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Grayson

Joined: 10 Aug 2008
Posts: 7

Posted: Tue May 03, 2011 7:37 am Post subject: Tailslides

Is there any consensus on doing tailslides in the Yak-52?



Grayson

mark.bitterlich(at)navy.m
Guest

Posted: Tue May 03, 2011 8:09 am Post subject: Tailslides

Hold on tightly?  

Mark

p.s. Sorry, could not resist.  



--

viperdoc(at)mindspring.co
Guest

Posted: Tue May 03, 2011 8:39 am Post subject: Tailslides

The translated RU pilots' manual states for the novice to avoid them.

No insinuation of experience made with this post. Just stating the

recommendations made by the guys that had the most experience.

Doc



--

Grayson

Joined: 10 Aug 2008
Posts: 7

Posted: Tue May 03, 2011 9:06 am Post subject: Re: Tailslides

So assuming pilot experience isn't a factor they are ok to perform? 

No structural limitations to perform them? Is that stated somewhere, perhaps in the 'RU Manual'? Is a copy of it available online?



 - Hold on tightly is right  , especially to the stick and rudder..

Grayson

radiopicture

Joined: 23 Jun 2008
Posts: 263

Posted: Tue May 03, 2011 11:12 am Post subject: Tailslides

Tail slides are verboten for structural reasons in some akro planes like the Great Lakes (expertise not being the issue). I'd want to know for sure.

On May 3, 2011, at 1:06 PM, Grayson wrote:



 	  Quote: 	
		   

 

 So assuming pilot experience isn't a factor they are ok to perform? 

 No structural limitations to perform them? Is that stated somewhere, perhaps in the 'RU Manual'? Is a copy of it available online?

 

 - Hold is is right  Especially to the stick and rudder..

 

 

 Grayson

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=338776#338776

markdavis(at)wbsnet.org
Guest

Posted: Tue May 03, 2011 11:29 am Post subject: Tailslides

I thought I remembered reading something about tailslides being prohibited 

due to fabric control surfaces on the YAK 52.  Can't recall where I read it 

though.



Mark Davis

N44YK

---

dsavarese0812(at)bellsout
Guest

Posted: Tue May 03, 2011 11:51 am Post subject: Tailslides

I am conversing with a gentleman in Lithuania as I write this and asked 

him the tailslide question.  His response was, "tailslides are forbidden 

in Yak 52 by the CAA in Lithuania."  I asked why was this?   His answer 

(and you'll really want to pay attention to this), " there were several 

elevator blocks by counterweight hammer".

Over the years I have been told by several expert Yak 52 aerobatic 

pilots/instructors outside the US that the Yak 52 was capable of and 

approved for all IAC intermediate level aerobatic maneuvers except 

tailslides.

FWIW

Dennis

On 5/3/2011 2:08 PM, Eric Wobschall wrote:

 	  Quote: 	

 Tail slides are verboten for structural reasons in some akro planes like the Great Lakes (expertise not being the issue). I'd want to know for sure.

 On May 3, 2011, at 1:06 PM, Grayson wrote:

> 

>

> So assuming pilot experience isn't a factor they are ok to perform?

> No structural limitations to perform them? Is that stated somewhere, perhaps in the 'RU Manual'? Is a copy of it available online?

>

> - Hold is is right  Especially to the stick and rudder..

> Grayson

>

>

> Read this topic online here:

>

> http://forums.matronics.com/viewtopic.php?p=338776#338776

>

>

mark.bitterlich(at)navy.m
Guest

Posted: Tue May 03, 2011 11:54 am Post subject: Tailslides

Mark, 



The Sukhoi 26, 29, and 31 have fabric control surfaces.  So does the

YAK-50.  I honestly don't think fabric control surfaces have any impact

on tail slides.  



For what it is worth, I have personally seen Sergei Boriak coach tumbles

and tail-slides in YAK-52's.  I have personally done many tail-slides in

my YAK-50.  



Mark Bitterlich

--

mark.bitterlich(at)navy.m
Guest

Posted: Tue May 03, 2011 12:01 pm Post subject: Tailslides

Glad to hear this.  



Then you think that would apply to the 50 as well?  



Hmmm.  



Interesting.... 



I am going to Sergei and ask him..... 



