Today's Message Index:
----------------------
1. 01:10 AM - Yak 18T parts (Anthony Hudacek)
2. 06:50 AM - Things (Bill Geipel)
3. 06:53 AM - Re: FW: Update on Doug and Kathleen Sapp (Bill Geipel)
4. 07:22 AM - =?utf-8?B?UmU6IFlhay1MaXN0OiBUaGluZ3M=? (=?utf-8?B?bXllcnNmQGNvbWNhc3QubmV0?=)
5. 07:38 AM - Re: Yak-52 Fuel Tanks. (Etienne Verhellen)
6. 08:27 AM - turn-back, props, drag, glide, feathering (Brian Lloyd)
7. 08:28 AM - Re: FW: Update on Doug and Kathleen Sapp (Brian Lloyd)
8. 08:36 AM - Re: FW: Update on Doug and Kathleen Sapp (Brian Lloyd)
9. 08:52 AM - Re: turn-back, props, drag, glide, feathering (Brian Lloyd)
10. 08:52 AM - Re: Yak 18T parts (A. Dennis Savarese)
Message 1
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Hi all,
-
Does anyone know where you can buy the turnbuckles that hold the wing root
covers together for an 18T.
-
Ant.
Message 2
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And u shut the mags off on your yak? I would advise against it. But u r a gr
own up.
It depends on the airplane to be sure. It was never mentioned. I am sure tha
t some twins won't windmill at lift off speed.Got the T shirt. I am also sur
e that when the engine seizes it won't windmill, and I am equally sure that a
t that speed and altitude, u may not have a chance to feather it. Sure, once
u reach 400' u have options. But the engine may not have read the same game
plan as u. Many light twins need to be windmilling to feather.
..
Bill
On Jun 27, 2011, at 11:15 PM, Brian Lloyd <brian@lloyd.com> wrote:
>
>
> On Mon, Jun 27, 2011 at 6:20 PM, Bill Geipel <czech6@mesanetworks.net> wro
te:
> What does caging the dead engine mean? If it's dead, you have lost the abi
lity to Feather it haven't you?
>
> No. A dead engine that is producing zero power is still providing a load o
n the windmilling propeller. If it is windmilling, you can feather it. If it
is NOT turning you can't feather it but then, if it is not windmilling, it i
s producing much less drag anyway. A stalled airfoil is producing much less d
rag than an airfoil that is producing lift near the critical AoA.
>
> Doubtful that is windmilling at takeoff speed.
>
> Oh yes, it will windmill at takeoff speed! Try it in your Yak or CJ. Slow d
own to take-off speed and pull the throttle to idle. I betcha the prop keeps
turning. If you aren't sure, turn the mags off for a couple of seconds. I p
romise you that the prop won't stop.
>
> --
> Brian Lloyd, WB6RQN/J79BPL
> 3191 Western Dr.
> Cameron Park, CA 95682
> brian@lloyd.com
> +1.767.617.1365 (Dominica)
> +1.916.877.5067 (USA)
>
>
>
==========================
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=========
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=========
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=========
>
Message 3
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| Subject: | Re: FW: Update on Doug and Kathleen Sapp |
One other point. I believe your runway abort point in a twin is called V1.
Bill
On Jun 27, 2011, at 8:00 PM, Walter Lannon <wlannon@persona.ca> wrote:
> While I have no experience with light twin feathering systems I am sure fe
athering is available with a "dead" engine.
> It most certainly is in the larger twins and multi's. Oil pressure is por
vided by a totally seperate, electrically driven, feathering pump. Some ins
tallations even include a seperate feathering oil supply.
>
> Whether the prop is windmilling or stopped it is producing a whole lot of u
ndesireable drag
>
> Walt
> ----- Original Message -----
> From: Bill Geipel
> To: yak-list@matronics.com
> Sent: Monday, June 27, 2011 6:20 PM
> Subject: Re: Yak-List: FW: Update on Doug and Kathleen Sapp
>
> What does caging the dead engine mean? If it's dead, you have lost the abi
lity to Feather it haven't you? Doubtful that is windmilling at takeoff spee
d.
