Spin testing

I think a case could be made that since most spins occur at too low an altitude for recovery (either traditional or parachute) that Lancair spin resistance is the only real world spin solution.<<

I tend to agree…but my gut tells me I don’t want some automatic device getting between me and my rudder pedals. Just old-fashioned, I guess. I’m also of the school that still believes in spin-training (and LOTS of it) for the basic pilot certificate.

In reply to:


I’m also of the school that still believes in spin-training (and LOTS of it) for the basic pilot certificate.


Statistically speaking that doesn’t demonstrate any benefit - an earlier Aviation Safety article covers that.

If I remember correctly, in the recent Palm Springs COPA meeting, Alan K said that it was a common (and annoying) misconception that Cirrus didn’t demonstrate spin recovery during certification because of the parachute. He said that they didn’t demonstrate spin recovery because of spin resistance. Due to the wing cuffs (and, I believe, the rudder-aileron coupling) the SR20 and SR22 are more difficult to spin than other airplanes.

Lancair used the same equivalent level of safety to avoid spin demonstration during certification, although they had to add a rudder limiter to achieve it.

So, all of the discussion about the parachute’s role in spin recovery during certification is moot.

-Mike

So, all of the discussion about the parachute’s role in spin recovery during certification is moot.

Then why is the parachute required for airworthiness? The Lancair says that with the rudder limiter you cannot spin the plane, not that it is hard to spin. The Cirruse on the other hand says it has reduced the likelihood of a spin but the POH says, if you do get into a spin the parachute is the only recovery. I suspect you misunderstood the comments.

Mike,

Thanks for your post. I was also at the COPA meeting, and your recollection of Alan K.'s remarks is correct.

Cheers,
Roger

As I understand it, the reason for the rudder limiter is to limit full left rudder deflection from its normal deflection of 20 degrees to about 12 degrees during a particular area of manifold pressure (more than 12 inches and the stall horn is activated). This is to prevent an area of the flight envelope that could result in an un-recoverable spin, at least using normal techniques.

I would question the source that told you that the Columbia would not spin.

myers

Not to be…ahem…overly technical on the aerodynamics, but the plane is likely not coordinated under the conditions you describe. Check the ball…it will be rolling to one side or another in turbulence, and the plane most definitely will not be coordinated if a gust manages to flip it over into a spin.

But your point is well taken…that a coordinated stall can be turned into a spin by uneven gusts or turbulence.

As I understand it, the reason for the rudder limiter is to limit full left rudder deflection from its normal deflection of 20 degrees to about 12 degrees during a particular area of manifold pressure (more than 12 inches and the stall horn is activated). This is to prevent an area of the flight envelope that could result in an un-recoverable spin, at least using normal techniques.

Any spin in the C300 (as in the Cirrus) is by definition (of the POH) unrecoverable. The rudder limiter was implemented to prevent a spin during power on stalls with and full left rudder deflection (presumably the only method of forcing the C300 to spin) to meet the FAA requirement for spin resistance/recovery. Cirrus chose the parachute for spin resistance/recovery.

Actually, nobody ever told me that the Columbia 300 can’t be spun. Both the C300 and the SR2X are spin-resistant, not spin-proof. I think it’s like watches that are billed as water-resistant, not waterproof :slight_smile:

-Mike

In reply to:


Any spin in the C300 (as in the Cirrus) is by definition (of the POH) unrecoverable.


The Cirrus POH says no such thing. It says:

“The only approved and demonstrated method of spin recovery is activation of the Cirrus Airframe Parachute System.”

This does not say or even imply that other (conventional) spin recovery methods will not be effective. It only says that CAPS is the only “approved and demonstrated” method. This may have been to address economic, rather than aerodynamic, considerations.

Art, I thought this dead horse had already been thoroughly beaten. While you can impute any meaning you wish to the POH, Alan Klapmeier stated that the parachute was NOT the reason they did not have to demonstrate spin recovery during certification. No offense, but on matters Cirrus, I’ll believe him over you.

Stating that since the parachute is required for airworthiness, it must be the only means of spin recovery is like saying that since tires are required, they play a part in spin recovery.

-Mike

Dave,
Right, we agree. Thanks for the clarification.
Bill

Stating that since the parachute is required for airworthiness, it must be the only means of spin recovery is like saying that since tires are required, they play a part in spin recovery.

