Today's Message Index:
----------------------
1. 05:01 AM - Re: CJ6 Shimmy damper problems (A. Dennis Savarese)
2. 05:03 AM - Wild Bill Walker (cjpilot710@aol.com)
3. 06:04 AM - the elevator horn, on Bill's airplane WAS NOT broken (cjpilot710@aol.com)
4. 06:04 AM - the elevator horn, on Bill's airplane WAS NOT broken (cjpilot710@aol.com)
5. 07:20 AM - Re: Yak-52 elevator failure (Cliff Coy)
6. 07:21 AM - Re: the elevator horn, on Bill's airplane WAS NOT broken (Roger Kemp M.D.)
7. 07:22 AM - Re: Wild Bill Walker (Bill Austin)
8. 08:16 AM - Re: Wild Bill Walker (George Coy)
9. 09:23 AM - Re: Yak-52 elevator failure (Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E)
10. 10:36 AM - Re: Yak-52 elevator failure (A. Dennis Savarese)
11. 11:18 AM - Wild Bill Walker Yak 52 crash (Hal)
12. 11:19 AM - Re: CJ6 Shimmy damper problems (Noplugs)
13. 12:30 PM - Re: Wild Bill Walker Yak 52 crash (Byron Fox)
14. 01:15 PM - B&C Alternator (adrian hale)
15. 02:38 PM - Re: B&C Alternator (A. Dennis Savarese)
16. 02:53 PM - Re: Yak-52 elevator failure (Walter Lannon)
17. 03:01 PM - Re: B&C Alternator (Eric Wobschall)
18. 03:31 PM - Re: Yak-52 elevator failure (A. Dennis Savarese)
19. 04:17 PM - Re: Yak-52 elevator failure (doug sapp)
Message 1
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| Subject: | Re: CJ6 Shimmy damper problems |
Very true Pappy. He should jack the nose up and try to move the nose
wheel assembly side to side and fore and aft to see if there is any play
in the bushings and bolts.
Dennis
On 3/27/2011 11:10 PM, cjpilot710@aol.com wrote:
> Not only out of balance but if the scissors is loose at all you'll get
> the same thing. There can not be any play in the bolts that are part of
> the scissor assembly.
> Jim "Pappy" Goolsby
> In a message dated 3/27/2011 10:51:58 P.M. Eastern Daylight Time,
> dsavarese0812@bellsouth.net writes:
>
> <dsavarese0812@bellsouth.net>
>
> You may also have an out of balance nose wheel tire and wheel. Very
> common problem.
> Dennis
>
> On 3/26/2011 10:35 PM, CJ6XXK wrote:
> >
> > I just done some high speed taxi runs in my cj6 today and have a
> few problems.
> >
> > First thing is that i raise the the nose of the plane then put it
> down again and i have got massive amounts of shimmy.
> > This was a brand new shimmy damper i bought and fitted as well.
> > Is there a special way to set them up?
> >
> > Thanks Daniel
> >
> >
> >
> >
> > Read this topic online here:
> >
> > http://forums.matronics.com/viewtopic.php?p=335149#335149
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >========================e ties Day
> ================================================ - MATRONICS WEB
> FORUMS ================================================ - List
> Contribution Web Site sp;
> ==================================================
>
>
> *
>
>
> *
Message 2
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| Subject: | Wild Bill Walker |
Troops,
As you may have already heard we lost "Wild Bill" Walker yesterday at Wings
over Flagler airshow, north of Daytona Beach.
Needless to say Bill's fellows Red Thunder team members are taking it
really hard. Of course his family must be devastated by his untimely
departure. All our prayers go out to them.
Bill failed to pull out of the down side of a loop in the sequence he was
flying with Jim Fordham in his Yak 52TD. Myself and one team member
checked the elevator control arm at the crash site, and found that it WAS not
broken. At this time none of us know why Bill went in. He died instantly.
There is video of the whole sequence, but at this time I am not aware of any
conclusion but know that the NTSB / FAA were investigating today.
I hope each of you will take a moment of reflection and prayer for Bill's
family and his memory. He loved flying. He genuinely loved the people he
flew with and we loved him. He was a gentleman and proud father. His loud
southern draw, joyous humor and sharp wit, will be missed.
Jim "Pappy" Goolsby
Message 3
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| Subject: | the elevator horn, on Bill's airplane WAS NOT broken |
Just to reemphasized, the elevator horn, on Bill's airplane WAS NOT
broken. Myself and Shane Golden went to the wreckage site, and inspected just
for that. The airplane was almost totally consumed by fire. The FAA/NTSB
will have a hard time determining if anything mechanically was amiss. The
distance from the impact point to the airplane was about 10 yards. I
personally did not see the crash but ensuing fireball. The video I saw showed
a
angle of about 80 degrees nose down, others who witnessed it said it was much
less a steep angle.
Bill and the team had flown this routine almost a hundred times. They
done the same routine twice already that day. Plus having practiced a number
of times while we were at Waycross earlier in the week.
Personally guys, all of us here loved this guy, and this is really hard to
take. There will be long hours trying to figure out what happen. There
will be some wild speculations, "told you so's", and a lot of Monday morning
quarter backing. I hope we can avoid that kind of BS at the same time we
as a group need to know what happened. But for his sake and that of his
family and friends, we need to get it right. Bill would have wanted that.
Jim "Pappy" Goolsby
Message 4
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| Subject: | the elevator horn, on Bill's airplane WAS NOT broken |
Just to reemphasized, the elevator horn, on Bill's airplane WAS NOT
broken. Myself and Shane Golden went to the wreckage site, and inspected just
for that. The airplane was almost totally consumed by fire. The FAA/NTSB
will have a hard time determining if anything mechanically was amiss. The
distance from the impact point to the airplane was about 10 yards. I
personally did not see the crash but ensuing fireball. The video I saw showed
a
angle of about 80 degrees nose down, others who witnessed it said it was much
less a steep angle.
Bill and the team had flown this routine almost a hundred times. They
done the same routine twice already that day. Plus having practiced a number
of times while we were at Waycross earlier in the week.
Personally guys, all of us here loved this guy, and this is really hard to
take. There will be long hours trying to figure out what happen. There
will be some wild speculations, "told you so's", and a lot of Monday morning
quarter backing. I hope we can avoid that kind of BS at the same time we
as a group need to know what happened. But for his sake and that of his
family and friends, we need to get it right. Bill would have wanted that.
Jim "Pappy" Goolsby
Message 5
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| Subject: | Re: Yak-52 elevator failure |
*Yes, the area of concern is below where the counterweight arm attaches to
the elevator bell crank.
The engineering is very sound for this location.
The bellcrank is mounted on a self aligning bearing to allow for twisting.
Mass balancing the elevator at the center allows for the horizontal
stabilizer structure to be smaller and lighter. The aircraft is already
tough to recover from flat spins so adding any more weight that far away
from the center of rotation isn't such a good idea.
