Please excuse me if this has been discussed before. When I query I cannot find evidence that it has.
I have a flight simulator called x-plane 6.0 running on a Mac G4. It is an remarkably accurate flight simulator. When I compare it to aircraft I have actually flown I find them to be identical.
The discussion about spins motivated me to post this. The SR 20 is VERY easy to recover from spins. One can try them over gross, very undergross, aft CG, etc. In evry instance it’s easy to recover and do so quickly. It is hard for me to get it into the spin.
It’s also interesting to see how it flies beyond the envelope in more normal flight regimes.
Any simulation is only as good as the data that went into it. Since, to the best of my knowledge no one has successfully done a spin in an SR20 and recovered, any simulation is pure speculation, probably based upon how other planes respond. All you can say with certianty is that the X-Plane version of the SR20 (which probably has very little relationship to the real plane behavior especially during maneuvers outside of the tested envelope) is easy to recover. The SR20 POH says it cannot be recovered, and that certainly carries more weight that X-Plane
A stalled wing is very difficult to model accurately in a flight sumulator since turbulent airflow is chaotic. There’s all sorts of wierd stuff going on near and during a stall. I’ve found that even though X Plane is very good, you can get completely ludicrous results when trying stalls and spins. Unfortunately, the author of X Plane, Austin Meyer, is a delusioned hermit who does nothing all day but program X Plane and who also has an ego the size of Montana. He claims you can build an airplane in X Plane and have it fly just like the real thing, but unfortunately no flight simulator is that good. I hope there aren’t a lot of people out there trying things in X Plane and then going out to a real airplane and expecting the results to be the same.
The SR20 POH does not say that the plane cannot be recovered from a spin, all it says is
The SR20 is not approved for spins,and has not been tested or certified for spin recovery characteristics.
The SR20 has been spun, and recovered. According to the SR20 test pilots, the spin recovery is quite conventional. Cirrus won’t put this in writing, of course, for legal reasons.
I share your caution with regard to extrapolating the results of a simulator to the real-world, and I have absolutely no intention of spinning an SR20 to test the theory, but I can assure you that if I did ever unintentionally get the SR20 into a spin, I would not reach for the CAPS handle.
Art,
I agree with you that X-Plane does not provide conclusive proof of the SR20’s handling in spins.
However, the SR20 POH most certainly does NOT say it cannot be recovered from a spin without the 'chute. It says:
“The SR20 is not approved for spins,and has not been tested or certified for spin recovery characteristics.The only approved and demonstrated method of spin recovery is activation of the Cirrus Airframe Parachute System”
I’ve spoken with a Cirrus test pilot, and he told me that he had spun the SR20, and it recovered without using the chute, with normal spin recovery technique.
I cannot speak for Cirrus as to why they didn’t certify it for spin recovery without the CAPS, but I’m guessing that it is a non-trivial part of the certification process, and they saved time and money by skipping that portion.
-Mike
I’ve spoken with a Cirrus test pilot, and he told me that he had spun the SR20, and it recovered without using the chute, with normal spin recovery technique.<
I have also spoken with someone who deliberately spun the plane, in a test, and recovered with normal procedure.
It is accurate to say that the Cirrus planes are not certified for spin recovery without the parachute. As someone else has suggested, this might be a good time for Cirrus to do some spin tests – with all proper precautions (like making sure a working parachute was in place). But it is inaccurate to say that the POH claims the planes can’t recover from a spin, and it’s illogical to assume that they would be unable to. I gather than certain characteristics of this design, including wing-cuffs, make it both harder for a SR2X to enter a spin and harder to get out of one, than for, say, a Cessna. But “harder” does not equal “impossible.”
Mike
You are probably right about time and expense in regards to certification of the Cirrus for spin recovery. You now have to wonder how much time and cost would have been involved. Guess that is 20/20 hindsight though.
Here’s my question - Is the MAIN purpose of the chute for spin recovery? I have always thought of chute as for totally unrecoverable situations like loss of controls due to collision or perhaps the pilot becoming incapacitated. Pulling the chute for me would be only after having tried and failed to recover with opposite rudder, etc.
I have spoken to a CFII who was giving SR20 transition training to a pilot and was involved in a spin entry, though not a fully developed spin. The transitioning pilot was mainly experienced in sailplanes and, during the departure stall sequence, relaxed his right rudder at the stall break. The result was a left wing drop and a spin entry. Recovery by the CFII was quick and conventional.
I think spin certification with CAPS was chosen as the quickest way to “kill two birds with one stone” rather than for some fundamental aerodynamic reason.
George Savage
SR22 N747SJ
In reply to:
Here’s my question - Is the MAIN purpose of the chute for spin recovery?
No, the main purpose is to provide a last line of defence against engine failure, structural failure, mid-air collision etc. Being able to use it for spin recovery was just a bonus that presumably shortened the flight testing required for certification.
With regard to Jim’s comment about planes that are hard to get into a spin being hard to get out of one, I don’t believe that’s true. While there are a lot of variables involved, the factors that make the SR20 hard to spin should, in my opinion, make it easier to recover. And the anecdotal reports from the Cirrus test pilots support that opinion.
My theory: Even given the problem with the chute activation cable, I will be you good money that CIrrus will not change the certification in the US. Even if they do all the testing that the Canadians and the British require, they will still not change it in the US. Right now, the chute is required to be operational in order to make the airplane airworthy.
Can you imagine the problems they’d have if the chute became optional and some idiot removed it? First off, the balance of the plane would be screwed up. Secondly, if they killed themselves in it, it would be a PR nightmare. They made their name on being “the one with the chute in it.” I doubt they’re going to run away from it now.
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From speaking with unnamed Cirrus test pilots, the Cirrus is difficult to spin but once involved, it is conventional AND easy to recover from a spin. To add to Clyde’s comment, “If in a spin over 2,000’ AGL I would not use the CAPS.”
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The CAPS is installed for a myriad of safety reasons. One advantage to Cirrus of the 'chute was that allowed them to avoid the full series of spin tests, tests which are both time consuming and expensive. I believe that the the current airworthiness standards for certification from the FAA require the the aircraft be ‘spin resistant.’ Lancair addressed this issue by installing a ‘rudder limiter’ which in certain modes of flight limits the throw of the rudder substantially. This combined with the other flight characteristics of the airplane [due in part ot ‘inovations’, such as leading edge cuffs] meets the FAA requirement. Rudder limiters are not uncommon in aircraft and even the A300 which crashed in NYC has them - unfortunately they did not address the situation which the jet encountered. but like anything else created by man, it too can fail.
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To the best of my knowledge, no certified Cirrus has ever crashed as a result of an unintentional [or intentional for that matter] spin. Obviously, the other ‘spin avoiding’ design attributes must be working well.
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The POH does in fact say that the only ‘approved’ method of recovering from a spin is the CAPS. It does not say that you can’t try. It just doesn’t provide any assurances that conventions methods will work. I believe this to be a legal requirement due to the lack of the full spin series in certification testing. The POH and placards also say that spins are prohibited, so logically, if you have already violated the design or certification parameters, if you have sufficient altitude to recover from a spin conventionally, it is up to you as PIC. The FAR’s also state that as PIC you are ultimately responsible for safety of flight. Furthermore, you may deviate from any FAR for safety reasons. Should you inadvertently enter s spin and recover using conventional techniques, I find it hard to believe that any FAA or NTSB panel or Administrative Law Judge would find fault with that decision. How you got involved in the spin may be another story.
Please exercise your privileges and authority as PIC with thought and safety.
Marty