Mark

--

radiopicture

Joined: 23 Jun 2008
Posts: 263

Posted: Tue May 03, 2011 12:14 pm Post subject: Tailslides

So that counterweight was bending over somehow and jamming?

On May 3, 2011, at 3:48 PM, A. Dennis Savarese wrote:

 	  Quote: 	

 I am conversing with a gentleman in Lithuania as I write this and asked him the tailslide question.  His response was, "tailslides are forbidden in Yak 52 by the CAA in Lithuania."  I asked why was this?   His answer (and you'll really want to pay attention to this), " there were several elevator blocks by counterweight hammer".

 Over the years I have been told by several expert Yak 52 aerobatic pilots/instructors outside the US that the Yak 52 was capable of and approved for all IAC intermediate level aerobatic maneuvers except tailslides.

 FWIW

 Dennis

 On 5/3/2011 2:08 PM, Eric Wobschall wrote:

> 

> 

> Tail slides are verboten for structural reasons in some akro planes like the Great Lakes (expertise not being the issue). I'd want to know for sure.

> 

> 

> On May 3, 2011, at 1:06 PM, Grayson wrote:

> 

>> 

>> 

>> So assuming pilot experience isn't a factor they are ok to perform?

>> No structural limitations to perform them? Is that stated somewhere, perhaps in the 'RU Manual'? Is a copy of it available online?

>> 

>> - Hold is is right  Especially to the stick and rudder..

>> 

>> 

>> Grayson

>> 

>> 

>> 

>> 

>> Read this topic online here:

>> 

>> http://forums.matronics.com/viewtopic.php?p=338776#338776

>> 

>> 

>> 

>> 

>> 

>> 

>> 

>> 

>> 

>> 

> 

> 

> 

> 

> 

> 

>

mark.bitterlich(at)navy.m
Guest

Posted: Tue May 03, 2011 12:27 pm Post subject: Tailslides

Well.... 



Let me say first of that I respect Dennis more than most anyone else in

the world, and I know that his Lithuanian friends are extremely

knowledgeable.  



That said, let me quote a conversation I just had.  



I called Sergei Boriak, who was the USSR National Champion Aerobatic

Pilot, and also a Test Pilot for Sukhoi (on the 26 program), and the

former coach for the United States Unlimited Aerobatic Team and asked

him this question:  "Sergei, do you know of any restrictions for doing

tailslides in the YAK-52 or YAK-50 aircraft?"



His response was:  "Mark, how in the world do you think the YAK-50

become World Champion Aircraft in 1980 when the tailslide was a required

maneuver in the unlimited category?"  



I pressed him again and asked if he knew of anything that would be

dangerous about doing tailslides in the YAK-52 aircraft.  



His response: "As long as the aircraft is in good shape and is properly

maintained there will be no problem".  



Ok.... that said, when I brought up the SPECIFIC issue of

counter-weights, he said: "Of course, if these components are loose or

damaged, that is a different story". 



With all this now said, I suggest that anyone contemplating tail-slides

in ANY aircraft receive instruction from an expert in the make and model

aircraft that they specifically are about to attempt them in.  I also

suggest that with all that has been said about the YAK elevator

counter-weight issue lately, that it might be a good idea to have that

area inspected... ESPECIALLY for proper rigging and travel movement

adjustment before putting excessive strains in that area.  



Tail-slides have the capability of imposing terrific forces on the

aircraft, although it is not as easy to do that as one might think.  The

airplane simply does NOT like to slide down backwards in a straight

line.  It wants to do everything BUT that really.  That said, if you

somehow manage to allow it to develop and are not prepared for the stick

forces that will be imposed when you begin the recovery, you can end up

SLAMMING controls into the stop.



As regards the IAC not approving YAK-52's for tail-slides, I am a member

and will inquire about that specifically.  



Mark 

  



--

markdavis(at)wbsnet.org
Guest

Posted: Tue May 03, 2011 12:41 pm Post subject: Tailslides

Mark,

     I'll look more for what I referred to, but what Dennis relates in a 

follow up is what I had heard, "everything but tailslides".  The only 

obvious difference would be the gross weight of the -52 with a crew of two 

compared to the -50 and other YAKs, Sukhois which wouldn't put the potential 

stress on the fabric surfaces.  Whoever initially told me that, my response 

was "what about the -52TW and others that have metal clad control surfaces". 