The original designers and engineers of this aircraft had many choices for
this and everything else on the aircraft. There are good reasons why they
chose this design.
**These aircraft are in the "Experimental" catagory in the U.S. and as such
we see a lot of modifications in which the owner or U.S. mechanic makes an
"improvement" to the design only to find out down the road that this
improvement detrimentally affects the performance and/or safety of the
aircraft.
Fuel flow transducers that critically reduce the fuel supply to the carb,
Air Tool oil into the pneumatic system which washes the grease out of the
system,
and Plugging the accelerator pump in the carburetor, to name a few.
**Replacing the arm with one manufactured from steel may also run into the
"Law of Unintended Consequences".
For instance, the center bearing mentioned above is pressed into the arm- an
easy and common practice when dissimilar metals are involved but not so easy
when they're both made of steel.
**As I've said before, I'm glad there is an alternative available but I'm
more curious as to the root cause of the failures involved. If it's due
more to metallurgy then I'm gung ho for an alternate but, if it's due to
other reasons (ie. mis-rigging), then I'm not.
Best regards,
Cliff
*
*
*
On Sun, Mar 27, 2011 at 17:47, Walter Lannon <wlannon@persona.ca> wrote:
> Hi Cliff;
>
> Thanks for your reply. There seems to be a bit of confusion re this part.
> It is not a control balance arm which would typically extend well forward
> of the control surface hinge line.
>
> This is the elevator control cable drive sector (bellcrank).
> It appears to have weight mounted on it directly above the hinge centre
> line.
> That would have absolutely zero effect on elevator balance if the weight is
> mounted where the attachment holes are located.
> But, I am beginning to get the picture!!!!!!! Is this the mounting
> location for the balance ARM?
>
> If so that takes my concern to a whole new level. That would be the
> absolutely dumbest place you could possibly imagine to attach a balance arm.
>
> Not only does the sector have to handle the balance weight the effect is
> severely magnified by the length of the arm.
> The cause of this cracking I believe is a direct result of that
> installation.
> Any asymmetrical rudder loads will induce horizontal loading of the
> ELEVATOR balance weight which will in turn
> induce a twisting moment in the elevator sector.
> Over (who knows how) many cycles this will result in a fatigue failure at
> the most likely focal point. Barring a severe nick or other mechanical
> damage that point is the section change.
>
> Now I begin to understand why they are suggesting a STEEL replacement.
>
> Walt
>
> PS:
> ---- Original Message -----
>
> *From:* Cliff Coy <cliff.coy@gmail.com>
> *To:* yak-list@matronics.com
> *Sent:* Sunday, March 27, 2011 12:58 PM
> *Subject:* Re: Yak-List: Yak-52 elevator failure
>
> *This is the elevator counter balance arm.
> The elevators, as well as the ailerons, are mass balanced controls.
> The rudder is both mass balanced and aerodynamically balanced.
>
> If you're not already familiar with aircraft control design, here is a good
> primer on aircraft:
>
> http://www.centennialofflight.gov/essay/Theories_of_Flight/control/TH28.htm
>
> Best regards,
> Cliff
> *
> On Sat, Mar 26, 2011 at 23:16, Walter Lannon <wlannon@persona.ca> wrote:
>
>>
>> Possibly. The crack is originating at the section change where loads
>> would tend to concentrate but it may also be subject to bending loads from
>> the balance weight attached to the upper, heavier, section.
>> Possibly rudder induced transverse loading?
>> I don't understand the use of a balance weight in this location.
>> Walt
>> ----- Original Message ----- From: "William Halverson" <
>> william@netpros.net>
>>
>> To: <yak-list@matronics.com>
>> Sent: Saturday, March 26, 2011 4:21 PM
>>
>> Subject: Re: Yak-List: Yak-52 elevator failure
>>
>>
>>>
>>>
>>> Well, the part is cracking on the upper side ... would it be due to
>>> aggressive pull back forces on the stick?
>>>
>>>
>>> +-----Original Message-----
>>> +From: Walter Lannon [mailto:wlannon@persona.ca]
>>> +Sent: Saturday, March 26, 2011 04:00 PM
>>> +To: yak-list@matronics.com
>>> +Subject: Re: Yak-List: Yak-52 elevator failure
>>> +
>>> +Interesting!
>>> +
>>> +How much weight is attached to this part? And for what purpose?
>>> +
>>> +Walt
>>> + ----- Original Message ----- + From: pilko2
>>> + To: yak-list@matronics.com
>>> + Sent: Saturday, March 26, 2011 5:25 AM
>>> + Subject: FW: Yak-List: Yak-52 elevator failure
>>> +
>>> +
>>> +
>>> +
>>> + Trawling the website of Yak UK reveals this to be a well known gotcha.
>>> +
>>> +
>>> +
>>> + http://www.yakuk.com/2000-004.doc
>>> +
>>> +
>>> +
>>> +
>>> +
>>> +
>>> +
>>> + MPD: 2000-004
>>> +
>>> +
>>> + Subject: Crack in elevator control system pulley.
>>> +
>>> +
>>> +
>>> + Applicability: Yakovlev/ Aerostar or a SA Y B AK 52 aircraft.
>>> +
>>> +
>>> +
>>> + Reason: A 19 mm crack has been discovered in the elevator actuation
>>> part number 5251 or 00-80-3 (referred to as "lever" in the Romanian parts
>>> catalogue). The failure of this component could result in loss of the
>>> elevator control.
>>> +
>>> +
>>> +
>>> + Compliance: Within 50 hours from the effective date of this MPD,
>>> inspect elevator actuation pulley parts number 525100-80-34 cracking on its
>>> periphery below the attachment for the balance weight bracket, at the point
>>> where the section reduces from a 10 mm to 7 mm. Inspect using dye penetrant
>>> techniques. if the component is cracked, replace it before Further Flight.
>>> Repeat this inspection annually at renewal of the permit to fly.
>>> +
>>> +
>>> +
>>> +
>>> +
>>> +
>>> +
>>> +
>>> +
>>> +
>>> +
>>> +
>>> http://www.matronics.com/Navigator?Yak-Listhttp://forums.matronics.comhttp://www.matronics.com/contribution
>>> +
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>
>> ==========
>> rget="_blank">http://www.matronics.com/Navigator?Yak-List
>> ==========
>> http://forums.matronics.com
>> ==========
>> le, List Admin.
>> ="_blank">http://www.matronics.com/contribution
>> ==========
>>
>>
>>
>>
>
>
> --
> Clifford Coy
> Border Air Ltd.
> 629 Airport Rd.
> Swanton, VT 05488
> 802-868-2822 TEL
> 802-868-4465 FAX
> Skype: Cliff.Coy
>
> *
>
> *
>
>
--
Clifford Coy
Border Air Ltd.
