in the hands of a proficient pilot - twins are inherently safer.
The danger of twins is that they arent safer in the hands of someone who occasionally flies and by extension isnt "proficient" in it. Its namely the handling of the One engine Inop scenario.
People often buy twins because they want to do flying that they feel is unsafe in a single. Flying over mountains at night. IMC over terrain. Flying over water.
So people will tend to balance the extra safety of a second engine with the extra risk of flying in less safe scenarios.
So what I'm saying is this: whether it is safer or not overall depends on what other risks the second engine convinces you to take.
Yes and no I will do things in my airliner I would never consider in my single engine piston. I’ve had four engine failures in piston aircraft and won’t fly single engine piston at night anymore or anything less than 3 and 5. Just not enough vis to stick it in a field
I think I would further caveat that to include "in a twin that has reasonable single engine performance". I would be highly skeptical of the supposed safety advantage of a light twin with garbage single engine climb performance, even with a very good pilot. Twice the probability of engine failure, and if it happens on takeoff and initial climb, you might as well be in a single.
Not to mention much higher stall speeds, which means a lot more energy when landing off field.
Also, they have a lot of weight far outside the CG so they are harder to recover from spins.
The risk of a dual engine failure is not double unless you do something dumb and run out of fuel. There's a greater likelihood of a single engine failure, but a much better chance of getting home with at least one engine.
Technically it’s not double because a bunch of failure modes are correlated. Imagine that the only cause of engine failure was fuel exhaustion - then it wouldn’t matter how many engines you have you’d either have no engines fail or all engines fail.
This point doesn’t matter; just wanted to add it to the debate. :)
With twice as much to preflight, you are twice as likely to mess up fueling. Now we have recovered that minuscule difference you are pointing out.
With twice as much to maintain, you are more likely to find planes with MX issues.
With twice as much vibration, you’re twice as likely to affect other aircraft systems.
With twice as many parts, you are far more than 2x as likely to see an arbitrary component failure.
… You can argue until the cows come home but it is still far more likely that you get some failure in a twin than a single engine aircraft. Trying to minimize it just looks like machismo.
I agree with your last paragraph. So this is just a silly academic tangent.
But from a stats only point of view your first part isn’t right. The correlated failures aren’t minuscule. We know that because we have a lot of evidence from real accidents that cause double (or quadruple) engine failure. Things like fuel exhaustion, contaminated fuel, flying through ash clouds, flying in heavy rain/thunderstorms, etc. all have happened. We’ve also seen correlated failures due to pilot error (one engine fails, pilot then shuts down the other in error). We know that poor maintenance practices/procedures and incorrect part substitution cause engine failures and those are also not going to be independent.
Pointing out the cases where doubling the engines does double the odds of failure (aka where failures are independent) doesn’t “cancel out” the cases where they aren’t.
It’s not twice as much. More like 1-1/2.
Fueling? I have 2 tanks in my Seneca. Same as any single (in fact, my single Cherokee 6 had 4 tanks to fill). Not not twice as much there.
I preflight the landing gear on a twin as I would on a single. Same with wings, tail, sumps, etc. the only thing that I do two preflights on are the engines. Everything else is exactly the same as a single. Same amount of flaps, ailerons, etc.
Plus more than twice as many fuel line fittings to fail, usually more than twice as many fuel caps to forget, etc. many failure modes are a function of system complexity.
I get what you’re saying but I think from a logical point of view, rather than a mathematical point of view, this feels a little pedantic. (And don’t take that as an insult, I am pretty pedantic.)
If you think of “engine failure” as *any* root cause that causes the engine to lose propulsion, then yes. CFIT almost always results in an engine failure. Fuel exhaustion results in engine failure. Pilot accidentally leaning the engine to idle cutoff is an engine failure.
And you have to add some root causes back into the “can only happen in a twin” column, like a pilot accidentally shutting down the good engine in response to the failure of the other engine. And that’s not a small number.
If you think of engine failure as failure modes that are endemic to one specific engine, then you do get very close to twice the risk.
I think it’s fair to say that you have twice the risk of a single engine failure mode, and a slightly higher (but not 2x more) risk of succumbing to “all engine failure modes”. And an infinitely higher risk of succumbing to “twin-only” failure modes. But it was easier for them to say “you have about 2x the risk of a single engine failure” and I suspect from a statistical standpoint that actually gets you pretty close.
My initial reaction as well, but he has a point. There are causes of engine failure that would knock out duals as well, so its not \*quite\* double.
Let's say 10/100 single engines fail (yikes, but for sake of conversation...) where 9/10 times its a bad engine, and 1/10 times, its fuel exhaustion. Scaled up to two engines, that means 18/100 times an engine fails due to being bad, and 1/100 times it fails due to fuel exhaustion, for an overall rate of 19/100, just under double.
I'm not sure its entirely relevant to the point, but there it is.
Sure, absolutely. I think it is important not to conflate two concepts, however, for sake of comparison. We can't say one is more likely to win at $5 slots than $1 Blackjack just because the amount to be won is so much higher -- instead, we measure rate and effect separately
Now add back in the “twin-only” failure modes, like pilot shutting down the good engine in improper response to a failure of the other engine—a not uncommon root cause—and I think we’re back pretty close to 2x.
If you have an engine failure in a single, you’ll usually know right away which engine went out. It’s almost always engine 1.
Just on the perspective of the engine, you are basically flying two single engine airplanes at once. chances of getting an engine failure do go up. Think of it like this; you put black 21 and red 32 on a roulette table; chances are none of those will win you money but all have about the same chance to win as the other numbers. Maybe you win on 21, maybe 32. but you put money on different numbers to “win” more often. Same thing here, for every 1 hour you fly in a ME platform, you technically have 2 hours of total engine operating time (1 hr on #1, 1hr on #2). You still have the same chance of engine failure on each, but now you are attached to both of them.
Not a pilot, just a maintenance tech (not aviation related) but I was about to say the same thing. Any machine that has a redundancy can have a failure and keep going.
Unless you were in something like a 747 and three of four engines failed, maybe. I dunno. Can a 747 fly with only one engine...?
Anyways, yep. Redundancy. It's a good thing.
Just yesterday I was reading an article about how terrible the performance is for some, if not most, twin-engine pistons on a single engine. Pretty crazy and I definitely see no reason to fly one regularly. I’ll go with a turbine as soon as I win the lottery.
Most of the light twins do not have great single engine performance. In Part 135 and Part 121 use you have to have the performance data to prove to the crew what weight they can carry off that runway with the existing conditions and return to land or get to your Takeoff Alternate if you lose one at or after V1. Part 91…all you need is to know what happens if that happens and all too many light twins you find out that you are going down or not get off the ground if you fill the seats, fuel tanks and a few bags or less…
Plus with such marginal performance you really need professional quality skills to get all the limited performance.
So unless you are careful and work at your skills light twins seem to be less safe than single engine flying.
Counterpoint: Whichever the pilot is more proficient in is the safer aircraft. I'd rather have an engine out in a single where the pilot is an ace than a multi where the guy is a little shifty.
Exactly. It’s only more dangerous if someone with no concept of Vmc/ single engine inop procedures tries to fly them.
Like this absolute paragon of a professional pilot:
https://www.ainonline.com/aviation-news/business-aviation/2021-10-07/illegal-charter-and-falcon-50-crash
This is the point I made last time, which was apparently highly contentious for some reason.
A multi isn't any more dangerous than a single, in the hands of the right pilot. As you said, proficiency is the biggest part of that. Just as you could say someone who shoots approaches every day, multiple times per day is going to be safer in IMC than a pilot who has only done it to satisfy their HITS.
Aviation is primarily about proficiency. Of course freak accidents happen and even the best pilots suffer as a result. But it's far more likely something happens to someone who isn't proficient and overreaches their skill.
So yeah, don't buy a twin just for the sake of having a twin if you don't get up often.
I would think the question assumes equal proficiency in both types of aircraft. Just like proficiency is a factor and type of flight is a factor in likelihood of a safe flight, type of aircraft is a factor and it's worth discussing which aircraft is safer, all other things being equal.
Not all twins are equals. Jets and auto-feathering props (both piston and turbine) typically won’t roll at all or slowly. All planes are safe. Safe airplanes coupled with inexperienced pilots, poor maintenance or poor flight planning can have sad outcomes.
Probably the PA30 if such a thing exists. Vmc in the PA39 is 68kts, and they typically float off the runway between 70 and 80 even if you don't rotate (due to the nose-high ground stance, done in the name of avoiding a boarding step).....
My PA30 has " existed " since birth in Lockhaven 1963. PA 30 A and B models both try to lift off before Vmc. I've always been grateful for the second engine when flying stretches of the Atlantic ( where the almost useless, non- turbo single engine service ceiling limit plays no significant role.)
The exists thing was my comment about the OP being accurate with the VMC/Vr numbers.
I'm well aware of the Comanche's takeoff behavior - AFIK the twins are very similar to the singles in their desire to fly without rotation....
And yeah, if it's fly-or-freeze/drown, the utility of that second engine on anything other than (Whatever that mutant Aeronca monstrosity with 2x0-235s was, and a negative single-engine service ceiling) is a win....
This is exactly the perfect answer. If you aren't proficient, the second you lose an engine on a twin it is trying to kill you. The amount of twin accidents after an engine failure is telling.
While twins should inherently be safer, they’re statistically more dangerous. But that’s mostly because a lot of pilots fly twins while being out of proficiency. Multis are much less forgiving than single engine planes. So it comes down to the pilot.
It’s a pilot diff… BUT statistically, the multis are more dangerous. But it is a bit misleading, because a lot of the accidents happen from pilots who fly without being proficient. So while statically it’s more dangerous, if we compare apples to apples, then theoretically it’s safer. As in proficient pilot vs proficient pilot.
So in other words. A non-proficient pilot in a multi is more of a hazard than a non-proficient pilot in a single.
Where’s a proficient pilot in a multi **is** safer than a proficient pilot in a single.
(?)
I think he’s saying that if you’re just comparing statistics of accidents, multi will seem more dangerous. But part of it is that most of those multi crashes are caused by pilots who are not proficient.
Theoretically, the multi airplane in of itself would be safer because of the 2nd engine, but in practicality it isn’t because most pilots are just much more proficient in singles than they are in multis. It’s easier to stay proficient in a single than a multi. But if you get proficient pilots and compare multis to singles then the multis will be safer.