They didn't know the answer.  It will be interesting to know the "why not" 

if the maneuvers are not recommended or prohibited.



Mark Davis

N44YK



---

mark.bitterlich(at)navy.m
Guest

Posted: Tue May 03, 2011 12:41 pm Post subject: Tailslides

Well, he said, that she said, that he heard, that Tom mentioned, who

heard it from Alex, that maybe it did exactly that.  



The simple fact is that Dennis has talked to one person that says one

thing.   I have talked to someone else that says something different.  



And until someone comes up with a document on paper that specifically

addresses THIS issue, it's all hear-say.  Everything else is conjecture

and as long as everyone realizes it is conjecture, there is no problem

what-so-ever.  



When conjecture somehow moves into the realm of "documented reality",

then gents... I do have a problem with that.  



Mark

--

mark.bitterlich(at)navy.m
Guest

Posted: Tue May 03, 2011 12:46 pm Post subject: Tailslides

Excuse me.  Excuse me. 



I misspoke, I made an error.  I said something that was INCORRECT.  



The Sukhoi aircraft, model's 26, 29 and 31 do NOT have fabric control

surfaces.  My bad, I am sorry.... I know better.   OOPS.  



Mark Bitterlich

--

mark.bitterlich(at)navy.m
Guest

Posted: Tue May 03, 2011 12:56 pm Post subject: Tailslides

Sergei Boriak teaches tail slides in the YAK-52.  



Mark Bitterlich

--

mark.bitterlich(at)navy.m
Guest

Posted: Tue May 03, 2011 1:25 pm Post subject: Tailslides

Ok, let's talk conjecture, just for the fun of it.  



When an aircraft flies backwards in a tail-slide, what is the estimated

speed and airflow over the control surfaces as it makes the reverse?

Any thoughts on that?  Before we talk about it, let's limit this

discussion please to pilots who have actually performed tail-slides in

any make or model of aircraft.  



Now.  How about a snap roll.  What are the speed and flow forces (that

would be AIR LOADS) over the control surfaces themselves when an

aircraft performs an accelerated snap roll.  Let's focus on elevator and

rudder please.  



Which is higher?  Tail Slide Air Loads, or Snap Roll Air Loads?  Well,

you tell me.  



The air load on the control surfaces during a tail slide are backwards.

Does this make them higher?   We are talking about the actual pressure

induced air loads on the surfaces of these controls.  Remember that

speed through the air during a tail slide is in reality very slow as

compared to normal flight.  



How about bending moments?  Are they higher during a tail-slide, or are

they higher during a 9 G pull at 150 knots?   We're talking about when

everything is done CORRECTLY!



On the other hand.... what happens if you manage to get into a good tail

slide and then just "let go" of the stick?   The result is that it will

SLAM with a very large degree of force right into the control stop.

Anything hooked to the elevator when this happens... such as a

COUNTER-WEIGHT is going to have a HUGE instantaneous load.  HUGE.  



Would it be possible to mismanage the aircraft to such a large degree,

then LET go of the stick, and ALLOW it to SLAM into the stop, and when

that happened, would it BE POSSIBLE to incur some type of mechanical

failure?  Yep... I do believe that is possible, and it can happen if the

pilot is not prepared for the forces that can happen in advance!  



That said, I fully agree that it is entirely possible for a pilot to put

an aircraft into a situation where it exceeds its design limits and

something breaks.  



I have watched tail-slides being taught in a YAK-52.  I have performed

tail-slides in a YAK-50.  I disagree with anyone that says that the YAK

model aircraft is not safe to do tail-slides... politely and

respectfully disagree.  The expert I believe in is my aerobatic coach.

Who anyone else believes is their own personal choice and I respect that

too.  If you have doubts, THEN DO NOT DO THEM!  