629 Airport Rd.
Swanton, VT 05488
802-868-2822 TEL
802-868-4465 FAX
Skype: Cliff.Coy
Message 6
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| Subject: | the elevator horn, on Bill's airplane WAS NOT broken |
Thanks Pappy.my thoughts and prayers are with Wild Bill's family as well as
the members of Red Thunder.
The NTSB investigation will answer most of the questions in time. If nothing
was jammed in the elevator bell crank and no other mechanical issues can be
determined then it comes down to physiological factors. On that we will just
have to wait on the tissue toxicology reports to make a call. No amount of
speculation will answer the questions until the final report. Even then it
may not give all the answers.
Blue Skies and Tail winds.Wild Bill. may God rest your soul.
Doc
From: owner-yak-list-server@matronics.com
[mailto:owner-yak-list-server@matronics.com] On Behalf Of cjpilot710@aol.com
Sent: Monday, March 28, 2011 7:14 AM
Subject: Yak-List: the elevator horn, on Bill's airplane WAS NOT broken
Just to reemphasized, the elevator horn, on Bill's airplane WAS NOT broken.
Myself and Shane Golden went to the wreckage site, and inspected just for
that. The airplane was almost totally consumed by fire. The FAA/NTSB will
have a hard time determining if anything mechanically was amiss. The
distance from the impact point to the airplane was about 10 yards. I
personally did not see the crash but ensuing fireball. The video I saw
showed a angle of about 80 degrees nose down, others who witnessed it said
it was much less a steep angle.
Bill and the team had flown this routine almost a hundred times. They done
the same routine twice already that day. Plus having practiced a number of
times while we were at Waycross earlier in the week.
Personally guys, all of us here loved this guy, and this is really hard to
take. There will be long hours trying to figure out what happen. There
will be some wild speculations, "told you so's", and a lot of Monday morning
quarter backing. I hope we can avoid that kind of BS at the same time we as
a group need to know what happened. But for his sake and that of his
family and friends, we need to get it right. Bill would have wanted that.
Jim "Pappy" Goolsby
Message 7
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| Subject: | Wild Bill Walker |
Thanks Pappy . I know Bill really appreciated your friendship Bill Austin
_____
From: owner-yak-list-server@matronics.com
[mailto:owner-yak-list-server@matronics.com] On Behalf Of cjpilot710@aol.com
Sent: Monday, March 28, 2011 6:33 AM
Subject: Yak-List: Wild Bill Walker
Troops,
As you may have already heard we lost "Wild Bill" Walker yesterday at Wings
over Flagler airshow, north of Daytona Beach.
Needless to say Bill's fellows Red Thunder team members are taking it really
hard. Of course his family must be devastated by his untimely departure.
All our prayers go out to them.
Bill failed to pull out of the down side of a loop in the sequence he was
flying with Jim Fordham in his Yak 52TD. Myself and one team member checked
the elevator control arm at the crash site, and found that it WAS not
broken. At this time none of us know why Bill went in. He died instantly.
There is video of the whole sequence, but at this time I am not aware of any
conclusion but know that the NTSB / FAA were investigating today.
I hope each of you will take a moment of reflection and prayer for Bill's
family and his memory. He loved flying. He genuinely loved the people he
flew with and we loved him. He was a gentleman and proud father. His loud
southern draw, joyous humor and sharp wit, will be missed.
Jim "Pappy" Goolsby
Message 8
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| Subject: | Wild Bill Walker |
Thanks for the update
George Coy
CAS Ltd.
714 Airport Rd.
Swanton VT 05488
802-868-5633 off
802-363-5782 cell
802-868-4465 Fax
george.coy@gmail.com
http://coyafct.com/
SKYPE george.coy
From: owner-yak-list-server@matronics.com
[mailto:owner-yak-list-server@matronics.com] On Behalf Of Bill Austin
Sent: Monday, March 28, 2011 9:53 AM
Subject: RE: Yak-List: Wild Bill Walker
Thanks Pappy . I know Bill really appreciated your friendship Bill Austin
_____
From: owner-yak-list-server@matronics.com
[mailto:owner-yak-list-server@matronics.com] On Behalf Of cjpilot710@aol.com
Sent: Monday, March 28, 2011 6:33 AM
Subject: Yak-List: Wild Bill Walker
Troops,
As you may have already heard we lost "Wild Bill" Walker yesterday at Wings
over Flagler airshow, north of Daytona Beach.
Needless to say Bill's fellows Red Thunder team members are taking it really
hard. Of course his family must be devastated by his untimely departure.
All our prayers go out to them.
Bill failed to pull out of the down side of a loop in the sequence he was
flying with Jim Fordham in his Yak 52TD. Myself and one team member checked
the elevator control arm at the crash site, and found that it WAS not
broken. At this time none of us know why Bill went in. He died instantly.
There is video of the whole sequence, but at this time I am not aware of any
conclusion but know that the NTSB / FAA were investigating today.
I hope each of you will take a moment of reflection and prayer for Bill's
family and his memory. He loved flying. He genuinely loved the people he
flew with and we loved him. He was a gentleman and proud father. His loud
southern draw, joyous humor and sharp wit, will be missed.
Jim "Pappy" Goolsby
http://www.matronics.com/Navigator?Yak-List
http://forums.matronics.com
http://www.matronics.com/contribution
Message 9
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| Subject: | Yak-52 elevator failure |
Cliff, what you are saying here makes perfect sense. Thanks for writing it.
Inspecting the part makes sense, but in my mind it is MUCH more important to determine
why it cracked in the first place.
Mark Bitterlich
-----Original Message-----
From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of Cliff Coy
Sent: Friday, March 25, 2011 10:33 PM
Subject: Re: Yak-List: Yak-52 elevator failure
Cracking in this area has been a known issue for many years.
The contributing factors seem to be:
Incorrect elevator cable tension
Incorrect elevator travel
and ~sigh~ abuse of the machinery....
These conditions allow for the elevator counterweight to strike the horizontal
stabilizer and/or up inside the vertical stabilizer. This places a bending moment
between the counterweight arm and the elevator whose weakest point is exactly
as Richard has shown.
If rapid movement to the elevator stop produces a hard knocking slap, inspect and
repair immediately.
I'm sure the change to steel will alleviate any work hardening issues that the
aluminum horns may be developing, but the contributing factors above will not
stop this kind of failure, it'll just move the failure to a different point- like
the counterweight bolts or center elevator bearing.
If nothing else, I'm glad to see the horns are available.
How are you addressing match drilling to each individual counterweight?
Thanks Richard!
Cliff
On Fri, Mar 25, 2011 at 13:16, Richard Goode <richard.goode@russianaeros.com> wrote:
To answer the queries of several people who have written to me directly:
I have passed on all that I know today - but it seemed to me that this is a
critical issue that any sensible owner would want to check on their own aircraft.
I understand from Yakovlev themselves that they will issue a formal Service
Bulletin (AD).
Again I understand that this will be made out of steel rather than aluminium
alloy.
However I do not know any more details of when/where the plate might be made
etc.
