genaperevedent(at)yahoo.c
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 Posted: Thu Feb 02, 2006 3:08 pm Post subject: Yak-55/55m gills |
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Russian Maintenanse Schedule has a large section devoted to seasonal maintenanse. Preparations for spring/ summer operation among other items require removal of gills. When gills are removed, don't forget to put fillets to the front inner parts of cawling covers.
Happy summer flying.
Gena P.
[quote] *
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Yak-List Digest Archive
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Total Messages Posted Tue 01/31/06: 33
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Today's Message Index:
----------------------
1. 04:00 AM - Re: Re: Iris Instead of Grills (Craig Payne)
2. 05:07 AM - Re: gear problem (cjpilot710(at)aol.com)
3. 05:33 AM - Re: gear problem (Fraser, Gus)
4. 05:40 AM - Re: Iris Instead of Grills (Fraser, Gus)
5. 06:42 AM - Re: Going after overzealous FedsGoing after overzealous Feds (Valkyre1)
6. 06:51 AM - CJ6A: stations for CG calculation (Brian Lloyd)
7. 06:51 AM - Re: Useful VFR Maps Site (Valkyre1)
8. 06:59 AM - Re: Going after overzealous Feds (Brian Lloyd)
9. 07:14 AM - Re: Useful VFR Maps Site (David McGirt)
10. 07:14 AM - Re: Nuclear waste and Us vs. the Government (was: Radium) [some of you will want to hit delete now] (Valkyre1)
11. 07:22 AM - Re: Iris Instead of Grills (marksorenson)
12. 07:34 AM - Re: Hangars (marksorenson)
13. 07:37 AM - Re: Useful VFR Maps Site (marksorenson)
14. 09:14 AM - CJ (doug sapp)
15. 09:20 AM - Re: CJ6A: stations for CG calculation (cjpilot710(at)aol.com)
16. 09:40 AM - Re: CJ6A: stations for CG calculation (Ernest Martinez)
17. 09:54 AM - Re: CJ (Scooter)
18. 10:50 AM - Re: Iri s Instead of Grills (Scott Kirk)
19. 10:52 AM - Re: Re: Iris Instead of Grills (Bitterlich GS11 Mark G)
20. 10:56 AM - Re: Re: Re: Iris Instead of Grills (Bitterlich GS11 Mark G)
21. 10:57 AM - RedStar S. E. Region Pilots (cjpilot710(at)aol.com)
22. 11:00 AM - Re: Re: CJ (doug sapp)
23. 12:44 PM - Re: CJ6A: stations for CG calculation (Brian Lloyd)
24. 12:44 PM - Re: CJ6A: stations for CG calculation (Brian Lloyd)
25. 01:55 PM - Re: CJ (cgalley)
26. 03:50 PM - Overzealous Feds (Frank Haertlein)
27. 03:50 PM - Fun to fly again (Frank Haertlein)
28. 03:52 PM - Re: Nuclear waste and Us vs. the Government (was: Radium) [some of you will want to hit delete now] (Frank Haertlein)
29. 04:27 PM - Re: Overzealous Feds (Brian Lloyd)
30. 07:28 PM - Check your computers folks. (fraseg)
31. 07:53 PM - Re: 4 sale (Michael Beach Hartwigs Trucks)
32. 08:19 PM - gear retract (jandefinley(at)comcast.net)
33. 09:26 PM - Re: Going after overzealous Feds (fish(at)aviation-tech.com)
________________________________ Message 1 _____________________________________
Time: 04:00:46 AM PST US
From: "Craig Payne"
Subject: Re: RE: Iris Instead of Grills
Mark G wrote:
| Quote: |
I ran them out from the front of the
engine supercharger cover
|
Hmmm, could that be the engine gearbox cover?
| Quote: | (using the same mounting studs that the IRIS would
attach to) HORIZONTALLY to the front cowl ring. Four of them, one every 90
degrees. These acted like spokes on a wheel, and gave back the support that
the original gills had.
Result? Problem cured. No more cowling damage... problem is 100% FIX
|
I too have removed the gills but left the gill outer ring in place with the original
mounting rods. Since I have the C rowder spinner in place now, I'm watching
it all very closely. Another problem I have noticed on cowls without gills
is that the cowl skin UNDER the lower mounting brackets tend to crack through
around the bracket that holds the "donuts" the pins go through. Doublers on the
skin are required.