>
> Bill
>
>
>
> On Jun 27, 2011, at 1:22 PM, Brian Lloyd <brian@lloyd.com> wrote:
>
>> On Sun, Jun 26, 2011 at 9:07 PM, Tom Elliott <N13472@aol.com> wrote:
>> The only possibility was a
>> small clearing to the right as Doug at 300-400' agl could not turn back.
>>
>> This is not a criticism of Doug but Hal's posting just reminded me of thi
s.
>>
>> I have experimented with the turn-back maneuver in various different airc
raft. I found that with some aircraft, turn back at 400agl is not only possi
ble but provides comfortable margin. With others (most notably the Yak-52 an
d CJ6A) turn back is not possible from ANY altitude. (Turn-back to land down
wind may be possible from some point after the beginning of the turn to cros
swind and possibly in the turn to downwind in the CJ/YAK. I haven't practice
d this ... yet.) (A stopped-prop helps immensely.)
>>
>> Bottom line: it is worth checking out with any airplane you fly. And if y
ou know the appropriate altitudes, you can put them in your take-off go/no-g
o list. Mine has two: abort point on the runway and turn back point/altitude
for singles. For gliders they are the turn-back point (downwind landing), a
bbreviated pattern point (midfield turn to land without running off the end)
, and normal turn-back point (from which a normal pattern can be completed).
>>
>> In a twin you have to also include the point in the take-off where you ha
ve enough altitude and airspeed to safely cage the dead engine and proceed s
ingle engine. Failure to reach that point means engine failure is the same a
s engine failure in a single -- you are going down. Period. I refer to the s
ection of take off from the time I pass my runway abort point to the safe al
titude/airspeed to proceed single-engine as the "dead zone". :-)
>>
>>
>>
>> --
>> 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 4
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Message 5
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| Subject: | Re: Yak-52 Fuel Tanks. |
1. Hi Doc, Yeah, new fuel tanks (from Jill- with Thanks) fitted. :D
But if the owner of the tanks sitting in the back of your hangar makes
up his mind quickly, I have a friend in the UK who is looking for Right
hand tank for his 52 but who is willing to replace both and so looking
for a good pair ! Contact me off-list at : janie@yak52.fr and I will give
you his details. Good luck with the work on your 50 ! Replacing the
engine !!!! Ahhhh ... the "joy" of owning and operating a Yakovlev flying
machine. ;-)
2. Hi Bill ! YES, smoke in the cockpit WAS a problem during Airshow flying,
especially at low speed/high angle of attack ! [Evil or Very Mad]
As you have noticed on pictures :
http://www.aviacioncr.net/foto.php?id=17925
http://www.airport-data.com/aircraft/photo/129004.html
http://forums.matronics.com/download.php?id=8504
http://forums.matronics.com/download.php?id=8505
http://forums.matronics.com/download.php?id=8506
http://forums.matronics.com/download.php?id=8507
Etc ...
But problem has been fixed ! [Idea]
http://www.jetphotos.net/viewphoto.php?id=6674723
http://www.abpic.co.uk/popup.php?q=1193448
http://www.militaryaircraft.de/pictures/military/aircraft/Yak-52/Yak-52_SANICOLE2009_301_800.jpg
http://www.militaryaircraft.de/pictures/military/aircraft/Yak-52/Yak-52_SANICOLE2009_303_800.jpg
http://forums.matronics.com/download.php?id=8502
http://www.matronics.com/photoshare/tis1_verod@scarlet.be.11.12.2008/Break.jpg
http://tagazous.free.fr/affichage2.php?img=16960
http://www.sgkoksijde.be/pictures/foto/2010/Sanicole%20airshow%202010/imagepages/image127.html
(also some magnificient Aerostars photos with their Yaks 50). Etc ... etc ...
Now only getting (a little bit) smoke during Lomcevaks and flat spins :
http://youtu.be/nEp-WMjJdvw
Nice video. The "Yak bit" on the video above is from 05:40 ...
So, Exhaust extensions fitted = less smoke (and CO2) inside 8)
But a reduction of 5 kph when going places ... [Exclamation] [Exclamation]
"C'est la vie !" as we say overhere !