I have no idea if there would be a potential similar problem with the 18T/50
etc, which have a similar design.
Richard Goode Aerobatics
Rhodds Farm
Lyonshall
Herefordshire
HR5 3LW
United Kingdom
Tel: +44 (0) 1544 340120 <tel:%2B44%20%280%29%201544%20340120>
Fax: +44 (0) 1544 340129 <tel:%2B44%20%280%29%201544%20340129>
www.russianaeros.com <http://www.russianaeros.com>
et="_blank">http://www.matronics.com/Navigator?Yak-List
tp://forums.matronics.com
_blank">http://www.matronics.com/contribution
--
Clifford Coy
Border Air Ltd.
629 Airport Rd.
Swanton, VT 05488
802-868-2822 TEL
802-868-4465 FAX
Skype: Cliff.Coy
Message 10
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| Subject: | Re: Yak-52 elevator failure |
Since the cause of the crack in the bellcrank has not been determined
(or published), as Cliff points out, it is also very important to make
certain your airplane is configured/rigged properly. ie: Elevator
travel is set to specs; rudder travel is set to specs; aileron travel is
set to specs; cable tensions are set to specs and the elevator counter
weight bolts and nuts are 100% tight.
Last but not least as Cliff points out, the elevator bellcrank bearing
CAN and WILL wear. It is a 6x19x6 mm self aligning bearing and they are
used in several places on the airplane. The ones used on the control
surfaces are open face bearings (not sealed) and are prone to collecting
dirt and grit which causes premature wear of the bearing. The elevator
bellcrank bearing is one of these bearings that can easily be degraded
because of dirt and grit migrating to the inside of the bearing.
Another one of these self aligning bearings is the inboard aileron
bearing. This one is the worst of all for collecting dirt because of
its proximity to the main wheel tires which flick the dirt upward during
ground operations.
Dennis
On 3/28/2011 10:47 AM, Bitterlich, Mark G CIV Det Cherry Point, MALS-14
64E wrote:
> --> Yak-List message posted by: "Bitterlich, Mark G CIV Det Cherry Point, MALS-14
64E"<mark.bitterlich@navy.mil>
>
> Cliff, what you are saying here makes perfect sense. Thanks for writing it.
>
> Inspecting the part makes sense, but in my mind it is MUCH more important to
determine why it cracked in the first place.
>
> Mark Bitterlich
>
>
> -----Original Message-----
> From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of Cliff Coy
> Sent: Friday, March 25, 2011 10:33 PM
> To: yak-list@matronics.com
> Subject: Re: Yak-List: Yak-52 elevator failure
>
> Cracking in this area has been a known issue for many years.
> The contributing factors seem to be:
> Incorrect elevator cable tension
> Incorrect elevator travel
> and ~sigh~ abuse of the machinery....
>
> These conditions allow for the elevator counterweight to strike the horizontal
stabilizer and/or up inside the vertical stabilizer. This places a bending moment
between the counterweight arm and the elevator whose weakest point is exactly
as Richard has shown.
>
> If rapid movement to the elevator stop produces a hard knocking slap, inspect
and repair immediately.
>
> I'm sure the change to steel will alleviate any work hardening issues that the
aluminum horns may be developing, but the contributing factors above will not
stop this kind of failure, it'll just move the failure to a different point-
like the counterweight bolts or center elevator bearing.
>
> If nothing else, I'm glad to see the horns are available.
> How are you addressing match drilling to each individual counterweight?
>
> Thanks Richard!
>
> Cliff
>
>
> On Fri, Mar 25, 2011 at 13:16, Richard Goode<richard.goode@russianaeros.com>
wrote:
>
>
> To answer the queries of several people who have written to me directly:
>
>
>
> I have passed on all that I know today - but it seemed to me that this is
a critical issue that any sensible owner would want to check on their own aircraft.
>
> I understand from Yakovlev themselves that they will issue a formal Service
Bulletin (AD).
>
> Again I understand that this will be made out of steel rather than aluminium
alloy.
>
> However I do not know any more details of when/where the plate might be made
etc.
>
> I have no idea if there would be a potential similar problem with the 18T/50
etc, which have a similar design.
>
>
>
> Richard Goode Aerobatics
>
> Rhodds Farm
>
> Lyonshall
>
> Herefordshire
>
> HR5 3LW
>
> United Kingdom
>
>
>
> Tel: +44 (0) 1544 340120<tel:%2B44%20%280%29%201544%20340120>
>
> Fax: +44 (0) 1544 340129<tel:%2B44%20%280%29%201544%20340129>
>
> www.russianaeros.com<http://www.russianaeros.com>
>
>
>
>
>
> et="_blank">http://www.matronics.com/Navigator?Yak-List
> tp://forums.matronics.com
> _blank">http://www.matronics.com/contribution
>
>
>
>
Message 11
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| Subject: | Wild Bill Walker Yak 52 crash |
We lost a friend and felow aviator this last weekend. Wild Bill was
participating with a demonstartion team in Florida when he apparantly failed
to pull out of a diving maneuver in his 52.
I could not help but notice the discussion that has been going on regarding
potential elevator failure in the 52 and the possibility that Wild Bill may
have experienced such a failure. Hopefully the investigation of the
accident will determine the cause.
Wild Bill was a good man and pilot - my heart goes out to his family and
friends.
Hal
Message 12
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| Subject: | Re: CJ6 Shimmy damper problems |
A friend of mine had the same problem on his CJ after he installed a US wheel and
tire mod. His first thought was the new mod was the problem and looked at everything
that the mod would cause the shimmy. Well to make the long story short
I told him to look at the shimmy dampener. He was skeptical because how could
it go bad in one flight. Well he took off the dampener, opened it up and found
the oil watery and dirty (His words to describe a light weight oil) and it
was not full of oil. He cleaned and re-serviced the unit reinstalled it and the
shimmy was gone. So my advice is to look at dampener, it does all the work
so it would be the weakest link in this issue.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=335302#335302
Message 13
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|
| Subject: | Re: Wild Bill Walker Yak 52 crash |
Indeed, he was a charming ad delightful guy. I've been following the discuss
ions well.
Sent from my iPhone
On Mar 28, 2011, at 10:24 AM, Hal <yakjock@gmail.com> wrote:
> We lost a friend and felow aviator this last weekend. Wild Bill was parti
cipating with a demonstartion team in Florida when he apparantly failed to p
ull out of a diving maneuver in his 52.
>
> I could not help but notice the discussion that has been going on regardin
g potential elevator failure in the 52 and the possibility that Wild Bill ma
y have experienced such a failure. Hopefully the investigation of the accid
ent will determine the cause.
>
> Wild Bill was a good man and pilot - my heart goes out to his family and f
riends.
>
> Hal
>
>
>
==========================
=========
==========================
=========
==========================
=========
==========================
=========
>
Message 14
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|
Has anyone experience with the 10 amp alt? Our A/C has the russian
radio but all other avionics and instruments are US. It has the small
Dynon Efis, and electronic tach and a transponder. will 10 amps keep
the bat up?