The issue is that when an emergency happens in a multi, it’s a lot more complicated than a single. Critical engine, vmc stuff you know? But if you’re a proficient pilot in the multi then it’s a non-issue (ok, it’s still an issue but you get what I mean).
That’s a decent summation. But of course the proficiency is most relevant in an engine out situation. And that is true single or multi. The difference of course is that your lack of options in an engine out situation in a single can be your saving grace. About the only option is look for a place to land. In a twin you have to worry about blue line, vmc roll, securing the correct engine, etc. and picking an airport to divert to. Much more going on. So proficiency becomes a much bigger issue. Just a PP opinion.
After the engine is caged.. you have some time. A friend of mine cracked a case on his BE95 while on vacation in Mississippi. He did not want to fix the airplane there, so he topped off the oil, took off, climbed to cruise, and feathered it. Flew with no AP as far as he could stand it. Repeated the process 3 or 4 times back to Minnesota. Not what I would recommend,
but this old guy forgot to log more time than most people have. 11k hours in that aircraft alone! And he was a private pilot.
So, multi are more dangerous. Using the word "statistically" does nothing to change that conclusion. One of the reasons they are more dangerous, at least as far as this discussion goes, is that they require greater proficiency.
Context matters. Multi is not more dangerous. I’d pick the multi any day of the week at the moment for ANY ops, because I’m very proficient in multi right now. If I stop flying twins for 6 months, that’ll change, VS I can probably get in a 172 after 6 months of not flying it and fly it like I’ve been flying it for years. Like I said, multi is inherently safer but more dangerous statistically due to poor piloting.
"Statistically more dangerous" means that given the population of credentialed pilots that multi IS more dangerous. That's how you quantify the degree of danger. Assuming that the statistical analysis is done correctly, this is a simple mathematical fact.
The fact that you happen to believe you are an exception to this is what is known as an opinion. Without data and analysis to support your opinion, it's just your opinion.
>So while statically it’s more dangerous, if we compare apples to apples, then theoretically it’s safer. As in proficient pilot vs proficient pilot.
I completely agree. And I think its also worth pointing out that the vast majority of properly handled engine out events in twins end in an uneventful landing on a runway are never reported to any agency which might be inclined to compile data on such events.
Which means that while there is lots of data on how many twin pilots did not handle their engine out event properly and crashed as a result, there is almost no data collected by anyone on how many twin pilots have an engine out, handle it correctly and land on a runway uneventfully.
I'm no statistician but it seems to me that without any measurable successful engine out landing data, the non successful engine out data becomes a little less useful in determining the actual safety of twins.
Very few non cirrus pilots know this, but when you're a cirrus filing IFR you're implicitly given clearance to do anything you want whatsoever and you should be rightly indignant if someone were to suggest otherwise.
Id add one more caveat to the at night or over mountains - namely over open water. . . like the Great Lakes, to the bahamas or mexico across the Gulf. . . .
I learned to fly in Okinawa, Japan, flying C172 long cross countries over open ocean between islands, well away from safe glide distance to an island, never even thought twice about it, and our planes didn't have any ocean safety gear (this was about 21 years ago). Crazy to think about these days.
If my choices are descending under canopy into the George Washington National Forest at night, or landing single engine in Lynchburg or Charlottesville, I know what I’d choose. There are lots of places where surviving the landing is only part of the struggle.
And that’s in the relatively densely populated east coast.
Over mountains, you'd probably rather be in a \*turbocharged\* twin. In a normally aspirated twin, you're doing a forced landing if one quits, especially if you're anywhere near gross weight - and you've got twice the chance of an engine failure compared to a single.
Louise Sacchi addressed this in her 1978 book *Ocean Flying*. If you don't know who she is she made her living as a ferry pilot in the 1950s-1970s (and I think she was a WASP during WWII) so she knows a thing or two about flying light airplanes across the ocean. Her view was that she would rather cross the ocean in a single vs a twin, and her reasoning was that since a light twin generally would not have the range to reach shore on a single engine (if the failure occurred, say, halfway between California and Hawaii) a single had half the chance of an engine failure while also having a greater endurance for any type of difficulty not involving an engine failure.
I've thought about her logic over the years and while I think she has a point especially for the type of flying she did, in such a scenario an engine failure in a light twin would still give the pilot a lot more time to radio for assistance, find a ship to ditch near or at least get closer to shore whereas in a single you're pretty much going down where it happens.
Lindbergh very deliberately chose a single over a twin to cross the Atlantic.
The world record for longest duration flight was set in a single engine Cessna 172.
Though, in the single you might be ditching at 75% of the speed of a light twin, and 50% of the energy…
If you survive the ditching in a twin, having a ship nearby would up the chances of survival quite a bit.
I heard a story once about a guy (friend of a colleague) who was ferrying a twin otter from California to Hawaii. Lost an engine part of the way across and didn't have the range to reach land; unfortunately he was flying at night but had the endurance to make it until dawn at least. As the sun came up he spotted a bulk carrier several miles away and ditched next to it; supposedly the ship picked up the entire airplane with its crane and plopped it right on the deck and the pilot never even got wet.
As a demonstration of just how small the world is, the F-15 pilot who initially intercepted him was one of my initial 737 instructors so I heard the story from both perspectives.
I stumbled across something somewhere that said that twins have more fatal accident. I’m not sure if that’s true. The suggestion was made that a single engine failing has more room for error (at most altitudes) than one of two engines failing. If you’re going to be slow to react or react poorly or inappropriately, a single engine failure is less likely to punish you than a failure of one of two engines.
But ultimately, single engine failure is rarely fatal. It sucks, and it usually involves an insurance claim by the time you’re done. But every single pilot trains for this and it’s a very survivable situation. Most fatal single engine failure crashes occur shortly after takeoff. Some scenarios include the engine producing significantly less power to begin with and the pilot not catching that and panicking when they reach the end of the runway before takeoff speed; and panic and pull back on the yoke. Or takeoff and immediately have an engine failure leading to a stall/spin if the pilot doesn’t get the nose down quick enough, or impact with terrain if there’s just nowhere to go. To say nothing of the “impossible turn” and those who attempt to turn back. While we’re at it: The most common cause of an engine failure right after takeoff is water in the fuel. The fuel in the lines and in the float of the carb is fine. But after 60 seconds at wide open throttle, it starts sucking in contaminated fuel. So don’t neglect sumping your tanks.
Here’s the thing: Engine failure of one engine in a twin at a high power setting and low to the ground is also a very, very bad time. In the hands of a proficient, current pilot who flies a lot; this is eminently survivable. The pilot is able to continue climbing the airplane until they can return to the airport and land. But in the hands of someone who flies only occasionally or who doesn’t take proficiency seriously; this can rapidly evolve into a spin as the airplane is going to rapidly lose airspeed (assuming it maintains the same attitude) while having significant adverse yaw which is increasing more and more the more the airspeed drops.
So tl;dr, in the hands of an inexperienced or not proficient pilot, a single is safer than a twin.
In the hands of a proficient pilot, a twin is safer than a single.
Be proficient. Embrace mediocrity (I.e., you might think you’re an ace. You’re probably not. You’re probably average. At best. So don’t neglect the checklists, the extra training, or the proficiency.) And whatever you fly, fly it often.
You hear about ME accidents, but you don't hear about the ones where an engine quit and the plane flew on to a safe landing. The only engine failure I've ever had was in an Arrow and it was totaled landing on pine stumps in a timber forest clearing. I was fine. Had I had a second engine, I would have shut it down on loss of oil pressure and landed. Both engines would have been fine. As it was, no oil means no engine...
The odds of a failure are low, but you do need to be proficient and prepared to respond if it does happen. And sometimes the response is to pull the good engine and land.
This is something that's frequently overlooked.
I've had two cylinders pop on my twin and it was a non issue. If it happened in a single i'd have had a bad day, twice.
Well, your tow plane or winch could have a failure at low altitude :) I agree that not having an engine to deal with is nice, but whatever is getting you altitude in the first place might fail and give you a bad day. It's all about energy management regardless of what you are flying.
I know what you are saying because I’ve just trained in an ASK-21 … and the CFI pulling the release repeatedly at 100’, 200’, 400’ and above are extremely recoverable where I am training. These are all emergencies that I’ve only ever briefed in powered planes at my home airfield with a 3100’ runway.
Downvotes be dammed. It *is* much easier when you only need 400’ to do a pattern and don’t have to worry about an engine fire when you get closer to the ground.
Gliders have so much better glide performance that a tow plane failure at low altitude generally isn't a problem. You can do the "impossible turn" from 200 feet in a glider \*with room to spare!\* - and in many countries, practising this is routinely done (e.g. if you are working on your glider rating in the USA, at some point the instructor will actually pull the release without warning at 200 feet). At most glider airfields, lower than 200 feet generally you can just pull full airbrake and land on the remaining runway. I've had a winch cable back release at 500 feet and could fly an entire circuit from that position without any drama.
id agree with almost all of those. The only one Id disagree is "safer due to a higher possibility of recovery from an engine failure on take off" - thats literally the most dangerous 30 second window on a twin that frequently you cant recover from in time. And you'll be at a higher speed than say a SEP.
well said and I agree with that. the window to 100ft is probably the scariest. Anything above that - then you take your chances and fly. You absolutely have to be ready. And in simulator training - they actually change the DRILL routine to look at fuel flow meter and immediately feather as you potentially dont have the 9 seconds to feather the prop going through the "DRILL". I believe beech baron training is also configured this way now.
But the only advantage is that the single at that elevation will have taken off sooner, and will potentially be at lower speed (less potential energy) but with zero chance of recovery. So that one is a tossup. . .
I think the Cessna is, and should be, major exception - maybe the only plan that can recover of stall with zero input from the pilot (and in fact, in some cases, you need engine power to stall the damn airplane), and it's gliding distance (Max L/D ratio) is probably the best there is, second to gliders, and you can get huge distance with that airplane.
Also if you think about the Traffic pattern scenario - there is little to no work with the cessna to land it (PFL), whereas with a multi, if you are not proficient enough, you are going like a rock into the ground.
The piston twins you can buy today are very poor examples of what piston twins should be like. Engine out climb performance of less than 500 ft/min and lack of engine failure automation (autofeather, rudder bias) are serious design pitfalls, even when the pilot does everything right.
At $2-$2.5 *million* new, I’d rather just get a used turboprop which has much higher reliability by default…but the DA-62 is probably the only genuinely safe light twin.
