proficiency.

Every airplane has multiple failure modes. No argument with your basic premise "Twins require more knowledge than singles..." The more complex the airplane the more the number of potential failure modes, and that certainly applies when comparing a twin to a single. It also applies when comparing a simple, slow speed, low horsepower single engine airplane to a more complex single engine. It wasn't the Cessna 150 or 172 that earned the moniker "Doctor Killer".

Even that airplane with the parachute (I have become a fan of the Cirrus CAPS system, even though I don't own one) can bite quickly, and even lethally, if one tries to fly it outside the envelope, as this terrible 2016 SR20 accident at Houston Hobby amply demonstrated:

http://www.kathrynsreport.com/2016/06/cirrus-sr20-n4252g-safe-aviation-llc.html

"...Data retrieved from the airplane revealed that, during the go-around, the pilot did not follow the recommended go-around procedure; specifically, the pilot did not attain a speed between 81 to 83 knots indicated airspeed (KIAS) before raising the flaps. Rather, the airplane's airspeed was 58 KIAS when the pilot raised the airplane's flaps while in a left turn, which resulted in exceedance of the critical angle of attack and a subsequent aerodynamic stall and spin into terrain..."
​

There's just no substitute for pilot proficiency, no matter what type of airplane one is discussing.

 

[PaulS]

I'm not ever going to argue that a twin is "safer" or "less safe" than a single engine airplane.

What I will argue is NO airplane is "safe" in the hands of a pilot that tries to fly it outside it's known flight envelope. Even a Cessna 150 will try to kill you if you disrespect this fact - but the faster, higher performance airplanes generally try to kill you faster. There's just no substitute for pilot proficiency.

Every airplane has multiple failure modes. No argument with your basic premise "Twins require more knowledge than singles..." The more complex the airplane the more the number of potential failure modes, and that certainly applies when comparing a twin to a single. It also applies when comparing a simple, slow speed, low horsepower single engine airplane to a more complex single engine. It wasn't the Cessna 150 or 172 that earned the moniker "Doctor Killer".

Even that airplane with the parachute (I have become a fan of the Cirrus CAPS system, even though I don't own one) can bite quickly, and even lethally, if one tries to fly it outside the envelope, as this terrible 2016 SR20 accident at Houston Hobby amply demonstrated:

http://www.kathrynsreport.com/2016/06/cirrus-sr20-n4252g-safe-aviation-llc.html

"...Data retrieved from the airplane revealed that, during the go-around, the pilot did not follow the recommended go-around procedure; specifically, the pilot did not attain a speed between 81 to 83 knots indicated airspeed (KIAS) before raising the flaps. Rather, the airplane's airspeed was 58 KIAS when the pilot raised the airplane's flaps while in a left turn, which resulted in exceedance of the critical angle of attack and a subsequent aerodynamic stall and spin into terrain..."
​

There's just no substitute for pilot proficiency, no matter what type of airplane one is discussing.

Well said.

 

[David Megginson]

I guess my issue, and trust me, I'd love to get a twin, is that based on anecdotal evidence twins should be much safer and much less accident prone than singles, because it removes one of the larger factors that contribute to single crashes, that is complete loss of power. Yet twins are not safer.

There seems to be two issues, proficiency and the appropriateness of the training that is being done. If every pilot addressed those two issues, then accident rates would most likely plummet for both single and multi.

Exactly. Like I wrote, it seems deceptively simple if you look at just one problem (e.g. ability to reach an airport after an engine failure enroute), but it gets impossibly complicated if you look at them all together and mix in human nature and risk compensation.