Message 15
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|
| Subject: | Re: B&C Alternator |
For the nominal price difference I think most people install the larger
of the two alternators. Better safe than sorry.
Don't forget, this is going to affect the W&B and would be a good idea
to re-weigh the airplane and prepare a new W&B sheet.
Dennis
On 3/28/2011 2:46 PM, adrian hale wrote:
>
> Has anyone experience with the 10 amp alt? Our A/C has the russian radio
> but all other avionics and instruments are US. It has the small Dynon
> Efis, and electronic tach and a transponder. will 10 amps keep the bat up?
>
>
Message 16
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|
| Subject: | Re: Yak-52 elevator failure |
Hi Cliff;
The self-aligning bearing is there to compensate for any minor mis-alignment in
the assembly of the sector to the rear spar attach fitting with the left & right
elevators attached
to the sector.
It will have no effect whatever on the any twisting/bending moments induced in
the upper (thicker) part of the sector. Those loads are transmitted to the thinner
(7mm) section which is firmly bolted to both elevators through the attachment
plates.
These plates are substantial and very effectively increase the bending resistance
of the sector in the area just below the section change. This of course further
defines the focal point for cracking at the section change by eliminating
any flexure below that point.
For the universal bearing to have any effect the entire elevator assembly would
have to translate laterally.
Sorry. I think it is a very poor design and probably dictated by a lack of space
in that area.
The CJ is quite different. The balance arm is attached to the primary structure
of the elevator assy.
I would expect the CJ system is a direct copy of the earlier Russian systems.
Jump in Doug -- how is the Yak 18 done?
Anyone know the Yak 50, Yak18A systems?
Cheers;
Walt
----- Original Message -----
From: Cliff Coy
To: yak-list@matronics.com
Sent: Monday, March 28, 2011 6:39 AM
Subject: Re: Yak-List: Yak-52 elevator failure
Yes, the area of concern is below where the counterweight arm attaches to the
elevator bell crank.
The engineering is very sound for this location.
The bellcrank is mounted on a self aligning bearing to allow for twisting.
Mass balancing the elevator at the center allows for the horizontal stabilizer
structure to be smaller and lighter. The aircraft is already tough to recover
from flat spins so adding any more weight that far away from the center of
rotation isn't such a good idea.
The original designers and engineers of this aircraft had many choices for this
and everything else on the aircraft. There are good reasons why they chose
this design.
These aircraft are in the "Experimental" catagory in the U.S. and as such we
see a lot of modifications in which the owner or U.S. mechanic makes an "improvement"
to the design only to find out down the road that this improvement detrimentally
affects the performance and/or safety of the aircraft.
Fuel flow transducers that critically reduce the fuel supply to the carb,
Air Tool oil into the pneumatic system which washes the grease out of the system,
and Plugging the accelerator pump in the carburetor, to name a few.
Replacing the arm with one manufactured from steel may also run into the "Law
of Unintended Consequences".
For instance, the center bearing mentioned above is pressed into the arm- an
easy and common practice when dissimilar metals are involved but not so easy when
they're both made of steel.
As I've said before, I'm glad there is an alternative available but I'm more
curious as to the root cause of the failures involved. If it's due more to metallurgy
then I'm gung ho for an alternate but, if it's due to other reasons (ie.
mis-rigging), then I'm not.
Best regards,
Cliff
On Sun, Mar 27, 2011 at 17:47, Walter Lannon <wlannon@persona.ca> wrote:
Hi Cliff;
Thanks for your reply. There seems to be a bit of confusion re this part.
It is not a control balance arm which would typically extend well forward of
the control surface hinge line.
This is the elevator control cable drive sector (bellcrank).
It appears to have weight mounted on it directly above the hinge centre line.
That would have absolutely zero effect on elevator balance if the weight is
mounted where the attachment holes are located.
But, I am beginning to get the picture!!!!!!! Is this the mounting location
for the balance ARM?
If so that takes my concern to a whole new level. That would be the absolutely
dumbest place you could possibly imagine to attach a balance arm.
Not only does the sector have to handle the balance weight the effect is severely
magnified by the length of the arm.
The cause of this cracking I believe is a direct result of that installation.
Any asymmetrical rudder loads will induce horizontal loading of the ELEVATOR
balance weight which will in turn
induce a twisting moment in the elevator sector.
Over (who knows how) many cycles this will result in a fatigue failure at the
most likely focal point. Barring a severe nick or other mechanical damage that
point is the section change.
Now I begin to understand why they are suggesting a STEEL replacement.
Walt
PS:
---- Original Message -----
From: Cliff Coy
To: yak-list@matronics.com
Sent: Sunday, March 27, 2011 12:58 PM
Subject: Re: Yak-List: Yak-52 elevator failure
This is the elevator counter balance arm.
The elevators, as well as the ailerons, are mass balanced controls.
The rudder is both mass balanced and aerodynamically balanced.
If you're not already familiar with aircraft control design, here is a good
primer on aircraft:
http://www.centennialofflight.gov/essay/Theories_of_Flight/control/TH28.htm
Best regards,
Cliff
On Sat, Mar 26, 2011 at 23:16, Walter Lannon <wlannon@persona.ca> wrote:
Possibly. The crack is originating at the section change where loads would
tend to concentrate but it may also be subject to bending loads from the
balance weight attached to the upper, heavier, section.
Possibly rudder induced transverse loading?
I don't understand the use of a balance weight in this location.
Walt
----- Original Message ----- From: "William Halverson" <william@netpros.net>
To: <yak-list@matronics.com>
Sent: Saturday, March 26, 2011 4:21 PM
Subject: Re: Yak-List: Yak-52 elevator failure
Well, the part is cracking on the upper side ... would it be due to aggressive
pull back forces on the stick?
+-----Original Message-----
+From: Walter Lannon [mailto:wlannon@persona.ca]
+Sent: Saturday, March 26, 2011 04:00 PM
+To: yak-list@matronics.com
+Subject: Re: Yak-List: Yak-52 elevator failure
+
+Interesting!
+
+How much weight is attached to this part? And for what purpose?
+
+Walt
+ ----- Original Message ----- + From: pilko2
+ To: yak-list@matronics.com
+ Sent: Saturday, March 26, 2011 5:25 AM
+ Subject: FW: Yak-List: Yak-52 elevator failure
+
+
+
+
+ Trawling the website of Yak UK reveals this to be a well known gotcha.
+
+
+
+ http://www.yakuk.com/2000-004.doc
+
+
+
+
+
+
+
+ MPD: 2000-004
+
+
+ Subject: Crack in elevator control system pulley.
+
+
+
+ Applicability: Yakovlev/ Aerostar or a SA Y B AK 52 aircraft.
+
+
+
+ Reason: A 19 mm crack has been discovered in the elevator actuation
part number 5251 or 00-80-3 (referred to as "lever" in the Romanian parts catalogue).
