In reply to:
the overall success rate is still only 2 out of 5.
Well that’s better than any baseball player hit this year.
Seriously, the point is that it is 2 (really 1) more than any other plane could have had. Lets ask the pilot what he thinks…
Marty
In reply to:
…the overall success rate is still only 2 out of 5.
Hmmm… just guessing here… but if the next attempted deployment is successful, saving at least one more life, we can look forward to your analysis: The overall success rate is still only 50% - right?
Art, we are all sorry for the miserable experience that you are having with Cirrus and that Cirrus is most likely having with you. However, any argument based on biased (and you are certainly entitled to your bias) conjecture is going to be flawed at most and on the fence of unreasonable at best. What we know for sure is that the CAPS was properly deployed by Mr. Morrison under circumstances which the system was designed to intervene. That’s 1 for 1. Please take a step back and give Cirrus credit where credit is due. This validation of CAPS ability to save our lives is a very important event for all Cirrus owners and all of general aviation. Perfect or not, at this point in general aviation, 1for 1, 2for 6, 1 for 20, I’ll take it.
Best of luck,
Once again I have to take issue with Art’s simplistic statistics. And, once again I’m breaking my own rule 'bout replying to a provocative post - oh well.
In reply to:
the overall success rate is still only 2 out of 5
Just as it is improper to compare apples to oranges, it is statistically improper to calculate failure rates combining events where different designs, or engineering-change (SB) levels, or generations of hardware are involved.
A valid statistical analysis determines rates within a group of the same configuration, else the result is often meaningless. A valid statistical analysis has sufficient numbers to reduce the chance of an incorrect conclusion to an acceptable level.
I can claim that for the current configuration (SB level) the success rate for the parachute is 1/1 or 100%. I would be laughed out of statistics class for doing so (for using absurdly small-number statistics - a sample size of 1). So, I won’t make the 100% claim.[:D]
Lastly, I’m very glad that the pilot is OK and I’m glad that Cirrus and BRS designed a parachute into my SR.
Mike,
I just had the SB performed while N224AZ was at the Service Center. I fly it home tomorrow morning. I informed the manager of the Texas incident and he doubled checked the safety wire, etc. He did have to remove the left aileron.
Walt
Maybe page two of the SB says “Replace the left aileron” and that page just got overlooked.
but if the next attempted deployment is successful, saving at least one more life, we can look forward to your analysis: The overall success rate is still only 50% - right?
Right. Which I think is about the minimum acceptable performance for a football coach.
I fly the plane so I hope the parachute does work. My perspective passengers who are nervous about small planes would be more like to fly with me if I could say the plane had a reliable parachute. But 2 out of 5 is not reliable. Cirrus could resolve the problem with another 3 plane demo with all 3 working. The record would be better than 50% and they would be able to say all of the deployments since the final parachute SB were successful.
"Maybe page two of the SB says “Replace the left aileron” and that page just got overlooked. "
And I’ll double check during the preflight that they replaced it!
Walt
In reply to:
Maybe page two of the SB says “Replace the left aileron” and that page just got overlooked.
Michael,
Funny! [:D]
Seriously, I was wondering what the aerodynamics would be like if an aileron were missing altogether. Intuition suggests that if the remaining aileron were still working, the airplane would still be controllable in the roll, although with perhaps half the roll-rate.
That’s not to say I’d have tried it if I had been in the failed airplane today – I think that pulling the CAPS was absolutely the right decision, for all sorts of reasons. Even if the airplane did seem controllable, down to what speed? And, if the work just done cause the left aileron to fall off, how long until the right one departs? No, I think today’s pilot did an exemplary job of keeping cool under pressure, and keeping the ol’ cranial matter hard at work. I just hope that I can do as well if I’m ever in such a tough, scary position.
Mike.
Congratulations to the pilot for fine judgment and performance in really hairy circumstances. I hope Mr. Morrison gets another '22 real soon if he wants it. Perhaps one of the November-December delivery slots that were deferred by those waiting for the PFD?
In reply to:
Intuition suggests that if the remaining aileron were still working, the airplane would still be controllable in the roll, although with perhaps half the roll-rate.
Mike,
Along with the aileron went a significant amount of lift on that wing. So you are going to have to raise the opposite aileron and spoil an equivalent amount of lift on the other wing. Now you are going to have to increase angle of attack to get your lift back. So, you’ve raised stall speed by an unknown amount. Yah, I’d rather have CAPS at a safe altitude than a stall-spin nearer the ground.