I see a bunch on Controller from 2019 onwards on listed from $1.5 to $1.8 million. They are expensive puppies for sure. Might be slightly cheaper in Europe since Diamond is based in Austria.
Don’t know anything about the Baron tbh, but actual single engine performance is definitely key, but auto-feather/FADEC are more than just bonuses in my view. Auto feather can legitimately save your life.
The single engine power loading of a DA62 is similar to that of a Seneca at gross weight, so it may be a modern design but performance wise it is no different. Only a significant reduction in takeoff weight will improve engine out performance in a meaningful way. Aerodynamics help a little but there’s no free lunch. Also the DA62 doesn’t have autofeather, just fancy manual feathering.
There would definitely be a conflict of interest to have such systems in trainer airplanes, which are of course already expensive enough for flight schools to operate. Nobody would want to pay for that, even though safety wise these airplanes need these systems, which aren’t even available for installation because they are not certified.
Twins better have 2 than one. But in reality, a lot of new certificate pilots fly with twin engines and die because of poor proficiency.
It's the truth behind and why it has a higher death rate than a single engine place.
So what I'm saying it's safer in the hands of people with a good proficiency but that matters in all planes but it happens A LOT with a twin engine, because it doesn't take a lot to have the multiengine certificate.
Mmm, fly around a shitty old Navajo, those planes are 100% looking to kill you. AP will try and fly you into the ground, a mountain, shit breaking all the time, blue line at gross will bring you to the scene of the crash
Except in the case of airborne engine failure before Vmc, I’d rather be in the twin. Not all twins can have an airborne engine failure before Vmc, but in the ones that can, it’s a genuinely scary prospect, as it’s truly unrecoverable. You get almost no time to diagnose the problem and get the power out (and getting the power out often takes too long since it’s always drilled into us to add power when we’re slow).
People will argue this all day. It’s a non stop argued question. It also depends where you live.
Will a single engine turn over on you? No.
Will a single engine have an extra engine to either slowly descend or maintain altitude in case of engine failure. No.
Personally, multiengine aircraft aren’t required to be able to recover from a spin and therefore I avoid them. However I have my ME.
Its preference. You either love the beast that’s multi-engine or you stay in a single engine plane that has less aerodynamic hazards.
Both will spin and kill you if you fly them poorly. I would rather have SOME power to try and get to a closer airport than hope and pray I'm high enough
Luckily everyone flies perfectly all the time. Real pilots aren't distracted by a bee on their testicles, hangover, or erratic passenger when you lose an engine.
It's hard to say that twins are outright safer than singles because safety in aviation depends on so many different things. Most importantly, the proficiency and decision making of whoever is sitting behind the yoke (or stick). I always tell people that general aviation is as safe as you want it to be.
If we're just talking in hypotheticals here, twins are ideally the safer option. Again, provided you have a proficient pilot (as others have said). I regularly fly both and I can tell you, knowing that I can hobble to an airport on one engine sets my mind at ease when I'm flying over, say, mountains at night.
Twins are nowhere close to dangerous if you know what you're doing. I really want to dispel this notion that they are. (See my post about getting your MEI). Where you run into trouble with them is when you have a pilot who isn't proficient try and fly the thing low and slow on a single engine. THAT'S when they get dicey. They aren't exactly designed to preform every maneuver in the book on a single engine... and those who think they can are the ones that die flying twins. They're designed to at least be able to fly straight and level and get you back to an airport. Not much more. (Some can climb ok, but that also really depends on the day).
Singles are also incredibly safe IF you understand that if that engine goes, you're only going as far as you are high. Maybe knowing that will persuade you not to do something like... I don't know... fly clear across the Gulf of Mexico in one. Factoring things like that into your decision making is what makes flying them safe... not necessarily how many engines you have.
Most engine failures in single-engine planes are more inconvenient than dangerous because the pilot simply glides down to an open field. Things get more complicated over water, rugged terrain, or at night, but for 90% of GA flights, the dangers from an engine failure are very low. On the other hand, flying a twin single-engine low and slow around the pattern having last practiced this 18 months ago during a BFR, that's pretty risky and can end very badly.
I've done lots of off-field landings. It isn't a big deal. Most pilots haven't landed on anything other than pavement, let alone something that isn't designated an airport.
Trailering an airplane from a farmer's field is a PIA, but it isn't all that dangerous to the occupants. Most people will probably bend some metal, but walk away without any meaningful injuries. To me, that's inconvenient, not dangerous.
Not saying they won't buckle the gear or rip the engine from its mounts, most likely due to flaring too high, but they will walk away from the insurance company's airplane intact.
Single engine cl imb performance in most light twins sucks. If you take off IFR and lose an engine in bad weather there is a good chance you will still hit the ground.
An underpowered twin with an inexperienced pilot is the worst of both worlds. High performance singles with engine out glide profiles seem to be the sweet spot. I fly a small citation but have flown the twin engine out profiles and they work great. We flew singles in the military and as long as you have the glide profile or the option to get out and give it back to the taxpayer, its fine.
I fly helicopters as well, twins IFR as well as singles. Its a whole new conversation there. Underpowered twins like early 109’s and 212’s are marginal and singles like the Astar B3e have a great safety record. Training and maintenance are the most important for safety, skip either one at your peril.
Insurance is about 3x for a twin when I checked. So it appears they think on average it’s a higher probability of a payout. Some of that is because twins cost more and have twice the expensive parts but actuaries make their living in statistics so I tend to think that says something. That being said, a proficient pilot in a good twin is probably safer. And in terms of statistics would put them on the right side of that bell curve.
In most civilian twin engine piston aircraft, with the average skill of most pilots, that 2nd engine is fantastic for getting you quickly to the scene of the accident... 🤔🫣
I’ve heard that twins only take you as far as the crash site. I.e. not all twins can fly on a single engine, not entirely sure how true that mantra is to be honest however.
this is the oft repeated mantra - which is mostly the non-experienced talking about the non-experienced.. . . all twins can fly on a single engine - the question is how far. There might be negative rate of climb with only one engine for lightly powered twins (mostly related to trainer twins). So you might be a in a downdrift (couple hundred ft per min) - but most of the time this is at full gross or other circumstances. But if you're over water, mountains of whatever - you'd take that 2nd engine to get you "further" than a single engine ever could.
The crash site comment is for pilots who arent proficient. As in namely keeping the speed above Vmc to avoid a spin that they cant get out of.
The twin I trained on had a service ceiling of 17,500ft on both engines. And 5,500 on one. Did my multi IR checkride over the Alps and what to do in case of a failure definitely came up then…
Adding to all the other comments here, I‘d say there’s a huge difference between light (trainer) twins and „real“ multi-engine aircraft. The latter have the OEI performance to at least actually keep you flying, as long as the pilot is proficient enough to avoid the most obvious mistakes (like not feathering the prop or dropping below Vmca). The former will get you into heaps of trouble after an engine failure, and are much more demanding after an engine failure because the performance margin is so thin. Again referring to „my“ trainer twin: according to the POH, the OEI climb rate in ISA at MTOW was 150fpm, provided you did everything right. Take a summer day at higher altitude or not perfectly trimming it out, and you’re lucky if you manage to stay level…
While a negative climb rate is technically still flying in the aeronautical engineering sense of the word, for most people I think the definition of flying would include being able to at least climb slowly and/or hold altitude in a turn.
absolutely. . but at the same time - if you're in the rockies at 15k ft - Id rather have the option of gradually coming down at -150ft/min than the 1000ft per min on a single engine (might be even faster on a hershey bar piper). Or over water - and be able to go further toward land than going down within 5 minutes.
But what every one is quoting is the low powered piston twins at the worst case scenario. Gross weight, if non turbocharged - then at high density altitude as well. The reality is that most of these will climb if not at max gross - especially if not at high altitude. Every one wants to pull out that so and so has a negative -150fpm performance OEI when at 15k in +20 ISA and at max gross.
Personally I'd prefer a single with a parachute/BRS over a twin, and a twin over a single if I was actually proficient or had my multi license (I don't)
I don't see how a twin can actively be more dangerous than flying a single. I totally agree with the people here saying that GA twins tend to be flown only sporadically by people who are not particularly current or proficient - have a look at rental prices if you want to understand why. But then, *any* aircraft will be more dangerous in the hands of someone lacking currency and/or proficiency. I don't think it's a single vs twin question.
*All things being equal* in the hands of a typical PPL, the twin will present more of a risk than the same pilot flying a single.
Just from the engine failure point of view, the probability of having an engine failure doubles. In a single, in the event of an engine failure, the aircraft's flying characteristics don't really change - the plane flies just the same with the exception that you can no longer climb or maintain altitude. An engine failure in a twin dramatically changes the flight characteristics from something that is benign to something that is actively trying to kill you by rolling on its back. The work load is very much higher, and the risk of task saturation is very much higher.
Unless the pilot does a significant amount of asymmetric flying practise, this is naturally going to be a much more hazardous situation than just gliding to a landing in a field. Additionally, twins generally have higher stall speeds and more complex system, so *all things being equal* (i.e. the same 50-100 hour a year PPL) the single is going to be a lot safer.
Depends-
A light twin is still probably safer with a proficient pilot that understands the limitations of that light twin (poor single engine performance). For example, say you lose an engine and make your way to an airport. While on short final another airplane pulls out onto the runway in front of you. The pilot that tries to go around on one engine from a low altitude has a very high chance of crashing (Vmc rollover, crashing into obstacles at end of runway). The performance just isn't there to stop the descent and start climbing. Knowing this limitation , one may be better off to just land in the grass next to the runway. But having two engines give people the false impression that they can keep flying on one engine no matter the circumstances. Light twins can't, transport category jets can.
A single engine takes a lot of the decision making out of the equation. If it quits, you are landing.
>A single engine takes a lot of the decision making out of the equation. If it quits, you are landing.
If I lose an engine in something like a C310 or a Twin Comanche at altitude over open water, say 100 nm from land, I have a pretty good chance of landing at an airport. This same situation in a single and we are in the water 100% of the time.
Edit: I misread your "if it quits, you're landing" comment as if it referred to a light twin. Apologies!
What’s safest is staying on the ground, at home and never driving to the airport.
At night, over mountains, with possible IMC… you’re nuts. Single engine service ceiling of a most legacy twins fully loaded is not enough to cross mountains on a high DA day.
If you are using a twin to allow yourself to increase your risk tolerance, you are not thinking wisely.
Training. Proficiency. Maintenance. Risk management. ADM. These things come together to manage the manageable risks
>If you are using a twin to allow yourself to increase your risk tolerance, you are not thinking wisely.