The failure of this component could result in loss of the elevator control.
+
+
+
+ Compliance: Within 50 hours from the effective date of this MPD, inspect
elevator actuation pulley parts number 525100-80-34 cracking on its periphery
below the attachment for the balance weight bracket, at the point where
the section reduces from a 10 mm to 7 mm. Inspect using dye penetrant techniques.
if the component is cracked, replace it before Further Flight. Repeat this
inspection annually at renewal of the permit to fly.
+
+
+
+
+
+
+
+
+
+
+
+ http://www.matronics.com/Navigator?Yak-Listhttp://forums.matronics.comhttp://www.matronics.com/contribution
+
==========
rget="_blank">http://www.matronics.com/Navigator?Yak-List
==========
http://forums.matronics.com
==========
le, List Admin.
="_blank">http://www.matronics.com/contribution
==========
--
Clifford Coy
Border Air Ltd.
629 Airport Rd.
Swanton, VT 05488
802-868-2822 TEL
802-868-4465 FAX
Skype: Cliff.Coy
--
Clifford Coy
Border Air Ltd.
629 Airport Rd.
Swanton, VT 05488
802-868-2822 TEL
802-868-4465 FAX
Skype: Cliff.Coy
Message 17
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|
| Subject: | Re: B&C Alternator |
That sounds skimpy to me, depending on battery capacity.
On Mar 28, 2011, at 3:46 PM, adrian hale wrote:
>
> Has anyone experience with the 10 amp alt? Our A/C has the russian radio but
all other avionics and instruments are US. It has the small Dynon Efis, and electronic
tach and a transponder. will 10 amps keep the bat up?
>
>
>
>
Message 18
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|
| Subject: | Re: Yak-52 elevator failure |
Yak 50 bellcrank and counterweight is the same design as the 52.
Dennis
On 3/28/2011 4:18 PM, Walter Lannon wrote:
> Hi Cliff;
> The self-aligning bearing is there to compensate for any minor
> mis-alignment in the assembly of the sector to the rear spar attach
> fitting with the left & right elevators attached
> to the sector.
> It will have no effect whatever on the any twisting/bending moments
> induced in the upper (thicker) part of the sector. Those loads are
> transmitted to the thinner (7mm) section which is firmly bolted to both
> elevators through the attachment plates.
> These plates are substantial and very effectively increase the bending
> resistance of the sector in the area just below the section change. This
> of course further defines the focal point for cracking at the section
> change by eliminating any flexure below that point.
> For the universal bearing to have any effect the entire elevator
> assembly would have to translate laterally.
> Sorry. I think it is a very poor design and probably dictated by a lack
> of space in that area.
> The CJ is quite different. The balance arm is attached to the primary
> structure of the elevator assy.
> I would expect the CJ system is a direct copy of the earlier Russian
> systems.
> Jump in Doug -- how is the Yak 18 done?
> Anyone know the Yak 50, Yak18A systems?
> Cheers;
> Walt
>
> ----- Original Message -----
> *From:* Cliff Coy <mailto:cliff.coy@gmail.com>
> *To:* yak-list@matronics.com <mailto:yak-list@matronics.com>
> *Sent:* Monday, March 28, 2011 6:39 AM
> *Subject:* Re: Yak-List: Yak-52 elevator failure
>
> *Yes, the area of concern is below where the counterweight arm
> attaches to the elevator bell crank.
>
> The engineering is very sound for this location.
> The bellcrank is mounted on a self aligning bearing to allow for
> twisting.
>
> Mass balancing the elevator at the center allows for the horizontal
> stabilizer structure to be smaller and lighter. The aircraft is
> already tough to recover from flat spins so adding any more weight
> that far away from the center of rotation isn't such a good idea.
>
> The original designers and engineers of this aircraft had many
> choices for this and everything else on the aircraft. There are good
> reasons why they chose this design.
>
> **These aircraft are in the "Experimental" catagory in the U.S. and
> as such we see a lot of modifications in which the owner or U.S.
> mechanic makes an "improvement" to the design only to find out down
> the road that this improvement detrimentally affects the performance
> and/or safety of the aircraft.
>
> Fuel flow transducers that critically reduce the fuel supply to the
> carb,
> Air Tool oil into the pneumatic system which washes the grease out
> of the system,
> and Plugging the accelerator pump in the carburetor, to name a few.
>
> **Replacing the arm with one manufactured from steel may also run
> into the "Law of Unintended Consequences".
> For instance, the center bearing mentioned above is pressed into the
> arm- an easy and common practice when dissimilar metals are involved
> but not so easy when they're both made of steel.
>
> **As I've said before, I'm glad there is an alternative available
> but I'm more curious as to the root cause of the failures involved.
> If it's due more to metallurgy then I'm gung ho for an alternate
> but, if it's due to other reasons (ie. mis-rigging), then I'm not.
>
> Best regards,
> Cliff
>
> *
> *
>
>
> *
> On Sun, Mar 27, 2011 at 17:47, Walter Lannon <wlannon@persona.ca
> <mailto:wlannon@persona.ca>> wrote:
>
> Hi Cliff;
> Thanks for your reply. There seems to be a bit of confusion re
> this part.
> It is not a control balance arm which would typically extend
> well forward of the control surface hinge line.
> This is the elevator control cable drive sector (bellcrank).
> It appears to have weight mounted on it directly above the hinge
> centre line.
> That would have absolutely zero effect on elevator balance if
> the weight is mounted where the attachment holes are located.
> But, I am beginning to get the picture!!!!!!! Is this the
> mounting location for the balance ARM?
> If so that takes my concern to a whole new level. That would be
> the absolutely dumbest place you could possibly imagine to
> attach a balance arm.
> Not only does the sector have to handle the balance weight the
> effect is severely magnified by the length of the arm.
> The cause of this cracking I believe is a direct result of that
> installation.
> Any asymmetrical rudder loads will induce horizontal loading of
> the ELEVATOR balance weight which will in turn
> induce a twisting moment in the elevator sector.
> Over (who knows how) many cycles this will result in a fatigue
> failure at the most likely focal point. Barring a severe nick or
> other mechanical damage that point is the section change.
> Now I begin to understand why they are suggesting a STEEL
> replacement.
> Walt
> PS:
> ---- Original Message -----
>
> *From:* Cliff Coy <mailto:cliff.coy@gmail.com>
> *To:* yak-list@matronics.com <mailto:yak-list@matronics.com>
> *Sent:* Sunday, March 27, 2011 12:58 PM
> *Subject:* Re: Yak-List: Yak-52 elevator failure
>
> *This is the elevator counter balance arm.
> The elevators, as well as the ailerons, are mass balanced
> controls.
> The rudder is both mass balanced and aerodynamically balanced.
