If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#121
|
|||
|
|||
Dave,
We may have reached the point where we are going to have to disagree on what we still disagree on. I believe that picking apart the record is LESS informative than using the statistic. Here are my reasons: 1. The records of many planes are simply too long to do this with. 2. For any individual accident, there is usually too much mystery to really assign a cause. 3. The interpretation process is full of opportunities for prejudice. 4. We all think we are above average. Saying that no one is an average pilot may be true, but I think that the big stats like this one are useful for all of us. Nothing can predict the future, but you have to use what data you have to make a decision. I think that if you take apart the 182 record, you will find a lot of the same nonsense behavior as in the Cirrus. The value is that less of them died for it. After all, we have limitations. Not being Superman, I still need a plane to fly. Also, I can't spend my life figuring out why Cirrus pilots are fairing poorly. If I did, I would not be able to have the money to buy one and the answer would be moot. I am not going to assume that because I have better judgement, that those things will not happen to me. I am going to exercise good judgement by buying the plane with a safer record, and then practice sound judgement again everytime I fly it. "Dave Katz" wrote in message ... "Dude" writes: This stat does paint with a broad brush, but if all you are looking for is a measure of average safety in average usage by average pilots (that fly that plane) then the measure is very accurate. Yes, if you compare two models that are used by vastly different skill levels or in different types of missions, then you may invalidate the data by means of asking the wrong question. That is not being done here at all. But this perverts the nature of statistics. Even very accurate and valid statistics (with lots of data points, etc.) can never predict the individual outcome; statistics can only predict the aggregate outcome. The "average" usage by the "average" pilot does not exist, and the characteristics of that average cannot even be described, nor do the statistics predict anything about them. Matter of fact, it is easy to make the case that the average pilot does *not* scud run in freezing rain and crash into mountains; it only takes a very small handful of "special" pilots to skew the statistics. You cannot even make probabilistic predictions ("I am more likely to die in a Cirrus than a 182") because the statistics only allow this if the population is either uniform (like coin flips) or the statistics can describe the differences between individuals in the population. The fatalities per 100K statistic is completely worthless for a quantitative assessment of individual risk. It is meaningful (to some extent, anyhow) if you are an insurance underwriter, since they deal in the aggregate, but it only tells them what has been, not what will be. Unless you are one of those people who believes you are above average, then it means a lot. What makes one person who buys and flies a Cirrus all that different from another? What about comparing them to other brands of new airplanes buyers? There is no obvious difference, you will have to propose one. This is not a picky little nit type of stat. Saying that Cirrus just attracts idiot pilots is not enough, you need say why. I haven't seen a good reason yet. I don't actually think the Cirrus attracts idiot pilots, that was someone else's statement. I was trying to use it to make a point. The statistics (assuming that they pass significance tests) really tell you only that something is going on, but they can't tell you what. This is a red flag to go and actually examine the accident records and try to make an honest evaluation and decide for yourself what they mean to you. That would be true, except that examining the records tell us nothing. You should rely on the BIG RED FLAG! Seriously. If they had a common thread that was fixed, I would grant an exceptional case (aka V tail break ups). Until then, no. Um, the records tell us a lot; the statistic tells us close to nothing (other than a number.) The records tell us that some of the dead pilots were scud running in terrible conditions, and if you can honestly say that you never scud run in terrible conditions, your personal risk level is much lower than someone who does. By only looking at the single number, you throw away all of the information that might help you make an informed risk assessment. If these planes were mysteriously "falling from the sky" I'd agree with you, but the failure in most of the cases was squarely in the left seat. My point is that the stat is such a large macro that the idiot factor gets rounded out. As an average idiot, we are all more likely to die flying a Cirrus, than we are flying a 182. We are all average