Craig Payne
________________________________ Message 2 _____________________________________
Time: 05:07:21 AM PST US
From: cjpilot710(at)aol.com
Subject: Re: gear problem
Terry,
Walt makes some good points. But I would check your gear handle valve. Me
thinks, that with the gear working AFTER you've put the handle in neutral
(dumping all pressure), that you may have a problem there in that the face of
the valve may be scratched or corroded allowing pressure to cross even if the
valve moved to the up side.
Also might want to recheck that emergency shuttle valve. If you can sake it
and hea r the valve spring back and forth, it's good. If that valve is not
seated just a little bit, the gear will not re track.
Jim "Pappy" Goolsby
________________________________ Message 3 _____________________________________
Time: 05:33:52 AM PST US
From: "Fraser, Gus"
Subject: RE: gear problem
Emergency shuttle valve gets my vote, I had exactly the same issue and that
was it.
Gus
_____
From: owner-yak-list-server(at)matronics.com
[mailto:owner-yak-list-server(at)matronics.com] On Behalf Of cjpilot710(at)aol.com
Sent: Tuesday, January 31, 2006 8:04 AM
Subject: Re: gear problem
Terry,
Walt makes some good points. But I would check your gear handle valve. Me
thinks, that with the gear working AFTER you've put the handle in neutral
(dumping all pressure), that you may have a problem there in that the face
of the valve may be scratched or corroded allowing pressure to cross even if
the valve moved to the up side.
Also might want to recheck that emergency shuttle valve. If you can sake it
and hear the valve spring back and forth, it's good. If that valve is not
seated just a little bit, the gear will not re track.
Jim "Pappy" Goolsby
bottomMargin=7 leftMargin=7 topMargin=7 rightMargin=7>
Emergency shuttle valve
gets my vote, I had exactly the same issue and that was it.
Gus
From: owner-yak-list-server(at)matronics.com
[mailto:owner-yak-list-server(at)matronics.com] On Behalf Of
cjpilot710(at)aol.com
Sent: Tuesday, January 31, 2006 8:04
AM
Subject: Re: gear
problem
style="BACKGROUND-COLOR: #80ff00">Terry,
style="BACKGROUND-CO LOR: #80ff00">
Walt makes some good
points. But I would check your gear handle valve. Me thinks, that
with the gear working AFTER you've put the handle in neutral (dumping all
pressure), that you may have a problem there in that the face of the valve may
be scratched or corroded allowing pressure to cross even if the valve moved to
the up side.
style="BACKGROUND-COLOR: #80ff00">
Also might want to
recheck that emergency shuttle valve. If you can sake it and hear the
valve spring back and forth, it's good. If that valve is not seated just
a little bit, the gear will not re track.
style="BACKGROUND-COLOR: #80ff00">
Jim "Pappy"
Goolsby
________________________________ Message 4 _____________________________________
Time: 05:40:24 AM PST US< br>From: "Fraser, Gus"
Subject: RE: Iris Instead of Grills
Un the Sukhoi and my SP the whole cowl is MUCH stronger than the standard
50/52 cowl. For example, the front of the cowl is shaped like a wing there
is baffling on the inside of the cowl that gives great strength. Also there
are support arms from all cylinders to the cowl (see attached picture) I bet
you have wondered what those bolts on the front of the cylinder were for,
well guess no more because they are the mounting for the support arms.
The diameter of the cowl opening is also slightly smaller hence the gap on a
52 cowl when the flaps are closed.
Hope this helps
Gus
_____
From: owner-yak-list-server(at)matronics.com
[mailto:owner-yak-list-server(at)matronics.com] On Behalf Of Bitterlich GS11
Mark G
Sent: Monday, January 30, 2006 6:22 PM
Subject: RE: Iris Instead of Grills
Hello Mark,
[b]This is ANOTHER "Mark" so this is bound to get confusing. Tim mentioned my
experience in regard to flying without gills, so I thought I would bring my
experiences in this regard to light.
There have been a number of people who have replaced the gill system with
the IRIS system, and the conversion is fairly simple. One thing to keep in
mind is that there are two different types of systems for controlling the
IRIS. The original system found on most Sukhoi 26's and their ilk used two
cables in semi hard tubes that each fed to a round wheel on the IRIS itself.
In the cockpit there is a control LEVER that pulls on one cable at a time...
obviously as you pull on one cable (and put it into tension) the other moves
backwards and is slack and at that point the wheel on the IRIS pulls keeping
it taught. Just picture two cables attached 180 degrees apart to the outer
rim of a wheel and you'll get the picture.