>
> If you're not already familiar with aircraft control design,
> here is a good primer on aircraft:
>
> http://www.centennialofflight.gov/essay/Theories_of_Flight/control/TH28.htm
>
> Best regards,
> Cliff
> *
> On Sat, Mar 26, 2011 at 23:16, Walter Lannon
> <wlannon@persona.ca <mailto:wlannon@persona.ca>> wrote:
>
> <wlannon@persona.ca <mailto:wlannon@persona.ca>>
>
> Possibly. The crack is originating at the section change
> where loads would tend to concentrate but it may also be
> subject to bending loads from the balance weight
> attached to the upper, heavier, section.
> Possibly rudder induced transverse loading?
> I don't understand the use of a balance weight in this
> location.
> Walt
> ----- Original Message ----- From: "William Halverson"
> <william@netpros.net <mailto:william@netpros.net>>
>
> To: <yak-list@matronics.com <mailto:yak-list@matronics.com>>
> Sent: Saturday, March 26, 2011 4:21 PM
>
> Subject: Re: Yak-List: Yak-52 elevator failure
>
>
> <william@netpros.net <mailto:william@netpros.net>>
>
>
> Well, the part is cracking on the upper side ...
> would it be due to aggressive pull back forces on
> the stick?
>
>
> +-----Original Message-----
> +From: Walter Lannon [mailto:wlannon@persona.ca
> <mailto:wlannon@persona.ca>]
> +Sent: Saturday, March 26, 2011 04:00 PM
> +To: yak-list@matronics.com
> <mailto:yak-list@matronics.com>
> +Subject: Re: Yak-List: Yak-52 elevator failure
> +
> +Interesting!
> +
> +How much weight is attached to this part? And for
> what purpose?
> +
> +Walt
> + ----- Original Message ----- + From: pilko2
> + To: yak-list@matronics.com
> <mailto:yak-list@matronics.com>
> + Sent: Saturday, March 26, 2011 5:25 AM
> + Subject: FW: Yak-List: Yak-52 elevator failure
> +
> +
> +
> +
> + Trawling the website of Yak UK reveals this to be
> a well known gotcha.
> +
> +
> +
> + http://www.yakuk.com/2000-004.doc
> +
> +
> +
> +
> +
> +
> +
> + MPD: 2000-004
> +
> +
> + Subject: Crack in elevator control system pulley.
> +
> +
> +
> + Applicability: Yakovlev/ Aerostar or a SA Y B AK
> 52 aircraft.
> +
> +
> +
> + Reason: A 19 mm crack has been discovered in the
> elevator actuation part number 5251 or 00-80-3
> (referred to as "lever" in the Romanian parts
> catalogue). The failure of this component could
> result in loss of the elevator control.
> +
> +
> +
> + Compliance: Within 50 hours from the effective
> date of this MPD, inspect elevator actuation pulley
> parts number 525100-80-34 cracking on its periphery
> below the attachment for the balance weight bracket,
> at the point where the section reduces from a 10 mm
> to 7 mm. Inspect using dye penetrant techniques. if
> the component is cracked, replace it before Further
> Flight. Repeat this inspection annually at renewal
> of the permit to fly.
> +
> +
> +
> +
> +
> +
> +
> +
> +
> +
> +
> +
> http://www.matronics.com/Navigator?Yak-Listhttp://forums.matronics.comhttp://www.matronics.com/contribution
> +
>
>
> ==========
> rget="_blank">http://www.matronics.com/Navigator?Yak-List
> ==========
> http://forums.matronics.com
> ==========
> le, List Admin.
> ="_blank">http://www.matronics.com/contribution
> ==========
>
>
> --
> Clifford Coy
> Border Air Ltd.
> 629 Airport Rd.
> Swanton, VT 05488
> 802-868-2822 <tel:802-868-2822> TEL
> 802-868-4465 <tel:802-868-4465> FAX
> Skype: Cliff.Coy
>
> *
>
>
> *
>
>
> --
> Clifford Coy
> Border Air Ltd.
> 629 Airport Rd.
> Swanton, VT 05488
> 802-868-2822 <tel:802-868-2822> TEL
> 802-868-4465 <tel:802-868-4465> FAX
> Skype: Cliff.Coy
>
> *
>
>
> *
>
Message 19
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|
| Subject: | Re: Yak-52 elevator failure |
Walt,
The elevator on the 18 attaches just like the CJ6. Don't know about the 50,
and have never seen a 52 elevator, so I'm afraid I can't be of much help
here.
Doug
On Mon, Mar 28, 2011 at 2:18 PM, Walter Lannon <wlannon@persona.ca> wrote:
> Hi Cliff;
>
> The self-aligning bearing is there to compensate for any minor
> mis-alignment in the assembly of the sector to the rear spar attach fitting
> with the left & right elevators attached
> to the sector.
>
> It will have no effect whatever on the any twisting/bending moments induced
> in the upper (thicker) part of the sector. Those loads are transmitted to
> the thinner (7mm) section which is firmly bolted to both elevators through
> the attachment plates.
> These plates are substantial and very effectively increase the bending
> resistance of the sector in the area just below the section change. This of
> course further defines the focal point for cracking at the section change by
> eliminating any flexure below that point.
>
> For the universal bearing to have any effect the entire elevator assembly
> would have to translate laterally.
>
> Sorry. I think it is a very poor design and probably dictated by a lack of
> space in that area.
>
> The CJ is quite different. The balance arm is attached to the primary
> structure of the elevator assy.
> I would expect the CJ system is a direct copy of the earlier Russian
> systems.
> Jump in Doug -- how is the Yak 18 done?
> Anyone know the Yak 50, Yak18A systems?
>
> Cheers;
> Walt
>
>
> ----- Original Message -----
> *From:* Cliff Coy <cliff.coy@gmail.com>
> *To:* yak-list@matronics.com
> *Sent:* Monday, March 28, 2011 6:39 AM
> *Subject:* Re: Yak-List: Yak-52 elevator failure
>
> *Yes, the area of concern is below where the counterweight arm attaches to
> the elevator bell crank.
>
> The engineering is very sound for this location.
> The bellcrank is mounted on a self aligning bearing to allow for twisting.
>
> Mass balancing the elevator at the center allows for the horizontal
> stabilizer structure to be smaller and lighter. The aircraft is already
> tough to recover from flat spins so adding any more weight that far away
> from the center of rotation isn't such a good idea.
>
> The original designers and engineers of this aircraft had many choices for
> this and everything else on the aircraft. There are good reasons why they
> chose this design.
>
> **These aircraft are in the "Experimental" catagory in the U.S. and as
> such we see a lot of modifications in which the owner or U.S. mechanic makes
> an "improvement" to the design only to find out down the road that this
> improvement detrimentally affects the performance and/or safety of the
> aircraft.
>
> Fuel flow transducers that critically reduce the fuel supply to the carb,
> Air Tool oil into the pneumatic system which washes the grease out of the
> system,
> and Plugging the accelerator pump in the carburetor, to name a few.
