Cirrus safety vs Mooney safety

[Capt.Crash'n'Burn]

I know this is a bit of an apples to oranges comparison, but which of these 2 safety systems do you think is most likely to save your life? a roll cage or a parachute??

 

[Jim Logajan]

I know this is a bit of an apples to oranges comparison, but which of these 2 safety systems do you think is most likely to save your life? a roll cage or a parachute??

It's a bogus and utterly useless comparison since the Cirrus has both a roll cage and a parachute!

Not only that, it has airbag seat belts. Here's the list of safety features the Cirrus claims:

http://cirrusaircraft.com/about/safety/

The Cirrus is likely to have a higher rate of utilization precisely because of its extra safety features. The net result is that it is probably flown by Cirrus pilots in conditions that would keep Mooney pilots in bed. :wink2: The result would be that the accident rates would be roughly comparable to other aircraft. In fact one claim says that the Cirrus has 1.76 fatal accidents per 100,000 flight hours, while the average for all single engine aircraft is 1.86. (http://www.cirruspilots.org/content/SafetyHowSafeIsACirrus.aspx)

 

[Jim Logajan]

Searching the NTSB database, there have been 30 accidents in the SR20, 13 of them fatal. There are 15 accidents listed for the DA40, with only 3 fatal. (As Gary mentioned, there has been another fatal - Just happened a week or two ago - But there's presumably some SR20 accidents that haven't made the database yet as well, so I'll stick to what the database has.)

Now, as for fleet size - There are 706 DA40's on the FAA registry, and 758 SR20's. So, less than a 10% difference, but with twice the total number of accidents and over 4 times the number of fatal accidents.

Now, you tell me which is the safer airplane. The DA40 is most certainly NOT a "Cirrus Light."

Turns out that the SR20s are flown three times as often as DA40s, and so the per trip and per hour accident rate for SR20s is lower than the DA40s.

OK - I just made that "three times" part up. The point of the above being that accidents normalized to "fleet size" is a statistic only of value to insurers. Fleet size normalization would work for aircraft that are comparable in the missions flown, but the DA40 and SR20 seem different enough (to the pilots flying them) that the latter are likely to see a higher utilization factor. Twice as much? That would be consistent with "risk compensation" (http://en.wikipedia.org/wiki/Risk_compensation)

 

[Jim Logajan]

Ummmm... Bull****.

The DA40 and SR20 are only 5-10 knots different in cruise speed, and less than 50 pounds different in payload. Their missions are nearly identical. I doubt there's any difference at all in utilization between the two.

If you have REAL statistics to back up your assertion, I'm all ears. But making stuff up as you've done above doesn't add anything to the discussion.

Sigh. You make stuff up about them being flown on comparable missions then demand others prove your made up assumption is false! Yeah, that makes sense. How come you get to make things up?

(By the way, I do appreciate the effort you took to look up the number of accidents and fleet sizes for each aircraft type.)

 

[Jim Logajan]

I don't own stock in Cirrus or Diamond (or Mooney), never flown in any of them, and don't have a dog in this show. But in trying to determine what the differences are between the Diamond DA40 and the Cirrus SR20, I came across some interesting material, starting with this marketing brochure from Cirrus comparing the specs, features, and costs of the two (gosh, can you imagine which came out looking like the better deal?):

http://www.whycirrus.com/compare/pdf/cirrus-vs-diamond-da40-xls.pdf

On the other side of the ledger, we have Diamond touting its safety (click on "Judge for yourself..." link):

http://www.diamondaircraft.com/why/safety.php

Diamond claims either 0.16 (text) or 0.208 (chart) fatal accidents per 100,000 flight hours. (A more useful metric than accidents per fleet size.) By comparison, they claim the average GA fatal accident rate is 1.27 per 100,000 hours. Their rate compared to the GA average is quite remarkable. They can thank the quality of their pilot population.

But wait! Here is what Cirrus claims:

http://www.whycirrus.com/safety/cirrus-history.aspx

All Diamond Single Engine (SE) planes are claimed to have twice as many accidents (fatal and non-fatal) per 100,000 hours than Cirrus!

So what about fatal accidents per 100,000 hours? I could not find it there, but this article makes some claims:

http://www.cirruspilots.org/content/SafetyHowSafeIsACirrus.aspx

Cirrus has between 1.42 and 1.76 fatal accidents per 100,000 hours. The article also claims average GA fatal accident rate is about 1.19 per 100,000 hours. Since the period covered by the Diamond stats above and this author are likely different, the average rates would be expected to be similar but not identical (1.27 vs 1.19).

So are there statistics that can tell us something about the Cirrus pilots who had fatal accidents? This article attempts to determine where myth and fact reside:

http://www.cirruspilots.org/content/Safetylessonslearned.aspx

Quoting some highlights:

• General experience:

"Surprisingly, high-time pilots are involved in more than half of the Cirrus fatal accidents. Critics of Cirrus Design often complain about the marketing to newbie pilots, so they expect a rash of accidents involving low-time pilots. Not so."

• Time in type:

"About half of the fatal accident pilots had less than 150 hours of experience in an SR2X. Two fatal Cirrus accidents occurred during training, one during transition training and the other during primary training of an experienced helicopter pilot."

• Poor weather decision making:

"Weather is a huge factor in Cirrus accidents [...] Two-thirds of Cirrus fatal accidents involve bad weather (IMC), including low ceilings, fog, icing and thunderstorms."

• Failure to use CAPS:

"My estimation is that 30% of the fatal accidents had a high probability of success if the pilot had pulled the CAPS handle; overall 23 of 41, or 56%, had a high-to-middle level probability of success"

 

[Jim Logajan]

YOU are the one who made something up, not me.

My post's style was semantically equivalent to beginning it with "Hypothetically, if...." (I had actually considered writing it that way.)

If I had made it up I wouldn't have said in the same post it was a hypothetical in order to demonstrate the possible erroneous assumption you were making!

By the way - nice research on the TTAF values from online used-aircraft listings. Very clever. The only thing I could think of prior to seeing your post was to somehow record the Hobbs hours of a random sample of aircraft by physically going to them. But in any case, you've made a good case to me with plausible statistics.

Yes, Diamond does seem to have a much lower fatal accident rate. But WHY?

I also noted a couple years back when I considered someday building an RV-9A that there had never been a fatal accident in that model (I was later corrected - someone told me privately that the test bed for the RV-9A crashed with fatalities. Ah, here it is: http://www.rv-9.com/prototype accident.html)

Do some aircraft seem to attract a better class of pilots? Or are remarkably more forgiving of flying mistakes? Or easier to land and take off?