idiots in this stat. It is too big to slice apart that way. See above. Statistically there is no "average idiot" and mathematically you cannot make the statement that you as an individual are more likely to die. If the fatality rates were constant, you could make the statement that more people were going to die next year per 100K hours in a Cirrus than in a 182, but you couldn't say anything about your own risk. Furthermore, the fatality rate in the Cirrus is plummeting as the fleet grows, so if you want to play the extrapolation game you could predict that the Cirrus rate will be much lower this year and thus will magically become more safe than the 182. No, all you have to do is set a standard. How much more risk are you willing to take on your flight to enjoy the Cirrus over the Cessna? If its double, go for it. In my standard, I find the high fatality rate unacceptable when compared to the ancient Cessna. It should be better. That's not the same as saying it's either Safe or Unsafe. Life is unsafe, and you make your risk assessment and live it. The problem is that we are generally lousy at risk assessment, and ultimately it's somewhat arbitrary and almost always rationalized (otherwise we'd never get in a car or take a shower.) I'm probably less safe in an ancient Cessna than in a Cirrus (this showed the last time I tried to land one!) Is my risk double in the Cirrus? I doubt it. I would like the Cirrus fatality rate to be better than it is (and all other airplane makes, for that matter.) It's hard to judge whether it "should" be or not. The trends are that it will be, as the number of fleet hours is growing much faster than linearly (due to the rapid rate of delivery) but the fatality rate is not keeping pace. Those are all good, but how does that compare with the Cessna which requires a very small time of dual instruction for familiarity? Diamond? Lancair? Cirrus gets this level of scrutiny by running around BRAGGING about the safe design of their plane with a chute. In his interview I recently read, Mr. K was all about how great his airfoil is. Also, they get this scrutiny because they have high fatalites. A new glass panel 182 probably takes almost as much time to transition into safely for serious use (IFR) as does a Cirrus, though the fact that so many people learned to fly in them helps with the basic airwork. The Lancair is in the same class as the Cirrus and I would expect the transition to be at least as difficult (they're also a bit faster than the comparable Cirri and the outside visibility isn't as good.) Cirrus bragging about safety is rather premature and unfortunate, I agree with you. Well, I think the SRV and SR 20 would be better placed in the hands of more experienced folk. Since I don't see too many of those folk clamoring for a VFR only, glass cockpit, nearly 200k plane, I say they are using it to attract low time pilots. I think the days of students buying a Cirrus heve been nixxed by the insurers. It's still happening with SR20s; SR22s are pretty much impossible to insure as a zero-time student, unless you come with a lot of money and don't expect to solo for a long time. The SR22 is arguably too much of a handful as a primary trainer, though a few people have done it. The insurance people are the main gatekeepers in this case. The number of low-total-time pilots flying SR22s is probably quite small. Arguably? Definitely. You may note the 22 is doing better than the 20 in the stats. I think this is because, as I have heard from more than one low time prospective Cirrus buyer, the plane scares them. The 22 must have higher time pilots at the yoke. Yep, and a lot of people trade up to the SR22 after building SR20 time. |
#122
|
|||
|
|||
Are you a COPA member Peter?
I was forwarded some rather ugly COPA posts (I think its funny that all the bad news is in the "members only" section as if it won't get out, and then you let anyone buy a membership). The root of the problem is suspected to be that pilots are killing the throttle to descend. They give the reason for having to kill the throttle as not having the option to reduce power sufficiently because of the limited settings available to them. I am not trying to claim that anyone has been advertising the Cirrus prop controls as FADEC or even FADEC like. However, they have commented on how "simple" the operation of this system is for the pilot. The unintended consequence of this system is that the pilots are not able to let the engine and prop combo run in its sweet spot, and vertical planning becomes more problematic. Of course, no one forwards me notes from happy Cirrus customers. If your level of positive thinking and optimism is bothered by the subject, you should not log on. Even I quit watching the local news, and I suggest you do the same. "Peter Duniho" wrote in message ... "Dude" wrote in message ... I reduce throttle in my plane, and I can increase rpm. The combination will slow