>
> **Replacing the arm with one manufactured from steel may also run into the
> "Law of Unintended Consequences".
> For instance, the center bearing mentioned above is pressed into the arm-
> an easy and common practice when dissimilar metals are involved but not so
> easy when they're both made of steel.
>
> **As I've said before, I'm glad there is an alternative available but I'm
> more curious as to the root cause of the failures involved. If it's due
> more to metallurgy then I'm gung ho for an alternate but, if it's due to
> other reasons (ie. mis-rigging), then I'm not.
>
> Best regards,
> Cliff
>
> *
> *
>
>
> *
> On Sun, Mar 27, 2011 at 17:47, Walter Lannon <wlannon@persona.ca> wrote:
>
>> Hi Cliff;
>>
>> Thanks for your reply. There seems to be a bit of confusion re this part.
>> It is not a control balance arm which would typically extend well forward
>> of the control surface hinge line.
>>
>> This is the elevator control cable drive sector (bellcrank).
>> It appears to have weight mounted on it directly above the hinge centre
>> line.
>> That would have absolutely zero effect on elevator balance if the weight
>> is mounted where the attachment holes are located.
>> But, I am beginning to get the picture!!!!!!! Is this the mounting
>> location for the balance ARM?
>>
>> If so that takes my concern to a whole new level. That would be the
>> absolutely dumbest place you could possibly imagine to attach a balance arm.
>>
>> Not only does the sector have to handle the balance weight the effect is
>> severely magnified by the length of the arm.
>> The cause of this cracking I believe is a direct result of that
>> installation.
>> Any asymmetrical rudder loads will induce horizontal loading of the
>> ELEVATOR balance weight which will in turn
>> induce a twisting moment in the elevator sector.
>> Over (who knows how) many cycles this will result in a fatigue failure at
>> the most likely focal point. Barring a severe nick or other mechanical
>> damage that point is the section change.
>>
>> Now I begin to understand why they are suggesting a STEEL replacement.
>>
>> Walt
>>
>> PS:
>> ---- Original Message -----
>>
>> *From:* Cliff Coy <cliff.coy@gmail.com>
>> *To:* yak-list@matronics.com
>> *Sent:* Sunday, March 27, 2011 12:58 PM
>> *Subject:* Re: Yak-List: Yak-52 elevator failure
>>
>> *This is the elevator counter balance arm.
>> The elevators, as well as the ailerons, are mass balanced controls.
>> The rudder is both mass balanced and aerodynamically balanced.
>>
>> If you're not already familiar with aircraft control design, here is a
>> good primer on aircraft:
>>
>>
>> http://www.centennialofflight.gov/essay/Theories_of_Flight/control/TH28.htm
>>
>> Best regards,
>> Cliff
>> *
>> On Sat, Mar 26, 2011 at 23:16, Walter Lannon <wlannon@persona.ca>wrote:
>>
>>>
>>> Possibly. The crack is originating at the section change where loads
>>> would tend to concentrate but it may also be subject to bending loads from
>>> the balance weight attached to the upper, heavier, section.
>>> Possibly rudder induced transverse loading?
>>> I don't understand the use of a balance weight in this location.
>>> Walt
>>> ----- Original Message ----- From: "William Halverson" <
>>> william@netpros.net>
>>>
>>> To: <yak-list@matronics.com>
>>> Sent: Saturday, March 26, 2011 4:21 PM
>>>
>>> Subject: Re: Yak-List: Yak-52 elevator failure
>>>
>>>
>>>> >
>>>>
>>>>
>>>> Well, the part is cracking on the upper side ... would it be due to
>>>> aggressive pull back forces on the stick?
>>>>
>>>>
>>>> +-----Original Message-----
>>>> +From: Walter Lannon [mailto:wlannon@persona.ca]
>>>> +Sent: Saturday, March 26, 2011 04:00 PM
>>>> +To: yak-list@matronics.com
>>>> +Subject: Re: Yak-List: Yak-52 elevator failure
>>>> +
>>>> +Interesting!
>>>> +
>>>> +How much weight is attached to this part? And for what purpose?
>>>> +
>>>> +Walt
>>>> + ----- Original Message ----- + From: pilko2
>>>> + To: yak-list@matronics.com
>>>> + Sent: Saturday, March 26, 2011 5:25 AM
>>>> + Subject: FW: Yak-List: Yak-52 elevator failure
>>>> +
>>>> +
>>>> +
>>>> +
>>>> + Trawling the website of Yak UK reveals this to be a well known
>>>> gotcha.
>>>> +
>>>> +
>>>> +
>>>> + http://www.yakuk.com/2000-004.doc
>>>> +
>>>> +
>>>> +
>>>> +
>>>> +
>>>> +
>>>> +
>>>> + MPD: 2000-004
>>>> +
>>>> +
>>>> + Subject: Crack in elevator control system pulley.
>>>> +
>>>> +
>>>> +
>>>> + Applicability: Yakovlev/ Aerostar or a SA Y B AK 52 aircraft.
>>>> +
>>>> +
>>>> +
>>>> + Reason: A 19 mm crack has been discovered in the elevator actuation
>>>> part number 5251 or 00-80-3 (referred to as "lever" in the Romanian parts
>>>> catalogue). The failure of this component could result in loss of the
>>>> elevator control.
>>>> +
>>>> +
>>>> +
>>>> + Compliance: Within 50 hours from the effective date of this MPD,
>>>> inspect elevator actuation pulley parts number 525100-80-34 cracking on its
>>>> periphery below the attachment for the balance weight bracket, at the point
>>>> where the section reduces from a 10 mm to 7 mm. Inspect using dye penetrant
>>>> techniques. if the component is cracked, replace it before Further Flight.
>>>> Repeat this inspection annually at renewal of the permit to fly.
>>>> +
>>>> +
>>>> +
>>>> +
>>>> +
>>>> +
>>>> +
>>>> +
>>>> +
>>>> +
>>>> +
>>>> +
>>>> http://www.matronics.com/Navigator?Yak-Listhttp://forums.matronics.comhttp://www.matronics.com/contribution
>>>> +
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>
>>> ==========
>>> rget="_blank">http://www.matronics.com/Navigator?Yak-List
>>> ==========
>>> http://forums.matronics.com
>>> ==========
>>> le, List Admin.
>>> ="_blank">http://www.matronics.com/contribution
>>> ==========
>>>
>>>
>>>
>>>
>>
>>
>> --
>> Clifford Coy
>> Border Air Ltd.
>> 629 Airport Rd.
>> Swanton, VT 05488
>> 802-868-2822 TEL
>> 802-868-4465 FAX
>> Skype: Cliff.Coy
>>
>> *
>>
>> *
>>
>>
>
>
> --
> Clifford Coy
> Border Air Ltd.
> 629 Airport Rd.
> Swanton, VT 05488
> 802-868-2822 TEL
> 802-868-4465 FAX
> Skype: Cliff.Coy
>
> *
>
> *
>
>
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