Cheers, Etienne.
--------
http://www.flyforfun.be/?q=yaks
http://www.planecheck.com/eu/index.asp?ent=dv&id=6711
http://www.airshowactionphotography.com/san07/page1.html
http://www.irishairpics.com/photo/1029467/L/Yakovlev-Yak-52/G-CBSS/Etienne-Verhellen/
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=344436#344436
Attachments:
http://forums.matronics.com//files/2010_05_15_tom_houquet_10_942.jpg
http://forums.matronics.com//files/yak52_143.jpg
Message 6
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| Subject: | turn-back, props, drag, glide, feathering |
(This needed a new thread.)
On Wed, Jun 29, 2011 at 6:48 AM, Bill Geipel <czech6@mesanetworks.net>
wrote:
> And u shut the mags off on your yak? I would advise against it. But u r a
> grown up.
>
It is far easier than moving the mixture to idle cut-off to ensure that the
engine is not making power. ;-)
I m? Darn. :-)
I suspect that you are right that most have not turned off the mags in
flight. I certainly don't make a habit of it but it is useful to see what
the behavior of the airframe is when the engine is truly producing zero
thrust. This is one of those things like practicing the turn-back maneuver.
You don't really know what is going to happen until you try it. There are
other ways to ensure the successful completion of the flight should the
engine fail to restart. I do real engine-out practice directly over a very
large runway (McClelan is 300'x12,000') so that if the engine doesn't
restart, a dead-stick landing is a non-event.
(I have made multiple dead-stick landings both intentionally AND
unintentionally in my flying career. There is no teacher like experience.)
> It depends on the airplane to be sure. It was never mentioned. I am sure
> that some twins won't windmill at lift off speed.Got the T shirt.
>
I am sure it is possible. There are [almost] always exceptions. The ones I
have flown don't want to stop turning at any rational speed, i.e. some
reasonable value above stall and/or Vmc. If they did, a feathering prop
wouldn't really be needed.
> I am also sure that when the engine seizes it won't windmill,
>
That is true and at that point the propeller airfoil is deeply stalled and
producing very little drag so the point is moot. Now the drag is from the
frontal area of the blades and not from the disk area.
> and I am equally sure that at that speed and altitude, u may not have a
> chance to feather it.
>
Yes, that is why I mentioned the "dead zone".
> Sure, once u reach 400' u have options.
>
It varies with the aircraft and it varies with energy. In the case of my
Aztec the magic "go" numbers are 100 and 100. If I have 100' AGL and 100mph
on the clock, I have sufficient energy to deal with a failed engine, i.e. to
feather and clean up the airframe for continued flight on one engine. If I
am faster I don't need as much altitude. If I have more altitude I can fudge
on the airspeed. One of my take-off call-outs is, "100 and 100, we are good
to go one one."
> But the engine may not have read the same game plan as u. Many light twins
> need to be windmilling to feather.
>
That is true but that was not the issue. If the engine isn't turning,
feathering isn't really needed. The deeply stalled prop does not produce
nearly the drag of a windmilling prop. This started out as a turn-back
discussion. Aircraft with constant-speed props are at a distinct
disadvantage. In fact, I have never found an aircraft with a constant-speed
prop that I felt I could safely execute the turn-back maneuver from any
altitude while on upwind on climb-out from take-off. I need to be either on
cross-wind or, worst-case, after turn to downwind. When teaching transition
to the CJ6A I point out that the earliest that the pilot can make it back to
the runway after engine failure is after the turn to downwind. From that
point it is possible to make it to a downwind landing on the runway. I am
currently flying a YAK-52 with the 400hp engine and large 3-bladed MT prop.
I have yet to figure out from where in the pattern I CAN make the field if
the engine quits making power. Pulling the prop back to corse pitch is the
only possibility for reducing drag enough to make the field.