my plane Reducing throttle in a Cirrus slows the plane down too. without over cooling the engine. I DO NOT want to get into an argument about shock cooling. Then stop making statements that rely on the assumption that shock cooling exists. Whether shock cooling occurs or not does not change the fact that many pilots fly in ways to avoid it. So what? First of all, your assumption that high RPM, low throttle power settings avoid shock cooling is simply wrong. If there is such a thing as shock cooling, then reducing power will cause shock cooling, regardless of what mix of RPM and MP you use. Additionally, at low throttle, high RPM settings, the engine is windmilling, being driven by the airflow through the prop, and is considered by many to be at least as damaging to an engine as shock cooling, if not more so. Secondly, the fact that "many pilots" fly in a way to try to avoid something that does not happen isn't relevant to any rational discussion. Why would an aircraft designer install speed brakes just to address some psychological need for a pilot to use them, even if there is no practical advantage to doing so? In other words, if you want to play the "avoid shock cooling card", you'd better darn well be prepared to argue that "shock cooling" is real. The Cirrus does not allow full control over prop and throttle (aka phony fadec) It's not a FADEC. It's not advertised as a FADEC. It cannot possibly be a "phony fadec [sic]", since no one's called it a FADEC in the first place. Well, the ones that have engines dying at 700 hours are a lot frigging louder than the ones that think it works just fine. I haven't seen any evidence to even buttress that statement. But even if it's true, how's that anything other than basic human nature? Why would someone for whom everything's going fine invest a huge effort complaining about that? Who do you expect to hear from, if not from the few folks who have had engine problems? Pete |
#123
|
|||
|
|||
And it better have a radial engine, wood spar, fabric covering, and not a
single working instrument except the engine gages (real men take care of the engine first, last, and always!). "Thomas Borchert" wrote in message ... Jd-10, Ha! I take your Cessnas and add A TAILDRAGGER. Anything else is just training wheels... -- Thomas Borchert (EDDH) |
#124
|
|||
|
|||
John Harper wrote:
: Won't carry 4 people (with useful fuel) though. The new : Mooneys are wonderful planes but if you even occasionally : need to carry four people then they don't work out. Shame, : because the recent Bravo is a really lovely plane to : fly. I beg to differ, here. With 60 Gal of fuel, you have 700 Lbs of useful load left. 60 gal gets you ~500 nm with a 1 hour reserve. (This is in the Ovation2 that I borrowed a couple months ago. Your mileage may vary.) If you fill it up to 90 gal of fuel, yes, it's a 2 place + luggage plane. You have 5 hours of range (~850 nm), with a 1 hour reserve. According to the Cirrus web site, useful load of an SR22 is 1150 lbs (about the same as the Ovation2). Fuel capacity is 81 gal. 1150 - (81 * 6) = 664 lbs useful load with full fuel. This gives ~670 nm range with a 1 hour reserve, assuming 17 GPH. (I don't know how Cirrus gets a 1000 nm range, that would imply 14.5 GPH to dry tanks, which would imply about 60% power.) I would say that the two airplanes are very comparable in terms of power, speed, range, price, payload flexability, etc. -- Aaron Coolidge |
#125
|
|||
|
|||
I tried flying other planes, but only the Cirrus had enough room for the
cooler full of quiche, and the Martha Stewart cookware I use to warm it up. A thermos full of latte' and you're good to go, girlfriend. -Mike "jd-10" wrote in message ... I don't know why you dorks won't face facts: A Cirrus is for a pilot with a very small penis. No real man would be caught dead in that Lexus-looking POS. "d00d, it's lie having a 'vette, man." PUSSIES! In fact, men with large penises ONLY fly single-engine Cessnas. They are the finest example of great airplane design in the world. They can take you where a Cirrus would BREAK UP ON LANDING! Real men don't need a ballistic parachute either. If you **** up, shut up and die like an aviator. I repeat, Cirri are for men with very small penises. That is all. -- JD-10 |
#126
|
|||
|
|||
Greg,
Ya, but I thought we were talking about a Cirrus and not a Bonanza. And, I think the point remains. We were comparing the Cirrus to "conventional" aircraft, and some were implying the older ones were no problem to recover at altitudes below 910 feet, while the Cirrus would be a problem. Turns out that the 910 feet are needed to recover from a one-turn spin (as certification requires) for the Cirrus. Well, I doubt you'd get away with much less in any comparable aircraft, e.g. the Bonanza. And in that case, that point does NOT remain. -- Thomas Borchert (EDDH) |
#127
|
|||
|
|||
Dude,