I suggest you first read FAR 23 subpart 221 which deals with certification requirements of a plane with regard to spins. It gives 2 options: either demonstrate spin recovery or demonstrate spin resistance (requires the plane to be flown in a stall with control pulled back to the stop, full power, full rudder, full opposite aileron, and complete a 360 degree turn in no less than 7 seconds without changing the controls or the power). Diamond did the spin recovery, Lancair did the spin resistance, and Circus chose to use FAR 21 subpart 21 which allows certification without meeting the requirements of FAR 23 if it can demonstrate an equivalent level of safety (the parachute demonstrated when the plane entered a spin).
I then suggest you read the Federal Register / Vol. 62, No. 200 / Thursday, October 16, 1997 / Rules and Regulations.

This deals with the certification of Cirrus and the paragraph below is the one which specifically exempts Cirrus requirements of FAR 23.221.

“The requirements for the functions
and operations of the parachute
recovery system will ensure all of the
following: (a) There is no fire hazard
associated with the system. (b) The
installation of this system allows relief
from another part 23 requirement, spins.”

In reply to:


Art, I thought this dead horse had already been thoroughly beaten.


Yes, I can confirm that as a fact. Here is an unretouched photo of the beaten, dead horse. (Apologies to our PETA-card-carrying members.)

In reply to:


I suggest you first read FAR 23 subpart 221 …


But nothing in any of the information in your post addresses the statement you seem to be at odds with, that being that none of these items, POH, FAR23, etc., say anything that indicate that the Cirrus will not recover from a spin with conventional techniques. If you want to infer that, and clearly you do, that’s your right. But it is a logical fallacy to do so.

Art, I bow to your superior knowledge of the relevant documents. Since I’m too lazy to read them, I’ll concede the argument to you.

Regards,

-Mike

This sub thread was started when Mike Murdock stated that Cirrus was not required to demonstrate spin recovery because it, like the Lancair, demonstrated spin resistance requirements of FAR 23. That is incorrect. Cirrus was exempted from any FAR 23 spin requirements because of the parachute.

As to whether the SR20 can be recovered from a spin in the conventional manner, the POH says the only recovery from a spin is the parachute. As pilots we are required to operate our planes according to the POH. That means the oxygen bottle must occupy the front seat, the mixture control must be full forward for landings, and the parachute is the only acceptable method of spin recovery.

In reply to:


As to whether the SR20 can be recovered from a spin in the conventional manner, the POH says the only recovery from a spin is the parachute.


Art - jeez, that just isn’t what it says! Word for word, literally, here it is again.
“The only approved and demonstrated method of spin recovery is activation of the Cirrus Airframe Parachute System.”

Your insistence on ignoring the words “approved and demonstrated” is getting pretty old.

Show me one whit of POH or FAR printed matter that states that the aircraft will not recover conventionally. You can’t, because no such document exists.

If I ever find myself in a spin in the airplane, my reflexes, driven by literally hundreds of spins I’ve done as a CFI, are going to be executing conventional spin recovery control inputs a heck of a lot faster than it will take my right hand to find and pull the red handle. So even as I’m starting to execute the POH recovery procedure I will have likely already recovered. See any problem with that? I don’t.

Alan K’s statement at Expo hit the nail on the head. The whole point of the design was to make it extremely difficult to enter a spin, either inadvertently or vertently [:)]. He said it was like they built a very high fence at the edge of the cliff. Does it mean that it is impossible to climb over that fence and fall off the cliff? No. So if someone does so, what, do you blame the fence or the guys that put it there? Is everyone better off if the fence isn’t even there?

In Reply To:
As to whether the SR20 can be recovered from a spin in the conventional manner, the POH says the only recovery from a spin is the parachute.
No it does NOT say that. It says “The only approved and demonstrated method of spin recovery is activation of the [CAPS]. Because of this, if the aircraft ‘departs controlled flight,’ the CAPS must be deployed.” It then goes on to describe how to tell whether or not the spiral / incipient spin / spin is recoverable or unrecoverable. If its recoverable, you recover (described procedure is standard spin recovery technique) ,if its not recoverable (DUH) you deploy the CAPS…
What does this tell any common sense pilot? Do what you think best in the circumstances. If you think you have the time and the skills to try conventional spin recovery, TRY IT! if it works, the plane never “departed controlled flight”. (Or are all those aerobatics-trained pilots departing controlled flight every time they spin a plane? I bet if you accused one of them of such a thing, you’d be nursing a bruised nose for a few days!) If you don’t have the time, skills, or confidence, pull the CAPS…
All these other arguments about what the plane is certified for, what performance criteria have been demonstrated, et cetera, ad nauseum, are just sophistry at its worst.

Gordon,

I agree with your post 100%. I know pilots who have inadvertently spun the SR20 and recovered using standard recovery techniques. The names have been withheld to protect the innocent (see below).

Cheers,
Roger