Now this does bring up another possibility and you more-or-less allude to
it. If the prop is stopped, drag decreases markedly. I would like to suggest
trying to see what happens to the glide ratio of a Yak or CJ if one could
get the prop to stop turning, but at that point it could be difficult to get
a restart thus making a dead-stick landing a necessity. I know that, if I
had an engine that completely packed it in but was still turning, i.e.
windmilling prop, if I didn't have a clear landing spot already made I would
probably stall the aircraft in an attempt to get the prop to stop turning in
order to increase my glide ratio. This would be a desperation maneuver on my
part because I have no experience flying either Yak-52 or CJ6A with a
stopped prop. Still, If the choice is the trees or a field beyond, I would
definitely try it. The outcome can't be any worse as I would just end up in
the trees anyway.
For those of you who live in SoCal, there is El Mirage dry lake. As a kid I
used to go out and land on the lake and camp out. (I was 17. I had an
airplane. What would you do?) While there I used to try things that I would
never try anywhere else. I practiced dead-stick landings as I could land in
any direction. If I screwed up, I would just roll wings-level and land in
whatever direction I was pointed at the time. No sweat. It also allowed me
to learn how to judge power-off spot landings better. I would suggest going
out and trying to land a Yak and/or CJ there with the prop both stopped and
windmilling to see what the effect on glide ratio is and whether it would be
possible to stop the prop and execute a turn-back maneuver. (I would try a
chandelle in an attempt to trade airspeed, i.e. kinetic energy, for
altitude, i.e. potential energy, and also end up at minimum airspeed where
the prop might stop. Definitely an interesting experiment.)
But I am not you. I find that not many people are comfortable doing some of
the things that I do with airplanes even though I know they are perfectly
safe, as these operations go against conventional wisdom. (This was fodder
for many discussions on this list 10+ years ago back when this was often the
Brian Lloyd/Mike McCoy show.) Examples include practicing shutting off the
engine and making intentional dead-stick landings, practicing the turn-back
maneuver to a landing (for real - but with throttle at idle), 450nm flight
legs in a CJ6A with stock fuel, etc. (The Huosai engine can be operated at
an average 11gph giving 130kts TAS at 11,500', resulting in a no-wind range
with 30min reserve of 430nm. It takes a very small tailwind component to
give a 450nm range.)
--
Brian Lloyd, WB6RQN/J79BPL
3191 Western Dr.
Cameron Park, CA 95682
brian@lloyd.com
+1.767.617.1365 (Dominica)
+1.916.877.5067 (USA)
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| Subject: | Re: FW: Update on Doug and Kathleen Sapp |
On Wed, Jun 29, 2011 at 6:50 AM, Bill Geipel <czech6@mesanetworks.net>wrote:
> One other point. I believe your runway abort point in a twin is called V1.
>
> Bill
>
>
> On Jun 27, 2011, at 8:00 PM, Walter Lannon <wlannon@persona.ca> wrote:
>
> While I have no experience with light twin feathering systems I am sure
> feathering is available with a "dead" engine.
> It most certainly is in the larger twins and multi's. Oil pressure is
> porvided by a totally seperate, electrically driven, feathering pump. Some
> installations even include a seperate feathering oil supply.
>
>
Or an accumulator.
>
> Whether the prop is windmilling or stopped it is producing a whole lot of
> undesireable drag
>
>
Drag is reduced *markedly* when the prop is stopped.
--
Brian Lloyd, WB6RQN/J79BPL
3191 Western Dr.
Cameron Park, CA 95682
brian@lloyd.com
+1.767.617.1365 (Dominica)
+1.916.877.5067 (USA)
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| Subject: | Re: FW: Update on Doug and Kathleen Sapp |
On Wed, Jun 29, 2011 at 6:50 AM, Bill Geipel <czech6@mesanetworks.net>wrote:
> One other point. I believe your runway abort point in a twin is called V1.
>
It is is in turbine powered aircraft. The assumption of V1 is that from that
point a successful take-off and climb is assured with a failed engine. This
is *not *the case with reciprocating-engine-powered light twins which have
the aforementioned "dead zone". The only way to achieve V1 in a light twin
would be to hold it on the ground until well after normal rotation and climb
speed, something that might exceed the normal ratings for the tires and
landing gear.
No, for a short period of time immediately following lift-off most
light-twins have no multi-engine advantage. (There may be in the case of
some aircraft with which I am not familiar or in the case of a very lightly
loaded aircraft but those are special cases that need to be determined by
experiment.) The only recourse is to close the throttle on the good engine
and plan an off-airport landing.