• a twin has two engines, so it has only ½ the chance of a complete power loss due to mechanical failure (but more forced landings come from fuel-mismanagement than mechanical failure, and a second engine won't help with that)
• a single has ½ the chance of an engine fire in flight (but because the engine's are out on the wings, you're less likely to have smoke pouring through the vents into the cabin)
  
• a single or inline-twin has 0 chance of asymmetrical thrust in a slow-speed/high-power situation (which can result in a VMC rollover)
  
• a twin or high-performance single can often top bad weather, when lower-powered single is forced to fly through or under it (which can result in a CFIT or unintended storm-cell penetration)
  
• a twin or high-performance single can often top mountains, when many lower-powered singles have to follow the valleys (which can result in a CFIT)
  
• singles typically have a slower stall speed, so a runway excursion, forced landing, etc is less likely to result in injury or death
• twins can fly in very light icing conditions, while most singles can't (or shouldn't); then again, pilots in singles are less tempted to try, and you can get in over your head very fast in SLD icing, even with FIKI

So we know that, over all, twins have had a worse safety record per flight hour than singles in the past (now improving), but we don't really know why or under what circumstances. There is no mathematical way to pick all of these apart — the data just doesn't exist at that level of disaggregation. However, it should be clear that saying "a twin is safer because it has two engines" is an absurdly-naive statement.

 

[EdFred]

When you calculate probabilities wrong....GIGO

Your half number is unequivocally wrong - which makes the rest of the extrapolation just as wrong.

 

[hindsight2020]

Indeed, that probability calculation was FUBAR. The probability of dual engine failure (as independent occurrences) happening in the same flight is :

(probability of single engine event)^2. Not (prob)/2. Way waaaaaay smaller than half.

So something with a probability of occurrence in the single digits like a total power loss in a piston engine, is gonna have a really small probability of occurrence as a dual event. What you meant to calculate was the comparative likelihood of a single event, which for the twin is indeed: (probability of single event) x (number of engines).

That's where twins are twice as likely to have an engine failure, but a non-linearly smaller eventuality of losing both on the same flight. The latter is the impetus behind airliners having two engines, beyond the obvious extra power loading capacity of modern high bypass turbofan engines when not dimensionally constrained by a relatively weak and small vertical stabilizer structure.

ETA: I did overwater in a single. But that's one Lycoming which is like 3 contis and a chute--

 

[Tantalum]

Cape Air actually had a total engine failure due to faulty maintenance work on the fuel system.. they were able to land successfully with all occupants surviving. I'm firmly in the twin camp. Or the parachute camp. To me flying SE without a second engine or a chute and solely depending on your superior aviation skills, having the goodluck of a suitable landing spot near you, and a "roll cage" are fairly thin insurance policies.

 

[David Megginson]

Indeed, that probability calculation was FUBAR. The probability of dual engine failure (as independent occurrences) happening in the same flight is :

(probability of single engine event)^2. Not (prob)/2. Way waaaaaay smaller than half.

Good point. Yes, the chance of both engines failing at the same time from a mechanical issue is smaller than x/2, but still much higher than x^2, because they're not totally independent. First, engine failures from fuel mismanagement are more common than engine failures from mechanical problems, and the extra engine doesn't help reduce the chance of those. And second, both engines tend to undergo maintenance at the same time (annual, oil changes, etc), there there's a non-trivial risk that a maintenance- or parts-induced failure could affect both simultaneously.

The real question — which we can't answer with the data we have — is how much of an impact that specific probability (whatever it is) of power loss has on the overall fatal accident rate. The benefit isn't apparent in the fatal-accident rate for twins (compared to singles), but that could be because something else about twins is cancelling it out.

 

[David Megginson]

Cape Air actually had a total engine failure due to faulty maintenance work on the fuel system.. they were able to land successfully with all occupants surviving. I'm firmly in the twin camp. Or the parachute camp. To me flying SE without a second engine or a chute and solely depending on your superior aviation skills, having the goodluck of a suitable landing spot near you, and a "roll cage" are fairly thin insurance policies.

If the second engine is a safety benefit, it's just not showing up in the fatal-accident stats (for whatever reason), so it's a case of "it ought to help" rather than "it does help." It's deductive rather than inductive reasoning.

