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1. 06:32 AM - Re: Twisted Yak 52 Airframe (Jean-Philippe Martel)
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| Subject: | Re: Twisted Yak 52 Airframe |
=F0=9F=98=82=F0=9F=98=8A
Le 26 mars 2017 01:54, "William Geipel" <l129bs@gmail.com> a =C3=A9crit :
> Pull 10g in the other direction. It will probably twist back. All good.
> Tape the charts to the windshield; keeps the sun out and they don
=99t blow
> away as often. Slide the chart into the crack.
>
> OR buy a CJ. They have so many issues that you won=99t notice that
you=99re
> twisted and flying sideways.
>
> Just a thought.
>
> On Mar 25, 2017, at 18:09, Roger Kemp <f16viperdoc@me.com> wrote:
>
> Paddles,
> You are doing better than me on paper charts. With the canopy cracked I
> can't keep them in the cockpit.
> Doc
>
> Sent from my iPad
>
> On Mar 25, 2017, at 9:47 AM, Mark Davis <markdavis@wbsnet.org> wrote:
>
> I don't know if you can twist a YAK52 airframe without running over it
> with a Russian tractor, mine has more rivets on it than the USS Missouri.
> I've been told two things about YAK 52 airframes, but I can't verify
> their accuracy. One, there has never been an inflight failure of a YAK 5
2
> airframe. Two, that the Soviets/Russians design their aircraft such that
> airframe failure shouldn't occur before twice the G limit of the aircraft
> vs. 1.5 times the G limit for U.S. certified aircraft. Therefore, even a
> +5/-3 airframe wouldn't fail before +10 g's, most will stall long before
> that or the pilot will be GLOC'd and not know the difference. Early in
> their history the YAK Design Bureau obviously saw an issue with the
> airframes and performed the modification to raise the limits to +7/-5 g's
.
> There are others who watch this list who may chime in the specifics.
>
> You may be onto something if one aileron has the fabric holes uncovered,
> but any drag would more likely be fixed by tweaking the rudder trim tab a
nd
> putting the ball in the center. Any airflow disruption would more likely
> cause a change in the effectiveness of aileron itself by disturbing the
> boundary layer. But, that big chunk of wood on the front of the YAK that
> the Russians call a V530 propeller creates so much P factor that any chan
ge
> in power settings or RPM noticeably changes roll trim on my YAK. So I tr
y
> to trim mine for a typical 70% rpm 125-130 KTAS cruising speed for cross
> country flights and live with the slightly out of trim one way or the oth
er
> aileron control pressures the rest of the time. Otherwise, seek out a
> cheap electric trim system or do what I do and make my wife take the stic
k
> for a few minutes if I'm trying to refold a sectional on a cross country.
> I may be the last dinosaur out there without ForeFlight that still keeps
a
> paper sectional in the airplane....and everywhere I go I have to either
> flip the chart or refold as I go from seam to seam.... : )
>
> Mark Davis
> N44YK
>
>
> *From:* owner-yak-list-server@matronics.com [mailto:owner-
> yak-list-server@matronics.com <owner-yak-list-server@matronics.com>] *On
> Behalf Of *Phillip Salter
> *Sent:* Saturday, March 25, 2017 7:36 AM
> *To:* yak-list@matronics.com
> *Subject:* Re: Yak-List: Twisted Yak 52 Airframe
>
> Mark,
>
> You peaked my interest in twisted airframes. I have contacted a few Yak
> folks and the common answer, spoke to how aircraft are set up during
> assembly, rather than a twist. Of course anything is possible, but twisti
ng
> a Yak airframe would take serious abuse, and most likely over G. The Yaks
> only have 4 deg of dihedral and are neutrally stable for aerobatic purpos
es
> so it does not take much to change from stabile flight to a slight roll o
ne
> way or the other. I talked with Yak owner who is an aeronautical engineer
> and his suggestion for my plane is to cover the lighting holes behind the
> right aileron first. This plane flew mostly hands off when I got it but i
t
> changed. The fabric covering the lightning holes came off which may be
> causing drag on the right wing from turbulence. My aircraft was not an
> aerobatic club plane, it was Romanian Military which I was told is a
> better or less aggressive service for the Yaks.
>
> Do you by chance know what actually twists on the Yak airframe?
> Measurements may be the answer to find a twist.
>
> Regards,
>
>
> Phil
>
> -----Original Message-----
> From: Mark Davis <markdavis@wbsnet.org>
> To: yak-list <yak-list@matronics.com>
> Sent: Fri, Mar 24, 2017 7:11 pm
> Subject: Re: Yak-List: Twisted Yak 52 Airframe
>
>
> With 4 degrees of dihedral, bending one a little might help with
> stability! I can tweak trim tabs and get close, but power changes due to
> fuel or passenger weight will change it enough that a wing is always goin
g
> to drop. The Soviets must have stolen the stability characteristics of an
> A-4 and applied them at the Yakovlev Design Bureau. They forgot to steal
Mr
> Heinemann's electric trim system design for the Scooter....
>
> Fly Navy,
> Mark Davis
>
> Sent from my iPhone
>
> > On Mar 24, 2017, at 5:29 PM, PS <psalter@aol.com> wrote:
> >
> >
> > Many of the Yaks that came out of Russia after the fall had been twiste
d
> by the aerobatics clubs. If you can get it to fly straight and level in
> cruise, let me know.
> >
> > I received the above email concerning my Yak. I have been involved and
> owned Yaks over 17 years, and never heard anyone mention a "twisted" Yak.
> Is there any validity to this? Being an nearly 0 deg dihedral aircraft, i
s
> a Yak 52 ever totally stable? My aircraft flies great but has a slight ro
ll
> to the right, so minor I never worry about it.
> >
> > Regards,
> >
> > Phil
> >
> > --------
> > Phil
> >
> >
> >
> >
> > Read this topic online here:
> >
> > http://forums.matronics.com/viewtopic.php?p=467584#467584
> >
> >
> >
> >
> >
> >
> >
> >
> >
>
>
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