--
Brian Lloyd, WB6RQN/J79BPL
3191 Western Dr.
Cameron Park, CA 95682
brian@lloyd.com
+1.767.617.1365 (Dominica)
+1.916.877.5067 (USA)
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| Subject: | Re: turn-back, props, drag, glide, feathering |
On Wed, Jun 29, 2011 at 7:19 AM, myersf@comcast.net <myersf@comcast.net>
wrote:
> I want chime in here a bit although not too much. As a lurker I hate to
> bring this up but...
>
No problem. Too few people actually think about what they were taught
originally, especially with airplanes. The problem is, what we were taught
may be wrong but the only way to find out is to do something that would be
considered dangerous and/or fatal. Welcome to flight testing. :-)
> It has always been my understanding that constant speed props are different
> whether on singles vs twins. I was taught that and I taught it that way.
>
Ouch! I understand the being taught that way. I have determined that several
things I was taught were wrong. That is why it behooves you as CFI to be
absolutely sure before passing on "knowledge."
>
> When oil pressure goes to zero, singles go to flat, twins go to course.
> Heck, I had to create a lesson plan for it on my CFI-ME or MEI.
>
It depends on the airplane and the prop. Both types of prop exist in both
worlds. Case in point, both the CJ6A and Yak-52 have props that go to course
pitch when oil-p goes to zero. And some twins require oil pressure to force
the prop to feather, implying that they will go to fine pitch (high RPM)
upon loss of oil-p. This is why you really need to know the characteristics
of the specific propeller and governor, even on the same aircraft. And you
might not be able to discern the information from the POH. You might
actually have to call the prop manufacturer or prop overhaul shop to get the
straight poop. (Welcome to transition training. This is why we spend 5 house
in ground school before flying the new airplane.)
>
> Turboprops are different again. Autocoursen, auto feather, garret type
> engine vs Pratt...
>
True. The point is that systems differ between aircraft and even within the
same make and model of aircraft. It pays to know the airplane.
> Now I have been corrected by other pilots about OWT I have perpetuated but
> I am pretty confident on this issue.
>
It is best to find out on a per-aircraft basis. Making assumptions is not a
safe thing to do even if you are attempting to, "err on the safe side."
>
> I don't know Mr Sapp but I think he had an experimental 4 blade prop on his
> plane. If the prop went to flat pitch when the engine failed, drag probably
> really increased even more than if he had the standard fixed found on a
> super cub.
>
That is very likely true. And if it were a constant-speed prop, it would be
worse still.
>
> On the other hand I wouldn't at all be surprised to hear that this prop was
> created to go course on failure or that Mr Sapp pulled the prop to full
> course to get more glide. Either way I think it was a great demonstration of
> airmanship.
>
No question about it. Clearly he kept his head and flew the plane as far
into the crash as possible, thus saving both he and his wife. Good on ya,
Doug!
>
> That plane must have had a lot of power to need a 4 blade prop....
>
Could be. More blades tend to produce more static thrust at the expense of
greater drag in cruise. Greater static thrust means better STOL performance
but at the greater drag results in either higher fuel burn or lower TAS in
cruise. For a bush plane this seems like a reasonable trade-off to me.
--
Brian Lloyd, WB6RQN/J79BPL
3191 Western Dr.
Cameron Park, CA 95682
brian@lloyd.com
+1.767.617.1365 (Dominica)
+1.916.877.5067 (USA)
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| Subject: | Re: Yak 18T parts |
I wonder if they are the same as the turnbuckles on the CJ's wing
section covers? Anthony, can you take a picture of the section of the
panel where the turnbuckle is suppose to go? Maybe we can tell from
that whether they are the same or not.
Dennis
A. Dennis Savarese
334-285-6263
334-546-8182 (cell)
Skype: Yakguy1
www.yak-52.com
On 6/29/2011 3:06 AM, Anthony Hudacek wrote:
> Hi all,
> Does anyone know where you can buy the turnbuckles that hold the wing
> root covers together for an 18T.
> Ant.
>
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