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How much spin testing is enough?

ChiefPilot

ChiefPilot

Well Known Member
I'm progressing through my phase 1 tasks, and today was the first test card with spins. I started with power on/off stalls, progressed to incipient spins, and ended the flight with a series of one turn spins.

The data I gathered shows that I need approximately 600 feet to recover from an incipient spin (technique may improve this), but I'm wondering what other information I should look for that might prove useful?

Beyond this, I was planning to explore 2, 3, and 4 turn spins. In light of the above, is there still merit in doing so?
 
More info, PLEASE!

I'm thinking you'd get more responses if you would tell us what you're test flying. Not even your public profile tells us whether you're doing spin tests in a 3, 4, 6, 7, 8, 9, 10, or 12. :eek:

Even though the answer to your question might be the same, it would be nice to know.
 
Data Point

Certfied aircraft approved for spins are tested to 3 turns.
 
When Van's spin tested the 7 ... I believe that they hired a test pilot and installed a drag chute...
 
rv7boy said:
I'm thinking you'd get more responses if you would tell us what you're test flying. Not even your public profile tells us whether you're doing spin tests in a 3, 4, 6, 7, 8, 9, 10, or 12. :eek:

Even though the answer to your question might be the same, it would be nice to know.
Click to expand...

Sorry - this is for an RV-6A.

The question was more in general, however. Aside from understanding the spin characteristics and various recovery techniques, what other information would be helpful or useful to understand from spin testing?

Thanks!
 
When Van tested the RV-6, it got his attention so much that he called Bob Herendeen to complete the testing. The -6 wraps up quite fast after about 1 1/2 turns.
Before Van had done the testing, we tested my -6 with 6 turns each direction. I do NOT recommend this.
I believe that Van now recommends no more than 1 1/2 turns in the -6/A
 
Mel said:
When Van tested the RV-6, it got his attention so much that he called Bob Herendeen to complete the testing. The -6 wraps up quite fast after about 1 1/2 turns.
Before Van had done the testing, we tested my -6 with 6 turns each direction. I do NOT recommend this.
I believe that Van now recommends no more than 1 1/2 turns in the -6/A
Click to expand...

I recall reading the article in the RVator about this, and in fact just recently re-read it. What I took away from the article was that the basis for recommending no more than two turns was that the rotation rate may be rather intimidating.

Regardless of the number of turns however , what other information would be helpful or useful to understand from spin testing?
 
Spin Testing Objectives

Unless you are planning to do hard core acro, the number of turns, while an interesting data point, isn't the objective. How the plane handles during the approach to and upon entry to a spin is what you are exploring. If for some reason you inadvertantly stray into the near spin or post spin entry part of the flight envelope, you want to at least have a "been there, done that" recall of optimum recovery procedures - especially if the ground is staring you in the face. At the least, it'll give you something to do until you die.
 
It would be useful to see how gross weight and CG position affects it.

Bear in mind, though, that spin testing is inherently hazardous, as Mel suggested.

Be darn careful!

Dave
 
pvalovich said:
Unless you are planning to do hard core acro, the number of turns, while an interesting data point, isn't the objective. How the plane handles during the approach to and upon entry to a spin is what you are exploring.
Click to expand...

That's exactly how I treated spin testing in my RV-8; I wasn't specifically counting turns and altitude but was more interested in checking the characteristics of the spin entry, but more importantly, the recovery. I did two to the left, two to the right and called it good. Maybe one of these days I'll go out and do a few more just to refresh my brain on it, but I recall that the -8 spin characteristics were pretty straightforward and normal.
 
David Paule said:
It would be useful to see how gross weight and CG position affects it.

Bear in mind, though, that spin testing is inherently hazardous, as Mel suggested.

Be darn careful!

Dave
Click to expand...

I did a few to the left and a few to the right, forward c.g. (full fuel, solo, no baggage). That was good enough for me. I had no interest in exploring the cg and spin envelope in the 6. That sucker spins up fast, but stops nicely when asked properly. The rest of my time was spent in stall recognition and partial spin entry to recovery at both ends of the envelope.
The best description I can give you is the spin entry is pretty docile, then she likes to snap and wrap up quickly. It is that snap that can be a bit un-settling.
 
jbDC9 said:
That's exactly how I treated spin testing in my RV-8; I wasn't specifically counting turns and altitude but was more interested in checking the characteristics of the spin entry, but more importantly, the recovery. I did two to the left, two to the right and called it good. Maybe one of these days I'll go out and do a few more just to refresh my brain on it, but I recall that the -8 spin characteristics were pretty straightforward and normal.
Click to expand...

