Today's Message Index:
----------------------
1. 01:35 PM - engine starvation (SRGraham)
2. 01:47 PM - Re: engine starvation (Brian Lloyd)
3. 02:33 PM - Yak-52 World Aerobatic Championship 2012 - FAI Yak WAC 2012. (Etienne Verhellen)
4. 02:49 PM - Re: Yak-52 World Aerobatic Championship 2012 - FAI Yak WAC 2012. (Etienne Verhellen)
5. 09:34 PM - Re: engine starvation (Javier Carrasco)
Message 1
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| Subject: | engine starvation |
Ladies and gents
I have had a problem with what appears to be fuel starvation on two
occasions on my M 14 in the yak 18 T
On both occasions, I was on descent, from approximately 8000 feet, into
CTA.
Both were relatively clear low humidity days. Prop setting moved from
cruise
(usually about 75% as manifold pressure is down around 650 mm at that
altitude and the plane wallows a good deal making IFR tolerances
difficult
to maintain) down to 60%. Manifold pressure dropped to 600 mm. On the
first
occasion carburettor heat wasn't used on the second occasion carburettor
heat was engaged at the top of dissent and was reading 50=B0 C.
All goes well until approximately 6000 feet, and then the rpm begins to
decrease, the engine note changes and we have become a glider.
On the first occasion, carburettor heat was applied, prop was moved to
approximately 80%, throttle moved to approximately the position of 700
mm
induction pressure, and within 5-10 seconds (although I admit it did
feel
longer) the engine is firing perfectly normally. On the second occasion
I
removed carburettor heat, adopted the same manifold and pitch positions,
with the engine starting again within five seconds.
I have not seen this at any other time with this engine in the last 300+
hours of operation, including aerobatics, prolonged cruise, slowing down
dramatically in the circuit to get you out, or on practised forced
landings.
We have not experienced the problem if the descent is actually conducted
a
good deal faster, with prop settings of 75%, and induction pressure at
600
mm or above of around 140- 150 kn indicated but always with the
carburettor
heat applied.
I am aware that some of the Dromader M18 aircraft have experienced
similar
situations, and will suck air through a number of connections of the
fuel
system, in particular passing through the firewall and priming system.
We
are fitted with manifold drains on the lower three cylinders, to drain
being
a spring-loaded mechanism as is common on most oil drains.
Has anyone any thoughts
Dr Stewart Graham MBBS FRACP Consultant Rheumatologist
Prov No. 462449A ABN-79105443463
Main Office: Suite1, 7 High St. Launceston, Tas 7250.
Clinics: Queenstown, King island, Burnie & Devonport
Email: srgrheumatology@bigpond.com Ph: 0363348631 Fax: 0363348547
Message 2
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| Subject: | Re: engine starvation |
On Sun, Dec 18, 2011 at 1:32 PM, SRGraham <sgyak18t@bigpond.com> wrote:
> Ladies and gents ****
>
> I have had a problem with what appears to be fuel starvation on two
> occasions on my M 14 in the yak 18 T
>
In your narrative you did not mention fuel pressure indication. Was it
normal? If you had normal fuel pressure readings and no fluctuations
(indicative of vapor in the fuel system) then I would be looking downstream
of the fuel pressure sensor, i.e. at the carburetor itself.
--
Brian Lloyd, WB6RQN/J79BPL
3191 Western Dr.
Cameron Park, CA 95682
brian@lloyd.com
+1.767.617.1365 (Dominica)
+1.916.877.5067 (USA)
Message 3
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| Subject: | Yak-52 World Aerobatic Championship 2012 - FAI Yak WAC 2012. |
-----------------------------------------------------------------------------------
Yak-52 World Aerobatic Championship 2012 - FAI Yak WAC 2012.
