L-13 Vivat motorglider
Jon Vedum
We are discussing buying one, so thanks for any comments.
-- Jon
Peter D. Brown
>Does anyone have practical experience with this plane?
>We are discussing buying one, so thanks for any comments.
Jon:
A partner and I investigated the Vivat and I had an afternoon in one in
England two years ago. I am no expert on them at all but here are my
comments:
Engine off I the air, the plane flew pretty much like a Blanik as you
would expect. Its soaring performance is modest but I was able to keep
it up on a pretty lousy English day. The range between min sink and
best L/D was very small, only a few knots if I remember correctly
however, I certainly had fun with it.
Under power at cruise the controls on the one I flew were stiff, almost
to the point of being uncomfortable. I didn’t get much time in cruise
so it may be that this wouldn’t be a problem if I were more familiar
with the plane.
The cockpit control layout was a bit awkward but nothing that you
couldn’t get used to. Gear retraction took a bit of muscle. I liked
the side by side seating and visibility was good.
The engine was one that, as an American, was unfamiliar to me.
Conversations with my English friends indicated that the design has been
around for a long time in eastern Europe and that it is a proven
design. As its an inverted inline, it does throw oil and the magnetos
require regular maintenance to keep them clean from the oil. Parts
availability to date has been good but I have no idea what the future
holds for either the engine or the airframe. Perhaps others more
knowledgeable could comment. Some models now come with a Limbach
engine. Parts may be easier to find for this.
The engine is vulnerable to overheating if the cowl flap setting is
incorrect and engine operating limits are not carefully observed. I
suspect it WOULD NOT make a good club machine because of this.
The fuselage is basically a Blanik from the wings TE aft, split and
widened to accommodate the side by side seating. The wings are
essentially Blanik wings. Overall quality was high, comparable to the
Blanik.
Two or three years ago, PILOT, an English aero magazine, had a good
review of the Vivat by Derrek Piggott. It would be worth your time to
get a reprint of that article.
Its no Stemme but its a lot more affordable and practical as leaving it
outside and assembled is no problem.
--
Pete Brown, ASEL/CFIG N4563C C-170B
Anchorage, Alaska N3864A SGS-1-23G
907-345-7529 (home) 907-564-0223 (fax) Frank Zaic Thermic 18
to reply delete "IHATESPAM"
"Once you have flown, you will walk the earth with
your eyes turned skyward, for there you have been,
there you long to return." -- Leonardo da Vinci.
John Giddy
outlanding checks, and helped with some of the maintenance:
We found that the very heavy undercarriage retraction force was helped
to a large degree if the bowden cables which retract the wing-tip wheels
were disconnected at the fuselage end, leaving these wheels unretracted.
Doesn't seem to have a serious effect on drag. The cables follow a very
tortuous course through the wing, with some short radius bends, and the
friction is very high.
The engine heating is critically dependant on *precise* magneto timing,
much more so than on any other engine the mechanic had experience of.
He finally got it right by using an automobile timing light.
The engine, when properly tuned, is delightful to listen to. It is so
smooth. Power seems to be adequate, with a cruising speed of about 80 -
85 kt easily achieved. Climb out is not spectacular, but is sufficient,
even in our (sometimes) 40C temperatures.
John G.
--
John Giddy ( ) ) Mangalore Gliding Club
5/287 Barkers Rd ) ) ) http://www.gfa.org.au/vic/mgc/
Kew, Victoria, 3101 ( ) ) _
Australia ( ) '------8------'
Peter D. Brown wrote:
>
> Jon Vedum <jon....@telecast.no> wrote:
>
> >Does anyone have practical experience with this plane?
> >We are discussing buying one, so thanks for any comments.
>
> Jon:
>
><<< snip >>>
>
> The cockpit control layout was a bit awkward but nothing that you
> couldn’t get used to. Gear retraction took a bit of muscle. I liked
> the side by side seating and visibility was good.
><<< snip >>>
Robert Youdan
in the example I have flown; enough to use for outlanding training in
Australia during summer. The undercarriage lever is a bit painful when two
broad people are flying it (from the left seat you have to push it back
behind your right side) but like anything, you can get used to it. When
retracting the main gear, cables and levers also retract the outrigger
wheels on the wing tips, hence the extra load some people complain about.
The engine is upside down, and this could lead to fowled plugs if your rings
are worn and you leave it stopped or on low revs for too long. But when
maintained well, it's a beautifully smooth powerplant, and goes well with
the variable pitch (3 position) Hoffmann prop (similar to Dimona). The prop
pitch is maintained by centifugal force on some counterweights, and this can
be hard to get the hang of, but again, once learned it's a piece of cake.
Glides OK and lands nicely with power on or off. Not a beginners' motor
glider, I would say, but then again, very few are!
Rob
Jon Vedum wrote in message <36C1C7E2...@telecast.no>...
>Does anyone have practical experience with this plane?
>We are discussing buying one, so thanks for any comments.
>
>-- Jon
>
JELEEDY
into a Taifun which is in the same price range but offers several advantages
in my mind and can be used as a glider with performance slightly better than
the vivat but yet cruises at 110 knots burning 3.5 gph while going under power.
a.g....@home.nl
> We are discussing buying one, so thanks for any comments.
>
> -- Jon
Are still parts for this plane for sale? I searched on line but not much luck. It might be my lack of Czech language skills though.
André