Mark Bitterlich





--

markdavis(at)wbsnet.org
Guest

Posted: Tue May 03, 2011 4:04 pm Post subject: Tailslides

Mark,



Now I know where I'd seen the prohibition on tail slides before.... in the 

POH for my YAK.  I found an online copy that is the same as the one that 

came with N44YK.  I'm not sure who generated it or if it is correct.  I'm 

sure tailslides have been done safely in YAK 52's by many for years, but I'm 

still curious why they are listed as prohibited on page 10 of this POH.  The 

link follows:



www.yak-52.com/downloads/?YAK52%20POH.doc



My copy of the above manual doesn't have the question marks in parenthesis 

like the link above shows.  Maybe Dennis knows the origin of the manual.



Oh...  for the record, so I can participate in the discussion, I have done 

tail slides in several aircraft (TA-4J and T-2C), just not in one that has 

the maneuver prohibited in it's POH (EA-6B NATOPS/SOP and my YAK-52 POH 

albeit possibly in error).   Must be my Navy flight training that makes me 

heed the "don't do it" stuff.



As for the tailslides themselves, I've seen some done that appear to create 

a much higher than typical backward airspeed.  Whether by luck (my case) or 

skill (Sergei Boriak) those would be the ones that would impart a 

potentially damaging load on control surfaces.  As for your question "Which 

is higher?  Tail Slide Air Loads, or Snap Roll Air Loads?  Well, you tell 

me", my simple mind goes back to learning as a small child that it wasn't a 

good idea to stick your hand out of the window of a car at 80 mph fingers 

pointing forward then deflecting your hand contrary to the prevailing wind. 

Nearly getting my shoulder yanked out of the socket taught me that fairing 

your hand downwind put a less rapid load on my joints.  Back to my flight 

training....don't yank on the G (or rolling pulls).



So, after all that, I still would be interested in knowing why SOMEONE 

deemed it apparently unsafe in a YAK 52 enough to include in a POH. 

Anecdotal evidence that the maneuver has been performed routinely without 

causing structural failure doesn't mean it hasn't been exceeding load limits 

that someone, somewhere thinks is excessive.  If it came from someone in the 

design, manufacture, or writing the initial operating limitations of the YAK 

52 then I'm interested.



Thanks for your input.  I enjoy the discussion.



Mark Davis

N44YK



---

czech6(at)mesanetworks.ne
Guest

Posted: Tue May 03, 2011 4:46 pm Post subject: Tailslides

There must be a reason that so much conversation is generated by this. Why would you want to do this during normal fun flying on a clear beautiful day? Unless you have something to prove to yourself. Cause  No one else will care. 

If it says in the manual, don't do it. If you believe something else, have at it. Go by yourself so the innocent don't get hurt or run risk of getting hurt.

It's like paying taxes, the book says do it, but there is always someone that pushes the envelope and tries to avoid it. And in the end, a burial at sea.



Blue Sky's

On May 3, 2011, at 11:15 AM, "Roger Kemp M.D." <viperdoc(at)mindspring.com> wrote:



[quote] 

 

 The translated RU pilots' manual states for the novice to avoid them.

 No insinuation of experience made with this post. Just stating the

 recommendations made by the guys that had the most experience.

 Doc

 

 --

dsavarese0812(at)bellsout
Guest

Posted: Tue May 03, 2011 4:54 pm Post subject: Tailslides

The Yak manual you speak of is on my web site and was given to me about 

13-14 years ago by a gentleman who is a CFI and was trained in Russia by 

Russian pilots.  He extracted, translated and condensed the information 

from the original Russian flight manual and from the instructors who 

trained him.



I think my only point is, regardless of who says it's OK or who says 

it's not OK is the fact that a government Civil Aviation Administration 

(CAA) has prohibited tail slides in Yak 52's.  There has to be something 

behind this prohibition, assuming it is true.  Now if I can find 

substantiating documentation, I will share that with the group.

Dennis



On 5/3/2011 7:00 PM, Mark Davis wrote:

[quote] 



 Mark,



 Now I know where I'd seen the prohibition on tail slides before.... in

 the POH for my YAK. I found an online copy that is the same as the one

 that came with N44YK. I'm not sure who generated it or if it is correct.

 I'm sure tailslides have been done safely in YAK 52's by many for years,

 but I'm still curious why they are listed as prohibited on page 10 of

 this POH. The link follows:



 www.yak-52.com/downloads/?YAK52%20POH.doc



 My copy of the above manual doesn't have the question marks in

 parenthesis like the link above shows. Maybe Dennis knows the origin of

 the manual.