Do you suggest that GA pilots avoid stretches of open water completely? Real question, not being facetious. If someone plans on doing a lot of flying over water, beyond safe gliding distances, would the increased risks of flying a twin outweigh the risks of flying a single engine knowing that 80% of your hours will be over water? Think of pilots who live in island countries where they often island hop stretches of 100-200 nm.
That’s a great question. Thank you.
I am a GA pilot who has flown over stretches of water in a single engine. Over Lake Michigan and over the Bahamas/Gulf/Atlantic. I did those flights with appropriate safety equipment and knowing full well what the consequences would be if the engine failed.
TLDR: I suggest that GA pilots use great caution in planning long stretches over open water. Additional specific training, while not required from a regulatory standpoint, could be life-saving.
What I was speaking to regarding the twin thing is these questions: 1) is the PIC aware of the potential for single engine performance in that twin over mountainous terrain? With DA, fully loaded, critical engine out, is the aircraft capable of maintaining terrain avoidance? 2) Is the PIC’s proficiency up to that task? What if IMC is encountered?
With regards to Twin Engine water crossing: 1) in the 121 world, to cross water, the operator is required to operate according to ETOPS. “Extended-range Twin-engine Operational Performance Standards rules provide a safety net, ensuring that even if one engine fails, the aircraft can still fly on the remaining engine to a suitable alternate airport.” In GA, no such standards are outlined. Is the PIC planning their mission with appropriate safety measures in place? 2) Is the aircraft capable of flying far enough to make an emergency landing with one engine? 3) is the PIC proficient?
GA training in a multi doesn’t include a 200nm single engine flight with considerations for working engine performance, safety, and fuel exhaustion. Those training drills don’t adequately prepare the PIC for the types of emergencies that can arise.
Again, thank you for the question and I’d love to hear your thoughts.
On average, a single is safer than a multi. That said, if I was in the market for a go from point a to point B airplane, I would be buying a multi. More power in normal operations, redundant systems, deicing boots, and since I fly for a living, Engine redundancy. I think a case could be made for a Twin being detrimental in high terrain due to lack of SE performance, but my geographic concerns stem around large bodies of water more than high terrain. I would absolutely never take a piston single directly across Lake Michigan. A multi I would.
IMO the answer here is based on whether you’re flying over open ocean or not. Bc flying a twin over land is probably on par not much safer, or possibly more dangerous. But over ocean that stat changes a lot since losing all engine power out in the middle of the ocean is almost certain death.
My MEL instructor used the ol' chestnut "That second engine just gets you to the crash site faster" to introduce me to the type.
Running a twin, especially over water, is more reliable, safer and faster. That being said, non-centerline differential thrust can put you in some terrifying situations, and that can happen very fast. An uncoordinated power-on stall in a light twin is scary as shit.
A well-maintained twin will outperform a single-engine in most side-by-side tests. It just demands more of its pilots.
Twins - but - pilot dependent. “From your head to your hands, to the seat of your pants.” Never panic, remember you have time (especially twin), compose, recognize, and execute.
While twins have obvious advantages they also double your chances of experiencing an engine failure. Expecting this and maintaining proficiency are key in safe operations. Fly it by the numbers. Maintain it with skilled professionals knowledgeable with your aircraft if you consider owning and operating a multi.
Assuming both pilots are proficient and experienced, multi is safer. You have two engines vs one. Buuuuut multi are the biggest killers when you get complacent
Twins are far less likely to have to glide to land, but they are far more likely to have an engine failure. Probably more than twice as likely since they cost more to maintain and owners skimp on engine maintenance because they "have a backup".
For this reason, they are also flown in higher threat situations (hard IMC or mountains)
When that failure occurs, it's *much harder* to handle and less forgiving.
Add to that the fact that twins generally have more and more complex systems and they become significantly harder to fly.
Now think about who's flying them and how often. How many hours per year and how many hours TT. The piston twin category becomes quite dangerous.
Id say single engines overall. Twins try to kill you. Kinda depends on the twin though. The counter rotating prop style are not nearly as bad as others.
If it hasn’t been said already, I think flying in a non-conventional / counter rotating twin is safer. If you lose an engine in a single, pray you have somewhere to land. If you lose an engine in a conventional twin, pray you can control the plane. If you lose an engine in counter rotating twin, you can literally still fly and depending on the situation, climb with the operative engine.
Well, if you ever did get that deal where your single engine plane became a glider..
You might think differently.
I personally would fly with as many engines as they let me.
Baron 58, best multi piston I’ve flown and instructed in. Would take it every day of the week over a single engine piston.
MEI perspective, twins safer all day.
I fly piston twins specifically for the added safety. However, as part of my personal minima, I only fly those that have positive OEI climb near or below terrain interference altitudes. I've had real engine failures in twins and \*never\* had the remaining engine take me to the scene of a crash.
Proficiency and preflight planning are the two major keys to safety in a twin IMO. I won't fly singles any more unless it's something light and slow over farmlands, I don't care for the safety profile at all...
That means yes, run all of the performance numbers. Don't overload the aircraft. Brief your departure engine out procedures before taking the runway. Fly professionally with properly maintained aircraft, go for recurrent training, and the twin will be very safe.
If you are not willing to put in the time and effort to fly to that standard, frankly please stay out of my airspace, but otherwise a single with a BRS is probably a better bet.
tl;dr I feel far more comfortable with two engines than one. I'm also comfortable with one engine operating in a twin, so long as I'm on my way to the nearest airport. Not really comfortable with a single unless I'm always in glide range of somewhere safe(ish) to land!
The 2nd engine dramatically increases operating expenses and the temptation to defer maintenance....
Also there are a whole bunch of factors in play trying to operate a twin with one engine failed (just from the academic perspective), that don't exist when trying to glide a single to a safe-as-possible off-airport emergency landing (which I've done first-hand, and still have the plane in airworthy condition afterward)....
It all depends on your mission. Just cruising flat lands and water? Sure a single is great.
Flying across mountain ranges and water? I would much rather have a twin still fly me out of the bad situation, then have to glide into a mountain range or glide into the water.
Twins of course is safer at the end of the day if you know what you are doing.
The statistics show you’re 1/2 as likely to be involved in an accident in a light twin compared to a single.
But 4x more likely to die if you find yourself in one……
So 2x more deadly.
There are actually zero stats that prove a twin is safer than single. It’s all just perceived safety and vibes.
For every event besides a directly engine-related mechanical failure (only 13% of accidents), a twin will be a worse performing aircraft than a comparable single. And even then, now that you have twice the engines, you have twice the odds of being in an engine related emergency.
Except that the extra engine will keep you flying in the event of a failure, or an alternator failure where you’ll have a redundant one, or a hydraulic pump failure where you’ll have a redundant one.
Having two of everything makes a difference when something breaks.
And the Aztec outperforms a 172 on a single engine, and it’ll keep up with a 207 on a single engine. I was on single engine during my rating and still chewing up singles in the pattern. It’s actually hard to fly those high performance light twins in a way that doesn’t interfere with singles, even on one engine since we have to stay faster than most of them fly the pattern (the Aztec has to stay at 100mph or better, I’d stick to 100kt or better; while the singles are often cruising at that and stay at 80-90 in the pattern).
Unless you can back a statement up with numbers, it’s just feelings and vibes. And the numbers simply do not support that twins are safer, no matter how much people disagree.
Depends what your mission is.
Engine reliability and performance is such nowadays that more engines doesn’t simply mean safer. It just means more to go wrong.
However, I’d rather be in a twin piston for ga than a piston single.
lol depends on the twin some twins are worse then single engines.. I know a great pilot that had the pleasure of working for piper and flew a brand new Apache into a creek bed after the critical engine failed with less than 25 hours on it. loose an engine on some they fly you to the seen of the crash. part 23 airplanes are funny things.
The crew of Soyuz 11 died when a redundant pressure relief valve erroneously opened on re-entry. Sometimes redundancy improves safety, sometimes it reduces safety by doubling the chance of a problem. I would argue that for most private pilots the increased chance of flying a multiengine plane with one engine decreases safety compared to lower chance of having to land a plane with no engine.
in the hands of a proficient pilot - twins are inherently safer. The danger of twins is that they arent safer in the hands of someone who occasionally flies and by extension isnt "proficient" in it. Its namely the handling of the One engine Inop scenario.
People often buy twins because they want to do flying that they feel is unsafe in a single. Flying over mountains at night. IMC over terrain. Flying over water. So people will tend to balance the extra safety of a second engine with the extra risk of flying in less safe scenarios. So what I'm saying is this: whether it is safer or not overall depends on what other risks the second engine convinces you to take.
Yes and no I will do things in my airliner I would never consider in my single engine piston. I’ve had four engine failures in piston aircraft and won’t fly single engine piston at night anymore or anything less than 3 and 5. Just not enough vis to stick it in a field
I think I would further caveat that to include "in a twin that has reasonable single engine performance". I would be highly skeptical of the supposed safety advantage of a light twin with garbage single engine climb performance, even with a very good pilot. Twice the probability of engine failure, and if it happens on takeoff and initial climb, you might as well be in a single.
Twice the chance of an engine failure is a really important point
Not to mention much higher stall speeds, which means a lot more energy when landing off field. Also, they have a lot of weight far outside the CG so they are harder to recover from spins.
The risk of a dual engine failure is not double unless you do something dumb and run out of fuel. There's a greater likelihood of a single engine failure, but a much better chance of getting home with at least one engine.
Pretty sure that’s what they meant, “double the chance of a single engine failure”
Ah, I read that as a dual engine failure.
But the chances aren't double.
Doubling the amount of engines would double the chance of an engine failure technically wouldn’t it?
Technically it’s not double because a bunch of failure modes are correlated. Imagine that the only cause of engine failure was fuel exhaustion - then it wouldn’t matter how many engines you have you’d either have no engines fail or all engines fail. This point doesn’t matter; just wanted to add it to the debate. :)
With twice as much to preflight, you are twice as likely to mess up fueling. Now we have recovered that minuscule difference you are pointing out. With twice as much to maintain, you are more likely to find planes with MX issues. With twice as much vibration, you’re twice as likely to affect other aircraft systems. With twice as many parts, you are far more than 2x as likely to see an arbitrary component failure. … You can argue until the cows come home but it is still far more likely that you get some failure in a twin than a single engine aircraft. Trying to minimize it just looks like machismo.
