Spins in the RV-14

One topic I haven't seen addressed (maybe I missed it?) on the RV-14 forum is spin testing the RV-14. I know with the RV-10 we were advised against spins, but they did spin chute testing and found that the RV-10 perhaps wasn't a good candidate to spin due to some issues.
What about the RV-14? Is it safe to assume that being an aerobatic capable plane, with a large rudder that this one has been tested and should recover nicely? It won't be too long and I'll be flight testing mine, and this would be something worth wasting an hour of that flyoff time on...

I never did get any replies on this, but was able to go out and complete a brief spin in the -14. It recovered very quickly, although as I said it was brief. Less than 1 turn. If anyone has the opportunity to spin one more, I'd love to hear your comments.

TimO said:

I know with the RV-10 we were advised against spins, but they did spin chute testing and found that the RV-10 perhaps wasn't a good candidate to spin due to some issues.
n...

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Although Vans was under no legal obligation to do so, I believe they were showing that the -10 met the certification rules wrt spins that apply to normally certified aircraft. e.g., recoverable up to 3 turns, but not recommended (not approved in the certified world) as the airframe g loads are limited to normal catagory standards.

Bob,

Yes, on the -10 they did talk about it. The thing is, on the RV-14 I heard nothing about the results of any spin testing. I would think that such info would be made public in the interest of safety?

TimO said:

Bob,

Yes, on the -10 they did talk about it. The thing is, on the RV-14 I heard nothing about the results of any spin testing. I would think that such info would be made public in the interest of safety?

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The same level of "talked about it" that was done with the RV-10 has also been done with the RV-14.

It was fully spin tested (with a spin recovery chute attached) by a professional contracted test pilot.

Results were similar to the other aerobatic side by side airplanes, and the same cautions that are recommended for the other side by side airplanes are recommended for the RV-14. Primarily, recreational spins beyond are turn or so are not recommended because the higher rate of rotation that develops beyond just a couple turns will likely surprise and possibly even panic an uninitiated pilot.
As for the RV-10 having a recommendation of no spins because of "issues".... that is not from any of Van's talk, so I am not sure where that came from.
The RV-10 is not approved for aerobatics. An airplane not approved for aerobatics has entirely different requirements regarding spin recovery, so that not recommended statement should not be construed to "issues" with the RV-10, any more than "not recommended" is for any non aerobatic certificated airplane.

Thanks Scott,
That fills in the blanks for me on the RV-14. It does seem like it will be no problem to recover from spins with standard input. For the RV-10 I'm not interested in trying.

spins

Scott,

Thanks for the clarification re -14 spins. Just wondering if there's any reason beyond being "surprised" why the spins shouldn't be extended beyond 1 turn.

Is the recovery method and time to recovery any different after 6 turns than after just 1 turn?

Spins

This is generic information that applies to most aircraft that are approved for spins. At one turn the spin is still in the incipient stage. It will take somewhere between 1 and 3 turns for a normal power off spin to stabilize in rotation rate.

The spin will speed up!

Hello Jake

The point is, that after the first revolution, the rotation speed will increase. The scenery that "flow" in front of you will getting faster and it will be more and more difficult to recognize things and count the revolutions. It is likely that if you are untraind to spins, you getting more and more trouble and difficulties to realize the situation and counteract.

In the plane I flew in the past, a Slingsby Firefly, the speed after the first revolution was heavily increasing. Iy youd like to stop it at three rotations, you start with the inputs at 2 1/4. If you where going up to 4, it will need a full revolution with opposit rudder to get it stopped.

Also the vertical speed will increase in the first revolutions quite a bit.

Get trainings in a known plane with someone that has the qualification to perform this!

In the Slingsby once I had difficulties to get out of a righthand spin (we mostly do the lefthand), it was only one and a half revolution more that I wanted ... but it felt like it will never stop ... and shocked me quite a bit!
I could not find out what was wrong, I just got back and picked up my aerobatic teacher to train it again with him.

Fly safe!

Jake14 said:

Scott,

Thanks for the clarification re -14 spins. Just wondering if there's any reason beyond being "surprised" why the spins shouldn't be extended beyond 1 turn.

Is the recovery method and time to recovery any different after 6 turns than after just 1 turn?

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Recovery method is standard procedures regardless of number of turns, but as already mentioned, the more turns (or fractions of) you do before recovery, the faster the rotation rate.
The faster the rotation rate... the longer the recovery time.

BobTurner said:

Although Vans was under no legal obligation to do so, I believe they were showing that the -10 met the certification rules wrt spins that apply to normally certified aircraft. e.g., recoverable up to 3 turns, but not recommended (not approved in the certified world) as the airframe g loads are limited to normal catagory standards.

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Stupid question here but if the 10 is limited to normal category and most of Vans' other airplanes are under the "utility" category, does this make the 10 less safe in turbulence? i.e. will the wings fail on a 10 easier than a 14? I am building a 10 and am kind of worried about this.
Thanks,
Casey

Certification

In the certified world 3.8 G vs 4.4 utility and 6.0 Aerobatic. These are minimum certification standards, most of the high performance aerobatic airplanes are certified to 10 or 11G.

Certs

Just to clarify I am talking about the Extras, Sukhois etc. The Pitts factory aircraft are certified to plus 6, same as the recommended max for the aerobatic RV's.

FL-flyer said:

Stupid question here but if the 10 is limited to normal category and most of Vans' other airplanes are under the "utility" category, does this make the 10 less safe in turbulence? i.e. will the wings fail on a 10 easier than a 14? I am building a 10 and am kind of worried about this.
Thanks,
Casey

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I think the only RV in the fleet that has a utility category designation is the RV-9(A), but that is at a reduced gross weight (1600 instead of the normal 1750)

Otherwise the RV-9 and RV-10 are both normal category loads at their max. recommended gross weight.