The chute is also hard to prove statistically. It also ought to help, but initially, the Cirrus had a much-higher fatal-accident rate than 40-year-old 172s or PA-28s. That's come down until it's about as safe as the older planes without chutes, but we're still not seeing any evidence that it's safer. That could just be due to human factors like risk compensation — e.g. knowing there's a chute, pilots take more risks, so the fatal accident rate comes out about the same.

 

[PaulS]

If the second engine is a safety benefit, it's just not showing up in the fatal-accident stats (for whatever reason), so it's a case of "it ought to help" rather than "it does help." It's deductive rather than inductive reasoning.

The chute is also hard to prove statistically. It also ought to help, but initially, the Cirrus had a much-higher fatal-accident rate than 40-year-old 172s or PA-28s. That's come down until it's about as safe as the older planes without chutes, but we're still not seeing any evidence that it's safer. That could just be due to human factors like risk compensation — e.g. knowing there's a chute, pilots take more risks, so the fatal accident rate comes out about the same.

The Cirrus issue was mainly due to reluctance to pull, which happened for a variety of reasons, not the least of which was pilots essentially saying pulling is the cowards way out, a real pilot flies to the end, die like a man. Fortunately, Cirrus addressed this via training and turned it around.

 

[hindsight2020]

The real question — which we can't answer with the data we have — is how much of an impact that specific probability (whatever it is) of power loss has on the overall fatal accident rate. The benefit isn't apparent in the fatal-accident rate for twins (compared to singles), but that could be because something else about twins is cancelling it out.

well, at least anecdotally we can take a stab at the bolded for the twins: Gomers who can't keep up with the OEI dexterity required will drag the twin "glove-save" rate down. And recurrent training in certain sectors still doesn't keep people from porking it up wholesale. Below is one example of an OEI cut handled so badly, they would positively have been better off in a single turbine, re-settling long, taking it off-roading thru the fence at airport rental speed, and lived to tell the insurance company about it.

 

[PaulS]

well, at least anecdotally we can take a stab at the bolded for the twins: Gomers who can't keep up with the OEI dexterity required will drag the twin "glove-save" rate down. And recurrent training in certain sectors still doesn't keep people from porking it up wholesale. Below is one example of an OEI cut handled so badly, they would positively have been better off in a single turbine, re-settling long, taking it off-roading thru the fence at airport rental speed, and lived to tell the insurance company about it.

There is probably at least a dozen videos like this on youtube. And the question is, did the gomer get the training that says push the nose down rather than pull it up in this situation. Some say no, that is a big part of the problem.

 

[David Megginson]

There is probably at least a dozen videos like this on youtube. And the question is, did the gomer get the training that says push the nose down rather than pull it up in this situation. Some say no, that is a big part of the problem.

Very true. But at the same time, we have lots of (mostly-single-engine) pilots who use inside rudder to "tighten" the turn from base to final and end up in a stall-spin, so pilot incompetence runs up the fatal-accident tally on both the single and twin sides. Perhaps the difference is that a skidding turn is something you have to initiate yourself (however unconsciously), while asymmetric thrust right after takeoff is something imposed on you out of the blue, when your mind is somewhere else (e.g. retracting the takeoff flaps, flying a SID, getting ready to switch frequencies, turning a VOR, or what-have-you).

I wouldn't actually say "no" to a twin myself, but both of the following conditions would have to apply (which they don't right now):

1. I'd have to have a lot more money available for flying than I do now — for example, I'd be looking at 8–12 cylinders instead of my current 4, 16–24 spark plugs instead of my current 8, etc etc, so I'd have to be able to deal with huge surprise repair bills from time to time, even if they didn't average out to so much more.
   