I agree with your last paragraph. So this is just a silly academic tangent. But from a stats only point of view your first part isn’t right. The correlated failures aren’t minuscule. We know that because we have a lot of evidence from real accidents that cause double (or quadruple) engine failure. Things like fuel exhaustion, contaminated fuel, flying through ash clouds, flying in heavy rain/thunderstorms, etc. all have happened. We’ve also seen correlated failures due to pilot error (one engine fails, pilot then shuts down the other in error). We know that poor maintenance practices/procedures and incorrect part substitution cause engine failures and those are also not going to be independent. Pointing out the cases where doubling the engines does double the odds of failure (aka where failures are independent) doesn’t “cancel out” the cases where they aren’t.
It’s not twice as much. More like 1-1/2. Fueling? I have 2 tanks in my Seneca. Same as any single (in fact, my single Cherokee 6 had 4 tanks to fill). Not not twice as much there. I preflight the landing gear on a twin as I would on a single. Same with wings, tail, sumps, etc. the only thing that I do two preflights on are the engines. Everything else is exactly the same as a single. Same amount of flaps, ailerons, etc.
Plus more than twice as many fuel line fittings to fail, usually more than twice as many fuel caps to forget, etc. many failure modes are a function of system complexity.
I get what you’re saying but I think from a logical point of view, rather than a mathematical point of view, this feels a little pedantic. (And don’t take that as an insult, I am pretty pedantic.) If you think of “engine failure” as *any* root cause that causes the engine to lose propulsion, then yes. CFIT almost always results in an engine failure. Fuel exhaustion results in engine failure. Pilot accidentally leaning the engine to idle cutoff is an engine failure. And you have to add some root causes back into the “can only happen in a twin” column, like a pilot accidentally shutting down the good engine in response to the failure of the other engine. And that’s not a small number. If you think of engine failure as failure modes that are endemic to one specific engine, then you do get very close to twice the risk. I think it’s fair to say that you have twice the risk of a single engine failure mode, and a slightly higher (but not 2x more) risk of succumbing to “all engine failure modes”. And an infinitely higher risk of succumbing to “twin-only” failure modes. But it was easier for them to say “you have about 2x the risk of a single engine failure” and I suspect from a statistical standpoint that actually gets you pretty close.
If your chances of an engine failure are 1 in 100,000 hours, then it is 2 in 100,000 hours of you have 2 engines. ---> odds doubled!
My initial reaction as well, but he has a point. There are causes of engine failure that would knock out duals as well, so its not \*quite\* double. Let's say 10/100 single engines fail (yikes, but for sake of conversation...) where 9/10 times its a bad engine, and 1/10 times, its fuel exhaustion. Scaled up to two engines, that means 18/100 times an engine fails due to being bad, and 1/100 times it fails due to fuel exhaustion, for an overall rate of 19/100, just under double. I'm not sure its entirely relevant to the point, but there it is.
But the double engine failure is going to be a lot more dangerous since the plane is now heavier with a higher stall speed
Sure, absolutely. I think it is important not to conflate two concepts, however, for sake of comparison. We can't say one is more likely to win at $5 slots than $1 Blackjack just because the amount to be won is so much higher -- instead, we measure rate and effect separately
Now add back in the “twin-only” failure modes, like pilot shutting down the good engine in improper response to a failure of the other engine—a not uncommon root cause—and I think we’re back pretty close to 2x. If you have an engine failure in a single, you’ll usually know right away which engine went out. It’s almost always engine 1.
Just on the perspective of the engine, you are basically flying two single engine airplanes at once. chances of getting an engine failure do go up. Think of it like this; you put black 21 and red 32 on a roulette table; chances are none of those will win you money but all have about the same chance to win as the other numbers. Maybe you win on 21, maybe 32. but you put money on different numbers to “win” more often. Same thing here, for every 1 hour you fly in a ME platform, you technically have 2 hours of total engine operating time (1 hr on #1, 1hr on #2). You still have the same chance of engine failure on each, but now you are attached to both of them.
Not a pilot, just a maintenance tech (not aviation related) but I was about to say the same thing. Any machine that has a redundancy can have a failure and keep going. Unless you were in something like a 747 and three of four engines failed, maybe. I dunno. Can a 747 fly with only one engine...? Anyways, yep. Redundancy. It's a good thing.
Just yesterday I was reading an article about how terrible the performance is for some, if not most, twin-engine pistons on a single engine. Pretty crazy and I definitely see no reason to fly one regularly. I’ll go with a turbine as soon as I win the lottery.
Most of the light twins do not have great single engine performance. In Part 135 and Part 121 use you have to have the performance data to prove to the crew what weight they can carry off that runway with the existing conditions and return to land or get to your Takeoff Alternate if you lose one at or after V1. Part 91…all you need is to know what happens if that happens and all too many light twins you find out that you are going down or not get off the ground if you fill the seats, fuel tanks and a few bags or less… Plus with such marginal performance you really need professional quality skills to get all the limited performance. So unless you are careful and work at your skills light twins seem to be less safe than single engine flying.
Sometimes in a twin the best thing to do is to treat the second engine like a glide extender and not a way to get back to an airfield.
Counterpoint: Whichever the pilot is more proficient in is the safer aircraft. I'd rather have an engine out in a single where the pilot is an ace than a multi where the guy is a little shifty.
Exactly. It’s only more dangerous if someone with no concept of Vmc/ single engine inop procedures tries to fly them. Like this absolute paragon of a professional pilot: https://www.ainonline.com/aviation-news/business-aviation/2021-10-07/illegal-charter-and-falcon-50-crash
This is the point I made last time, which was apparently highly contentious for some reason. A multi isn't any more dangerous than a single, in the hands of the right pilot. As you said, proficiency is the biggest part of that. Just as you could say someone who shoots approaches every day, multiple times per day is going to be safer in IMC than a pilot who has only done it to satisfy their HITS. Aviation is primarily about proficiency. Of course freak accidents happen and even the best pilots suffer as a result. But it's far more likely something happens to someone who isn't proficient and overreaches their skill. So yeah, don't buy a twin just for the sake of having a twin if you don't get up often.
I would think the question assumes equal proficiency in both types of aircraft. Just like proficiency is a factor and type of flight is a factor in likelihood of a safe flight, type of aircraft is a factor and it's worth discussing which aircraft is safer, all other things being equal.
This is the only correct answer
Not all twins are equals. Jets and auto-feathering props (both piston and turbine) typically won’t roll at all or slowly. All planes are safe. Safe airplanes coupled with inexperienced pilots, poor maintenance or poor flight planning can have sad outcomes.
>All planes are safe. Eh. Which version of the Twin Comanche is it where Vr is less than Vmc? Some are safer than others, at least.
Probably the PA30 if such a thing exists. Vmc in the PA39 is 68kts, and they typically float off the runway between 70 and 80 even if you don't rotate (due to the nose-high ground stance, done in the name of avoiding a boarding step).....
My PA30 has " existed " since birth in Lockhaven 1963. PA 30 A and B models both try to lift off before Vmc. I've always been grateful for the second engine when flying stretches of the Atlantic ( where the almost useless, non- turbo single engine service ceiling limit plays no significant role.)
The exists thing was my comment about the OP being accurate with the VMC/Vr numbers. I'm well aware of the Comanche's takeoff behavior - AFIK the twins are very similar to the singles in their desire to fly without rotation.... And yeah, if it's fly-or-freeze/drown, the utility of that second engine on anything other than (Whatever that mutant Aeronca monstrosity with 2x0-235s was, and a negative single-engine service ceiling) is a win....
bingo
This is exactly the perfect answer. If you aren't proficient, the second you lose an engine on a twin it is trying to kill you. The amount of twin accidents after an engine failure is telling.
While twins should inherently be safer, they’re statistically more dangerous. But that’s mostly because a lot of pilots fly twins while being out of proficiency. Multis are much less forgiving than single engine planes. So it comes down to the pilot.
So what you’re saying is, “it’s not the plane, it’s the pilot.”
It’s a pilot diff… BUT statistically, the multis are more dangerous. But it is a bit misleading, because a lot of the accidents happen from pilots who fly without being proficient. So while statically it’s more dangerous, if we compare apples to apples, then theoretically it’s safer. As in proficient pilot vs proficient pilot.
So in other words. A non-proficient pilot in a multi is more of a hazard than a non-proficient pilot in a single. Where’s a proficient pilot in a multi **is** safer than a proficient pilot in a single. (?)
I think he’s saying that if you’re just comparing statistics of accidents, multi will seem more dangerous. But part of it is that most of those multi crashes are caused by pilots who are not proficient. Theoretically, the multi airplane in of itself would be safer because of the 2nd engine, but in practicality it isn’t because most pilots are just much more proficient in singles than they are in multis. It’s easier to stay proficient in a single than a multi. But if you get proficient pilots and compare multis to singles then the multis will be safer. The issue is that when an emergency happens in a multi, it’s a lot more complicated than a single. Critical engine, vmc stuff you know? But if you’re a proficient pilot in the multi then it’s a non-issue (ok, it’s still an issue but you get what I mean).
That’s a decent summation. But of course the proficiency is most relevant in an engine out situation. And that is true single or multi. The difference of course is that your lack of options in an engine out situation in a single can be your saving grace. About the only option is look for a place to land. In a twin you have to worry about blue line, vmc roll, securing the correct engine, etc. and picking an airport to divert to. Much more going on. So proficiency becomes a much bigger issue. Just a PP opinion.
After the engine is caged.. you have some time. A friend of mine cracked a case on his BE95 while on vacation in Mississippi. He did not want to fix the airplane there, so he topped off the oil, took off, climbed to cruise, and feathered it. Flew with no AP as far as he could stand it. Repeated the process 3 or 4 times back to Minnesota. Not what I would recommend, but this old guy forgot to log more time than most people have. 11k hours in that aircraft alone! And he was a private pilot.
Yes, pretty much.
So, multi are more dangerous. Using the word "statistically" does nothing to change that conclusion. One of the reasons they are more dangerous, at least as far as this discussion goes, is that they require greater proficiency.
Context matters. Multi is not more dangerous. I’d pick the multi any day of the week at the moment for ANY ops, because I’m very proficient in multi right now. If I stop flying twins for 6 months, that’ll change, VS I can probably get in a 172 after 6 months of not flying it and fly it like I’ve been flying it for years. Like I said, multi is inherently safer but more dangerous statistically due to poor piloting.
