The following assumes piston twins, there are VERY few engine out jet landings that result in fatalities:

Unfortunately, we have no idea what the statistics are for successful twin engine landings after an engine failure. It's easy to assume (as many do) that it happens often and without peril. But, we really have no idea. I suspect it's not as common as most people think and that the percentage that end badly is higher than commonly assumed.
Further, the risk of fatal injury in a twin running on one engine is non-trivial. It goes down with frequent training, but it's still non trivial.

The real question is, which is greater: The risk of a fatal accident under a Cirrus chute or landing a twin on one engine (with average ability/recurrent training)?

Unfortunately, we have no idea what the statistics are for successful twin engine landings after an engine failure. It's easy to assume (as many do) that it happens often and without peril. But, we really have no idea. I suspect it's not very common at all.

Further, the risk of fatal injury in a twin running on one engine is non-trivial. It goes down with frequent training, but it's still non trivial.

The real question is, which is greater: The risk of a fatal accident under a Cirrus chute or landing a twin on one engine (with average ability/recurrent training)?

I'm saying that the only number we have is how many crash. We have no idea how many land safely after an engine failure, since it's not tracked.

Most people assume that many twins have engine failures and land safely. I don't think that happens nearly as often as people assume. I suspect that twin engine failures are much rarer than common pilots sense believes. (failures/100,000 hrs flown)

If I'm correct, the ratio fatalities/failures will be much larger than most assume because the number of failures is lower than everyone assumes.

My bottom line question is comparing fatalities/failures for twins and Cirri. But, we don't have the denominator for the twins group, so the ratios cannot be computer/compared.

Your bet is as legitimate as "I bet humans will colonize the moon".

Maybe you will have more success with that one. Might need to find people who are less sharp than those around here.

Mike C.

I'm saying that the only number we have is how many crash. We have no idea how many land safely after an engine failure, since it's not tracked.

Most people assume that many twins have engine failures and land safely. I don't think that happens nearly as often as people assume. I suspect that twin engine failures are much rarer than common pilots sense believes. (failures/100,000 hrs flown)

If I'm correct, the ratio fatalities/failures will be much larger than most assume because the number of failures is lower than everyone assumes.

My bottom line question is comparing fatalities/failures for twins and Cirri. But, we don't have the denominator for the twins group, so the ratios cannot be computer/compared.

The chute advocates implicitly assume the chute is 100% reliable. Pull it and you are saved.

Not so. You can find yourself in a truly fatal situation and still end up dead.

We have 21 fatal accidents in the last 3 years in the SR series. So we know, as a hard number, there were those 21 fatal situations where the chute didn't work, including those cases where the pilot simply didn't use it, or they were too low, or there wasn't time, or anything else.

There were 27 chute pulls in the last 3 years (a significant increase over previous years). I judge that about a third of them MIGHT be truly fatal situations where the chute saved a life(*).

So we had 30 truly fatal situations arise in the last 3 years, the chute saved 9 of them.

That's a chute success rate of 30%.

If you go on a flight ASSUMING the chute will save your life should anything go wrong, you may have misjudged the effectiveness by 70%.

This means you took a higher risk than you expected.

This means you potentially flew beyond your risk tolerance and didn't know it.

This leads to a high fatal accident record.

Mike C.

(*) We know it wasn't all 27. We know it probably wasn't zero, either. I realize my number is subjective, but it would take a very detailed analysis to assign probabilities to every event and then compute the expected value of the outcomes. This is good debate fodder.

So why does anyone end up dead in a Cirrus?

Happened 21 times in the last 3 years.

No safe landing for those folks.

Mike C.

Mike,

You have so many logical fallacies and assumptions that I am not even sure where to start.
I will take a shot at it, but, I am sure I am going to miss a lot.
1. The 21 fatalities. Why do you assume the chute made the pilot take the plane where it was not capable? Why do you assume the chute would not have saved them?
2. How do you get 1/3 of the time the plane was not capable and encouraged the pilot to go beyond the ability of the plane? To determine the plane was not capable, look at the cause of the accident. Thunderstorms and Ice are really the only two types I would expect to see in this category. The remainder of the chute pulls the pilot made a choice; and the training is very specific. If you do not have a 100% guarantee and confidence of landing, pull the chute. So you can pretty count on the fact that the pilot did not have 100% confidence in a positive outcome without the chute.
3. Your math needs lots of help; and you need to talk to Cirrus pilots who have been through the training programs, or go read more on COPA, or talk to more Cirrus pilots. Go back and read my post as a starting point. Roughly 80% of accidents are caused by the pilot with 20% caused by some mechanical failure. When you go through the probable causes for GA accidents, you will find that the chute can actually save the pilots and passengers life in a super majority of the accidents (I forget the stats, but it was a lot of them).

Tim

Edit: Fix a typo

So why does anyone end up dead in a Cirrus?

Happened 21 times in the last 3 years.

No safe landing for those folks.

Mike C.

Mike I hear ya. You're a very persuasive and smart fella, no doubt about it. If you were on my opposing debate team, I'd be nervous. By this time of the evening most of us (well me in particular) needs a couple of glasses of wine to put the kids to bed (or not hear the whining).

So in my trips to New Orleans, which am I safer in, the Mooney or the Cirrus?

Now replace the 'I' with my family.....which is my family safer in?

Once you crack that answer, you'll see the light.........

Marriage? Family? Now there's a sure way to crash and burn

I'm saying that the only number we have is how many crash. We have no idea how many land safely after an engine failure, since it's not tracked.

Most people assume that many twins have engine failures and land safely. I don't think that happens nearly as often as people assume. I suspect that twin engine failures are much rarer than common pilots sense believes. (failures/100,000 hrs flown)

If I'm correct, the ratio fatalities/failures will be much larger than most assume because the number of failures is lower than everyone assumes.

My bottom line question is comparing fatalities/failures for twins and Cirri. But, we don't have the denominator for the twins group, so the ratios cannot be computer/compared.

There once was two guys, Mr. Cirrus and Mr. Twin. Both smoke cigarettes.

Mr. Cirrus lived in a house made of straw.

Mr. Twin lived in a house made of brick.

They met one day.

"Mr. Cirrus, why don't you move into a brick house? I worry that your smoking habit will cause a fire and burn your place down!"

"Why Mr. Twin, I have this fire extinguisher which will put the fire out if it ever occurs. I don't need a brick house. I don't know how to build one, anyway."

"But Mr. Cirrus, we both smoke, but you take a higher risk with your house!"

"Mr. Twin, I assure you the fire extinguisher works like a charm, I'd rather have that than your brick house. This makes my risk no higher than yours. Besides, my wife likes having the fire extinguisher in case she needs to use it."

Then one day, Mr. Cirrus dropped his cigarette and it started a fire. He ran for his extinguisher only to find out that it works only about 30% of the time.

His house burned down around him and he died.

Mr. Cirrus's friends all mourned his loss.

"What should we do now?" they cried, since they all lived in straw houses, too.

They decided they should teach each other to use the fire extinguisher sooner and more often. They organized classes on how to do this. Over time, more and more fire extinguishers got used this way, but still some houses burned down.

Then came a big wind storm and blew their straw houses all down.

The End.

Mike C.

I know they do. Local guy to Billings was at 13,000 in northern Utah about 5 years ago, lost an engine in his 310 and couldn't handle it.

Mike, that's the first post where I saw you crack