real men take care of the engine first, last, and always!) REAL MEN flap their arms to fly. -- Thomas Borchert (EDDH) |
#128
|
|||
|
|||
"Dude" wrote in message
... Are you a COPA member Peter? No, why should I be? I was forwarded some rather ugly COPA posts (I think its funny that all the bad news is in the "members only" section as if it won't get out, and then you let anyone buy a membership). By whom? People who have done extensive testing and actually know? Or one or two irate owners who have had unusual problems with their airplanes? If you have the posts, make them publicly available. The root of the problem is suspected to be that pilots are killing the throttle to descend. Suspected by whom? Anyone who ought to know? Or random armchair mechanics like those of posting to this thread? They give the reason for having to kill the throttle as not having the option to reduce power sufficiently because of the limited settings available to them. I've flown the SR20. I had no trouble at all using partial power reductions to slow the airplane. I am not trying to claim that anyone has been advertising the Cirrus prop controls as FADEC or even FADEC like. Then why do you keep writing "phony FADEC"? Sure looks like a claim to me. However, they have commented on how "simple" the operation of this system is for the pilot. It *is* simple. The unintended consequence of this system is that the pilots are not able to let the engine and prop combo run in its sweet spot, and vertical planning becomes more problematic. What "sweet spot"? A reduction in power is a reduction in power. Less power means less thrust which means less speed. There's absolutely no reason for vertical planning to be "more problematic", no more so than all the other low-drag airframes out there that also don't have speed brakes. Nothing about the engine control is relevant here. Of course, no one forwards me notes from happy Cirrus customers. If your level of positive thinking and optimism is bothered by the subject, you should not log on. Log on to what? Even I quit watching the local news, and I suggest you do the same. I have no idea what you're talking about. You show up here spouting all sorts of nonsense about how the Cirrus airplanes need speed brakes, and then you accuse me of having my "level of positive thinking and optimism" bothered? All I'm doing is pointing out how stupid your claims are. I'm not bothered at all. Pete |
#129
|
|||
|
|||
"Michael" wrote in message om... "C J Campbell" wrote Therefore, the Cirrus cannot recover from a spin when below 900' AGL. Many other aircraft can. Name one aircraft that can cruise better than 170 kts, carry four people, and can recover from a spin at 900 AGL. The occupants of a Cirrus can hope to "survive" a spin from 900 AGL if all goes well, and I honestly feel that that is a great thing, but not the same as "recovering" from the spin. The airplane will be bent, probably off the field (possibly in a schoolyard, or the middle of an interstate, or...) and there may well be injuries, inside and outside the plane. Vaughn Michael |
#130
|
|||
|
|||
I was really thinking of the Bravo, which is a bit heavier
than the Ovation (obviously). "Guideline" useful load for the Bravo seems to be around 950-1000 but I've seen them on ASO etc in the 850-900 range by the time they get TKS and fancy avionics. So with 60 gals that gets you to around 500 lbs, not even 3 normal people with some baggage. John "Aaron Coolidge" wrote in message ... John Harper wrote: : Won't carry 4 people (with useful fuel) though. The new : Mooneys are wonderful planes but if you even occasionally : need to carry four people then they don't work out. Shame, : because the recent Bravo is a really lovely plane to : fly. I beg to differ, here. With 60 Gal of fuel, you have 700 Lbs of useful load left. 60 gal gets you ~500 nm with a 1 hour reserve. (This is in the Ovation2 that I borrowed a couple months ago. Your mileage may vary.) If you fill it up to 90 gal of fuel, yes, it's a 2 place + luggage plane. You have 5 hours of range (~850 nm), with a 1 hour reserve. According to the Cirrus web site, useful load of an SR22 is 1150 lbs (about the same as the Ovation2). Fuel capacity is 81 gal. 1150 - (81 * 6) = 664 lbs useful load with full fuel. This gives ~670 nm range with a 1 hour reserve, assuming 17 GPH. (I don't know how Cirrus gets a 1000 nm range, that would imply 14.5 GPH to dry tanks, which would imply about 60% power.) I would say that the two airplanes are very comparable in terms of power, speed, range, price, payload flexability, etc. -- Aaron Coolidge |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Boeing Boondoggle | Larry Dighera | Military Aviation | 77 | September 15th 04 02:39 AM |
New Cirrus SR22 Lead Time | Lenny Sawyer | Owning | 4 | March 6th 04 09:22 AM |
Fractional Ownership - Cirrus SR22 | Rich Raine | Owning | 3 | December 24th 03 05:36 AM |
New Cessna panel | C J Campbell | Owning | 48 | October 24th 03 04:43 PM |