Today's Message Index:
----------------------
1. 12:18 AM - Re: M-14P TBO (Richard Goode)
2. 12:23 AM - YAK55m wing bolt replacement (Steve Geard)
3. 12:25 AM - Re: M14P questions. (Richard Goode)
4. 12:49 AM - Re: M-14P TBO (Looigi)
5. 05:21 AM - Re: one way air valves (emergency system) (Greg Wrobel)
6. 08:46 AM - Re: M14P questions. (HawkerPilot2015)
7. 05:20 PM - Re: M14P questions. (Roger Kemp)
8. 08:10 PM - Re: YAK55m wing bolt replacement (Walter Lannon)
9. 10:15 PM - Re: YAK55m wing bolt replacement (Royden Heays)
10. 11:04 PM - Re: YAK55m wing bolt replacement (Jason Bialek)
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The essential problem is that the Russians were extremely conservative;
working in a "military" environment and trying to employ 300 million people
- hence the very low TBO of these engines. But, those are the official
figures from the manufacturer. We know from experience that if operated
sensibly the engines are good for much longer TBOs. On the other hand, if an
engine is in a Sukhoi in airshow work; operating at 103%; rapid changes of
power settings, then you would be lucky to get more than 500 hours.
But the fundamental international practice is that the original manufacturer
dictates the TBO, and it is extremely rare that another body would give a
conflicting figure. This is particularly true in the USA where the engine is
not certified and is operated "experimentally" and therefore has no formal
TBO figure. So, I would be very surprised if the FAA, or indeed any other
aviation authority, had issued more generous figures for these engines.
Unfortunately, in Europe, we have to obey the original manufacturer's
figures. However, we no longer scrap an engine at 2250 hours but continue to
use them, as long as each component is completely tested and is the
equivalent of a new one.
Richard Goode Aerobatics
Rhodds Farm
Lyonshall
Hereford
HR5 3LW
Tel: +44 (0) 1544 340120
Fax: +44 (0) 1544 340129
www.russianaeros.com
-----Original Message-----
From: owner-yak-list-server@matronics.com
[mailto:owner-yak-list-server@matronics.com] On Behalf Of Looigi
Sent: 14 February 2017 03:01
Subject: Yak-List: M-14P TBO
Hi All,
I am starting a new thread because I don't want to hijack any of the others
here. I know I am opening an old debate and I have also searched old posts
but I have not found what I am looking for.
I am trying to find some documentation on the M-14P overhaul periods on a
Yak-52 to satisfy our New Zealand CAA. I have been told that paper work
exists to backup TBO's other than the 750 + 500 + 500 + 500, scrap at 2250
hours that is 'popular' here. Other guys here have managed to get TBO's
past them with 2250 hours between overhauls! In the absence of
manufacturers data the CAA seem to believe Wikipedia, not that they can show
me any manufacturers data to back that up either!!
They have said that if I can get a copy of an FAA approved Maintenance
Program with longer TBO's they would accept that.
Does anyone have a copy of such an FAA approved program that they would be
willing to share please?
Is there any other information available that looks credible with longer
TBO's?
Many thanks in advance
Chris
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=466156#466156
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| Subject: | YAK55m wing bolt replacement |
Hello all my 1992 YAK55m has 440 hours on it and is showing signs of play in both
the front and rear wing attachments.
Has anyone done a replacement of wing bolts?
We're thinking if we reamed the holes oversize and bush them back to standard size
all we need to do is refit original type bolts, also any future repair means
replacing bush only.
Also does anyone know what the attachments castings are made from :-)
And whats the maximum oversize we can bore out to?
Cheers Steve.
Life's short fly aerobatics.
--------
SteveO
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=466164#466164
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Not true! As I wrote before, the port is for an intended modification
for a centrifugal oil filter. But the more recent electric start
conversion uses the mountings for the port, simply because they are
convenient and in the right place.
Richard Goode Aerobatics
Rhodds Farm
Lyonshall
Hereford
HR5 3LW
Tel: +44 (0) 1544 340120
Fax: +44 (0) 1544 340129
www.russianaeros.com
From: owner-yak-list-server@matronics.com
[mailto:owner-yak-list-server@matronics.com] On Behalf Of Roger Kemp
Sent: 14 February 2017 01:52
Subject: Re: Yak-List: M14P questions.
The large port on the nose case was for an electric starter.
Series two cylinders have varying length fins for better cooling as I
understand. They are apparently interchangeable since I have seen
engines with a mix. Well maybe the assembler in St. Elsewhere was cheap
and lazy.
Doc
Sent from my iPad
On Feb 12, 2017, at 10:45 PM, Walter Lannon <wlannon@shaw.ca> wrote:
A couple of questions for the M14P experts on the list. Doing some
work on a Series 2 engine and mystified by a couple of changes
from the earlier model. Can anyone enlighten me?
1. What is the purpose of the large access port in the LH side of the
nose case.
2. Significant changes to cylinder fin design. Presumably to improve
cooling efficiency yet appears to reduce rather than increase cooling
area.
Many thanks;
Walt
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Thanks for that Richard.