The newer method (and more preferable by far) is found on the newer SU-31's,
and uses a HARD TUBE PUSH/PULL ROD very close to what controls the original
YAK prop and gills. If you get the NEWER IRIS, you should be able to use
the existing YAK control that comes on the aircraft that used to control
your gills.
Ok, now the bad news.
My YAK-50 came with the Les Crowder big spinner mod. (I mean as in HUGE..
looks good though, and I have been told that this is really a YAK-18T
spinner, but I don't know for sure). Anyway, this mod required all the
gills to be removed.
So, when I originally bought the aircraft, it had 110 hours on it since new,
and away I went... no gills, no problem, who cares anyway?
After about 150 additional hours or so, I started getting all sorts of
cracking on the cowling leading edges. Then the hollow tubes that the front
of the top and bottom cowling are riveted to, started cracking too. This
problem became mor e serious as time went on, because at the same time, the
little red tubes/struts that hold the cowl MOUNTING ring in place started to
crack and break TOO! These are the little adjustable things that bolt to
the front of each cylinder and go straight out to the cowl mounting ring.
At the time, I could not imagine what was causing all this. When my cowl
was closed, it closed fairly firmly on the front cowl ring I just described
above. I thought this might be the problem so I loosened everything up.
Wrong Answer. The problem got worse.
I put soft fabric material between the mounting ring and the cowl ring....
this helped a little, but it could still easily be seen that things were
just vibrating too darn much. I might also mention that my two bladed prop
was also out of balance quite a bit. Balanced the prop.... and that helped,
but did not STOP the problem.
I then got the chance to study a YAK-52 up close and personal , and could see
that those gills added quite a lot of support to that front cowl ring. So,
I made four adjustable struts out of stainless steel tubing.... identical in
design and function to the ones coming straight out from the cylinder
attachment points, but for these... I ran them out from the front of the
engine supercharger cover (using the same mounting studs that the IRIS would
attach to) HORIZONTALLY to the front cowl ring. Four of them, one every 90
degrees. These acted like spokes on a wheel, and gave back the support that
the original gills had.
Result? Problem cured. No more cowling damage... problem is 100% FIXED.
This leads me to advise AGAINST putting an IRIS system on a YAK-50/52,
UNLESS you also take additional steps to support that front cowl ring.
There are a lot of other factors involved here... such as: "What condition
are your engine mounting rubbers in?" Bottom line, the front of the cowls
MUST MOVE WITH THE ENGINE, and if you take out the gills, you basically have
a situation best pictured by imagining a person holding a HULA-HOOP out in
front of himself with outstretched arms. Then picture something/ANYTHING,
"hanging from the hula-hoop itself"... you can see, there just is not any
structural strength in that kind of assembly. Put the gills in, and mount
the gills to the engine itself, and you can see that the above picture
regains all of its strength.
By the bye, this is yet another reason to keep those leather mounting pads
in good condition that are located on the engine itself. These ALSO provide
quite an amount of structural support to the whole upper and lower cowl.
Sorry for the long post, but the details were needed in my opinion.
Mark Bitterlich
N50YK
Here are some other interesting things that I learned the hard way about...
last week!
p.s. Another tid bit for the YAK list. The YAK-52 /50/55 and the
Sukhoi-26/29/31 AND the CJ-6, all use the exact same piston in the
air-compressor relief valve. This piston and seal are what you adjust to
control the peak pressure in your air system in the aircraft. Doug Sapp
sells the whole assy. for the CJ.... and you can take it right apart, take
out the piston and spring (and locking nut) and put the whole mess into your
YAK, if you want to do that instead of repair what you have with a new
rubber bushing. Here's the TID BIT: The YAK-52W (and I am GUESSING the
YAK-52TW as well) has a DIFFERENT PISTON in the pressure relief assy. It is
slightly BIGGER and is NOT a direct replacement with all the others
mentioned earlier. Why not? Go figure.
p.p.s. YAK-52W guys... did you know that there is an emergency pressure
relief valve behind the seat that allows you to eliminate emergency air
pressure to the landing gear without having to crack fittings and jack and
cycle the gear, i f you ever do happen to open the emergency bottle valve?
p.p.p.s. For those aircraft with the manual engine starting valves (YAK-55,
Sukhoi's) be aware that the rubber replacement tab for the starter valve
MUST have a whole cut in the middle of it. Ignore that fact, and the lever
will work a few times and then fail forever. Trust me on this and save
yourself a lot of head scratching.
--
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