=============================================
After Novosibirsk (Siberia) in 2008 :
http://www.civa-results.com/2008/WYAC08/indexpage.htm
http://www.civa-results.com/2008/WYAC08/wpics_yakwac08.htm
And Rojunai (Lithuania) in 2009 :
http://www.civa-results.com/2009/WYAC09/indexpage.htm
http://www.yakwac.info/users/www/uploaded/2nd%20Yak-52%20WAC%20Rojunai.pdf
FAI (Fdration Aronautique Internationale) will organise the 3rd Yak-52
World Aerobatic Championship in Russia in June 2012 - Yak WAC 2012 :
http://www.civa-results.com/2012/WY52AC_2012/indexpage.htm
http://www.fai.org/civa-events/civa-events-calendar-and-results?id=31506&EventCalendarId=7689
And this the Q Sequence for Yak WAC 2012 :
http://www.fai.org/civa-our-sport/index.php?option=com_phocadownload&view=category&download=4344:2011-yak-52-known-q-sequence&id
Easier Q Sequence than in YakWAC 2008 and YakWAC 2009 :
http://www.wayakc2008.ru/2008-yak-52-known-q-sequence.html
http://www.civa-results.com/2009/WYAC09/Known%20(Q)%20-%20Yak52.jpg
(copy and paste in your browser).
Merry Xmas & HAPPY 2012 !
-------------------------------------------------------------------------------------
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=361159#361159
Message 4
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| Subject: | Re: Yak-52 World Aerobatic Championship 2012 - FAI Yak WAC 2012. |
Merry Xmas & Happy New Year !
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=361160#361160
Attachments:
http://forums.matronics.com//files/merry_xmas_and_happy_new_year_200.jpg
Message 5
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| Subject: | Re: engine starvation |
Hello Stewart, just my 2 cents.
-
I had an issue similar to that, After descending from 6.000 to 2.000 I can
hear the engine surge and then go back to normal.
-
One thing keep your engine temps close to 180 C and not lower on decent by
closing the shutters.
-
Also I had the Autoplug convertion installed and never had this issue again
, but also going back to the temp, one of the Russian Gurus told me that th
at might had been the issue, leting the engine cool down too much.
-
Hope that helps.
-
Javier Carrasco
Yak-55m
--- On Sun, 12/18/11, SRGraham <sgyak18t@bigpond.com> wrote:
From: SRGraham <sgyak18t@bigpond.com>
Subject: Yak-List: engine starvation
Ladies and gents
I have had a problem with what appears to be fuel starvation on two occasio
ns on my M 14 in the yak 18 T
On both occasions, I was on descent, from approximately 8000 feet, into CTA
. Both were relatively clear low humidity days. Prop setting moved from cru
ise (usually about 75% as manifold pressure is down around 650 mm at that a
ltitude and the plane wallows a good deal making IFR tolerances difficult t
o maintain) down to 60%. Manifold pressure dropped to 600 mm. On the first
occasion carburettor heat wasn't used on the second occasion carburettor he
at was engaged at the top of dissent and was reading 50=B0 C.
All goes well until approximately 6000 feet, and then the rpm begins to dec
rease, the engine note changes and we have become a glider.
On the first occasion, carburettor heat was applied, prop was moved to appr
oximately 80%, throttle moved to approximately the position of 700 mm induc
tion pressure, and within 5-10 seconds (although I admit it did feel longer
) the engine is firing perfectly normally. On the second occasion I removed
carburettor heat, adopted the same manifold and pitch positions, with the
engine starting again within five seconds.
-
I have not seen this at any other time with this engine in the last 300+ ho
urs of operation, including aerobatics, prolonged cruise, slowing down dram
atically in the circuit to get you out, or on practised forced landings. We
have not experienced the problem if the descent is actually conducted a go
od deal faster, with prop settings of 75%, and induction pressure at 600 mm
or above of around 140- 150 kn indicated but always with the carburettor h
eat applied.
-
I am aware that some of the Dromader M18 aircraft -have experienced simil
ar situations, and will suck air through a number of connections of the fue
l system, in particular passing through the firewall and priming system. We
are fitted with manifold drains on the lower three cylinders, to drain bei
ng a spring-loaded mechanism as is common on most oil drains.
-
Has anyone any thoughts
-
Dr Stewart Graham MBBS FRACP- Consultant Rheumatologist
Prov No. 462449A ABN-79105443463
Main Office: Suite1, 7 High St. Launceston, Tas 7250.-
Clinics: Queenstown, King island, Burnie & Devonport
Email: srgrheumatology@bigpond.com- Ph: 0363348631- Fax: 0363348547
-
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