If you obey the speed limitations (top of green arc, maneuvering speed, etc.) the RV-10 is no less safe than an RV-14.

What airplanes do you have prior flight experience in?

They all likely had normal category ratings at max gross weight, and if the had a utility category rating it was likely at a reduced gross weight (and usually also a more restrictive CG range).
That makes them not much different than an RV-10.

Spins

rvbuilder2002 said:

Recovery method is standard procedures regardless of number of turns, but as already mentioned, the more turns (or fractions of) you do before recovery, the faster the rotation rate.
The faster the rotation rate... the longer the recovery time.

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I disagree with this. In most aircraft the rotation rate is stable after three turns. The rotation rate CAN be increased by accelerating the spin by using elevator input ranging from neutral to full down elevator in the case of an upright spin.
In all the popular high performance aerobatic aircraft that I have flown the spin can be stopped almost instantly by accelerating the spin and using full power.
If you watch any of the high performance aircraft in airshows you can see this.
Search a video of Kevin Coleman doing a multi turn accelerated spin transitioning into a vertical descending snap that is rotating so rapidly it is difficult to count the turns. The stoppage of the rotation is very quick and appears quite violent.

Spins

I timed the late Bob Herendeen on two consecutive days performing a multi turn inverted flat spin. One of the days was with a fairly large camera mounted on struts that placed it just above the vertical tail.
Both days were 32 turns in 52 seconds, no measurable difference with/without the camera. If my math is correct this comes out to a rotation rate of 220 degrees second in round numbers. Some of the current high performance monoplanes advertise a roll rate with ailerons in excess of 400 degrees/second.
Some early aerobatic books would have one believe that a full power inverted flat spin in the Pitts S1S is in excess of 400 degrees/sec. I believe this to be a gross exaggeration.

rvbuilder2002 said:

I think the only RV in the fleet that has a utility category designation is the RV-9(A), but that is at a reduced gross weight (1600 instead of the normal 1750)

Otherwise the RV-9 and RV-10 are both normal category loads at their max. recommended gross weight.

If you obey the speed limitations (top of green arc, maneuvering speed, etc.) the RV-10 is no less safe than an RV-14.

What airplanes do you have prior flight experience in?

They all likely had normal category ratings at max gross weight, and if the had a utility category rating it was likely at a reduced gross weight (and usually also a more restrictive CG range).
That makes them not much different than an RV-10.

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Hi Scott,
Thanks for that information. I have only flown PA28s and C172s which I did my private training in. I believe both of these were utility category but I felt safe in the 172 because of the wing struts.

I am aware that the wing spars on the 10 are a completely different design then a 172 so I know I need to get over my fears. Was just wondering why all RVs are not designed in the utility category. Sure it would add a little weight but wouldn't this also add an extra margin of safety? I am not too familiar with this topic (or aircraft design for that matter) so please forgive me if I sound a little inexperienced.

jrs14855 said:

I disagree with this. In most aircraft the rotation rate is stable after three turns. The rotation rate CAN be increased by accelerating the spin by using elevator input ranging from neutral to full down elevator in the case of an upright spin.
In all the popular high performance aerobatic aircraft that I have flown the spin can be stopped almost instantly by accelerating the spin and using full power.
If you watch any of the high performance aircraft in airshows you can see this.
Search a video of Kevin Coleman doing a multi turn accelerated spin transitioning into a vertical descending snap that is rotating so rapidly it is difficult to count the turns. The stoppage of the rotation is very quick and appears quite violent.

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I didn't say it keeps accelerating for as long as the spin occurs. I meant from the initial rotation rate. And Yes, RV's generally stabilize the rotation rate after about 3 turns.
The point I was trying to emphasize is that the rotation rate delta of the side by side RV's, between initial entry and stabilized at max rotation rate is much bigger than it is in a lot of other aircraft.

FL-flyer said:

Hi Scott,
Thanks for that information. I have only flown PA28s and C172s which I did my private training in. I believe both of these were utility category but I felt safe in the 172 because of the wing struts.

I am aware that the wing spars on the 10 are a completely different design then a 172 so I know I need to get over my fears. Was just wondering why all RVs are not designed in the utility category. Sure it would add a little weight but wouldn't this also add an extra margin of safety? I am not too familiar with this topic (or aircraft design for that matter) so please forgive me if I sound a little inexperienced.

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I might be wrong, but I am pretty sure if you check the chart for the C-172 you will find that the utility category rating is at less than maximum gross weight. That is primarily how they get the higher allowable load factor.... by reducing the load that the airplane is carrying.
If an RV-10 is operated at less than gross weight, it would also have some level of additional margin for the load factor, but it is not published because there is a lot more other things that have to be considered. For example, the maneuvering speed actually goes down as the aircraft weight goes down.

rvbuilder2002 said:

I might be wrong, but I am pretty sure if you check the chart for the C-172 you will find that the utility category rating is at less than maximum gross weight. That is primarily how they get the higher allowable load factor.... by reducing the load that the airplane is carrying.
If an RV-10 is operated at less than gross weight, it would also have some level of additional margin for the load factor, but it is not published because there is a lot more other things that have to be considered. For example, the maneuvering speed actually goes down as the aircraft weight goes down.

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I think you are absolutely right. I forgot that some performance figures are calculated at max weight. Seeing that the 10 has a gross weight that is about 300lbs heaver than the 172, this all makes sense now.