 Oh... for the record, so I can participate in the discussion, I have

 done tail slides in several aircraft (TA-4J and T-2C), just not in one

 that has the maneuver prohibited in it's POH (EA-6B NATOPS/SOP and my

 YAK-52 POH albeit possibly in error). Must be my Navy flight training

 that makes me heed the "don't do it" stuff.



 As for the tailslides themselves, I've seen some done that appear to

 create a much higher than typical backward airspeed. Whether by luck (my

 case) or skill (Sergei Boriak) those would be the ones that would impart

 a potentially damaging load on control surfaces. As for your question

 "Which is higher? Tail Slide Air Loads, or Snap Roll Air Loads? Well,

 you tell me", my simple mind goes back to learning as a small child that

 it wasn't a good idea to stick your hand out of the window of a car at

 80 mph fingers pointing forward then deflecting your hand contrary to

 the prevailing wind. Nearly getting my shoulder yanked out of the socket

 taught me that fairing your hand downwind put a less rapid load on my

 joints. Back to my flight training....don't yank on the G (or rolling

 pulls).



 So, after all that, I still would be interested in knowing why SOMEONE

 deemed it apparently unsafe in a YAK 52 enough to include in a POH.

 Anecdotal evidence that the maneuver has been performed routinely

 without causing structural failure doesn't mean it hasn't been exceeding

 load limits that someone, somewhere thinks is excessive. If it came from

 someone in the design, manufacture, or writing the initial operating

 limitations of the YAK 52 then I'm interested.



 Thanks for your input. I enjoy the discussion.



 Mark Davis

 N44YK



 ---

dsavarese0812(at)bellsout
Guest

Posted: Tue May 03, 2011 5:00 pm Post subject: Tailslides

I may not be associated with the vertical speed.  Maybe it is the snap- 

over motion into the nose down attitude (from nose up) that exerts the 

stress on the elevator and horizontal stab?

Dennis



On 5/3/2011 7:00 PM, Mark Davis wrote:

[quote] 



 Mark,



 Now I know where I'd seen the prohibition on tail slides before.... in

 the POH for my YAK. I found an online copy that is the same as the one

 that came with N44YK. I'm not sure who generated it or if it is correct.

 I'm sure tailslides have been done safely in YAK 52's by many for years,

 but I'm still curious why they are listed as prohibited on page 10 of

 this POH. The link follows:



 www.yak-52.com/downloads/?YAK52%20POH.doc



 My copy of the above manual doesn't have the question marks in

 parenthesis like the link above shows. Maybe Dennis knows the origin of

 the manual.



 Oh... for the record, so I can participate in the discussion, I have

 done tail slides in several aircraft (TA-4J and T-2C), just not in one

 that has the maneuver prohibited in it's POH (EA-6B NATOPS/SOP and my

 YAK-52 POH albeit possibly in error). Must be my Navy flight training

 that makes me heed the "don't do it" stuff.



 As for the tailslides themselves, I've seen some done that appear to

 create a much higher than typical backward airspeed. Whether by luck (my

 case) or skill (Sergei Boriak) those would be the ones that would impart

 a potentially damaging load on control surfaces. As for your question

 "Which is higher? Tail Slide Air Loads, or Snap Roll Air Loads? Well,

 you tell me", my simple mind goes back to learning as a small child that

 it wasn't a good idea to stick your hand out of the window of a car at

 80 mph fingers pointing forward then deflecting your hand contrary to

 the prevailing wind. Nearly getting my shoulder yanked out of the socket

 taught me that fairing your hand downwind put a less rapid load on my

 joints. Back to my flight training....don't yank on the G (or rolling

 pulls).



 So, after all that, I still would be interested in knowing why SOMEONE

 deemed it apparently unsafe in a YAK 52 enough to include in a POH.

 Anecdotal evidence that the maneuver has been performed routinely

 without causing structural failure doesn't mean it hasn't been exceeding

 load limits that someone, somewhere thinks is excessive. If it came from

 someone in the design, manufacture, or writing the initial operating

 limitations of the YAK 52 then I'm interested.



 Thanks for your input. I enjoy the discussion.



 Mark Davis

 N44YK



 ---

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