Originally Posted by
FullMetalJackass
Firstly, I said that when stalling straight and level, the Cirrus will not drop a wing. That instance, the pilot was banking at 25°, performing the fabled base to final turn with associated stall / spin. Most planes would drop a wing and enter a spin if the plane is not co-ordinated. However it might interest you to note that EASA considers the SR 20 / 22 aircraft to be one of the few truly spin resistant aircraft to have been certified - not spin immune, but spin resistant.
However, let's go back to that incident with the salesman / pilot. Why did the Pilot fail to recover? Because, according to the passenger who was also a pilot. he applied pro spin rudder rather than anti. Had he acted correctly, he would have had no issue. However he did at least remember his hard deck and pulled before it became too late.
You might recall your exact words were "How does sudden pilot incapacitation result in an aircraft plummeting to the ground?" You didn't refer to a Cirrus but to an aircraft hence I answered. Go check what you wrote and you will see you did NOT specify a Cirrus plummeting to the ground otherwise I would not have made such a suggestion. Please check your original post.
Firstly,. I refuse to accept it was deliberate action, let me get that part out of the way. However history shows that Cirrus don't typically have wing spar issues like certain other brands therefore a catastrophic failure in the absence of CBs is unlikely. Their BRS system has been proven as reliable over the decades, the two issues you refer to were caused after the change to electronic ignition which was then rectified by an SB. This aircraft would have had its chute repacked last year so was not susceptible to spurious ignition. I therefore rule out any uncommanded activation or inability to pull - unless the owner flew with the safety pin still in the handle - some do, you know.....
I'm not "running interference for the manufacturer" because I know from first hand experience how good those aircraft are and what it takes to cause them to fail. I'm a fan of Cirrus aircraft - except, perhaps, for their pricing policy, especially of the costs for BRS repacking...You, on the other hand, appear to be searching for reasons which would require multiple issues happening at the same time, allowing the holes in the swiss cheese to line up whereas I am merely saying that the most likely cause is an aircraft being hand flown in moderate icing - the GAFOR said that clouds above freezing level inferred moderate icing - with an incapacitated pilot causing it to ice up and stall.
At the end of the day, the aircraft went from cruise climb to a rapid descent - within 15 seconds his vertical speed had changed from 800 feet upwards to 3700 feet downwards. The only way I have seen a light aircraft change that rapidly without a commensurate gain in airspeed is either structural failure - which has been ruled out so far - or for the plane to stall - and knowing how well these aircraft are built, I cannot believe a mechanical defect could force a plane into such a 90° nose down dive within 15 seconds. Perhaps you can think of such a failure mode - otherwise I remain by my belief that the aircraft stalled due to ice, that was the start of the incident.
The question remains: Why did the pilot not react? Why did he not recover or at least pull the chute? The most logical solution is - because he couldn't.... I find it amusing that you are opining that the plane could become inverted, that CAPS could be deployed which then became tangled with the aircraft..... Sure, this theoretically could happen but it begs the question: what caused the upset? How does an SR22, climbing along suddenly become inverted and, within 15 seconds, start descending at nearly 4000fpm??? If the accident aircraft had become inverted and wrapped up in its Chute, the pilot would have known that it's effectively game over, I would have expected him to make a call.
Historically speaking, Cirrus had a worse fatality rate than similar aircraft so COPA initiated a "pull early, pull often" mantra - which was basically to tell them: You have the chute, use it. Ridicule came because pilots were accused of pulling when they flew a tank ran empty rather than trouble shooting the issue within the time (altitude) available to them. However, typically the training at CPPPs is, if you have an issue in cruise at, say, 8000 feet, to first trim to maintain airspeed, point yourself towards the nearest airfield / suitable landing spot then trouble shoot the issue whilst remaining aware of the lowest deployment altitude. If a landing is not 100% assured when a few hundred feet above your hard deck, pull CAPS.
The fatal over the rockies was IIRC, a pilot caught in icing and he deployed CAPS after exceeding more than 180KTAS - here, the pilot was nowhere near this sort of airspeed. Concerning operational limits of CAPS, the question is: how does a plane flown by a competent and current IFR rated pilot suddenly experience an upset which, if CAPS was deployed, would cause entanglement around the aircraft? How does the plane invert itself?
The difference between what LB and I are speculating is that we are not trying to attribute a cause or say it's one thing over another. Just debating if that theory has merit.
There is nothing ruling out mechanical failure at this point, just because the tail/wings are still attached does not rule out control failure, or structure deformation where it was all remains attached.
There is nothing ruling out chute malfinction.
There is nothing ruling out incapacitation.
There is nothing presently ruling out ice, stall, spin.
However as stated before the profile does not realy fit with stall/spin due the speeds involved as discussed eatlier, neither does it fit with an incapacitated pilot that well for similar reasoning. It could still be either as we just don't know anything except the profile.
We
may get a definitive answer on the pilot incapacitation aspect though.