Just to give you an additional data point, I basically did the same thing on both my -8 and our -3....did enough in each direction to characterize the entry and recovery, and called it good. I enjoy spins in Cubs and other slow stuff....spins in the RV are sort of like sustained inverted flight - yeah, you can do it, but I don't actually enjoy it that much....

Paul
 
In order to answer your question, you have to ask yourself: What's my goal for spin testing? If it is to evaluate how the aircraft performs in all types of departures and recoveries, at all CG and weights ... well, there's a lot of risk in that, and you should be prepared for a unrecoverable spin.

If instead you want to understand how the aircraft spins within the Van's recommended CG and weight range and recover within 1 rotation, well, that makes more sense, and should be testable in a few flights.

Personally? Unless I intended to intentionally spin the thing, I would keep it to a few spins at conservative CG and weight, only allow 1-2 rotations. YMMV.

Paul's comments are well taken, spins are fun, but only in moderation. I can do a a few, but after the third one, my balance starts to suffer. It also depends on how many rotations you allow - letting the spin get fully developed in a Citabria is very different from a departure and recovery spin in the glider.

TODR
 
Yep!

jbDC9 said:
but I recall that the -8 spin characteristics were pretty straightforward and normal.
Click to expand...

Spin characteristics for the single seat and tandem RVs are pretty benign. Only the SBS models seem to accelerate rotation speed.
 
Is Spin testing necessary?

Hello all:

Just wondering, it has been a long time since training in 1981 is it necessary to spin test the RV?

I am building the RV 7 and although I did the spin training I really would rather NOT test it. :confused:
 
dave4754 said:
Hello all:

Just wondering, it has been a long time since training in 1981 is it necessary to spin test the RV?

I am building the RV 7 and although I did the spin training I really would rather NOT test it. :confused:
Click to expand...

There's nothing saying you need to spin test them; in fact, there is nothing saying that you need to test much of anything aside from determining a handful of speeds at a specific W&B configuration.

I set up a couple of test cards for spin testing because I am interested in how easy they are to get in/out of, how much altitude is lost prior to recovery, etc.
 
Thanks all for the helpful responses!

So far, I've found my -6A to be not all that bad in a spin; in fact, I'd say the incipient stage is less dramatic than the -152 I learned to fly in which would drop the left wing in a stall and flip over in a heart beat if you were even thinking about uncoordinated flight.

Recovery is brisk in the incipient stage; less so from a developed spin but certainly not something that caused me any concern this far. I do not intend to explore flat spins, inverted spins, etc. at this time.

BTW, I'm doing these tests with a chute, jettisonable canopy, and a floor of 4500' MSL (~3500' AGL). Starting between 7500' and 11,500' gives plenty of time to observe and think about things :)

Thanks!
 
pvalovich said:
Unless you are planning to do hard core acro, the number of turns, while an interesting data point, isn't the objective.
Click to expand...

I will add that unless you are paying attention to the number of rotations, you will not know whether the spin is fully-developed or not. Most airplanes stabilize into the spin after about 2 turns and may take on a different spin rate or attitude compared to the incipient phase. Recovery time might be slightly different as well. If you are simply entering a spin, waiting a few seconds, and recovering, you are likely not in the developed phase. Nothing says you must test all spin modes. I don't know anyone who has. I have never heard of anyone reporting their flat spin test (upright and inverted) results in an RV. As an aerobatic pilot, I have an interest in behavior during all spin modes. But that isn't necessarily needed, depending on what you are doing with the airplane.
 
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testing...or practice?

From the Transport Canada review quoted earlier, seems that recognizing the
'danger zone' is one of the key benefits of spin training...if it can be called that.

Five pilots stalled after turning back to the runway following an engine failure after takeoff.

not to rehash the turnback controversy, but I think both recognizing, staying out of, and ability to recover, are all important elements of stall/spin awareness.
 
Just as a point of reference....

my -6 takes approximately 1 1/2 turns to recover after a 6 turn spin.
 
Mel said:
my -6 takes approximately 1 1/2 turns to recover after a 6 turn spin.
Click to expand...

Thanks Mel! Good to have confirmation of what the book says.

I rather enjoyed the spin tests; I have one test card for them left that I'm perhaps a little anxious about only because it's at the aerobatic CG limit, which is further aft than I've done them so far. I don't know that I'll go six turns though - that's pretty hard core :)
 
Spins

There was an extensive write up documenting thorough testing of all basic spin types upright and inverted to multiple turns in an RV-8 in England. This was carefully done and well reported. IIRC it was printed in the RVator. Will try to find and post.
 
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