   
2. I'd have to have a lot more time available for flying than I do now — after 1,250 hours, I'm confident that I'm a reasonably-competent pilot for the demands of my simple (and much-loved) Piper PA-28-161, even when I can't fly for a few weeks, or when I manage only 50 hours in a year. A twin would not let me get away with that — I'd want to fly 150 hours/year minimum, and do at least annual recurrent training in a sim somewhere like FlightSafety. Without that, in a twin I'd just be a statistic waiting to happen. And I don't have room in my life right now (pre-retirement) for that level of intense commitment to flying.

 

[Tantalum]

I'm bet all those Cape Air passengers were sure happy that the company had invested in twins vs a fleet of 206s and 210s..

It's just hard for me to fathom that anyone can realistically argue that a parachute, or second engine redundancy, are not nice tools to have in the bag. Money aside, would anyone here genuinely prefer to cross the Gulf of Mexico in a 210 vs a 310?

It's all about pilot skill.

 

[Tantalum]

I'd have to have a lot more time available for flying than I do now — after 1,250 hours, I'm confident that I'm a reasonably-competent pilot for the demands of my simple (and much-loved) Piper PA-28-161, even when I can't fly for a few weeks, or when I manage only 50 hours in a year. A twin would not let me get away with that — I'd want to fly 150 hours/year minimum, and do at least annual recurrent training in a sim somewhere like FlightSafety. Without that, in a twin I'd just be a statistic waiting to happen. And I don't have room in my life right now (pre-retirement) for that level of intense commitment to flying.

all of this I fully agree with

 

[GRG55]

The Cirrus issue was mainly due to reluctance to pull, which happened for a variety of reasons, not the least of which was pilots essentially saying pulling is the cowards way out, a real pilot flies to the end, die like a man. Fortunately, Cirrus addressed this via training and turned it around.

What Cirrus did to address this issue is a good example of improving pilot proficiency.
Up to about 2010 or 2011 the Cirrus fatal accident rate was about double the GA fleet average. The training had a measurable effect on the Cirrus fatal accident rate, which I understand is now running slightly below the fleet average rate.

well, at least anecdotally we can take a stab at the bolded for the twins: Gomers who can't keep up with the OEI dexterity required will drag the twin "glove-save" rate down. And recurrent training in certain sectors still doesn't keep people from porking it up wholesale. Below is one example of an OEI cut handled so badly, they would positively have been better off in a single turbine, re-settling long, taking it off-roading thru the fence at airport rental speed, and lived to tell the insurance company about it...

This might be the single largest issue with piston (or turbine?) twins - an engine failure early in the climb out after take-off. I really get the impression that many pilots take off without actually calculating if on that specific day, at that specific density altitude and that specific loading they can maintain a climb if they lose one engine. One needs to know, before pushing those throttles up. It is a critical part of the pre-flight planning and decision making.

I fly out of a 4000 ASL airport in the Rockies. If I am still at too low an altitude in conditions that do not allow a comfortable climb margin I know, in advance, my out is to not hesitate to close the throttle on the good engine to get rid of Vmc entirely, and put the airplane down wings level at the slowest reasonable airspeed above the stall. My options are no worse than if I had an engine failure at the exact same point in the flight in a comparable single engine airplane - the Aztec's stall speeds are virtually identical to an A36 Bonanza.

Just as some single engine airplanes end up in a crater because the pilot tried to "stretch the glide" after an engine failure, I believe some twins end up in a Vmc induced crater because the pilot won't consciously consider how they are going to deal with the loss of an engine at low speed, close to the ground. Among other things, I do not climb out at Vx or Vy, unless I have the rare situation of an obstacle clearance. I want a margin above blue line during the climb because I know if an engine grenades there is a recognition and response time needed to get the nose down. Gawd knows how many twin takeoffs I witness at my busy airport where the pilots are catering to the spectators with a pitch to steep climb attitude right after the gear is in the wells. Engine failures are rare enough that most can get away with this through all their years of flying. But, there's always that possibility.

It's a trade off between the time and $ invested in effective recurrent training, or the savings vs risk of not doing it.

 

[RudyP]

Isn't this one of the most beat to death issues in GA??