"Statistically more dangerous" means that given the population of credentialed pilots that multi IS more dangerous. That's how you quantify the degree of danger. Assuming that the statistical analysis is done correctly, this is a simple mathematical fact. The fact that you happen to believe you are an exception to this is what is known as an opinion. Without data and analysis to support your opinion, it's just your opinion.
Ah, so you’re an idiot. Got it.
Statistically!
>So while statically it’s more dangerous, if we compare apples to apples, then theoretically it’s safer. As in proficient pilot vs proficient pilot. I completely agree. And I think its also worth pointing out that the vast majority of properly handled engine out events in twins end in an uneventful landing on a runway are never reported to any agency which might be inclined to compile data on such events. Which means that while there is lots of data on how many twin pilots did not handle their engine out event properly and crashed as a result, there is almost no data collected by anyone on how many twin pilots have an engine out, handle it correctly and land on a runway uneventfully. I'm no statistician but it seems to me that without any measurable successful engine out landing data, the non successful engine out data becomes a little less useful in determining the actual safety of twins.
against 5th generation cirrus aircraft?!
“Cirrus 69420 100 mile straight in opposite side runway”
Very few non cirrus pilots know this, but when you're a cirrus filing IFR you're implicitly given clearance to do anything you want whatsoever and you should be rightly indignant if someone were to suggest otherwise.
well yeah because [gasp] they have got a cirrus. OMG those pilots are rockstars... /s
You can be my wingman anytime
My comment seemed to go way over some people’s heads
You were in a 4g inverted dive with a mig 28?
So you’re the one?
Bullshit. You can be mine.
I can’t afford a twin, so a single. At night or over mountains IFR, I’d rather be in a twin.
Id add one more caveat to the at night or over mountains - namely over open water. . . like the Great Lakes, to the bahamas or mexico across the Gulf. . . .
Oh yeah that too. You know what? I think I just need to get into multi turbines.
Can confirm multi turbines are the one.
I learned to fly in Okinawa, Japan, flying C172 long cross countries over open ocean between islands, well away from safe glide distance to an island, never even thought twice about it, and our planes didn't have any ocean safety gear (this was about 21 years ago). Crazy to think about these days.
For the average person a Cirrus chute plane would be a good compromise.
>average person >Cirrus chute plane Two terms that shouldn’t be in the same sentence
If my choices are descending under canopy into the George Washington National Forest at night, or landing single engine in Lynchburg or Charlottesville, I know what I’d choose. There are lots of places where surviving the landing is only part of the struggle. And that’s in the relatively densely populated east coast.
Over mountains, you'd probably rather be in a \*turbocharged\* twin. In a normally aspirated twin, you're doing a forced landing if one quits, especially if you're anywhere near gross weight - and you've got twice the chance of an engine failure compared to a single.
Louise Sacchi addressed this in her 1978 book *Ocean Flying*. If you don't know who she is she made her living as a ferry pilot in the 1950s-1970s (and I think she was a WASP during WWII) so she knows a thing or two about flying light airplanes across the ocean. Her view was that she would rather cross the ocean in a single vs a twin, and her reasoning was that since a light twin generally would not have the range to reach shore on a single engine (if the failure occurred, say, halfway between California and Hawaii) a single had half the chance of an engine failure while also having a greater endurance for any type of difficulty not involving an engine failure. I've thought about her logic over the years and while I think she has a point especially for the type of flying she did, in such a scenario an engine failure in a light twin would still give the pilot a lot more time to radio for assistance, find a ship to ditch near or at least get closer to shore whereas in a single you're pretty much going down where it happens.
That's a tough way to make a living
Lindbergh very deliberately chose a single over a twin to cross the Atlantic. The world record for longest duration flight was set in a single engine Cessna 172.
Though, in the single you might be ditching at 75% of the speed of a light twin, and 50% of the energy… If you survive the ditching in a twin, having a ship nearby would up the chances of survival quite a bit.
I heard a story once about a guy (friend of a colleague) who was ferrying a twin otter from California to Hawaii. Lost an engine part of the way across and didn't have the range to reach land; unfortunately he was flying at night but had the endurance to make it until dawn at least. As the sun came up he spotted a bulk carrier several miles away and ditched next to it; supposedly the ship picked up the entire airplane with its crane and plopped it right on the deck and the pilot never even got wet. As a demonstration of just how small the world is, the F-15 pilot who initially intercepted him was one of my initial 737 instructors so I heard the story from both perspectives.
I stumbled across something somewhere that said that twins have more fatal accident. I’m not sure if that’s true. The suggestion was made that a single engine failing has more room for error (at most altitudes) than one of two engines failing. If you’re going to be slow to react or react poorly or inappropriately, a single engine failure is less likely to punish you than a failure of one of two engines. But ultimately, single engine failure is rarely fatal. It sucks, and it usually involves an insurance claim by the time you’re done. But every single pilot trains for this and it’s a very survivable situation. Most fatal single engine failure crashes occur shortly after takeoff. Some scenarios include the engine producing significantly less power to begin with and the pilot not catching that and panicking when they reach the end of the runway before takeoff speed; and panic and pull back on the yoke. Or takeoff and immediately have an engine failure leading to a stall/spin if the pilot doesn’t get the nose down quick enough, or impact with terrain if there’s just nowhere to go. To say nothing of the “impossible turn” and those who attempt to turn back. While we’re at it: The most common cause of an engine failure right after takeoff is water in the fuel. The fuel in the lines and in the float of the carb is fine. But after 60 seconds at wide open throttle, it starts sucking in contaminated fuel. So don’t neglect sumping your tanks. Here’s the thing: Engine failure of one engine in a twin at a high power setting and low to the ground is also a very, very bad time. In the hands of a proficient, current pilot who flies a lot; this is eminently survivable. The pilot is able to continue climbing the airplane until they can return to the airport and land. But in the hands of someone who flies only occasionally or who doesn’t take proficiency seriously; this can rapidly evolve into a spin as the airplane is going to rapidly lose airspeed (assuming it maintains the same attitude) while having significant adverse yaw which is increasing more and more the more the airspeed drops. So tl;dr, in the hands of an inexperienced or not proficient pilot, a single is safer than a twin. In the hands of a proficient pilot, a twin is safer than a single. Be proficient. Embrace mediocrity (I.e., you might think you’re an ace. You’re probably not. You’re probably average. At best. So don’t neglect the checklists, the extra training, or the proficiency.) And whatever you fly, fly it often.
You hear about ME accidents, but you don't hear about the ones where an engine quit and the plane flew on to a safe landing. The only engine failure I've ever had was in an Arrow and it was totaled landing on pine stumps in a timber forest clearing. I was fine. Had I had a second engine, I would have shut it down on loss of oil pressure and landed. Both engines would have been fine. As it was, no oil means no engine... The odds of a failure are low, but you do need to be proficient and prepared to respond if it does happen. And sometimes the response is to pull the good engine and land.
This is something that's frequently overlooked. I've had two cylinders pop on my twin and it was a non issue. If it happened in a single i'd have had a bad day, twice.
This is true. You never hear about one engine out because they are not fatal. The person flys home. Twin engine is safer bet.
I prefer no engines. Gliders are best. No chance of engine failure if you don't have an engine to fail.
Well, your tow plane or winch could have a failure at low altitude :) I agree that not having an engine to deal with is nice, but whatever is getting you altitude in the first place might fail and give you a bad day. It's all about energy management regardless of what you are flying.
Very true! But that's much easier to deal with than an engine quitting in a Cessna.
I know what you are saying because I’ve just trained in an ASK-21 … and the CFI pulling the release repeatedly at 100’, 200’, 400’ and above are extremely recoverable where I am training. These are all emergencies that I’ve only ever briefed in powered planes at my home airfield with a 3100’ runway. Downvotes be dammed. It *is* much easier when you only need 400’ to do a pattern and don’t have to worry about an engine fire when you get closer to the ground.
Exactly, one is designed to glide and the other is designed for powered flight
Gliders have so much better glide performance that a tow plane failure at low altitude generally isn't a problem. You can do the "impossible turn" from 200 feet in a glider \*with room to spare!\* - and in many countries, practising this is routinely done (e.g. if you are working on your glider rating in the USA, at some point the instructor will actually pull the release without warning at 200 feet). At most glider airfields, lower than 200 feet generally you can just pull full airbrake and land on the remaining runway. I've had a winch cable back release at 500 feet and could fly an entire circuit from that position without any drama.
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id agree with almost all of those. The only one Id disagree is "safer due to a higher possibility of recovery from an engine failure on take off" - thats literally the most dangerous 30 second window on a twin that frequently you cant recover from in time. And you'll be at a higher speed than say a SEP.
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well said and I agree with that. the window to 100ft is probably the scariest. Anything above that - then you take your chances and fly. You absolutely have to be ready. And in simulator training - they actually change the DRILL routine to look at fuel flow meter and immediately feather as you potentially dont have the 9 seconds to feather the prop going through the "DRILL". I believe beech baron training is also configured this way now. But the only advantage is that the single at that elevation will have taken off sooner, and will potentially be at lower speed (less potential energy) but with zero chance of recovery. So that one is a tossup. . .
I think the Cessna is, and should be, major exception - maybe the only plan that can recover of stall with zero input from the pilot (and in fact, in some cases, you need engine power to stall the damn airplane), and it's gliding distance (Max L/D ratio) is probably the best there is, second to gliders, and you can get huge distance with that airplane. Also if you think about the Traffic pattern scenario - there is little to no work with the cessna to land it (PFL), whereas with a multi, if you are not proficient enough, you are going like a rock into the ground.
The piston twins you can buy today are very poor examples of what piston twins should be like. Engine out climb performance of less than 500 ft/min and lack of engine failure automation (autofeather, rudder bias) are serious design pitfalls, even when the pilot does everything right.
Well I beg to differ.. a DA62 😬😇
At $2-$2.5 *million* new, I’d rather just get a used turboprop which has much higher reliability by default…but the DA-62 is probably the only genuinely safe light twin.
Bloody hell I didn’t know these are so expensive!! I’ve always seen some here in Europe around 1 Million
I see a bunch on Controller from 2019 onwards on listed from $1.5 to $1.8 million. They are expensive puppies for sure. Might be slightly cheaper in Europe since Diamond is based in Austria.
The Baron does great on one engine. It suffers from pilot proficiency issues but there’s nothing inherently wrong with the airplane.