Can you point me at some data on using the engine beyond the 2250 hours I can beat
our CAA about the head with please?
Cheers
Chris
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| Subject: | Re: one way air valves (emergency system) |
Morning Jon. Don't feel bad I am having same issue. One other time, I had
this happen it WAS the emergency check valve as Ernie describes on the
starboard firewall. My emmergency air would then hold forever and then for
no apparent reason it would bleed to 30 atms in the first 24 hours and 24
hours later be at 0. I rebuilt the emmergency valve again but no change. I
was told the other day to also check my gages so today I'm pulling the
right panels and putting the leak check at the gages. I'll let you know if
I find anything. Last week I rebuilt and/or replaced all 6 check valves on
the firewall, all gear locks, 8 diverted valves, compressor banjo fitting,
air drier and over pressure regulator. What an eye opener!
On Feb 13, 2017 14:18, "Jon Boede" <jonboede@hotmail.com> wrote:
> My emergency air system on a stock CJ goes up *and down* with the main
> air pressure.
>
>
> This is a recent development. So I changed out all the one-way air valves
> on the firewall and that didn't stop it.
>
>
> Is there a one-way valve for the emergency air system, not forward on the
> firewall, that I missed?
>
>
> Or is there another reason the emergency air system would bleed down? The
> emergency air valve hadn't been touched at any time around when this
> started happening.
>
>
> Jon
>
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| Subject: | Re: M14P questions. |
I like the gun story...so I am going with that.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=466175#466175
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| Subject: | Re: M14P questions. |
Copy Richard. The engines I have seen came with TWs and the Americanized 52
W. Was not intending to cast doubt.
Doc
Sent from my iPad
> On Feb 14, 2017, at 2:25 AM, Richard Goode <richard.goode@russianaeros.com
> wrote:
>
> Not true! As I wrote before, the port is for an intended modification for a
centrifugal oil filter. But the more recent electric start conversion uses t
he mountings for the port, simply because they are convenient and in the rig
ht place.
>
> Richard Goode Aerobatics
> Rhodds Farm
> Lyonshall
> Hereford
> HR5 3LW
>
> Tel: +44 (0) 1544 340120
> Fax: +44 (0) 1544 340129
> www.russianaeros.com
>
> From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@ma
tronics.com] On Behalf Of Roger Kemp
> Sent: 14 February 2017 01:52
> To: yak-list@matronics.com
> Subject: Re: Yak-List: M14P questions.
>
> The large port on the nose case was for an electric starter.
> Series two cylinders have varying length fins for better cooling as I unde
rstand. They are apparently interchangeable since I have seen engines with a
mix. Well maybe the assembler in St. Elsewhere was cheap and lazy.
> Doc
>
> Sent from my iPad
>
> On Feb 12, 2017, at 10:45 PM, Walter Lannon <wlannon@shaw.ca> wrote:
>
> A couple of questions for the M14P experts on the list. Doing some work o
n a Series 2 engine and mystified by a couple of changes
> from the earlier model. Can anyone enlighten me?
>
> 1. What is the purpose of the large access port in the LH side of the no
se case.
>
> 2. Significant changes to cylinder fin design. Presumably to improve c
ooling efficiency yet appears to reduce rather than increase cooling area.
>
> Many thanks;
> Walt
>
>
>
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> believed to be clean.
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| Subject: | Re: YAK55m wing bolt replacement |
Hi Steve;
I have no specific information to offer you on the Yak 55 wing attachment,
only a few general observations:
The wing attach straps are not castings. These are high strength steel
forgings, probably a Russian equivalent of AMS 4340 (or similar) and heat
treated to a minimum UTS (ultimate tensile strength) of not less than
170,000 psi.
The factory manual may allow the use of an oversize bolt (factory supplied)
with rework of the fittings possibly by precision grinding rather than
reaming.
The maximum increase in hole dia. will likely be in the order of 0.25 - 0.5
mm (0.010 - 0.020 in.) A typical maximum clearance between the bolt and
wing fitting would be in the order of 0.05 mm (0.002 in).
If you know a good professional engineer have him do some measurements and
calculate the lower attachment load at your normal (positive) max. "G" load.
He will probably give you a number around 30 ton.
Fly safe;
Walt
-----Original Message-----
From: Steve Geard
Sent: Tuesday, February 14, 2017 12:22 AM
Subject: Yak-List: YAK55m wing bolt replacement
Hello all my 1992 YAK55m has 440 hours on it and is showing signs of play in
both the front and rear wing attachments.
Has anyone done a replacement of wing bolts?
We're thinking if we reamed the holes oversize and bush them back to
standard size all we need to do is refit original type bolts, also any
future repair means replacing bush only.
Also does anyone know what the attachments castings are made from :-)
And whats the maximum oversize we can bore out to?
Cheers Steve.
Life's short fly aerobatics.
--------
SteveO
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=466164#466164
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| Subject: | YAK55m wing bolt replacement |
Hi Steve,
I'm told that the main spar wing and fuselage fittings are titanium.
Those fittings take on an oval shape with long term aerobatic loadings while
the bolt remains perfectly circular at its original diameter.