The one thing I will add is that not all twins are the same in terms of requiring pilot competence. Not that I would advocate for poor pilot performance, but most jets (which are twins) are pretty easy to handle in 99% of situations if an engine fails. The combination of lots of excess thrust, close to centerline thrust and 61.58 annual training checks makes it pretty easy to feel confident in case of an engine failure after takeoff in a jet. I only have 4-5 hours in a piston twin (DA62) but I'd feel a lot less comfortable losing one in that airplane than the C510 I fly.

I know this discussion is pretty much about piston GA but I would assume the point still holds somewhat, i.e. some piston twins have more power to weight ratio than others and must provide a bit more safety padding than others... But my experience is pretty much entirely piston singles and turbofan twins so I may be wrong about this.

 

[Crashnburn]

I was going to respond with "financing is for poor people" but thought it potentially tone deaf lol

People can always justify whatever it is they prefer. To me the fact that Boeing and Airbus as well as GE, Rolls-Royce, and Pratt & Whitney aren't racing to build a single engine commercial airliner is the proof to me that for a competent and well-trained pilot a twin is always safer

There’s a regulation ETOPS -Engines turn or people swim. It’s easier to qualify a twin over water than a single.

 

[Tantalum]

regs evolve. The 767 and A300 paved the way for extended twin ops. For the vast majority of regional routes ETOPS are not even part of the equation. One GE-90 could easily power just about anything 757 sized or smaller

But they're not. Somehow a trained crew can capitalize on the safety a second engine brings.

 

[texasclouds]

Twins?!?!

F N A, man!

 

[David Megginson]

I know this discussion is pretty much about piston GA but I would assume the point still holds somewhat, i.e. some piston twins have more power to weight ratio than others and must provide a bit more safety padding than others... But my experience is pretty much entirely piston singles and turbofan twins so I may be wrong about this.

Yes, this discussion is 100% about piston twins. Few/none of the points I've made earlier (except, of course, operating cost) apply to turbine-powered twins, with their surplus power and ease of operation.

I don't think the question is "twin good, single bad" or vice-versa (except when people are oversimplifying other people's arguments to make a strawman); it's more an exploration of the different situations where a typical piston twin is / might or might not be / isn't safer than a piston single, and other issues like operating cost and higher demands for currency.

In particular, when a new-ish pilot looking for a first plane comes on the forum and asks if a twin is "better" or "safer" than a single, "yes" is an irresponsible answer (it's not going to be safer for an inexperienced pilot, and a first-time owner may be scared away from flying for life by the the operating costs); "come back and talk to me when you have 1,000 hours, you've owned one or two planes, and you're making over $250K/year," OTOH, is an entirely reasonable answer (maybe a bit less on all counts, but I picked numbers high enough to be uncontroversial, I hope).

 

[EdFred]

Yes, this discussion is 100% about piston twins. Few/none of the points I've made earlier (except, of course, operating cost) apply to turbine-powered twins, with their surplus power and ease of operation.

I don't think the question is "twin good, single bad" or vice-versa (except when people are oversimplifying other people's arguments to make a strawman); it's more an exploration of the different situations where a typical piston twin is / might or might not be / isn't safer than a piston single, and other issues like operating cost and higher demands for currency.

In particular, when a new-ish pilot looking for a first plane comes on the forum and asks if a twin is "better" or "safer" than a single, "yes" is an irresponsible answer (it's not going to be safer for an inexperienced pilot, and a first-time owner may be scared away from flying for life by the the operating costs); "come back and talk to me when you have 1,000 hours, you've owned one or two planes, and you're making over $250K/year," OTOH, is an entirely reasonable answer (maybe a bit less on all counts, but I picked numbers high enough to be uncontroversial, I hope).

Unless of course you started your training in twins from the get-go and have that mindset from the start. I would take that person with 100 hours over somebody with a thousand hours and 10 hours of twin time.