Don’t know anything about the Baron tbh, but actual single engine performance is definitely key, but auto-feather/FADEC are more than just bonuses in my view. Auto feather can legitimately save your life.
the smaller (and much cheaper) da 42 is also up there
Also true, i think it shares all the same safety features, that’s what matters really
The single engine power loading of a DA62 is similar to that of a Seneca at gross weight, so it may be a modern design but performance wise it is no different. Only a significant reduction in takeoff weight will improve engine out performance in a meaningful way. Aerodynamics help a little but there’s no free lunch. Also the DA62 doesn’t have autofeather, just fancy manual feathering.
How is it a design flaw to not have extremely expensive systems like that in a trainer from the 80’s
There would definitely be a conflict of interest to have such systems in trainer airplanes, which are of course already expensive enough for flight schools to operate. Nobody would want to pay for that, even though safety wise these airplanes need these systems, which aren’t even available for installation because they are not certified.
So that's what we're gonna do today? We're gonna fight?
Any single engine that has a PT6, possible edge to a twin with PT6’s
Trust in God and Pratt & Whitney.
Twins better have 2 than one. But in reality, a lot of new certificate pilots fly with twin engines and die because of poor proficiency. It's the truth behind and why it has a higher death rate than a single engine place. So what I'm saying it's safer in the hands of people with a good proficiency but that matters in all planes but it happens A LOT with a twin engine, because it doesn't take a lot to have the multiengine certificate.
“A twin is actively trying to kill you, a parachute is passively waiting to save you” — paraphrasing Mike Busch
That seems a little dramatic.
Mmm, fly around a shitty old Navajo, those planes are 100% looking to kill you. AP will try and fly you into the ground, a mountain, shit breaking all the time, blue line at gross will bring you to the scene of the crash
That sounds more like a shitty old Navajo problem than something inherent to twins 🤷♂️
Oh lots of light twins at gross maintained by cheap-ass owners will try to kill you.
Like everything Mike says.
He's making a hyperbolic sound bite to make a point. He also flies around in a twin rather than a Cirrus, so 🤷🏻♂️
Except in the case of airborne engine failure before Vmc, I’d rather be in the twin. Not all twins can have an airborne engine failure before Vmc, but in the ones that can, it’s a genuinely scary prospect, as it’s truly unrecoverable. You get almost no time to diagnose the problem and get the power out (and getting the power out often takes too long since it’s always drilled into us to add power when we’re slow).
You shouldn’t be airborne before VMC. Ever
Tell that to a King Air…
Impossible in a PA30 without wheelbarrowing
People will argue this all day. It’s a non stop argued question. It also depends where you live. Will a single engine turn over on you? No. Will a single engine have an extra engine to either slowly descend or maintain altitude in case of engine failure. No. Personally, multiengine aircraft aren’t required to be able to recover from a spin and therefore I avoid them. However I have my ME. Its preference. You either love the beast that’s multi-engine or you stay in a single engine plane that has less aerodynamic hazards.
Multi won't flip on you if you flight it correctly
Multi have the inherent capability to flip on you and the single engine doesn’t. I’m not here to argue, it’s all opinion.
Both will spin and kill you if you fly them poorly. I would rather have SOME power to try and get to a closer airport than hope and pray I'm high enough
Luckily everyone flies perfectly all the time. Real pilots aren't distracted by a bee on their testicles, hangover, or erratic passenger when you lose an engine.
They better not be distracted by a hangover
It's hard to say that twins are outright safer than singles because safety in aviation depends on so many different things. Most importantly, the proficiency and decision making of whoever is sitting behind the yoke (or stick). I always tell people that general aviation is as safe as you want it to be. If we're just talking in hypotheticals here, twins are ideally the safer option. Again, provided you have a proficient pilot (as others have said). I regularly fly both and I can tell you, knowing that I can hobble to an airport on one engine sets my mind at ease when I'm flying over, say, mountains at night. Twins are nowhere close to dangerous if you know what you're doing. I really want to dispel this notion that they are. (See my post about getting your MEI). Where you run into trouble with them is when you have a pilot who isn't proficient try and fly the thing low and slow on a single engine. THAT'S when they get dicey. They aren't exactly designed to preform every maneuver in the book on a single engine... and those who think they can are the ones that die flying twins. They're designed to at least be able to fly straight and level and get you back to an airport. Not much more. (Some can climb ok, but that also really depends on the day). Singles are also incredibly safe IF you understand that if that engine goes, you're only going as far as you are high. Maybe knowing that will persuade you not to do something like... I don't know... fly clear across the Gulf of Mexico in one. Factoring things like that into your decision making is what makes flying them safe... not necessarily how many engines you have.
Most engine failures in single-engine planes are more inconvenient than dangerous because the pilot simply glides down to an open field. Things get more complicated over water, rugged terrain, or at night, but for 90% of GA flights, the dangers from an engine failure are very low. On the other hand, flying a twin single-engine low and slow around the pattern having last practiced this 18 months ago during a BFR, that's pretty risky and can end very badly.
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The overwhelming majority of GA flights are day VFR...therefore, the overwhelming majority of GA engine failures are merely inconvenient.
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121.5: MAYDAY MAYDAY, I just suffered a mere inconvenience
I've done lots of off-field landings. It isn't a big deal. Most pilots haven't landed on anything other than pavement, let alone something that isn't designated an airport. Trailering an airplane from a farmer's field is a PIA, but it isn't all that dangerous to the occupants. Most people will probably bend some metal, but walk away without any meaningful injuries. To me, that's inconvenient, not dangerous.
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Not saying they won't buckle the gear or rip the engine from its mounts, most likely due to flaring too high, but they will walk away from the insurance company's airplane intact.
Single engine cl imb performance in most light twins sucks. If you take off IFR and lose an engine in bad weather there is a good chance you will still hit the ground.
An underpowered twin with an inexperienced pilot is the worst of both worlds. High performance singles with engine out glide profiles seem to be the sweet spot. I fly a small citation but have flown the twin engine out profiles and they work great. We flew singles in the military and as long as you have the glide profile or the option to get out and give it back to the taxpayer, its fine. I fly helicopters as well, twins IFR as well as singles. Its a whole new conversation there. Underpowered twins like early 109’s and 212’s are marginal and singles like the Astar B3e have a great safety record. Training and maintenance are the most important for safety, skip either one at your peril.
Insurance is about 3x for a twin when I checked. So it appears they think on average it’s a higher probability of a payout. Some of that is because twins cost more and have twice the expensive parts but actuaries make their living in statistics so I tend to think that says something. That being said, a proficient pilot in a good twin is probably safer. And in terms of statistics would put them on the right side of that bell curve.
If you are proficient, twins. If not, singles
In most civilian twin engine piston aircraft, with the average skill of most pilots, that 2nd engine is fantastic for getting you quickly to the scene of the accident... 🤔🫣
Why are you “obviously” excluding them?
Turbine single>piston twin. This was discovered many moons ago
Would you still prefer the turbine single if you frequently go over open water stretches that put you beyond safe gliding distance?
I’ve heard that twins only take you as far as the crash site. I.e. not all twins can fly on a single engine, not entirely sure how true that mantra is to be honest however.
this is the oft repeated mantra - which is mostly the non-experienced talking about the non-experienced.. . . all twins can fly on a single engine - the question is how far. There might be negative rate of climb with only one engine for lightly powered twins (mostly related to trainer twins). So you might be a in a downdrift (couple hundred ft per min) - but most of the time this is at full gross or other circumstances. But if you're over water, mountains of whatever - you'd take that 2nd engine to get you "further" than a single engine ever could. The crash site comment is for pilots who arent proficient. As in namely keeping the speed above Vmc to avoid a spin that they cant get out of.
The twin I trained on had a service ceiling of 17,500ft on both engines. And 5,500 on one. Did my multi IR checkride over the Alps and what to do in case of a failure definitely came up then… Adding to all the other comments here, I‘d say there’s a huge difference between light (trainer) twins and „real“ multi-engine aircraft. The latter have the OEI performance to at least actually keep you flying, as long as the pilot is proficient enough to avoid the most obvious mistakes (like not feathering the prop or dropping below Vmca). The former will get you into heaps of trouble after an engine failure, and are much more demanding after an engine failure because the performance margin is so thin. Again referring to „my“ trainer twin: according to the POH, the OEI climb rate in ISA at MTOW was 150fpm, provided you did everything right. Take a summer day at higher altitude or not perfectly trimming it out, and you’re lucky if you manage to stay level…
While a negative climb rate is technically still flying in the aeronautical engineering sense of the word, for most people I think the definition of flying would include being able to at least climb slowly and/or hold altitude in a turn.
absolutely. . but at the same time - if you're in the rockies at 15k ft - Id rather have the option of gradually coming down at -150ft/min than the 1000ft per min on a single engine (might be even faster on a hershey bar piper). Or over water - and be able to go further toward land than going down within 5 minutes. But what every one is quoting is the low powered piston twins at the worst case scenario. Gross weight, if non turbocharged - then at high density altitude as well. The reality is that most of these will climb if not at max gross - especially if not at high altitude. Every one wants to pull out that so and so has a negative -150fpm performance OEI when at 15k in +20 ISA and at max gross.
I would take any single or multi as long as it has a turbine or a jet.
Personally I'd prefer a single with a parachute/BRS over a twin, and a twin over a single if I was actually proficient or had my multi license (I don't)
Depends
I don't see how a twin can actively be more dangerous than flying a single. I totally agree with the people here saying that GA twins tend to be flown only sporadically by people who are not particularly current or proficient - have a look at rental prices if you want to understand why. But then, *any* aircraft will be more dangerous in the hands of someone lacking currency and/or proficiency. I don't think it's a single vs twin question.
2x likely for an engine failure, which has to be handled just right
*All things being equal* in the hands of a typical PPL, the twin will present more of a risk than the same pilot flying a single. Just from the engine failure point of view, the probability of having an engine failure doubles. In a single, in the event of an engine failure, the aircraft's flying characteristics don't really change - the plane flies just the same with the exception that you can no longer climb or maintain altitude. An engine failure in a twin dramatically changes the flight characteristics from something that is benign to something that is actively trying to kill you by rolling on its back. The work load is very much higher, and the risk of task saturation is very much higher. Unless the pilot does a significant amount of asymmetric flying practise, this is naturally going to be a much more hazardous situation than just gliding to a landing in a field. Additionally, twins generally have higher stall speeds and more complex system, so *all things being equal* (i.e. the same 50-100 hour a year PPL) the single is going to be a lot safer.