The fix is to ream the fittings and install over- sized bolts to match.
Reaming titanium is not an easy matter and doing it while keeping the holes
aligned so as not to change the rig is an added challenge. I was told you
need a 17 flute reamer.
There are two ways of getting oversized bolts. One is to build up the
existing bolts and grind them back to the oversize diameter needed. The
other is to order oversized bolts from the Yak 55 factory in Eastern Russia.
As of two years ago Vladimir Yestremi had the equipment and contacts to do
the whole job. I'm not sure if Vladimir is still in that business.
Jill and Carl at M14P also have knowledge of the process. Jill - are you
there - can you please comment?
I did some calcs a couple of years ago as attached. Walt's 30 tons (imperial
tons?) is pretty close to the 28 T (metric tons) I calculated.
I'm not an aircraft engineer and don't stand behind the calcs. But they
certainly convinced me to be very wary of having the right bolt strength.
They are high end bolts that are required.
Hopefully Vladimir reads this and can correct me if needed.
Regards
Royden
-----Original Message-----
From: owner-yak-list-server@matronics.com
[mailto:owner-yak-list-server@matronics.com] On Behalf Of Walter Lannon
Sent: Tuesday, February 14, 2017 8:10 PM
Subject: Re: Yak-List: YAK55m wing bolt replacement
Hi Steve;
I have no specific information to offer you on the Yak 55 wing attachment,
only a few general observations:
The wing attach straps are not castings. These are high strength steel
forgings, probably a Russian equivalent of AMS 4340 (or similar) and heat
treated to a minimum UTS (ultimate tensile strength) of not less than
170,000 psi.
The factory manual may allow the use of an oversize bolt (factory supplied)
with rework of the fittings possibly by precision grinding rather than
reaming.
The maximum increase in hole dia. will likely be in the order of 0.25 - 0.5
mm (0.010 - 0.020 in.) A typical maximum clearance between the bolt and
wing fitting would be in the order of 0.05 mm (0.002 in).
If you know a good professional engineer have him do some measurements and
calculate the lower attachment load at your normal (positive) max. "G" load.
He will probably give you a number around 30 ton.
Fly safe;
Walt
-----Original Message-----
From: Steve Geard
Sent: Tuesday, February 14, 2017 12:22 AM
Subject: Yak-List: YAK55m wing bolt replacement
Hello all my 1992 YAK55m has 440 hours on it and is showing signs of play in
both the front and rear wing attachments.
Has anyone done a replacement of wing bolts?
We're thinking if we reamed the holes oversize and bush them back to
standard size all we need to do is refit original type bolts, also any
future repair means replacing bush only.
Also does anyone know what the attachments castings are made from :-) And
whats the maximum oversize we can bore out to?
Cheers Steve.
Life's short fly aerobatics.
--------
SteveO
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=466164#466164
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Message 10
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| Subject: | Re: YAK55m wing bolt replacement |
Usually forward spar is 80 percent and rear spar is 20 percent. There are load
cases where one wing takes more load than the other when combining rolling loads
with "under G" pitch rate loads. Regardless, important to know what the max
gross we're trying to figure this out for. based on max gross and worst case
maneuvering load we can begin to sneak up on the number the bolt should be
good for.
Jason Bialek
yak55m KAWO
> On Feb 14, 2017, at 9:15 PM, "Walter Lannon" <wlannon@shaw.ca> wrote:
>
>
> Hi Steve;
>
> I have no specific information to offer you on the Yak 55 wing attachment, only
a few general observations:
>
> The wing attach straps are not castings. These are high strength steel forgings,
probably a Russian equivalent of AMS 4340 (or similar) and heat treated
to a minimum UTS (ultimate tensile strength) of not less than 170,000 psi.
>
> The factory manual may allow the use of an oversize bolt (factory supplied) with
rework of the fittings possibly by precision grinding rather than reaming.
>
> The maximum increase in hole dia. will likely be in the order of 0.25 - 0.5 mm
(0.010 - 0.020 in.) A typical maximum clearance between the bolt and wing fitting
would be in the order of 0.05 mm (0.002 in).
>
> If you know a good professional engineer have him do some measurements and calculate
the lower attachment load at your normal (positive) max. "G" load.
> He will probably give you a number around 30 ton.
>
> Fly safe;
> Walt
>
> -----Original Message----- From: Steve Geard
> Sent: Tuesday, February 14, 2017 12:22 AM
> To: yak-list@matronics.com
> Subject: Yak-List: YAK55m wing bolt replacement
>
>
> Hello all my 1992 YAK55m has 440 hours on it and is showing signs of play in
both the front and rear wing attachments.
> Has anyone done a replacement of wing bolts?
> We're thinking if we reamed the holes oversize and bush them back to standard
size all we need to do is refit original type bolts, also any future repair means
replacing bush only.
> Also does anyone know what the attachments castings are made from :-)
> And whats the maximum oversize we can bore out to?
> Cheers Steve.
> Life's short fly aerobatics.
>
> --------
> SteveO
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=466164#466164
>
>
>
>
>
>
>
>
>
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