-Curt
Mike,
Interesting points you make with regard to knowing when to pull the CAPS. I can’t tell you how many times I (and many others in the glider crowd) have had this discussion in reference to bailing out of the glider. Flying gliders (especially competitively) requires flying at slow airspeed in medium bank turns in choppy air while in close proximity to other gliders. I have flown in many thermals within 50-100’ of other gliders while trying to find the center of lift in a thermal. Sometimes, there are 30-40 gliders in one thermal. Because of this, parachutes are required equipment. Midairs do happen and pilots do bailout. I asked two of the ones that bailed out about their decision making process leading up to stepping out of their gliders. I had always wondered if I would have the courage to bail out and if this would cause some degree of hesitation I might regret. Both of them gave me essentially the same response, “Don’t worry, you will know when it’s time, and you will just go”. Of course, one of the two was a highly experienced jumper, the other one was like the rest of us.
I was happy to know I would have this clarity of thought when I needed it! We have talked a great deal in this forum about when use of the CAPS is appropriate. I am sure we all have our list of times we each think it would be necessary. Hopefully, there is a great deal of commonality among lists. But, the important thing is to have a list and have it dedicated to memory. Loss of a control surface would be right up there on my list. Having a list will help to ensure you have that clarity of thought needed when the time comes.
How many matches from a single box of matches do you have to strike before you assume all the rest will work? Conversely, how many dud matches does it take to imply that none of the rest in the box will light?
Interesting thing about independent, mutually exclusive events – whatever happens one time has absolutely no effect on what happens the next time…
The last time I saw Alan K., I suggested that the first pilot to deploy the chute get a free new airplane from Cirrus. He thought it was an interesting idea.
We HAVE to get a pirep from the pilot!
-Mike
In Reply To:
“I hope Mr. Morrison gets another '22 real soon if he wants it.”
Perhaps Cirrus should give him a STEEP discount (read greater than 50% off) on a replacement, in exchange for a thorough debriefing and publication of his account of the ride all the way down under canopy. I know I’d like to hear all the details, from what the 'chute felt and sounded like going out, to how the plane behaved after it was under full canopy, to how the landing felt. etc., etc., etc. Being a test pilot, even if it wasn’t intentional, should be worth a good portion of new plane…Are you reading this Ian? [:)]
CPPP should also book him for all the rest of the CPPP ground schools, to lecture on the subject!
Congrats to the pilot! Thank GOD that CAPS worked as advertised! This is “the ultimate test” that CirrusDesign needed! It is just amazing that this happened just after the CAPS AD was completed too! In a weird twist of circumstances it was perhaps also because other unrelated but simultaneous work was completed that resulted in the catastrophic aileron separation. The successful outcome of this event is just what Cirrus, and BRS needed to prove their concept! Especially emotionally to non-pilots. I am grateful for the increased confidence it will instill in me and my non-pilot passengers …just in case.
I have no aeronautical engineering experience so this is all just idle speculation.
I would assume that if the aileron departed the aircraft cleanly, then the wing in question would have a significant amount of drag. I don’t know about a decrease in lift as the airflow tends to separate before it reaches as far back as the aileron. But the drag would probably cause a turn towards the affected wing and that if left uncorrected, would tend to give more lift to the outer, unaffected wing. Whether the unaffected aileron would have much authority is pure conjecture.
I would also tend to doubt that the aileron came off cleanly and quickly. Therefore, IMHO a hanging aileron would have totally unpredictable effects on the airplane and the affects would certainly be much worse than the effects of a cleanly departed aileron.
Depending upon how the aileron departed, a myriad of problems could have been encountered including flutter, damage to the tail and damage to the control cables interfering with the normal operation of the rudder and good aileron.
In all events, the pilot of a airplane so stricken would be a test pilot.
Marty
Agreed Clyde,
We all were hopeful one day this was coming…a chute deployment that unquestionably saved the pilot. Many of us purchased our Cirrus for a circumstance like this…The presence of a chute was a ‘huge’ asset for me and my wife/family since I began learning to fly in my 20 just 17 months ago (600 on the hobbs now!)
Heretofore, first some previous crashes created some doubt whether the chute would actually work (I have publicly stated I gave it a 70% chance) and second would it save lives if it did in a single engine.
Well, now that those questions have been firmly resolved…I think the GA industry will be talking about this for a long time (us too) and in many aspects…it has changed forever!
If this proves to be mechanic error…Cirrus will probably have a big-time demand increase…If it turns out the dam airleron just broke away…I think the successful CAPS deployment will be overshadowed by the seriousness of a control surface failure. Let’s hope not!
TC
Be interesting to see if Cessna have a rethink now…
Yup. They’ve got that scheduled for the next meeting, right after they revamp their half-a-century-old single-engine aircraft design.
(Sung to the tune of Pink Floyd’s “Brick in the Wall”) We don’t need no innovation …
-Mike
As far as the cause of the problem in the first place - I am usually not one to speculate about things like this, but given that a) we are told the trim cartridge SB had just been done, which involves removal of the left aileron, and b) the left aileron departed the aircraft on the first flight after that maintenance, and c) there have been no similar incidents to the fleet, I think the odds of it turning out to be unrelated to the maintenance are remote.
Unfortunately human error in all its forms will always be with us - that’s why the parachute is there.