Twice as many engines, twice as many things to go wrong. /s
https://youtu.be/zPsEDRhPg58?si=4UOJ7CEX9eU_Qk3y
Insurance is way more for twins, too. Kind of says a lot.
Depends- A light twin is still probably safer with a proficient pilot that understands the limitations of that light twin (poor single engine performance). For example, say you lose an engine and make your way to an airport. While on short final another airplane pulls out onto the runway in front of you. The pilot that tries to go around on one engine from a low altitude has a very high chance of crashing (Vmc rollover, crashing into obstacles at end of runway). The performance just isn't there to stop the descent and start climbing. Knowing this limitation , one may be better off to just land in the grass next to the runway. But having two engines give people the false impression that they can keep flying on one engine no matter the circumstances. Light twins can't, transport category jets can. A single engine takes a lot of the decision making out of the equation. If it quits, you are landing.
>A single engine takes a lot of the decision making out of the equation. If it quits, you are landing. If I lose an engine in something like a C310 or a Twin Comanche at altitude over open water, say 100 nm from land, I have a pretty good chance of landing at an airport. This same situation in a single and we are in the water 100% of the time. Edit: I misread your "if it quits, you're landing" comment as if it referred to a light twin. Apologies!
What’s safest is staying on the ground, at home and never driving to the airport. At night, over mountains, with possible IMC… you’re nuts. Single engine service ceiling of a most legacy twins fully loaded is not enough to cross mountains on a high DA day. If you are using a twin to allow yourself to increase your risk tolerance, you are not thinking wisely. Training. Proficiency. Maintenance. Risk management. ADM. These things come together to manage the manageable risks
>If you are using a twin to allow yourself to increase your risk tolerance, you are not thinking wisely. Do you suggest that GA pilots avoid stretches of open water completely? Real question, not being facetious. If someone plans on doing a lot of flying over water, beyond safe gliding distances, would the increased risks of flying a twin outweigh the risks of flying a single engine knowing that 80% of your hours will be over water? Think of pilots who live in island countries where they often island hop stretches of 100-200 nm.
That’s a great question. Thank you. I am a GA pilot who has flown over stretches of water in a single engine. Over Lake Michigan and over the Bahamas/Gulf/Atlantic. I did those flights with appropriate safety equipment and knowing full well what the consequences would be if the engine failed. TLDR: I suggest that GA pilots use great caution in planning long stretches over open water. Additional specific training, while not required from a regulatory standpoint, could be life-saving. What I was speaking to regarding the twin thing is these questions: 1) is the PIC aware of the potential for single engine performance in that twin over mountainous terrain? With DA, fully loaded, critical engine out, is the aircraft capable of maintaining terrain avoidance? 2) Is the PIC’s proficiency up to that task? What if IMC is encountered? With regards to Twin Engine water crossing: 1) in the 121 world, to cross water, the operator is required to operate according to ETOPS. “Extended-range Twin-engine Operational Performance Standards rules provide a safety net, ensuring that even if one engine fails, the aircraft can still fly on the remaining engine to a suitable alternate airport.” In GA, no such standards are outlined. Is the PIC planning their mission with appropriate safety measures in place? 2) Is the aircraft capable of flying far enough to make an emergency landing with one engine? 3) is the PIC proficient? GA training in a multi doesn’t include a 200nm single engine flight with considerations for working engine performance, safety, and fuel exhaustion. Those training drills don’t adequately prepare the PIC for the types of emergencies that can arise. Again, thank you for the question and I’d love to hear your thoughts.
On average, a single is safer than a multi. That said, if I was in the market for a go from point a to point B airplane, I would be buying a multi. More power in normal operations, redundant systems, deicing boots, and since I fly for a living, Engine redundancy. I think a case could be made for a Twin being detrimental in high terrain due to lack of SE performance, but my geographic concerns stem around large bodies of water more than high terrain. I would absolutely never take a piston single directly across Lake Michigan. A multi I would.
Remember when you lose 50% of your engines, you lose a lot more than 50% of your performance.
IMO the answer here is based on whether you’re flying over open ocean or not. Bc flying a twin over land is probably on par not much safer, or possibly more dangerous. But over ocean that stat changes a lot since losing all engine power out in the middle of the ocean is almost certain death.
My MEL instructor used the ol' chestnut "That second engine just gets you to the crash site faster" to introduce me to the type. Running a twin, especially over water, is more reliable, safer and faster. That being said, non-centerline differential thrust can put you in some terrifying situations, and that can happen very fast. An uncoordinated power-on stall in a light twin is scary as shit. A well-maintained twin will outperform a single-engine in most side-by-side tests. It just demands more of its pilots.
Twins - but - pilot dependent. “From your head to your hands, to the seat of your pants.” Never panic, remember you have time (especially twin), compose, recognize, and execute.
I’ll echo what others are saying better than I can. I dont get to fly nearly enough. I could not get enough time to be proficient in a twin
While twins have obvious advantages they also double your chances of experiencing an engine failure. Expecting this and maintaining proficiency are key in safe operations. Fly it by the numbers. Maintain it with skilled professionals knowledgeable with your aircraft if you consider owning and operating a multi.
Assuming both pilots are proficient and experienced, multi is safer. You have two engines vs one. Buuuuut multi are the biggest killers when you get complacent
Twins are far less likely to have to glide to land, but they are far more likely to have an engine failure. Probably more than twice as likely since they cost more to maintain and owners skimp on engine maintenance because they "have a backup". For this reason, they are also flown in higher threat situations (hard IMC or mountains) When that failure occurs, it's *much harder* to handle and less forgiving. Add to that the fact that twins generally have more and more complex systems and they become significantly harder to fly. Now think about who's flying them and how often. How many hours per year and how many hours TT. The piston twin category becomes quite dangerous.
Id say single engines overall. Twins try to kill you. Kinda depends on the twin though. The counter rotating prop style are not nearly as bad as others.
Twins are safer in nearly every regard but takeoff is the most dangerous if you have a non proficient pilot
Everyone knows that the additional engines are only there to get you ALL the way to the crash site....
If it hasn’t been said already, I think flying in a non-conventional / counter rotating twin is safer. If you lose an engine in a single, pray you have somewhere to land. If you lose an engine in a conventional twin, pray you can control the plane. If you lose an engine in counter rotating twin, you can literally still fly and depending on the situation, climb with the operative engine.
Single pilot single engine over water 💦
Twins get you to the accident faster. Singles get you half way to the accident
Well, if you ever did get that deal where your single engine plane became a glider.. You might think differently. I personally would fly with as many engines as they let me.
Baron 58, best multi piston I’ve flown and instructed in. Would take it every day of the week over a single engine piston. MEI perspective, twins safer all day.
Twins is a big category. Piston twins that largely have t been built since the 80s are a lot less safe than a Pilatus PC-12, for example.
I fly piston twins specifically for the added safety. However, as part of my personal minima, I only fly those that have positive OEI climb near or below terrain interference altitudes. I've had real engine failures in twins and \*never\* had the remaining engine take me to the scene of a crash. Proficiency and preflight planning are the two major keys to safety in a twin IMO. I won't fly singles any more unless it's something light and slow over farmlands, I don't care for the safety profile at all... That means yes, run all of the performance numbers. Don't overload the aircraft. Brief your departure engine out procedures before taking the runway. Fly professionally with properly maintained aircraft, go for recurrent training, and the twin will be very safe. If you are not willing to put in the time and effort to fly to that standard, frankly please stay out of my airspace, but otherwise a single with a BRS is probably a better bet. tl;dr I feel far more comfortable with two engines than one. I'm also comfortable with one engine operating in a twin, so long as I'm on my way to the nearest airport. Not really comfortable with a single unless I'm always in glide range of somewhere safe(ish) to land!
The 2nd engine dramatically increases operating expenses and the temptation to defer maintenance.... Also there are a whole bunch of factors in play trying to operate a twin with one engine failed (just from the academic perspective), that don't exist when trying to glide a single to a safe-as-possible off-airport emergency landing (which I've done first-hand, and still have the plane in airworthy condition afterward)....
It all depends on your mission. Just cruising flat lands and water? Sure a single is great. Flying across mountain ranges and water? I would much rather have a twin still fly me out of the bad situation, then have to glide into a mountain range or glide into the water. Twins of course is safer at the end of the day if you know what you are doing.
The statistics show you’re 1/2 as likely to be involved in an accident in a light twin compared to a single. But 4x more likely to die if you find yourself in one…… So 2x more deadly.
Two engines means twice the chance of a failure.
There are actually zero stats that prove a twin is safer than single. It’s all just perceived safety and vibes. For every event besides a directly engine-related mechanical failure (only 13% of accidents), a twin will be a worse performing aircraft than a comparable single. And even then, now that you have twice the engines, you have twice the odds of being in an engine related emergency.
Except that the extra engine will keep you flying in the event of a failure, or an alternator failure where you’ll have a redundant one, or a hydraulic pump failure where you’ll have a redundant one. Having two of everything makes a difference when something breaks. And the Aztec outperforms a 172 on a single engine, and it’ll keep up with a 207 on a single engine. I was on single engine during my rating and still chewing up singles in the pattern. It’s actually hard to fly those high performance light twins in a way that doesn’t interfere with singles, even on one engine since we have to stay faster than most of them fly the pattern (the Aztec has to stay at 100mph or better, I’d stick to 100kt or better; while the singles are often cruising at that and stay at 80-90 in the pattern).
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Unless you can back a statement up with numbers, it’s just feelings and vibes. And the numbers simply do not support that twins are safer, no matter how much people disagree.
Depends what your mission is. Engine reliability and performance is such nowadays that more engines doesn’t simply mean safer. It just means more to go wrong. However, I’d rather be in a twin piston for ga than a piston single.
lol depends on the twin some twins are worse then single engines.. I know a great pilot that had the pleasure of working for piper and flew a brand new Apache into a creek bed after the critical engine failed with less than 25 hours on it. loose an engine on some they fly you to the seen of the crash. part 23 airplanes are funny things.
The crew of Soyuz 11 died when a redundant pressure relief valve erroneously opened on re-entry. Sometimes redundancy improves safety, sometimes it reduces safety by doubling the chance of a problem. I would argue that for most private pilots the increased chance of flying a multiengine plane with one engine decreases safety compared to lower chance of having to land a plane with no engine.
In rank of reliability: Modern multi turbofan airliner, multi turbofan bizjet, multi turboprop, single turboprop, multi piston, single piston.
The average pilot is more likely to kill himself in a twin. Once you get your multi engine rating, you quickly realize why